Sample records for flexible aircraft maintenance

  1. A Grounded Theory Study of Aircraft Maintenance Technician Decision-Making

    NASA Astrophysics Data System (ADS)

    Norcross, Robert

    Aircraft maintenance technician decision-making and actions have resulted in aircraft system errors causing aircraft incidents and accidents. Aircraft accident investigators and researchers examined the factors that influence aircraft maintenance technician errors and categorized the types of errors in an attempt to prevent similar occurrences. New aircraft technology introduced to improve aviation safety and efficiency incur failures that have no information contained in the aircraft maintenance manuals. According to the Federal Aviation Administration, aircraft maintenance technicians must use only approved aircraft maintenance documents to repair, modify, and service aircraft. This qualitative research used a grounded theory approach to explore the decision-making processes and actions taken by aircraft maintenance technicians when confronted with an aircraft problem not contained in the aircraft maintenance manuals. The target population for the research was Federal Aviation Administration licensed aircraft and power plant mechanics from across the United States. Nonprobability purposeful sampling was used to obtain aircraft maintenance technicians with the experience sought in the study problem. The sample population recruitment yielded 19 participants for eight focus group sessions to obtain opinions, perceptions, and experiences related to the study problem. All data collected was entered into the Atlas ti qualitative analysis software. The emergence of Aircraft Maintenance Technician decision-making themes regarding Aircraft Maintenance Manual content, Aircraft Maintenance Technician experience, and legal implications of not following Aircraft Maintenance Manuals surfaced. Conclusions from this study suggest Aircraft Maintenance Technician decision-making were influenced by experience, gaps in the Aircraft Maintenance Manuals, reliance on others, realizing the impact of decisions concerning aircraft airworthiness, management pressures, and legal concerns

  2. A manpower scheduling heuristic for aircraft maintenance application

    NASA Astrophysics Data System (ADS)

    Sze, San-Nah; Sze, Jeeu-Fong; Chiew, Kang-Leng

    2012-09-01

    This research studies a manpower scheduling for aircraft maintenance, focusing on in-flight food loading operation. A group of loading teams with flexible shifts is required to deliver and upload packaged meals from the ground kitchen to aircrafts in multiple trips. All aircrafts must be served within predefined time windows. The scheduling process takes into account of various constraints such as meal break allocation, multi-trip traveling and food exposure time limit. Considering the aircrafts movement and predefined maximum working hours for each loading team, the main objective of this study is to form an efficient roster by assigning a minimum number of loading teams to the aircrafts. We proposed an insertion based heuristic to generate the solutions in a short period of time for large instances. This proposed algorithm is implemented in various stages for constructing trips due to the presence of numerous constraints. The robustness and efficiency of the algorithm is demonstrated in computational results. The results show that the insertion heuristic more efficiently outperforms the company's current practice.

  3. Flexible manufacturing of aircraft engine parts

    NASA Astrophysics Data System (ADS)

    Hassan, Ossama M.; Jenkins, Douglas M.

    1992-06-01

    GE Aircraft Engines, a major supplier of jet engines for commercial and military aircraft, has developed a fully integrated manufacturing facility to produce aircraft engine components in flexible manufacturing cells. This paper discusses many aspects of the implementation including process technologies, material handling, software control system architecture, socio-technical systems and lessons learned. Emphasis is placed on the appropriate use of automation in a flexible manufacturing system.

  4. Examining the Relationship Between Passenger Airline Aircraft Maintenance Outsourcing and Aircraft Safety

    NASA Astrophysics Data System (ADS)

    Monaghan, Kari L.

    The problem addressed was the concern for aircraft safety rates as they relate to the rate of maintenance outsourcing. Data gathered from 14 passenger airlines: AirTran, Alaska, America West, American, Continental, Delta, Frontier, Hawaiian, JetBlue, Midwest, Northwest, Southwest, United, and USAir covered the years 1996 through 2008. A quantitative correlational design, utilizing Pearson's correlation coefficient, and the coefficient of determination were used in the present study to measure the correlation between variables. Elements of passenger airline aircraft maintenance outsourcing and aircraft accidents, incidents, and pilot deviations within domestic passenger airline operations were analyzed, examined, and evaluated. Rates of maintenance outsourcing were analyzed to determine the association with accident, incident, and pilot deviation rates. Maintenance outsourcing rates used in the evaluation were the yearly dollar expenditure of passenger airlines for aircraft maintenance outsourcing as they relate to the total airline aircraft maintenance expenditures. Aircraft accident, incident, and pilot deviation rates used in the evaluation were the yearly number of accidents, incidents, and pilot deviations per miles flown. The Pearson r-values were calculated to measure the linear relationship strength between the variables. There were no statistically significant correlation findings for accidents, r(174)=0.065, p=0.393, and incidents, r(174)=0.020, p=0.793. However, there was a statistically significant correlation for pilot deviation rates, r(174)=0.204, p=0.007 thus indicating a statistically significant correlation between maintenance outsourcing rates and pilot deviation rates. The calculated R square value of 0.042 represents the variance that can be accounted for in aircraft pilot deviation rates by examining the variance in aircraft maintenance outsourcing rates; accordingly, 95.8% of the variance is unexplained. Suggestions for future research include

  5. 14 CFR 91.1109 - Aircraft maintenance: Inspection program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Aircraft maintenance: Inspection program... Ownership Operations Program Management § 91.1109 Aircraft maintenance: Inspection program. Each program... conduct of inspections for the particular make and model aircraft, including necessary tests and checks...

  6. 14 CFR 91.1109 - Aircraft maintenance: Inspection program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aircraft maintenance: Inspection program... Ownership Operations Program Management § 91.1109 Aircraft maintenance: Inspection program. Each program... conduct of inspections for the particular make and model aircraft, including necessary tests and checks...

  7. 14 CFR 91.1109 - Aircraft maintenance: Inspection program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aircraft maintenance: Inspection program... Ownership Operations Program Management § 91.1109 Aircraft maintenance: Inspection program. Each program... conduct of inspections for the particular make and model aircraft, including necessary tests and checks...

  8. Licencing and Training Reform in the Australian Aircraft Maintenance Industry

    ERIC Educational Resources Information Center

    Hampson, Ian; Fraser, Doug

    2016-01-01

    The training and licencing of aircraft maintenance engineers fulfils a crucial protective function since it is they who perform and supervise aircraft maintenance and certify that planes are safe afterwards. In Australia, prior to training reform, a trades-based system of aircraft maintenance engineer training existed in an orderly relation with…

  9. Life cycle cost analysis of aging aircraft airframe maintenance

    NASA Astrophysics Data System (ADS)

    Sperry, Kenneth Robert

    Scope and method of study. The purpose of this study was to examine the relationship between an aircraft's age and its annual airframe maintenance costs. Common life cycle costing methodology has previously not recognized the existence of this cost growth potential, and has therefor not determined the magnitude nor significance of this cost element. This study analyzed twenty-five years of DOT Form 41-airframe maintenance cost data for the Boeing 727, 737, 747 and McDonnell Douglas DC9 and DC-10 aircraft. Statistical analysis included regression analysis, Pearson's r, and t-tests to test the null hypothesis. Findings and conclusion. Airframe maintenance cost growth was confirmed to be increasing after an aircraft's age exceeded its designed service objective of approximately twenty-years. Annual airframe maintenance cost growth increases were measured ranging from 3.5% annually for a DC-9, to approximately 9% annually for a DC-10 aircraft. Average measured coefficient of determination between age and airframe maintenance, exceeded .80, confirming a strong relationship between cost: and age. The statistical significance of the difference between airframe costs sampled in 1985, compared to airframe costs sampled in 1998 was confirmed by t-tests performed on each subject aircraft group. Future cost forecasts involving aging aircraft subjects must address cost growth due to aging when attempting to model an aircraft's economic service life.

  10. Trajectory Control for Very Flexible Aircraft

    DTIC Science & Technology

    2006-10-30

    aircraft are coupled with the aeroelastic equations that govern the geometrically nonlinear structural response of the vehicle. A low -order strain...nonlinear structural formulation, the finite state aerodynamic model, and the nonlinear rigid body equations together provide a low -order complete...nonlinear aircraft analysis tool. Due to the inherent flexibility of the aircraft modeling, the low order structural fre- quencies are of the same order

  11. Aviation Maintenance Technology. General. G102 Fundamentals of Aircraft Maintenance. Instructor Material.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    These instructor materials for an aviation maintenance technology course contain four instructional modules. The modules cover the following topics: identifying basic components of aircraft, performing aircraft cleaning and corrosion control, interpreting blueprints and drawing sketches, identifying structural materials, and performing basic…

  12. AGFATL- ACTIVE GEAR FLEXIBLE AIRCRAFT TAKEOFF AND LANDING ANALYSIS

    NASA Technical Reports Server (NTRS)

    Mcgehee, J. R.

    1994-01-01

    The Active Gear, Flexible Aircraft Takeoff and Landing Analysis program, AGFATL, was developed to provide a complete simulation of the aircraft takeoff and landing dynamics problem. AGFATL can represent an airplane either as a rigid body with six degrees of freedom or as a flexible body with multiple degrees of freedom. The airframe flexibility is represented by the superposition of up to twenty free vibration modes on the rigid-body motions. The analysis includes maneuver logic and autopilots programmed to control the aircraft during glide slope, flare, landing, and takeoff. The program is modular so that performance of the aircraft in flight and during landing and ground maneuvers can be studied separately or in combination. A program restart capability is included in AGFATL. Effects simulated in the AGFATL program include: (1) flexible aircraft control and performance during glide slope, flare, landing roll, and takeoff roll under conditions of changing winds, engine failures, brake failures, control system failures, strut failures, restrictions due to runway length, and control variable limits and time lags; (2) landing gear loads and dynamics for up to five gears; (3) single and multiple engines (maximum of four) including selective engine reversing and failure; (4) drag chute and spoiler effects; (5) wheel braking (including skid-control) and selective brake failure; (6) aerodynamic ground effects; (7) aircraft carrier operations; (8) inclined runways and runway perturbations; (9) flexible or rigid airframes; 10) rudder and nose gear steering; and 11) actively controlled landing gear shock struts. Input to the AGFATL program includes data which describe runway roughness; vehicle geometry, flexibility and aerodynamic characteristics; landing gear(s); propulsion; and initial conditions such as attitude, attitude change rates, and velocities. AGFATL performs a time integration of the equations of motion and outputs comprehensive information on the airframe

  13. Robots for Aircraft Maintenance

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Marshall Space Flight Center charged USBI (now Pratt & Whitney) with the task of developing an advanced stripping system based on hydroblasting to strip paint and thermal protection material from Space Shuttle solid rocket boosters. A robot, mounted on a transportable platform, controls the waterjet angle, water pressure and flow rate. This technology, now known as ARMS, has found commercial applications in the removal of coatings from jet engine components. The system is significantly faster than manual procedures and uses only minimal labor. Because the amount of "substrate" lost is minimal, the life of the component is extended. The need for toxic chemicals is reduced, as is waste disposal and human protection equipment. Users of the ARMS work cell include Delta Air Lines and the Air Force, which later contracted with USBI for development of a Large Aircraft Paint Stripping system (LARPS). LARPS' advantages are similar to ARMS, and it has enormous potential in military and civil aircraft maintenance. The technology may also be adapted to aircraft painting, aircraft inspection techniques and paint stripping of large objects like ships and railcars.

  14. Aircraft Maintenance Engineering: Factors Impacting Airlines E-Maintenance Technologies, Authoring and Illustrations

    NASA Astrophysics Data System (ADS)

    Karayianes, Frank

    The purpose of this research was to evaluate factors influencing acceptance and use of technologies in the field of aircraft maintenance authoring, graphics, and documentation. Maintenance engineering authors convert complex engineering used in aircraft production and transform that data using technology (tools) into usable technical publications data. While the current literature includes a large volume of research in technology acceptance in various domains of industry and business, the problem is that no such studies exist with respect to the aircraft maintenance engineering authoring, allowing any number of tools to be used and acceptance to be unsure. The study was based on theoretical approaches of the Technology Acceptance Model and the associated hypothesis related to eight research questions. A survey questionnaire was developed for data collection from a selected population of aircraft maintenance engineering authors. Data collected from 148 responses were exposed to a range of statistical methods and analyses. Analysis of data were performed within the structural equation model using exploratory factor analysis, confirmatory factor analysis, and a range of regression methods. The analyses generally provided results consistent with prior literature. Two survey questions yielded unexpected results contrary to similar studies. The relationship between prior experience and job level did not show a significant relationship with perceived usefulness or perceived ease of use. Other results included the significant relationship between Perceived Usefulness and Perceived Ease of Use with Technology acceptance. Recommendations include understanding how Technology Acceptance can be improved for the industry and the need for further research not covered to refine recommendations for technology acceptance related to the aviation industry.

  15. Flight Dynamics of Flexible Aircraft with Aeroelastic and Inertial Force Interactions

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.; Tuzcu, Ilhan

    2009-01-01

    This paper presents an integrated flight dynamic modeling method for flexible aircraft that captures coupled physics effects due to inertial forces, aeroelasticity, and propulsive forces that are normally present in flight. The present approach formulates the coupled flight dynamics using a structural dynamic modeling method that describes the elasticity of a flexible, twisted, swept wing using an equivalent beam-rod model. The structural dynamic model allows for three types of wing elastic motion: flapwise bending, chordwise bending, and torsion. Inertial force coupling with the wing elasticity is formulated to account for aircraft acceleration. The structural deflections create an effective aeroelastic angle of attack that affects the rigid-body motion of flexible aircraft. The aeroelastic effect contributes to aerodynamic damping forces that can influence aerodynamic stability. For wing-mounted engines, wing flexibility can cause the propulsive forces and moments to couple with the wing elastic motion. The integrated flight dynamics for a flexible aircraft are formulated by including generalized coordinate variables associated with the aeroelastic-propulsive forces and moments in the standard state-space form for six degree-of-freedom flight dynamics. A computational structural model for a generic transport aircraft has been created. The eigenvalue analysis is performed to compute aeroelastic frequencies and aerodynamic damping. The results will be used to construct an integrated flight dynamic model of a flexible generic transport aircraft.

  16. Flight Control of Flexible Aircraft

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2017-01-01

    This presentation presents an overview of flight control research for flexible high aspect wing aircraft in support of the NASA ARMD Advanced Air Transport Technology (AATT) project. It summarizes multi-objective flight control technology being developed for drag optimization, flutter suppression, and maneuver and gust load alleviation.

  17. Modified Dynamic Inversion to Control Large Flexible Aircraft: What's Going On?

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.

    1999-01-01

    High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper explores dynamic inversion application to an advanced highly flexible aircraft. An initial application has been made to a large flexible supersonic aircraft. In the course of controller design for this advanced vehicle, modifications were made to the standard dynamic inversion methodology. The results of this application were deemed rather promising. An analytical study has been undertaken to better understand the nature of the made modifications and to determine its general applicability. This paper presents the results of this initial analytical look at the modifications to dynamic inversion to control large flexible aircraft.

  18. Unsafe acts and unsafe outcomes in aircraft maintenance

    NASA Technical Reports Server (NTRS)

    Hobbs, Alan; Williamson, Ann

    2002-01-01

    Road safety studies using the Driver Behaviour Questionnaire (DBQ) have provided support for a three-way distinction between violations, skill-based errors and mistakes, and have indicated that a tendency to commit driving violations is associated with an increased risk of accident involvement. The aims of this study were to examine whether the three-way distinction of unsafe acts is applicable in the context of aircraft maintenance, and whether involvement in maintenance safety occurrences can be predicted on the basis of self-reported unsafe acts. A Maintenance Behaviour Questionnaire (MBQ) was developed to explore patterns of unsafe acts committed by aircraft maintenance mechanics. The MBQ was completed anonymously by over 1300 Australian aviation mechanics, who also provided information on their involvement in workplace accidents and incidents. Four factors were identified: routine violations, skill-based errors, mistakes and exceptional violations. Violations and mistakes were related significantly to the occurrence of incidents that jeopardized the quality of aircraft maintenance, but were not related to workplace injuries. Skill-based errors, while not related to work quality incidents, were related to workplace injuries. The results are consistent with the three-way typology of unsafe acts described by Reason et al. (1990) and with the DBQ research indicating an association between self-reported violations and accidents. The current findings suggest that interventions addressed at maintenance quality incidents should take into account the role of violations and mistakes, and the factors that promote them. In contrast, interventions directed at reducing workplace injury are likely to require a focus on skill-based errors.

  19. Flight Controller Software Protects Lightweight Flexible Aircraft

    NASA Technical Reports Server (NTRS)

    2015-01-01

    Lightweight flexible aircraft may be the future of aviation, but a major problem is their susceptibility to flutter-uncontrollable vibrations that can destroy wings. Armstrong Flight Research Center awarded SBIR funding to Minneapolis, Minnesota-based MUSYN Inc. to develop software that helps program flight controllers to suppress flutter. The technology is now available for aircraft manufacturers and other industries that use equipment with automated controls.

  20. Infrared thermographic diagnostic aid to aircraft maintenance

    NASA Astrophysics Data System (ADS)

    Delo, Michael; Delo, Steve

    2007-04-01

    Thermographic data can be used as a supplement to aircraft maintenance operations in both back shop and flight line situations. Aircraft systems such as electrical, propulsion, environmental, pitot static and hydraulic/pneumatic fluid, can be inspected using a thermal infrared (IR) imager. Aircraft systems utilize electro-hydraulic, electro-mechanical, and electro-pneumatic mechanisms, which, if accessible, can be diagnosed for faults using infrared technology. Since thermographs are images of heat, rather than light, the measurement principle is based on the fact that any physical object (radiating energy at infrared wavelengths within the IR portion of the electro-magnetic spectrum), can be imaged with infrared imaging equipment. All aircraft systems being tested with infrared are required to be energized for troubleshooting, so that valuable baseline data from fully operational aircraft can be collected, archived and referenced for future comparisons.

  1. Stability Result For Dynamic Inversion Devised to Control Large Flexible Aircraft

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.

    2001-01-01

    High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper is an initial attempt to establish global stability results for dynamic inversion methodology as applied to a large, flexible aircraft. This work builds on a previous result for rigid fighter aircraft and adds a new level of complexity that is the flexible aircraft dynamics, which cannot be ignored even in the most basic flight control. The results arise from observations of the control laws designed for a new generation of the High-Speed Civil Transport aircraft.

  2. Maintenance cost study of rotary wing aircraft, phase 2

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The Navy's maintenance and materials management data base was used in a study to determine the feasibility of predicting unscheduled maintenance costs for the dynamic systems of military rotary wing aircraft. The major operational and design variables were identified and the direct maintenance man hours per flight hour were obtained by step-wise multiple regression analysis. Five nonmilitary helicopter users were contacted to supply data on which variables were important factors in civil applications. These uses included offshore oil exploration and support, police and fire department rescue and enforcement, logging and heavy equipment movement, and U.S. Army military operations. The equations developed were highly effective in predicting unscheduled direct maintenance man hours per flying hours for military aircraft, but less effective for commercial or public service helicopters, probably because of the longer mission durations and the much higher utilization of civil users.

  3. An optimization method for condition based maintenance of aircraft fleet considering prognostics uncertainty.

    PubMed

    Feng, Qiang; Chen, Yiran; Sun, Bo; Li, Songjie

    2014-01-01

    An optimization method for condition based maintenance (CBM) of aircraft fleet considering prognostics uncertainty is proposed. The CBM and dispatch process of aircraft fleet is analyzed first, and the alternative strategy sets for single aircraft are given. Then, the optimization problem of fleet CBM with lower maintenance cost and dispatch risk is translated to the combinatorial optimization problem of single aircraft strategy. Remain useful life (RUL) distribution of the key line replaceable Module (LRM) has been transformed into the failure probability of the aircraft and the fleet health status matrix is established. And the calculation method of the costs and risks for mission based on health status matrix and maintenance matrix is given. Further, an optimization method for fleet dispatch and CBM under acceptable risk is proposed based on an improved genetic algorithm. Finally, a fleet of 10 aircrafts is studied to verify the proposed method. The results shows that it could realize optimization and control of the aircraft fleet oriented to mission success.

  4. An Optimization Method for Condition Based Maintenance of Aircraft Fleet Considering Prognostics Uncertainty

    PubMed Central

    Chen, Yiran; Sun, Bo; Li, Songjie

    2014-01-01

    An optimization method for condition based maintenance (CBM) of aircraft fleet considering prognostics uncertainty is proposed. The CBM and dispatch process of aircraft fleet is analyzed first, and the alternative strategy sets for single aircraft are given. Then, the optimization problem of fleet CBM with lower maintenance cost and dispatch risk is translated to the combinatorial optimization problem of single aircraft strategy. Remain useful life (RUL) distribution of the key line replaceable Module (LRM) has been transformed into the failure probability of the aircraft and the fleet health status matrix is established. And the calculation method of the costs and risks for mission based on health status matrix and maintenance matrix is given. Further, an optimization method for fleet dispatch and CBM under acceptable risk is proposed based on an improved genetic algorithm. Finally, a fleet of 10 aircrafts is studied to verify the proposed method. The results shows that it could realize optimization and control of the aircraft fleet oriented to mission success. PMID:24892046

  5. Aircraft Electronics Maintenance Training Simulator. Curriculum Outlines.

    ERIC Educational Resources Information Center

    Blackhawk Technical Coll., Janesville, WI.

    Instructional materials are provided for nine courses in an aircraft electronics maintenance training program. Courses are as follows: aviation basic electricity, direct current and alternating current electronics, basic avionic installations, analog electronics, digital electronics, microcomputer electronics, radio communications, aircraft…

  6. Determining the state-of-health of maintenance-free aircraft batteries

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vutetakis, D.G.; Viswanathan, V.V.

    1995-07-01

    This paper presents an overview of methods to determine the state-of-health of maintenance-free aircraft batteries. The various failure modes of aircraft batteries are discussed, along with methods of detecting failed batteries. Specific examples of detection methods are presented for the F-16, F-18, AV-8B, B-1B, and B-52 aircraft batteries.

  7. Changes in the mean hearing threshold levels in military aircraft maintenance conscripts.

    PubMed

    Park, Won-Ju; Moon, Jai-Dong

    2016-11-01

    Aircraft maintenance crews are constantly exposed to severe aircraft noise. The purpose of this study was to verify whether noise from aircraft adversely affects the hearing threshold levels (HTLs) of aircraft maintenance conscripts during their 2 years of mandatory military service. This study included 3,000 male aircraft maintenance conscripts who work in the military runway area. We measured and analyzed HTLs at 2-4 kHz. The duration of exposure to noise increased with an increase in rank; however, HTLs showed a tendency to decrease. We attributed such contradicting results to the learning effect and adaptation to military service. However, we suspected that sudden deafness in 6 conscripts (0.2%) was due to loud noise in the runway area during military service. The effectiveness of the hearing conservation program for short-term military service personnel could be increased by focusing on preventing sudden deafness and preenlistment baseline audiogram tests.

  8. Flight dynamics simulation modeling and control of a large flexible tiltrotor aircraft

    NASA Astrophysics Data System (ADS)

    Juhasz, Ondrej

    A high order rotorcraft mathematical model is developed and validated against the XV-15 and a Large Civil Tiltrotor (LCTR) concept. The mathematical model is generic and allows for any rotorcraft configuration, from single main rotor helicopters to coaxial and tiltrotor aircraft. Rigid-body and inflow states, as well as flexible wing and blade states are used in the analysis. The separate modeling of each rotorcraft component allows for structural flexibility to be included, which is important when modeling large aircraft where structural modes affect the flight dynamics frequency ranges of interest, generally 1 to 20 rad/sec. Details of the formulation of the mathematical model are given, including derivations of structural, aerodynamic, and inertial loads. The linking of the components of the aircraft is developed using an approach similar to multibody analyses by exploiting a tree topology, but without equations of constraints. Assessments of the effects of wing flexibility are given. Flexibility effects are evaluated by looking at the nature of the couplings between rigid-body modes and wing structural modes and vice versa. The effects of various different forms of structural feedback on aircraft dynamics are analyzed. A proportional-integral feedback on the structural acceleration is deemed to be most effective at both improving the damping and reducing the overall excitation of a structural mode. A model following control architecture is then implemented on full order flexible LCTR models. For this aircraft, the four lowest frequency structural modes are below 20 rad/sec, and are thus needed for control law development and analysis. The impact of structural feedback on both Attitude-Command, Attitude-Hold (ACAH) and Translational Rate Command (TRC) response types are investigated. A rigid aircraft model has optimistic performance characteristics, and a control system designed for a rigid aircraft could potentially destabilize a flexible one. The various

  9. A Comparison of Aircraft Maintenance Organizational Structures

    DTIC Science & Technology

    1992-09-01

    Outputs ... ...................... 85 Appendix E : Double Cross-Validation ........... 117 Appendix F: Exchange of Independent Variables...splits into three major production branches (6). See Figure 8. 26 Aircraf t Interm ia•’ e Maintenance Off icerzI A ssistantAIKO I 1|A/ant a A Traiing...responsible for all aircraft maintenance activities, see Figure 9 (4:3). rdor ! E •; e Techn•1i Se~rvices Wff oE r I f .1 Bass Airaraf t Iaintenanoc E

  10. Vibration and aeroelastic analysis of highly flexible HALE aircraft

    NASA Astrophysics Data System (ADS)

    Chang, Chong-Seok

    The highly flexible HALE (High Altitude Long Endurance) aircraft analysis methodology is of interest because early studies indicated that HALE aircraft might have different vibration and aeroelastic characteristics from those of conventional aircraft. Recently the computer code Nonlinear Aeroelastic Trim And Stability of HALE Aircraft (NATASHA) was developed under NASA sponsorship. NATASHA can predict the flight dynamics and aeroelastic behavior for HALE aircraft with a flying wing configuration. Further analysis improvements for NATASHA were required to extend its capability to the ground vibration test (GVT) environment and to both GVT and aeroelastic behavior of HALE aircraft with other configurations. First, the analysis methodology, based on geometrically exact fully intrinsic beam theory, was extended to treat other aircraft cofigurations. Conventional aircraft with flexible fuselage and tail can now be modeled by treating the aircraft as an assembly of beam elements. NATASHA is now applicable to any aircraft cofiguration that can be modeled this way. The intrinsic beam formulation, which is a fundamental structural modeling approach, is now capable of being applying to a structure consisting of multiple beams by relating the virtual displacements and rotations at points where two or more beam elements are connected to each other. Additional aspects are also considered in the analysis such as auxiliary elevator input in the horizontal tail and fuselage aerodynamics. Second, the modeling approach was extended to treat the GVT environment for HALE aircraft, which have highly flexible wings. GVT has its main purpose to provide modal characteristics for model validation. A bungee formulation was developed by the augmented Lagrangian method and coupled to the intrinsic beam formulation for the GVT modeling. After the coupling procedure, the whole formulation cannot be fully intrinsic because the geometric constraint by bungee cords makes the system statically

  11. 40 CFR 141.804 - Aircraft water system operations and maintenance plan.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Aircraft water system operations and maintenance plan. 141.804 Section 141.804 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Aircraft Drinking Water Rule § 141.804 Aircraft water system...

  12. Space shuttle recommendations based on aircraft maintenance experience

    NASA Technical Reports Server (NTRS)

    Spears, J. M.; Fox, C. L.

    1972-01-01

    Space shuttle design recommendations based on aircraft maintenance experience are developed. The recommendations are specifically applied to the landing gear system, nondestructive inspection techniques, hydraulic system design, materials and processes, and program support.

  13. Handling Qualities of Large Flexible Aircraft. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Poopaka, S.

    1980-01-01

    The effects on handling qualities of elastic modes interaction with the rigid body dynamics of a large flexible aircraft are studied by a mathematical computer simulation. An analytical method to predict the pilot ratings when there is a severe modes interactions is developed. This is done by extending the optimal control model of the human pilot response to include the mode decomposition mechanism into the model. The handling qualities are determined for a longitudinal tracking task using a large flexible aircraft with parametric variations in the undamped natural frequencies of the two lowest frequency, symmetric elastic modes made to induce varying amounts of mode interaction.

  14. Selecting a preventive maintenance treatment for flexible pavements

    DOT National Transportation Integrated Search

    2000-06-14

    Maintenance engineers have been applying treatments to both flexible and rigid pavements for as long as such pavements have existed. The types and application of various treatments for both corrective and preventive maintenance have been the subject ...

  15. Coupled nonlinear aeroelasticity and flight dynamics of fully flexible aircraft

    NASA Astrophysics Data System (ADS)

    Su, Weihua

    This dissertation introduces an approach to effectively model and analyze the coupled nonlinear aeroelasticity and flight dynamics of highly flexible aircraft. A reduced-order, nonlinear, strain-based finite element framework is used, which is capable of assessing the fundamental impact of structural nonlinear effects in preliminary vehicle design and control synthesis. The cross-sectional stiffness and inertia properties of the wings are calculated along the wing span, and then incorporated into the one-dimensional nonlinear beam formulation. Finite-state unsteady subsonic aerodynamics is used to compute airloads along lifting surfaces. Flight dynamic equations are then introduced to complete the aeroelastic/flight dynamic system equations of motion. Instead of merely considering the flexibility of the wings, the current work allows all members of the vehicle to be flexible. Due to their characteristics of being slender structures, the wings, tail, and fuselage of highly flexible aircraft can be modeled as beams undergoing three dimensional displacements and rotations. New kinematic relationships are developed to handle the split beam systems, such that fully flexible vehicles can be effectively modeled within the existing framework. Different aircraft configurations are modeled and studied, including Single-Wing, Joined-Wing, Blended-Wing-Body, and Flying-Wing configurations. The Lagrange Multiplier Method is applied to model the nodal displacement constraints at the joint locations. Based on the proposed models, roll response and stability studies are conducted on fully flexible and rigidized models. The impacts of the flexibility of different vehicle members on flutter with rigid body motion constraints, flutter in free flight condition, and roll maneuver performance are presented. Also, the static stability of the compressive member of the Joined-Wing configuration is studied. A spatially-distributed discrete gust model is incorporated into the time simulation

  16. Inertial Force Coupling to Nonlinear Aeroelasticity of Flexible Wing Aircraft

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.; Ting, Eric

    2016-01-01

    This paper investigates the inertial force effect on nonlinear aeroelasticity of flexible wing aircraft. The geometric are nonlinearity due to rotational and tension stiffening. The effect of large bending deflection will also be investigated. Flutter analysis will be conducted for a truss-braced wing aircraft concept with tension stiffening and inertial force coupling.

  17. Optimal manpower allocation in aircraft line maintenance (Case in GMF AeroAsia)

    NASA Astrophysics Data System (ADS)

    Puteri, V. E.; Yuniaristanto, Hisjam, M.

    2017-11-01

    This paper presents a mathematical modeling to find the optimal manpower allocation in an aircraft line maintenance. This research focuses on assigning the number and type of manpower that allocated to each service. This study considers the licenced worker or Aircraft Maintenance Engineer Licence (AMEL) and non licenced worker or Aircraft Maintenance Technician (AMT). In this paper, we also consider the relationship of each station in terms of the possibility to transfer the manpower among them. The optimization model considers the number of manpowers needed for each service and the requirement of AMEL worker. This paper aims to determine the optimal manpower allocation using the mathematical modeling. The objective function of the model is to find the minimum employee expenses. The model was solved using the ILOG CPLEX software. The results show that the manpower allocation can meet the manpower need and the all load can be served.

  18. Analysis of flexible aircraft longitudinal dynamics and handling qualities. Volume 1: Analysis methods

    NASA Technical Reports Server (NTRS)

    Waszak, M. R.; Schmidt, D. S.

    1985-01-01

    As aircraft become larger and lighter due to design requirements for increased payload and improved fuel efficiency, they will also become more flexible. For highly flexible vehicles, the handling qualities may not be accurately predicted by conventional methods. This study applies two analysis methods to a family of flexible aircraft in order to investigate how and when structural (especially dynamic aeroelastic) effects affect the dynamic characteristics of aircraft. The first type of analysis is an open loop model analysis technique. This method considers the effects of modal residue magnitudes on determining vehicle handling qualities. The second method is a pilot in the loop analysis procedure that considers several closed loop system characteristics. Volume 1 consists of the development and application of the two analysis methods described above.

  19. Static Aeroelastic and Longitudinal Trim Model of Flexible Wing Aircraft Using Finite-Element Vortex-Lattice Coupled Solution

    NASA Technical Reports Server (NTRS)

    Ting, Eric; Nguyen, Nhan; Trinh, Khanh

    2014-01-01

    This paper presents a static aeroelastic model and longitudinal trim model for the analysis of a flexible wing transport aircraft. The static aeroelastic model is built using a structural model based on finite-element modeling and coupled to an aerodynamic model that uses vortex-lattice solution. An automatic geometry generation tool is used to close the loop between the structural and aerodynamic models. The aeroelastic model is extended for the development of a three degree-of-freedom longitudinal trim model for an aircraft with flexible wings. The resulting flexible aircraft longitudinal trim model is used to simultaneously compute the static aeroelastic shape for the aircraft model and the longitudinal state inputs to maintain an aircraft trim state. The framework is applied to an aircraft model based on the NASA Generic Transport Model (GTM) with wing structures allowed to flexibly deformed referred to as the Elastically Shaped Aircraft Concept (ESAC). The ESAC wing mass and stiffness properties are based on a baseline "stiff" values representative of current generation transport aircraft.

  20. Identifying Human Factors Issues in Aircraft Maintenance Operations

    NASA Technical Reports Server (NTRS)

    Veinott, Elizabeth S.; Kanki, Barbara G.; Shafto, Michael G. (Technical Monitor)

    1995-01-01

    Maintenance operations incidents submitted to the Aviation Safety Reporting System (ASRS) between 1986-1992 were systematically analyzed in order to identify issues relevant to human factors and crew coordination. This exploratory analysis involved 95 ASRS reports which represented a wide range of maintenance incidents. The reports were coded and analyzed according to the type of error (e.g, wrong part, procedural error, non-procedural error), contributing factors (e.g., individual, within-team, cross-team, procedure, tools), result of the error (e.g., aircraft damage or not) as well as the operational impact (e.g., aircraft flown to destination, air return, delay at gate). The main findings indicate that procedural errors were most common (48.4%) and that individual and team actions contributed to the errors in more than 50% of the cases. As for operational results, most errors were either corrected after landing at the destination (51.6%) or required the flight crew to stop enroute (29.5%). Interactions among these variables are also discussed. This analysis is a first step toward developing a taxonomy of crew coordination problems in maintenance. By understanding what variables are important and how they are interrelated, we may develop intervention strategies that are better tailored to the human factor issues involved.

  1. Optimum Wing Shape of Highly Flexible Morphing Aircraft for Improved Flight Performance

    NASA Technical Reports Server (NTRS)

    Su, Weihua; Swei, Sean Shan-Min; Zhu, Guoming G.

    2016-01-01

    In this paper, optimum wing bending and torsion deformations are explored for a mission adaptive, highly flexible morphing aircraft. The complete highly flexible aircraft is modeled using a strain-based geometrically nonlinear beam formulation, coupled with unsteady aerodynamics and six-degrees-of-freedom rigid-body motions. Since there are no conventional discrete control surfaces for trimming the flexible aircraft, the design space for searching the optimum wing geometries is enlarged. To achieve high performance flight, the wing geometry is best tailored according to the specific flight mission needs. In this study, the steady level flight and the coordinated turn flight are considered, and the optimum wing deformations with the minimum drag at these flight conditions are searched by utilizing a modal-based optimization procedure, subject to the trim and other constraints. The numerical study verifies the feasibility of the modal-based optimization approach, and shows the resulting optimum wing configuration and its sensitivity under different flight profiles.

  2. Modeling procedures for handling qualities evaluation of flexible aircraft

    NASA Technical Reports Server (NTRS)

    Govindaraj, K. S.; Eulrich, B. J.; Chalk, C. R.

    1981-01-01

    This paper presents simplified modeling procedures to evaluate the impact of flexible modes and the unsteady aerodynamic effects on the handling qualities of Supersonic Cruise Aircraft (SCR). The modeling procedures involve obtaining reduced order transfer function models of SCR vehicles, including the important flexible mode responses and unsteady aerodynamic effects, and conversion of the transfer function models to time domain equations for use in simulations. The use of the modeling procedures is illustrated by a simple example.

  3. Effects of Inertial and Geometric Nonlinearities in the Simulation of Flexible Aircraft Dynamics

    NASA Astrophysics Data System (ADS)

    Bun Tse, Bosco Chun

    This thesis examines the relative importance of the inertial and geometric nonlinearities in modelling the dynamics of a flexible aircraft. Inertial nonlinearities are derived by employing an exact definition of the velocity distribution and lead to coupling between the rigid body and elastic motions. The geometric nonlinearities are obtained by applying nonlinear theory of elasticity to the deformations. Peters' finite state unsteady aerodynamic model is used to evaluate the aerodynamic forces. Three approximate models obtained by excluding certain combinations of nonlinear terms are compared with that of the complete dynamics equations to obtain an indication of which terms are required for an accurate representation of the flexible aircraft behavior. A generic business jet model is used for the analysis. The results indicate that the nonlinear terms have a significant effect for more flexible aircraft, especially the geometric nonlinearities which leads to increased damping in the dynamics.

  4. Depression Prevalence and Exposure to Organophosphate Esters in Aircraft Maintenance Workers.

    PubMed

    Hardos, Jennifer E; Whitehead, Lawrence W; Han, Inkyu; Ott, Darrin K; Waller, D Kim

    2016-08-01

    Previous studies found that aircraft maintenance workers may be exposed to organophosphates in hydraulic fluid and engine oil. Studies have also illustrated a link between long-term low-level organophosphate pesticide exposure and depression. A questionnaire containing the Patient Health Questionnaire 8 depression screener was e-mailed to 52,080 aircraft maintenance workers (with N = 4801 complete responses) in a cross-sectional study to determine prevalence and severity of depression and descriptions of their occupational exposures. There was no significant difference between reported depression prevalence and severity in similar exposure groups in which aircraft maintenance workers were exposed or may have been exposed to organophosphate esters compared to similar exposure groups in which they were not exposed. However, a dichotomous measure of the prevalence of depression was significantly associated with self-reported exposure levels from low (OR: 1.21) to moderate (OR: 1.68) to high exposure (OR: 2.70) and with each exposure route including contact (OR: 1.68), inhalation (OR: 2.52), and ingestion (OR: 2.55). A self-reported four-level measure of depression severity was also associated with a self-reported four-level measure of exposure. Based on self-reported exposures and outcomes, an association is observed between organophosphate exposure and depression; however, we cannot assume that the associations we observed are causal because some workers may have been more likely to report exposure to organophosphate esters and also more likely to report depression. Future studies should consider using a larger sample size, better methods for characterizing crew chief exposures, and bioassays to measure dose rather than exposure. Hardos JE, Whitehead LW, Han I, Ott DK, Waller DK. Depression prevalence and exposure to organophosphate esters in aircraft maintenance workers. Aerosp Med Hum Perform. 2016; 87(8):712-717.

  5. Group 3 Unmanned Aircraft Systems Maintenance Challenges Within The Naval Aviation Enterprise

    DTIC Science & Technology

    2017-12-01

    cross winds . We again went through the mishap processes and reviewed training and maintenance records. A couple months later, there was a third crash...gas turbine engines powering aircraft with humans on board (DON, 2017). Group 3 unmanned aircraft utilize a sealed fuel system. The tank is filled...aircraft do not use gas turbine engines. They use either rotary Wankle or piston driven engines with much simpler fuel delivery systems such as carburetors

  6. A performance improvement case study in aircraft maintenance and its implications for hazard identification.

    PubMed

    Ward, Marie; McDonald, Nick; Morrison, Rabea; Gaynor, Des; Nugent, Tony

    2010-02-01

    Aircraft maintenance is a highly regulated, safety critical, complex and competitive industry. There is a need to develop innovative solutions to address process efficiency without compromising safety and quality. This paper presents the case that in order to improve a highly complex system such as aircraft maintenance, it is necessary to develop a comprehensive and ecologically valid model of the operational system, which represents not just what is meant to happen, but what normally happens. This model then provides the backdrop against which to change or improve the system. A performance report, the Blocker Report, specific to aircraft maintenance and related to the model was developed gathering data on anything that 'blocks' task or check performance. A Blocker Resolution Process was designed to resolve blockers and improve the current check system. Significant results were obtained for the company in the first trial and implications for safety management systems and hazard identification are discussed. Statement of Relevance: Aircraft maintenance is a safety critical, complex, competitive industry with a need to develop innovative solutions to address process and safety efficiency. This research addresses this through the development of a comprehensive and ecologically valid model of the system linked with a performance reporting and resolution system.

  7. Optimum Wing Shape Determination of Highly Flexible Morphing Aircraft for Improved Flight Performance.

    PubMed

    Su, Weihua; Swei, Sean Shan-Min; Zhu, Guoming G

    2016-09-01

    In this paper, optimum wing bending and torsion deformations are explored for a mission adaptive, highly flexible morphing aircraft. The complete highly flexible aircraft is modeled using a strain-based geometrically nonlinear beam formulation, coupled with unsteady aerodynamics and 6-dof rigid-body motions. Since there are no conventional discrete control surfaces for trimming the flexible aircraft, the design space for searching the optimum wing geometries is enlarged. To achieve high performance flight, the wing geometry is best tailored according to the specific flight mission needs. In this study, the steady level flight and the coordinated turn flight are considered, and the optimum wing deformations with the minimum drag at these flight conditions are searched by utilizing a modal-based optimization procedure, subject to the trim and other constraints. The numerical study verifies the feasibility of the modal-based optimization approach, and shows the resulting optimum wing configuration and its sensitivity under different flight profiles.

  8. Optimum Wing Shape Determination of Highly Flexible Morphing Aircraft for Improved Flight Performance

    PubMed Central

    Su, Weihua; Swei, Sean Shan-Min; Zhu, Guoming G.

    2018-01-01

    In this paper, optimum wing bending and torsion deformations are explored for a mission adaptive, highly flexible morphing aircraft. The complete highly flexible aircraft is modeled using a strain-based geometrically nonlinear beam formulation, coupled with unsteady aerodynamics and 6-dof rigid-body motions. Since there are no conventional discrete control surfaces for trimming the flexible aircraft, the design space for searching the optimum wing geometries is enlarged. To achieve high performance flight, the wing geometry is best tailored according to the specific flight mission needs. In this study, the steady level flight and the coordinated turn flight are considered, and the optimum wing deformations with the minimum drag at these flight conditions are searched by utilizing a modal-based optimization procedure, subject to the trim and other constraints. The numerical study verifies the feasibility of the modal-based optimization approach, and shows the resulting optimum wing configuration and its sensitivity under different flight profiles. PMID:29348697

  9. Maintenance-free lead acid battery for inertial navigation systems aircraft

    NASA Astrophysics Data System (ADS)

    Johnson, William R.; Vutetakis, David G.

    1995-05-01

    Historically, Aircraft Inertial Navigation System (INS) Batteries have utilized vented nickel-cadmium batteries for emergency DC power. The United States Navy and Air Force developed separate systems during their respective INS developments. The Navy contracted with Litton Industries to produce the LTN-72 and Air Force contracted with Delco to produce the Carousel IV INS for the large cargo and specialty aircraft applications. Over the years, a total of eight different battery national stock numbers (NSNs) have entered the stock system along with 75 battery spare part NSNs. The Standard Hardware Acquisition and Reliability Program is working with the Aircraft Battery Group at Naval Surface Warfare Center Crane Division, Naval Air Systems Command (AIR 536), Wright Laboratory, Battelle Memorial Institute, and Concorde Battery Corporation to produce a standard INS battery. This paper discusses the approach taken to determine whether the battery should be replaced and to select the replacement chemistry. The paper also discusses the battery requirements, aircraft that the battery is compatible with, and status of Navy flight evaluation. Projected savings in avoided maintenance in Navy and Air Force INS Systems is projected to be $14.7 million per year with a manpower reduction of 153 maintenance personnel. The new INS battery is compatible with commercially sold INS systems which represents 66 percent of the systems sold.

  10. The potential risk of communication media in conveying critical information in the aircraft maintenance organisation: a case study

    NASA Astrophysics Data System (ADS)

    Shukri, S. Ahmad; Millar, R. M.; Gratton, G.; Garner, M.

    2016-10-01

    In the world of aircraft maintenance organisation, verbal and written communication plays a pivotal role in transferring critical information in relation to aircraft safety and efficiency. The communication media used to convey the critical information between departments at an aircraft maintenance organisation have potential risk in misunderstanding of the information. In this study, technical and non-technical personnel from five different departments at an aircraft maintenance organisation were interviewed on the communication media they normally utilised to communicate six different work procedures that are closely related to aircraft safety and efficiency. This is to discover which communication media pose higher risk in misunderstanding critical information. The findings reveal that written communication pose higher risk of misinterpretation compared with verbal communication when conveying critical information between departments.

  11. Analysis of flexible aircraft longitudinal dynamics and handling qualities. Volume 2: Data

    NASA Technical Reports Server (NTRS)

    Waszak, M. R.; Schmidt, D. K.

    1985-01-01

    Two analysis methods are applied to a family of flexible aircraft in order to investigate how and when structural (especially dynamic aeroelastic) effects affect the dynamic characteristics of aircraft. The first type of analysis is an open loop modal analysis technique. This method considers the effect of modal residue magnitudes on determining vehicle handling qualities. The second method is a pilot in the loop analysis procedure that considers several closed loop system characteristics. Both analyses indicated that dynamic aeroelastic effects caused a degradation in vehicle tracking performance, based on the evaluation of some simulation results. Volume 2 consists of the presentation of the state variable models of the flexible aircraft configurations used in the analysis applications mode shape plots for the structural modes, numerical results from the modal analysis frequency response plots from the pilot in the loop analysis and a listing of the modal analysis computer program.

  12. Blood lead level and types of aviation fuel in aircraft maintenance crew.

    PubMed

    Park, Won-Ju; Gu, Hye-Min; Lee, Suk-Ho

    2013-10-01

    This study inquired into any significant difference in blood lead levels (BLLs) among aircraft maintenance crews at the air-bases, each with a different aviation fuel in use, and confirmed an environmental impact of leaded aviation gasoline (AVGAS). This study included a total of 256 male aircraft maintenance personnel, among whom 105 used only AVGAS as their aviation fuel, while 151 used only jet propellant 8 (JP-8), a kerosene variety. BLLs were measured and the data on related factors were obtained. The arithmetic and geometric means of BLLs of the personnel at the airbases that used only AVGAS were 4.20 microg x dl(-1) and 4.01 microg x dl(-1) and that used only JP-8 were 3.79 microg x dl(-1) and 3.57 microg x dl(-1), respectively. The BLLs of the maintenance crew of the main workspace that was located within a 200-m distance from the runway were higher than those of the main workspace that was located 200 m or farther from the runway. The longer the work hours in the runway or the longer the work duration, the higher the BLLs of the maintenance crew. This investigation exposed the fact that a body's BLL could be increased by AVGAS emissions through the examination of aircraft maintenance crew. This result is in agreement with results of previous studies that suggest proximity to an airport may be associated with elevated BLLs for adults and children. Collectively, the results of the current study and previous research suggest that long-duration inhabitation and/or activities in close proximity to an air facility should be limited given that lead poses known health risks.

  13. Repair and maintenance of fiber optic data links on Navy aircraft

    NASA Astrophysics Data System (ADS)

    Fryland, Eric

    1992-02-01

    This paper will examine the problems and concerns of repairing fiber optic data links on carrier based Navy aircraft and will present the results of fiber optic splice testing that was performed aboard the USS Abraham Lincoln (CVN-72) in January 1991. Mechanical splicing of 50/125 micrometer fiber was performed at the various Navy maintenance levels in order to quantify the effects of the aircraft carrier environment on fiber optic splicing. Results, conclusions and recommendations will be given.

  14. Exposure to fall hazards and safety climate in the aircraft maintenance industry.

    PubMed

    Neitzel, Richard L; Seixas, Noah S; Harris, Michael J; Camp, Janice

    2008-01-01

    Falls represent a significant occupational hazard, particularly in industries with dynamic work environments. This paper describes rates of noncompliance with fall hazard prevention requirements, perceived safety climate and worker knowledge and beliefs, and the association between fall exposure and safety climate measures in commercial aircraft maintenance activities. Walkthrough observations were conducted on aircraft mechanics at two participating facilities (Sites A and B) to ascertain the degree of noncompliance. Mechanics at each site completed questionnaires concerning fall hazard knowledge, personal safety beliefs, and safety climate. Questionnaire results were summarized into safety climate and belief scores by workgroup and site. Noncompliance rates observed during walkthroughs were compared to the climate-belief scores, and were expected to be inversely associated. Important differences were seen in fall safety performance between the sites. The study provided a characterization of aircraft maintenance fall hazards, and also demonstrated the effectiveness of an objective hazard assessment methodology. Noncompliance varied by height, equipment used, location of work on the aircraft, shift, and by safety system. Although the expected relationship between safety climate and noncompliance was seen for site-average climate scores, workgroups with higher safety climate scores had greater observed noncompliance within Site A. Overall, use of engineered safety systems had a significant impact on working safely, while safety beliefs and climate also contributed, though inconsistently. The results of this study indicate that safety systems are very important in reducing noncompliance with fall protection requirements in aircraft maintenance facilities. Site-level fall safety compliance was found to be related to safety climate, although an unexpected relationship between compliance and safety climate was seen at the workgroup level within site. Finally, observed

  15. Psychosocial indicators among aircraft maintenance workers with and without neck and shoulder musculoskeletal symptoms.

    PubMed

    Oliveira, A; Nogueira, H; Diniz, A; Barbieri, D

    2012-01-01

    In the aircraft maintenance industry, most of workers performs manual handling tasks of different materials, varying from small objects up to large pieces of the aircraft. It can increase the occurrence of work-related musculoskeletal disorders (WMSDs), which are strongly associated with high physical demands required by the task. Moreover, psychosocial demands are considered as risk factors for musculoskeletal disorders in both the upper limbs and lumbar spine. Thus, the objective of this study was to assess psychosocial indicators among aircraft maintenance workers according to the presence of neck and shoulder musculoskeletal symptoms. Eighty workers of an aircraft maintenance company were evaluated (32.69 ± 8.25 years, 79.8 ± 13.4 kg, 175 ± 7 cm). According to physical examination, 50 workers were classified as asymptomatic (AS - 4.1 ± 3.17 positive signs) whilst 30 workers were classified as symptomatic (SS - 26.72 ± 11.44 positive signs). AS and SS have shown similar profile of demand (p = 0.62), control (p = 0.66) and social support (p = 0.74) according to the Job Content Questionnaire. However, the groups are different when considering work engagement variables. In general, SS have higher scores than AS (p < 0.05).

  16. General-Purpose Electronic System Tests Aircraft

    NASA Technical Reports Server (NTRS)

    Glover, Richard D.

    1989-01-01

    Versatile digital equipment supports research, development, and maintenance. Extended aircraft interrogation and display system is general-purpose assembly of digital electronic equipment on ground for testing of digital electronic systems on advanced aircraft. Many advanced features, including multiple 16-bit microprocessors, pipeline data-flow architecture, advanced operating system, and resident software-development tools. Basic collection of software includes program for handling many types of data and for displays in various formats. User easily extends basic software library. Hardware and software interfaces to subsystems provided by user designed for flexibility in configuration to meet user's requirements.

  17. A framework for the design of a voice-activated, intelligent, and hypermedia-based aircraft maintenance manual

    NASA Astrophysics Data System (ADS)

    Patankar, Manoj Shashikant

    Federal Aviation Regulations require Aviation Maintenance Technicians (AMTs) to refer to approved maintenance manuals when performing maintenance on airworthy aircraft. Because these manuals are paper-based, larger the size of the aircraft, more cumbersome are the manuals. Federal Aviation Administration (FAA) recognized the difficulties associated with the use of large manuals and conducted studies on the use of electronic media as an alternative to the traditional paper format. However, these techniques do not employ any artificial intelligence technologies and the user interface is limited to either a keyboard or a stylus pen. The primary emphasis of this research was to design a generic framework that would allow future development of voice-activated, intelligent, and hypermedia-based aircraft maintenance manuals. A prototype (VIHAMS-Voice-activated, Intelligent, and Hypermedia-based Aircraft Maintenance System) was developed, as a secondary emphasis, using the design and development techniques that evolved from this research. An evolutionary software design approach was used to design the proposed framework and the structured rapid prototyping technique was used to produce the VIHAMS prototype. VoiceAssist by Creative Labs was used to provide the voice interface so that the users (AMTs) could keep their hands free to work on the aircraft while maintaining complete control over the computer through discrete voice commands. KnowledgePro for Windows sp{TM}, an expert system shell, provided "intelligence" to the prototype. As a result of this intelligence, the system provided expert guidance to the user. The core information contained in conventional manuals was available in a hypermedia format. The prototype's operating hardware included a notebook computer with a fully functional audio system. An external microphone and the built-in speaker served as the input and output devices (along with the color monitor), respectively. Federal Aviation Administration

  18. A Survey of the Aircraft Maintenance Industry to Solicit Perceptions Regarding the Effectiveness of Recent Graduates of F.A.A. Approved Maintenance Schools.

    ERIC Educational Resources Information Center

    O'Brian, Benjamin H.

    A study examined the perceptions of employers in the aircraft maintenance industry regarding the effectiveness of recent graduates of Federal Aeronautics Administration (FAA)-approved maintenance schools. Of the 100 employers who were contacted, 68 returned usable surveys. Based on responses, it was concluded that the views of employers in the…

  19. Vocational Training and European Standardisation of Qualifications: The Case of Aircraft Maintenance

    ERIC Educational Resources Information Center

    Haas, Joachim; Ourtau, Maurice

    2009-01-01

    Initiatives to standardise the conditions for practising certain regulated activities are being taken at European level, particularly in light of the free movement of people and the recognition of qualifications in Member states. This paper looks at the introduction of european licences for aircraft maintenance engineers. It follows an in-depth…

  20. Flexible Twist for Pitch Control in a High Altitude Long Endurance Aircraft with Nonlinear Response

    DTIC Science & Technology

    2008-12-01

    Information dominance is the key motivator for employing high-altitude long-endurance (HALE) aircraft to provide continuous coverage in the theaters of operation A joined-wing configuration of such a craft gives the advantage of a platform for higher resolution sensors. Design challenges emerge with structural flexibility that arise from a long-endurance aircraft design. The goal was to demonstrate that scaling the nonlinear response of a full-scale finite element model of a high-altitude long-endurance (HALE) aircraft was possible if the model was aeroelastically and

  1. Integrated Approach to the Dynamics and Control of Maneuvering Flexible Aircraft

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R. (Technical Monitor); Meirovitch, Leonard; Tuzcu, Ilhan

    2003-01-01

    This work uses a fundamental approach to the problem of simulating the flight of flexible aircraft. To this end, it integrates into a single formulation the pertinent disciplines, namely, analytical dynamics, structural dynamics, aerodynamics, and controls. It considers both the rigid body motions of the aircraft, three translations (forward motion, sideslip and plunge) and three rotations (roll, pitch and yaw), and the elastic deformations of every point of the aircraft, as well as the aerodynamic, propulsion, gravity and control forces. The equations of motion are expressed in a form ideally suited for computer processing. A perturbation approach yields a flight dynamics problem for the motions of a quasi-rigid aircraft and an 'extended aeroelasticity' problem for the elastic deformations and perturbations in the rigid body motions, with the solution of the first problem entering as an input into the second problem. The control forces for the flight dynamics problem are obtained by an 'inverse' process and the feedback controls for the extended aeroservoelasticity problem are determined by the LQG theory. A numerical example presents time simulations of rigid body perturbations and elastic deformations about 1) a steady level flight and 2) a level steady turn maneuver.

  2. Associations between errors and contributing factors in aircraft maintenance

    NASA Technical Reports Server (NTRS)

    Hobbs, Alan; Williamson, Ann

    2003-01-01

    In recent years cognitive error models have provided insights into the unsafe acts that lead to many accidents in safety-critical environments. Most models of accident causation are based on the notion that human errors occur in the context of contributing factors. However, there is a lack of published information on possible links between specific errors and contributing factors. A total of 619 safety occurrences involving aircraft maintenance were reported using a self-completed questionnaire. Of these occurrences, 96% were related to the actions of maintenance personnel. The types of errors that were involved, and the contributing factors associated with those actions, were determined. Each type of error was associated with a particular set of contributing factors and with specific occurrence outcomes. Among the associations were links between memory lapses and fatigue and between rule violations and time pressure. Potential applications of this research include assisting with the design of accident prevention strategies, the estimation of human error probabilities, and the monitoring of organizational safety performance.

  3. The effect of low versus high approach-motivated positive affect on the balance between maintenance and flexibility.

    PubMed

    Liu, Liting; Xu, Baihua

    2016-05-27

    Successful goal-directed behavior in a constantly changing environment requires a balance between maintenance and flexibility. Although some studies have found that positive affect influences this balance differently than neutral affect, one recent study found that motivational intensity of positive affective states influences this balance in a cognitive set-shifting paradigm. However, working memory updating and set shifting are interrelated but distinct components of cognitive control. The present study examined the effect of low versus high approach-motivated positive affect on the balance between maintenance and flexibility in working memory. A simple cuing paradigm (the AX Continuous Performance Task) was employed, and neutral affect and high and low approach-motivated positive affect were induced using affective pictures. The results revealed that, relative to neutral affect, low approach-motivated positive affect attenuated maintenance and increased flexibility, whereas high approach-motivated positive affect promoted maintenance and decreased flexibility. These findings offer further evidence that the effects of positive affect on cognitive control are modulated by approach motivational intensity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. 14 CFR 91.407 - Operation after maintenance, preventive maintenance, rebuilding, or alteration.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... flies the aircraft, makes an operational check of the maintenance performed or alteration made, and logs... maintenance, preventive maintenance, rebuilding, or alteration. (a) No person may operate any aircraft that... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Operation after maintenance, preventive...

  5. 14 CFR 91.407 - Operation after maintenance, preventive maintenance, rebuilding, or alteration.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... flies the aircraft, makes an operational check of the maintenance performed or alteration made, and logs... maintenance, preventive maintenance, rebuilding, or alteration. (a) No person may operate any aircraft that... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Operation after maintenance, preventive...

  6. 14 CFR 91.407 - Operation after maintenance, preventive maintenance, rebuilding, or alteration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... flies the aircraft, makes an operational check of the maintenance performed or alteration made, and logs... maintenance, preventive maintenance, rebuilding, or alteration. (a) No person may operate any aircraft that... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Operation after maintenance, preventive...

  7. 14 CFR 91.407 - Operation after maintenance, preventive maintenance, rebuilding, or alteration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... flies the aircraft, makes an operational check of the maintenance performed or alteration made, and logs... maintenance, preventive maintenance, rebuilding, or alteration. (a) No person may operate any aircraft that... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Operation after maintenance, preventive...

  8. 14 CFR 91.407 - Operation after maintenance, preventive maintenance, rebuilding, or alteration.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... flies the aircraft, makes an operational check of the maintenance performed or alteration made, and logs... maintenance, preventive maintenance, rebuilding, or alteration. (a) No person may operate any aircraft that... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Operation after maintenance, preventive...

  9. [Characteristics of a negative effect of aviation noise on hearing organ of aircraft maintenance personnel].

    PubMed

    Zinkin, V N; Soldatov, S K; Sheshegov, P M

    2007-01-01

    Otolaryngological examination was carried out of 80 engineers and technicians engaged in maintenance of aircrafts in the airports. They are continuously exposed to occupational aviation noise and therefore are at risk for chronic neurosensory hypoacusis. Pure tone audiogram registers in them a rise in hearing thresholds throughout the whole band of frequencies studied. This means that aviation maintenance staff is exposed to noise containing highly intensive infrasound and high-frequency components. The detected pathology directly correlated with duration of exposure to noise. Development of neurosensory hypoacusis in aviation maintenance specialists starts earlier than in other specialists exposed to noise.

  10. Fuzzy Model-based Pitch Stabilization and Wing Vibration Suppression of Flexible Wing Aircraft.

    NASA Technical Reports Server (NTRS)

    Ayoubi, Mohammad A.; Swei, Sean Shan-Min; Nguyen, Nhan T.

    2014-01-01

    This paper presents a fuzzy nonlinear controller to regulate the longitudinal dynamics of an aircraft and suppress the bending and torsional vibrations of its flexible wings. The fuzzy controller utilizes full-state feedback with input constraint. First, the Takagi-Sugeno fuzzy linear model is developed which approximates the coupled aeroelastic aircraft model. Then, based on the fuzzy linear model, a fuzzy controller is developed to utilize a full-state feedback and stabilize the system while it satisfies the control input constraint. Linear matrix inequality (LMI) techniques are employed to solve the fuzzy control problem. Finally, the performance of the proposed controller is demonstrated on the NASA Generic Transport Model (GTM).

  11. Maintenance problems associated with the operation of the F402 /Pegasus/ engine in the AV-8A /Harrier/ aircraft

    NASA Technical Reports Server (NTRS)

    Stanley, C. W.; Hood, W. E.

    1981-01-01

    The U.S. Marine Corp (USMC) has been operating the only V/STOL attack aircraft in the western world since 1971. Some of the maintenance problems experienced are related to the unique V/STOL design criteria of the Pegasus engine. However, the major part of the required maintenance effort is found to involve the more conventional engine problems. A description of the aircraft engine is provided and the problems resulting from V/STOL design demands are examined. Attention is given to the fuel system control, the engine air bleed, foreign object damage to the hp compressor, and the engine exhaust system.

  12. Current and Future Research in Active Control of Lightweight, Flexible Structures Using the X-56 Aircraft

    NASA Technical Reports Server (NTRS)

    Ryan, John J.; Bosworth, John T.; Burken, John J.; Suh, Peter M.

    2014-01-01

    The X-56 Multi-Utility Technology Testbed aircraft system is a versatile experimental research flight platform. The system was primarily designed to investigate active control of lightweight flexible structures, but is reconfigurable and capable of hosting a wide breadth of research. Current research includes flight experimentation of a Lockheed Martin designed active control flutter suppression system. Future research plans continue experimentation with alternative control systems, explore the use of novel sensor systems, and experiments with the use of novel control effectors. This paper describes the aircraft system, current research efforts designed around the system, and future planned research efforts that will be hosted on the aircraft system.

  13. Musculoskeletal disorders and psychosocial risk factors among workers of the aircraft maintenance industry.

    PubMed

    Nogueira, Helen Cristina; Diniz, Ana Carolina Parise; Barbieri, Dechristian França; Padula, Rosimeire Simprini; Carregaro, Rodrigo Luiz; de Oliveira, Ana Beatriz

    2012-01-01

    During the recent decades Brazil has experienced an exponential growth in the aviation sector resulting in an increasing workforce. The aircraft maintenance industry stands out, where the workers have to handle different kind of objects. The aim of this study was to evaluate psychosocial indicators as well as musculoskeletal symptoms and disorders among aircraft maintenance workers. One hundred and one employees were evaluated (32.69 ± 8.25 yr, 79.8 ± 13.4 kg, and 1.75 ± 0.07 m). Musculoskeletal symptoms and disorders were assessed through the Nordic Musculoskeletal Questionnaire (NMQ) and a standardized physical examination. The Job Content Questionnaire (JCQ) and the Utrecht Work Engagement Scale (UWES) were applied to evaluate psychosocial indicators. Results of the NMQ indicate the lower back as the most affected body region. On the other hand, the physical examination has shown clinical diagnosis of shoulder disorders. Neck, upper back and ankle/foot were also reported as painful sites. Most of workers have active work-demand profile and high work engagement levels. We suggest that musculoskeletal symptoms may be related to high biomechanical demand of the tasks performed by workers, what must be further investigated.

  14. Flight control synthesis for flexible aircraft using Eigenspace assignment

    NASA Technical Reports Server (NTRS)

    Davidson, J. B.; Schmidt, D. K.

    1986-01-01

    The use of eigenspace assignment techniques to synthesize flight control systems for flexible aircraft is explored. Eigenspace assignment techniques are used to achieve a specified desired eigenspace, chosen to yield desirable system impulse residue magnitudes for selected system responses. Two of these are investigated. The first directly determines constant measurement feedback gains that will yield a close-loop system eigenspace close to a desired eigenspace. The second technique selects quadratic weighting matrices in a linear quadratic control synthesis that will asymptotically yield the close-loop achievable eigenspace. Finally, the possibility of using either of these techniques with state estimation is explored. Application of the methods to synthesize integrated flight-control and structural-mode-control laws for a large flexible aircraft is demonstrated and results discussed. Eigenspace selection criteria based on design goals are discussed, and for the study case it would appear that a desirable eigenspace can be obtained. In addition, the importance of state-space selection is noted along with problems with reduced-order measurement feedback. Since the full-state control laws may be implemented with dynamic compensation (state estimation), the use of reduced-order measurement feedback is less desirable. This is especially true since no change in the transient response from the pilot's input results if state estimation is used appropriately. The potential is also noted for high actuator bandwidth requirements if the linear quadratic synthesis approach is utilized. Even with the actuator pole location selected, a problem with unmodeled modes is noted due to high bandwidth. Some suggestions for future research include investigating how to choose an eigenspace that will achieve certain desired dynamics and stability robustness, determining how the choice of measurements effects synthesis results, and exploring how the phase relationships between desired

  15. ACFA 2020 - An FP7 project on active control of flexible fuel efficient aircraft configurations

    NASA Astrophysics Data System (ADS)

    Maier, R.

    2013-12-01

    This paper gives an overview about the project ACFA 2020 which is funded by the European Commission within the 7th framework program. The acronym ACFA 2020 stands for Active Control for Flexible Aircraft 2020. The project is dealing with the design of highly fuel efficient aircraft configurations and, in particular, on innovative active control concepts with the goal to reduce loads and structural weight. Major focus lays on blended wing body (BWB) aircraft. Blended wing body type aircraft configurations are seen as the most promising future concept to fulfill the so-called ACARE (Advisory Council for Aeronautics Research in Europe) vision 2020 goals in regards to reduce fuel consumption and external noise. The paper discusses in some detail the overall goals and how they are addressed in the workplan. Furthermore, the major achievements of the project are outlined and a short outlook on the remaining work is given.

  16. Wing Shaping and Gust Load Controls of Flexible Aircraft: An LPV Approach

    NASA Technical Reports Server (NTRS)

    Hammerton, Jared R.; Su, Weihua; Zhu, Guoming; Swei, Sean Shan-Min

    2018-01-01

    In the proposed paper, the optimum wing shape of a highly flexible aircraft under varying flight conditions will be controlled by a linear parameter-varying approach. The optimum shape determined under multiple objectives, including flight performance, ride quality, and control effort, will be determined as well. This work is an extension of work done previously by the authors, and updates the existing optimization and utilizes the results to generate a robust flight controller.

  17. A modal analysis of flexible aircraft dynamics with handling qualities implications

    NASA Technical Reports Server (NTRS)

    Schmidt, D. K.

    1983-01-01

    A multivariable modal analysis technique is presented for evaluating flexible aircraft dynamics, focusing on meaningful vehicle responses to pilot inputs and atmospheric turbulence. Although modal analysis is the tool, vehicle time response is emphasized, and the analysis is performed on the linear, time-domain vehicle model. In evaluating previously obtained experimental pitch tracking data for a family of vehicle dynamic models, it is shown that flexible aeroelastic effects can significantly affect pitch attitude handling qualities. Consideration of the eigenvalues alone, of both rigid-body and aeroelastic modes, does not explain the simulation results. Modal analysis revealed, however, that although the lowest aeroelastic mode frequency was still three times greater than the short-period frequency, the rigid-body attitude response was dominated by this aeroelastic mode. This dominance was defined in terms of the relative magnitudes of the modal residues in selected vehicle responses.

  18. An Overview of Modifications Applied to a Turbulence Response Analysis Method for Flexible Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Funk, Christie J.

    2013-01-01

    A software program and associated methodology to study gust loading on aircraft exists for a classification of geometrically simplified flexible configurations. This program consists of a simple aircraft response model with two rigid and three flexible symmetric degrees of freedom and allows for the calculation of various airplane responses due to a discrete one-minus-cosine gust as well as continuous turbulence. Simplifications, assumptions, and opportunities for potential improvements pertaining to the existing software program are first identified, then a revised version of the original software tool is developed with improved methodology to include more complex geometries, additional excitation cases, and output data so as to provide a more useful and accurate tool for gust load analysis. Revisions are made in the categories of aircraft geometry, computation of aerodynamic forces and moments, and implementation of horizontal tail mode shapes. In order to improve the original software program to enhance usefulness, a wing control surface and horizontal tail control surface is added, an extended application of the discrete one-minus-cosine gust input is employed, a supplemental continuous turbulence spectrum is implemented, and a capability to animate the total vehicle deformation response to gust inputs in included. These revisions and enhancements are implemented and an analysis of the results is used to validate the modifications.

  19. Smart aircraft fastener evaluation (SAFE) system: a condition-based corrosion detection system for aging aircraft

    NASA Astrophysics Data System (ADS)

    Schoess, Jeffrey N.; Seifert, Greg; Paul, Clare A.

    1996-05-01

    The smart aircraft fastener evaluation (SAFE) system is an advanced structural health monitoring effort to detect and characterize corrosion in hidden and inaccessible locations of aircraft structures. Hidden corrosion is the number one logistics problem for the U.S. Air Force, with an estimated maintenance cost of $700M per year in 1990 dollars. The SAFE system incorporates a solid-state electrochemical microsensor and smart sensor electronics in the body of a Hi-Lok aircraft fastener to process and autonomously report corrosion status to aircraft maintenance personnel. The long-term payoff for using SAFE technology will be in predictive maintenance for aging aircraft and rotorcraft systems, fugitive emissions applications such as control valves, chemical pipeline vessels, and industrial boilers. Predictive maintenance capability, service, and repair will replace the current practice of scheduled maintenance to substantially reduce operational costs. A summary of the SAFE concept, laboratory test results, and future field test plans is presented.

  20. Sexual function in F-111 maintenance workers: the study of health outcomes in aircraft maintenance personnel.

    PubMed

    Brown, Anthony; Gibson, Richard; Tavener, Meredith; Guest, Maya; D'Este, Catherine; Byles, Julie; Attia, John; Horsley, Keith; Harrex, Warren; Ross, James

    2009-06-01

    In Australia, four formal F-111 fuel tank deseal/reseal (DSRS) repair programs were implemented over more than two decades, each involving different processes and using a range of hazardous substances. However, health concerns were raised by a number of workers. The "Study of Health Outcomes in Aircraft Maintenance Personnel" was commissioned by the Australian Department of Defence to investigate potential adverse health outcomes as a result of being involved in the deseal/reseal processes. To compare measures of sexual function in F-111 aircraft fuel tank DSRS maintenance workers, against two appropriate comparison groups. Exposed and comparison participants completed a postal questionnaire which included general questions of health and health behavior, and two specific questions on sexual functioning. They also completed the International Index of Erectile Function (IIEF) questionnaire. Logistic regression was used to explore exposure status and outcome while adjusting for potential confounders. The three outcomes of interest for this study were the proportion of participants with erectile dysfunction (ED) according to the IIEF, the proportion with self-reported loss of interest in sex, and the proportion with self-reported problems with sexual functioning. Compared with each of the comparison groups, a larger proportion of the exposed group reported sexual problems and were classified as having ED according to the IIEF. In logistic regression, the odds of all three outcomes were higher for exposed participants relative to each comparison group and after adjustment for potentially confounding variables including anxiety and depression. There was a consistent problem with sexual functioning in the exposed group that is not explained by anxiety and depression, and it appears related to DSRS activities.

  1. Flexible twist for pitch control in a high altitude long endurance aircraft with nonlinear response

    NASA Astrophysics Data System (ADS)

    Bond, Vanessa L.

    Information dominance is the key motivator for employing high-altitude long-endurance (HALE) aircraft to provide continuous coverage in the theaters of operation. A joined-wing configuration of such a craft gives the advantage of a platform for higher resolution sensors. Design challenges emerge with structural flexibility that arise from a long-endurance aircraft design. The goal of this research was to demonstrate that scaling the nonlinear response of a full-scale finite element model was possible if the model was aeroelastically and "nonlinearly" scaled. The research within this dissertation showed that using the first three modes and the first bucking modes was not sufficient for proper scaling. In addition to analytical scaling several experiments were accomplished to understand and overcome design challenges of HALE aircraft. One such challenge is combated by eliminating pitch control surfaces and replacing them with an aft-wing twist concept. This design option was physically realized through wind tunnel measurement of forces, moments and pressures on a subscale experimental model. This design and experiment demonstrated that pitch control with aft-wing twist is feasible. Another challenge is predicting the nonlinear response of long-endurance aircraft. This was addressed by experimental validation of modeling nonlinear response on a subscale experimental model. It is important to be able to scale nonlinear behavior in this type of craft due to its highly flexible nature. The validation accomplished during this experiment on a subscale model will reduce technical risk for full-scale development of such pioneering craft. It is also important to experimentally reproduce the air loads following the wing as it deforms. Nonlinearities can be attributed to these follower forces that might otherwise be overlooked. This was found to be a significant influence in HALE aircraft to include the case study of the FEM and experimental models herein.

  2. Commercial Aircraft Maintenance Experience Relating to Engine External Hardware

    NASA Technical Reports Server (NTRS)

    Soditus, Sharon M.

    2006-01-01

    Airlines are extremely sensitive to the amount of dollars spent on maintaining the external engine hardware in the field. Analysis reveals that many problems revolve around a central issue, reliability. Fuel and oil leakage due to seal failure and electrical fault messages due to wire harness failures play a major role in aircraft delays and cancellations (D&C's) and scheduled maintenance. Correcting these items on the line requires a large investment of engineering resources and manpower after the fact. The smartest and most cost effective philosophy is to build the best hardware the first time. The only way to do that is to completely understand and model the operating environment, study the field experience of similar designs and to perform extensive testing.

  3. Handling qualities of large flexible control-configured aircraft

    NASA Technical Reports Server (NTRS)

    Swaim, R. L.

    1980-01-01

    The effects on handling qualities of low frequency symmetric elastic mode interaction with the rigid body dynamics of a large flexible aircraft was analyzed by use of a mathematical pilot modeling computer simulation. An extension of the optimal control model for a human pilot was made so that the mode interaction effects on the pilot's control task could be assessed. Pilot ratings were determined for a longitudinal tracking task with parametric variations in the undamped natural frequencies of the two lowest frequency symmetric elastic modes made to induce varying amounts of mode interaction. Relating numerical performance index values associated with the frequency variations used in several dynamic cases, to a numerical Cooper-Harper pilot rating has proved successful in discriminating when the mathematical pilot can or cannot separate rigid from elastic response in the tracking task.

  4. A maintenance model for k-out-of-n subsystems aboard a fleet of advanced commercial aircraft

    NASA Technical Reports Server (NTRS)

    Miller, D. R.

    1978-01-01

    Proposed highly reliable fault-tolerant reconfigurable digital control systems for a future generation of commercial aircraft consist of several k-out-of-n subsystems. Each of these flight-critical subsystems will consist of n identical components, k of which must be functioning properly in order for the aircraft to be dispatched. Failed components are recoverable; they are repaired in a shop. Spares are inventoried at a main base where they may be substituted for failed components on planes during layovers. Penalties are assessed when failure of a k-out-of-n subsystem causes a dispatch cancellation or delay. A maintenance model for a fleet of aircraft with such control systems is presented. The goals are to demonstrate economic feasibility and to optimize.

  5. Environmental Assessment: Construction and Operation of Aircraft Maintenance Hangar Project Number UHHZ023005

    DTIC Science & Technology

    2008-05-12

    Aircraft Maintenance Hangar 2 peaking power generators, boilers , and various sources of fugitive volatile organic compounds (VOCs). There are...nature. The boilers on the base are used primarily for generating steam for comfort heating of the buildings. Natural gas is used as the primary...fuel, with No. 2 Diesel Fuel and Air Mixed Propane as backups for most of the large boilers . 4.3 Air Quality Requirements at Robins AFB Robins AFB is

  6. Skills, rules and knowledge in aircraft maintenance: errors in context

    NASA Technical Reports Server (NTRS)

    Hobbs, Alan; Williamson, Ann

    2002-01-01

    Automatic or skill-based behaviour is generally considered to be less prone to error than behaviour directed by conscious control. However, researchers who have applied Rasmussen's skill-rule-knowledge human error framework to accidents and incidents have sometimes found that skill-based errors appear in significant numbers. It is proposed that this is largely a reflection of the opportunities for error which workplaces present and does not indicate that skill-based behaviour is intrinsically unreliable. In the current study, 99 errors reported by 72 aircraft mechanics were examined in the light of a task analysis based on observations of the work of 25 aircraft mechanics. The task analysis identified the opportunities for error presented at various stages of maintenance work packages and by the job as a whole. Once the frequency of each error type was normalized in terms of the opportunities for error, it became apparent that skill-based performance is more reliable than rule-based performance, which is in turn more reliable than knowledge-based performance. The results reinforce the belief that industrial safety interventions designed to reduce errors would best be directed at those aspects of jobs that involve rule- and knowledge-based performance.

  7. Aircraft components structural health monitoring using flexible ultrasonic transducer arrays

    NASA Astrophysics Data System (ADS)

    Liu, W.-L.; Jen, C.-K.; Kobayashi, M.; Mrad, N.

    2011-04-01

    A damage detection capability based on a flexible ultrasonic transducer (FUT) array bonded onto a planar and a curved surface is presented. The FUT array was fabricated on a 75 μm titanium substrate using sol-gel spray technique. Room temperature curable adhesive is used as the bonding agent and ultrasonic couplant between the transducer and the test article. The bonding agent was successfully tested for aircraft environmental temperatures between -80 °C and 100 °C. For a planar test article, selected FUT arrays were able to detect fasteners damage within a planar distance of 176 mm, when used in the pulse-echo mode. Such results illustrate the effectiveness of the developed FUT transducer as compared to commercial 10MHz ultrasonic transducer (UT). These FUT arrays were further demonstrated on a curved test article. Pulse-echo measurements confirmed the reflected echoes from the specimen. Such measurement was not possible with commercial UTs due to the curved nature of the test article and its accessibility, thus demonstrating the suitability and superiority of the developed flexible ultrasonic transducer capability.

  8. An ℋ∞ full information approach for the feedforward controller design of a large blended wing body flexible aircraft

    NASA Astrophysics Data System (ADS)

    Westermayer, C.; Schirrer, A.; Hemedi, M.; Kozek, M.

    2013-12-01

    An ℋ∞ full information feedforward design approach for longitudinal motion prefilter design of a large flexible blended wing body (BWB) aircraft is presented. An existing onset is extended such that specifications concerning command tracking, limited control energy, and manoeuvre load reduction can be addressed simultaneously. Therefore, the utilized design architecture is provided and manual tuning aspects are considered. In order to increase controller tuning efficiency, an automated tuning process based on several optimization criteria is proposed. Moreover, two design methodologies for the parameter-varying design case are investigated. The obtained controller is validated on a high-order nonlinear model, indicating the high potential of the presented approach for flexible aircraft control.

  9. Greedy Sampling and Incremental Surrogate Model-Based Tailoring of Aeroservoelastic Model Database for Flexible Aircraft

    NASA Technical Reports Server (NTRS)

    Wang, Yi; Pant, Kapil; Brenner, Martin J.; Ouellette, Jeffrey A.

    2018-01-01

    This paper presents a data analysis and modeling framework to tailor and develop linear parameter-varying (LPV) aeroservoelastic (ASE) model database for flexible aircrafts in broad 2D flight parameter space. The Kriging surrogate model is constructed using ASE models at a fraction of grid points within the original model database, and then the ASE model at any flight condition can be obtained simply through surrogate model interpolation. The greedy sampling algorithm is developed to select the next sample point that carries the worst relative error between the surrogate model prediction and the benchmark model in the frequency domain among all input-output channels. The process is iterated to incrementally improve surrogate model accuracy till a pre-determined tolerance or iteration budget is met. The methodology is applied to the ASE model database of a flexible aircraft currently being tested at NASA/AFRC for flutter suppression and gust load alleviation. Our studies indicate that the proposed method can reduce the number of models in the original database by 67%. Even so the ASE models obtained through Kriging interpolation match the model in the original database constructed directly from the physics-based tool with the worst relative error far below 1%. The interpolated ASE model exhibits continuously-varying gains along a set of prescribed flight conditions. More importantly, the selected grid points are distributed non-uniformly in the parameter space, a) capturing the distinctly different dynamic behavior and its dependence on flight parameters, and b) reiterating the need and utility for adaptive space sampling techniques for ASE model database compaction. The present framework is directly extendible to high-dimensional flight parameter space, and can be used to guide the ASE model development, model order reduction, robust control synthesis and novel vehicle design of flexible aircraft.

  10. How performance-contingent reward prospect modulates cognitive control: Increased cue maintenance at the cost of decreased flexibility.

    PubMed

    Hefer, Carmen; Dreisbach, Gesine

    2017-10-01

    Growing evidence suggests that reward prospect promotes cognitive stability in terms of increased context or cue maintenance. In 3 Experiments, using different versions of the AX-continuous performance task, we investigated whether this reward effect comes at the cost of decreased cognitive flexibility. Experiment 1 shows that the reward induced increase of cue maintenance perseverates even when reward is no longer available. Experiment 2 shows that this reward effect not only survives the withdrawal of reward but also delays the adaptation to changed task conditions that make cue usage maladaptive. And finally in Experiment 3, it is shown that this reduced flexibility to adapt is observed in a more demanding modified version of the AX-continuous performance task and is even stronger under conditions of sustained reward. Taken together, all 3 Experiments thus speak to the idea that the prospect of reward increases cue maintenance and thereby cognitive stability. This increased cognitive stability however comes at the cost of decreased flexibility in terms of delayed adaptation to new reward and task conditions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. Integrated Flight/Structural Mode Control for Very Flexible Aircraft Using L1 Adaptive Output Feedback Controller

    NASA Technical Reports Server (NTRS)

    Che, Jiaxing; Cao, Chengyu; Gregory, Irene M.

    2012-01-01

    This paper explores application of adaptive control architecture to a light, high-aspect ratio, flexible aircraft configuration that exhibits strong rigid body/flexible mode coupling. Specifically, an L(sub 1) adaptive output feedback controller is developed for a semi-span wind tunnel model capable of motion. The wind tunnel mount allows the semi-span model to translate vertically and pitch at the wing root, resulting in better simulation of an aircraft s rigid body motion. The control objective is to design a pitch control with altitude hold while suppressing body freedom flutter. The controller is an output feedback nominal controller (LQG) augmented by an L(sub 1) adaptive loop. A modification to the L(sub 1) output feedback is proposed to make it more suitable for flexible structures. The new control law relaxes the required bounds on the unmatched uncertainty and allows dependence on the state as well as time, i.e. a more general unmatched nonlinearity. The paper presents controller development and simulated performance responses. Simulation is conducted by using full state flexible wing models derived from test data at 10 different dynamic pressure conditions. An L(sub 1) adaptive output feedback controller is designed for a single test point and is then applied to all the test cases. The simulation results show that the L(sub 1) augmented controller can stabilize and meet the performance requirements for all 10 test conditions ranging from 30 psf to 130 psf dynamic pressure.

  12. Model Order Reduction of Aeroservoelastic Model of Flexible Aircraft

    NASA Technical Reports Server (NTRS)

    Wang, Yi; Song, Hongjun; Pant, Kapil; Brenner, Martin J.; Suh, Peter

    2016-01-01

    This paper presents a holistic model order reduction (MOR) methodology and framework that integrates key technological elements of sequential model reduction, consistent model representation, and model interpolation for constructing high-quality linear parameter-varying (LPV) aeroservoelastic (ASE) reduced order models (ROMs) of flexible aircraft. The sequential MOR encapsulates a suite of reduction techniques, such as truncation and residualization, modal reduction, and balanced realization and truncation to achieve optimal ROMs at grid points across the flight envelope. The consistence in state representation among local ROMs is obtained by the novel method of common subspace reprojection. Model interpolation is then exploited to stitch ROMs at grid points to build a global LPV ASE ROM feasible to arbitrary flight condition. The MOR method is applied to the X-56A MUTT vehicle with flexible wing being tested at NASA/AFRC for flutter suppression and gust load alleviation. Our studies demonstrated that relative to the fullorder model, our X-56A ROM can accurately and reliably capture vehicles dynamics at various flight conditions in the target frequency regime while the number of states in ROM can be reduced by 10X (from 180 to 19), and hence, holds great promise for robust ASE controller synthesis and novel vehicle design.

  13. 14 CFR 91.1425 - CAMP: Maintenance, preventive maintenance, and alteration programs.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... RULES Fractional Ownership Operations Program Management § 91.1425 CAMP: Maintenance, preventive maintenance, and alteration programs. Each program manager who maintains program aircraft under a CAMP must... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false CAMP: Maintenance, preventive maintenance...

  14. A Summary of Revisions Applied to a Turbulence Response Analysis Method for Flexible Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Funk, Christie J.; Perry, Boyd, III; Silva, Walter A.; Newman, Brett

    2014-01-01

    A software program and associated methodology to study gust loading on aircraft exists for a classification of geometrically simplified flexible configurations. This program consists of a simple aircraft response model with two rigid and three flexible symmetric degrees-of - freedom and allows for the calculation of various airplane responses due to a discrete one-minus- cosine gust as well as continuous turbulence. Simplifications, assumptions, and opportunities for potential improvements pertaining to the existing software program are first identified, then a revised version of the original software tool is developed with improved methodology to include more complex geometries, additional excitation cases, and additional output data so as to provide a more useful and precise tool for gust load analysis. In order to improve the original software program to enhance usefulness, a wing control surface and horizontal tail control surface is added, an extended application of the discrete one-minus-cosine gust input is employed, a supplemental continuous turbulence spectrum is implemented, and a capability to animate the total vehicle deformation response to gust inputs is included. These revisions and enhancements are implemented and an analysis of the results is used to validate the modifications.

  15. 22 CFR 151.11 - Notification of ownership, maintenance or use of vessel and/or aircraft; evidence of insurance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Notification of ownership, maintenance or use of vessel and/or aircraft; evidence of insurance. 151.11 Section 151.11 Foreign Relations DEPARTMENT OF STATE DIPLOMATIC PRIVILEGES AND IMMUNITIES COMPULSORY LIABILITY INSURANCE FOR DIPLOMATIC MISSIONS...

  16. 22 CFR 151.11 - Notification of ownership, maintenance or use of vessel and/or aircraft; evidence of insurance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Notification of ownership, maintenance or use of vessel and/or aircraft; evidence of insurance. 151.11 Section 151.11 Foreign Relations DEPARTMENT OF STATE DIPLOMATIC PRIVILEGES AND IMMUNITIES COMPULSORY LIABILITY INSURANCE FOR DIPLOMATIC MISSIONS...

  17. 22 CFR 151.11 - Notification of ownership, maintenance or use of vessel and/or aircraft; evidence of insurance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Notification of ownership, maintenance or use of vessel and/or aircraft; evidence of insurance. 151.11 Section 151.11 Foreign Relations DEPARTMENT OF STATE DIPLOMATIC PRIVILEGES AND IMMUNITIES COMPULSORY LIABILITY INSURANCE FOR DIPLOMATIC MISSIONS...

  18. 22 CFR 151.11 - Notification of ownership, maintenance or use of vessel and/or aircraft; evidence of insurance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Notification of ownership, maintenance or use of vessel and/or aircraft; evidence of insurance. 151.11 Section 151.11 Foreign Relations DEPARTMENT OF STATE DIPLOMATIC PRIVILEGES AND IMMUNITIES COMPULSORY LIABILITY INSURANCE FOR DIPLOMATIC MISSIONS...

  19. 22 CFR 151.11 - Notification of ownership, maintenance or use of vessel and/or aircraft; evidence of insurance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Notification of ownership, maintenance or use of vessel and/or aircraft; evidence of insurance. 151.11 Section 151.11 Foreign Relations DEPARTMENT OF STATE DIPLOMATIC PRIVILEGES AND IMMUNITIES COMPULSORY LIABILITY INSURANCE FOR DIPLOMATIC MISSIONS...

  20. Mission management aircraft operations manual

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This manual prescribes the NASA mission management aircraft program and provides policies and criteria for the safe and economical operation, maintenance, and inspection of NASA mission management aircraft. The operation of NASA mission management aircraft is based on the concept that safety has the highest priority. Operations involving unwarranted risks will not be tolerated. NASA mission management aircraft will be designated by the Associate Administrator for Management Systems and Facilities. NASA mission management aircraft are public aircraft as defined by the Federal Aviation Act of 1958. Maintenance standards, as a minimum, will meet those required for retention of Federal Aviation Administration (FAA) airworthiness certification. Federal Aviation Regulation Part 91, Subparts A and B, will apply except when requirements of this manual are more restrictive.

  1. 14 CFR 135.419 - Approved aircraft inspection program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance, Preventive Maintenance, and Alterations § 135.419 Approved aircraft inspection program. (a... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Approved aircraft inspection program. 135...

  2. 14 CFR 135.419 - Approved aircraft inspection program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance, Preventive Maintenance, and Alterations § 135.419 Approved aircraft inspection program. (a... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Approved aircraft inspection program. 135...

  3. 14 CFR 135.419 - Approved aircraft inspection program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance, Preventive Maintenance, and Alterations § 135.419 Approved aircraft inspection program. (a... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Approved aircraft inspection program. 135...

  4. 14 CFR 135.419 - Approved aircraft inspection program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance, Preventive Maintenance, and Alterations § 135.419 Approved aircraft inspection program. (a... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Approved aircraft inspection program. 135...

  5. 14 CFR 135.419 - Approved aircraft inspection program.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance, Preventive Maintenance, and Alterations § 135.419 Approved aircraft inspection program. (a... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Approved aircraft inspection program. 135...

  6. Flexible aircraft dynamic modeling for dynamic analysis and control synthesis

    NASA Technical Reports Server (NTRS)

    Schmidt, David K.

    1989-01-01

    The linearization and simplification of a nonlinear, literal model for flexible aircraft is highlighted. Areas of model fidelity that are critical if the model is to be used for control system synthesis are developed and several simplification techniques that can deliver the necessary model fidelity are discussed. These techniques include both numerical and analytical approaches. An analytical approach, based on first-order sensitivity theory is shown to lead not only to excellent numerical results, but also to closed-form analytical expressions for key system dynamic properties such as the pole/zero factors of the vehicle transfer-function matrix. The analytical results are expressed in terms of vehicle mass properties, vibrational characteristics, and rigid-body and aeroelastic stability derivatives, thus leading to the underlying causes for critical dynamic characteristics.

  7. Additive Manufacturing (3D Printing) Aircraft Parts and Tooling at the Maintenance Group Level

    DTIC Science & Technology

    The purpose of this research was to evaluate the effectiveness of additive manufacturing (AM) or 3D printing for the Air Force aircraft maintenance...case study of the 552d MXGs 3D printing operation explores their use of a Fused Deposition Modeling (FDM) thermoplastic material to manufacture parts...by applying the case study’s analysis toward a proof of concept, producing a C-130J Aft Cargo Door Rub Strip for 3D printing . The study concluded by

  8. KC-46 Workforce Requirements for Depot Maintenance Activation

    DTIC Science & Technology

    2014-03-27

    commercial derivative aircraft . These are aircraft originally designed for commercial aviation but with modifications that change the aircraft to fit the... designing the process to capture the data needed to infer answers to the research questions. More needs to be understood about how aircraft maintenance...Air Force projects receiving new KC-46 aircraft in 2016 and headquarters is directing organic maintenance. Oklahoma City ALC is the depot projected

  9. 14 CFR 33.90 - Initial maintenance inspection test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Initial maintenance inspection test. 33.90 Section 33.90 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.90 Initial maintenance...

  10. 14 CFR 33.90 - Initial maintenance inspection test.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Initial maintenance inspection test. 33.90 Section 33.90 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.90 Initial maintenance...

  11. 14 CFR 33.90 - Initial maintenance inspection test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Initial maintenance inspection test. 33.90 Section 33.90 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.90 Initial maintenance...

  12. 14 CFR 33.90 - Initial maintenance inspection test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Initial maintenance inspection test. 33.90 Section 33.90 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.90 Initial maintenance...

  13. The adaptation of sustainable biojet fuels and its effect on aircraft engine maintenance

    NASA Astrophysics Data System (ADS)

    Mohd Noh, H.; Rodrigo, G. A.; Rahman, N. A. Abdul

    2016-10-01

    Aviation industries are looking into several resources for renewable and sustainable energy. Among those attention is focused in biojet fuel. This paper engages the issue of biojet fuel emissions that increase the environmental concern in the air transport sector. The paper presents the use of biojet fuel and its effect on aircraft engine maintenance through preliminary data collections, and a review of its development process in operations for time and goal. As conclusion, airlines management needs to adapt and adopt the transition to alternative fuels, especially given the global biofuel trend emerging due to the authority approval.

  14. Human Factors in Aviation Maintenance. Phase 1

    DTIC Science & Technology

    1991-11-01

    Aircraft Maintenance Information SystemSupyyse AMP ......... Aircraft Maintenance Personnel CRM ....... Cockpit Resource Management AMT... developments were sponsored by the Department of interchange of relevant information between system par- Defense (DoD). Fewer than twenty systems are...ofindividuals without complicating lines ofcommand andothers in the maintenance system is repeated for row "I." orthe allocation ofresponsibility

  15. Coupled Vortex-Lattice Flight Dynamic Model with Aeroelastic Finite-Element Model of Flexible Wing Transport Aircraft with Variable Camber Continuous Trailing Edge Flap for Drag Reduction

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan; Ting, Eric; Nguyen, Daniel; Dao, Tung; Trinh, Khanh

    2013-01-01

    This paper presents a coupled vortex-lattice flight dynamic model with an aeroelastic finite-element model to predict dynamic characteristics of a flexible wing transport aircraft. The aircraft model is based on NASA Generic Transport Model (GTM) with representative mass and stiffness properties to achieve a wing tip deflection about twice that of a conventional transport aircraft (10% versus 5%). This flexible wing transport aircraft is referred to as an Elastically Shaped Aircraft Concept (ESAC) which is equipped with a Variable Camber Continuous Trailing Edge Flap (VCCTEF) system for active wing shaping control for drag reduction. A vortex-lattice aerodynamic model of the ESAC is developed and is coupled with an aeroelastic finite-element model via an automated geometry modeler. This coupled model is used to compute static and dynamic aeroelastic solutions. The deflection information from the finite-element model and the vortex-lattice model is used to compute unsteady contributions to the aerodynamic force and moment coefficients. A coupled aeroelastic-longitudinal flight dynamic model is developed by coupling the finite-element model with the rigid-body flight dynamic model of the GTM.

  16. A linear parameter-varying multiobjective control law design based on youla parametrization for a flexible blended wing body aircraft

    NASA Astrophysics Data System (ADS)

    Demourant, F.; Ferreres, G.

    2013-12-01

    This article presents a methodology for a linear parameter-varying (LPV) multiobjective flight control law design for a blended wing body (BWB) aircraft and results. So, the method is a direct design of a parametrized control law (with respect to some measured flight parameters) through a multimodel convex design to optimize a set of specifications on the full-flight domain and different mass cases. The methodology is based on the Youla parameterization which is very useful since closed loop specifications are affine with respect to Youla parameter. The LPV multiobjective design method is detailed and applied to the BWB flexible aircraft example.

  17. Exposure of aircraft maintenance technicians to organophosphates from hydraulic fluids and turbine oils: a pilot study.

    PubMed

    Schindler, Birgit Karin; Koslitz, Stephan; Weiss, Tobias; Broding, Horst Christoph; Brüning, Thomas; Bünger, Jürgen

    2014-01-01

    Hydraulic fluids and turbine oils contain organophosphates like tricresyl phosphate isomers, triphenyl phosphate and tributyl phosphate from very small up to high percentages. The aim of this pilot study was to determine if aircraft maintenance technicians are exposed to relevant amounts of organophosphates. Dialkyl and diaryl phosphate metabolites of seven organophosphates were quantified in pre- and post-shift spot urine samples of technicians (N=5) by GC-MS/MS after solid phase extraction and derivatization. Pre- and post shift values of tributyl phosphate metabolites (dibutyl phosphate (DBP): median pre-shift: 12.5 μg/L, post-shift: 23.5 μg/L) and triphenyl phosphate metabolites (diphenyl phosphate (DPP): median pre-shift: 2.9 μg/L, post-shift: 3.5 μg/L) were statistically higher than in a control group from the general population (median DBP: <0.25 μg/L, median DPP: 0.5 μg/L). No tricresyl phosphate metabolites were detected. The aircraft maintenance technicians were occupationally exposed to tributyl and triphenyl phosphate but not to tricresyl phosphate, tri-(2-chloroethyl)- and tri-(2-chloropropyl)-phosphate. Further studies are necessary to collect information on sources, routes of uptake and varying exposures during different work tasks, evaluate possible health effects and to set up appropriate protective measures. Copyright © 2013 Elsevier GmbH. All rights reserved.

  18. IMIS: Integrated Maintenance Information System. A maintenance information delivery concept

    NASA Technical Reports Server (NTRS)

    Vonholle, Joseph C.

    1987-01-01

    The Integrated Maintenance Information System (IMIS) will optimize the use of available manpower, enhance technical performance, improve training, and reduce the support equipment and documentation needed for deployment. It will serve as the technician's single, integrated source of all the technical information required to perform modern aircraft maintenance.

  19. Stretchable, Highly Durable Ternary Nanocomposite Strain Sensor for Structural Health Monitoring of Flexible Aircraft

    PubMed Central

    Yin, Feng; Ye, Dong; Zhu, Chen; Qiu, Lei; Huang, YongAn

    2017-01-01

    Harmonious developments of electrical and mechanical performances are crucial for stretchable sensors in structural health monitoring (SHM) of flexible aircraft such as aerostats and morphing aircrafts. In this study, we prepared a highly durable ternary conductive nanocomposite made of polydimethylsiloxane (PDMS), carbon black (CB) and multi-walled carbon nanotubes (MWCNTs) to fabricate stretchable strain sensors. The nanocomposite has excellent electrical and mechanical properties by intensively optimizing the weight percentage of conducting fillers as well as the ratio of PDMS pre-polymer and curing agent. It was found that the nanocomposite with homogeneous hybrid filler of 1.75 wt % CB and 3 wt % MWCNTs exhibits a highly strain sensitive characteristics of good linearity, high gauge factor (GF ~ 12.25) and excellent durability over 105 stretching-releasing cycles under a tensile strain up to 25% when the PDMS was prepared at the ratio of 12.5:1. A strain measurement of crack detection for the aerostats surface was also employed, demonstrating a great potential of such ternary nanocomposite used as stretchable strain sensor in SHM. PMID:29156620

  20. Aircraft Maintenance Expert Systems.

    DTIC Science & Technology

    1983-11-01

    PARA 2 -104)) 44: (( JETCAL ANALYSIS SHOWS SYSTEM READS CORRECT) (REPLACE FAULTY PARTS)) 45: ((OVERTEMP EXCEEDED SERVICE LIMITS) 46: I(ENGINE CONTROL...CIRCUITS WITHIN LIMITS ON JETCAL ) (REPLACE FAULTY PARTS)) 47: (ADJUST EST AT AMPLIFIER AND CHECK TENP)) (SEND ENGINE TO HIGHER LEVEL MAINTENANCE)) 48: 2

  1. Detection of structural deterioration and associated airline maintenance problems

    NASA Technical Reports Server (NTRS)

    Henniker, H. D.; Mitchell, R. G.

    1972-01-01

    Airline operations involving the detection of structural deterioration and associated maintenance problems are discussed. The standard approach to the maintenance and inspection of aircraft components and systems is described. The frequency of inspections and the application of preventive maintenance practices are examined. The types of failure which airline transport aircraft encounter and the steps taken to prevent catastrophic failure are reported.

  2. Brominated flame retardant exposure of aircraft personnel.

    PubMed

    Strid, Anna; Smedje, Greta; Athanassiadis, Ioannis; Lindgren, Torsten; Lundgren, Håkan; Jakobsson, Kristina; Bergman, Åke

    2014-12-01

    The use of brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) in aircraft is the result of high fire safety demands. Personnel working in or with aircraft might therefore be exposed to several BFRs. Previous studies have reported PBDE exposure in flight attendants and in passengers. One other group that may be subjected to significant BFR exposure via inhalation, are the aircraft maintenance workers. Personnel exposure both during flights and maintenance of aircraft, are investigated in the present study. Several BFRs were present in air and dust sampled during both the exposure scenarios; PBDEs, hexabromocyclododecane (HBCDD), decabromodiphenyl ethane (DBDPE) and 1,2-bis (2,4,6-tribromophenoxy) ethane. PBDEs were also analyzed in serum from pilots/cabin crew, maintenance workers and from a control group of individuals without any occupational aircraft exposure. Significantly higher concentrations of PBDEs were found in maintenance workers compared to pilots/cabin crew and control subjects with median total PBDE concentrations of 19, 6.8 and 6.6 pmol g(-1) lipids, respectively. Pilots and cabin crew had similar concentrations of most PBDEs as the control group, except for BDE-153 and BDE-154 which were significantly higher. Results indicate higher concentrations among some of the pilots compared to the cabin crew. It is however, evident that the cabin personnel have lower BFR exposures compared to maintenance workers that are exposed to such a degree that their blood levels are significantly different from the control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. How Performance-Contingent Reward Prospect Modulates Cognitive Control: Increased Cue Maintenance at the Cost of Decreased Flexibility

    ERIC Educational Resources Information Center

    Hefer, Carmen; Dreisbach, Gesine

    2017-01-01

    Growing evidence suggests that reward prospect promotes cognitive stability in terms of increased context or cue maintenance. In 3 Experiments, using different versions of the AX-continuous performance task, we investigated whether this reward effect comes at the cost of decreased cognitive flexibility. Experiment 1 shows that the reward induced…

  4. Computing Linear Mathematical Models Of Aircraft

    NASA Technical Reports Server (NTRS)

    Duke, Eugene L.; Antoniewicz, Robert F.; Krambeer, Keith D.

    1991-01-01

    Derivation and Definition of Linear Aircraft Model (LINEAR) computer program provides user with powerful, and flexible, standard, documented, and verified software tool for linearization of mathematical models of aerodynamics of aircraft. Intended for use in software tool to drive linear analysis of stability and design of control laws for aircraft. Capable of both extracting such linearized engine effects as net thrust, torque, and gyroscopic effects, and including these effects in linear model of system. Designed to provide easy selection of state, control, and observation variables used in particular model. Also provides flexibility of allowing alternate formulations of both state and observation equations. Written in FORTRAN.

  5. Aircraft Ground Operation, Servicing, Fluid Lines and Fittings, Mechanics Privileges and Limitations, and Maintenance Publications, Forms and Records (Course Outline), Aviation Mechanics 1 (Power and Frame): 9073.02.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The course outline consists of five instructional blocks of several units each: (1) Aircraft Ground Operation and Servicing; (2) Fluid Lines and Fittings; (3) Mechanics Requirements, Privileges and Limitations; (4) Maintenance Publications; and, (5) Maintenance forms and Records. It is a basic course of knowledge and skills necessary to any…

  6. 40 CFR 141.804 - Aircraft water system operations and maintenance plan.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... calendar quarter of initial operation of the aircraft. (e) Any changes to the aircraft water system... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Aircraft water system operations and...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Aircraft Drinking Water Rule...

  7. 40 CFR 141.804 - Aircraft water system operations and maintenance plan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... calendar quarter of initial operation of the aircraft. (e) Any changes to the aircraft water system... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Aircraft water system operations and...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Aircraft Drinking Water Rule...

  8. 14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... data approved by the Administrator. (e) The holder of an air carrier operating certificate or an... holder of a repairman certificate (light-sport aircraft) with a maintenance rating may approve an aircraft issued a special airworthiness certificate in light-sport category for return to service, as...

  9. Progress in supersonic cruise aircraft technology

    NASA Technical Reports Server (NTRS)

    Driver, C.

    1978-01-01

    The supersonic cruise aircraft research program identified significant improvements in the technology areas of propulsion, aerodynamics, structures, takeoff and landing procedures, and advanced configuration concepts. Application of these technology areas to a commercial aircraft is discussed. An advanced SST family of aircraft which may be environmentally acceptable, have flexible range-payload capability, and be economically viable is projected.

  10. Aviation Maintenance Technology. Course Content Guides. FAA Approved Curriculum.

    ERIC Educational Resources Information Center

    Shrawder, Jack; And Others

    Course content guides are provided for the 30 courses in this aviation maintenance technology curriculum approved by the Federal Aviation Administration. Course titles are physics for technicians; aircraft information, regulations, and procedures; aircraft assembly; fundamentals of aircraft electronics; aircraft electrical components; aircraft…

  11. Flexibility within working memory and the focus of attention for sequential verbal information does not depend on active maintenance.

    PubMed

    Sandry, Joshua; Schwark, Jeremy D; MacDonald, Justin

    2014-10-01

    The focus of attention seems to be a static element within working memory when verbal information is serially presented, unless additional time is available for processing or active maintenance. Experiment 1 manipulated the reward associated with early and medial list positions in a probe recognition paradigm and found evidence that these nonterminal list positions could be retrieved faster and more accurately if participants were appropriately motivated-without additional time for processing or active maintenance. Experiment 2 used articulatory suppression and demonstrated that the underlying maintenance mechanism cannot be attributed to rehearsal, leaving attentional refreshing as the more likely mechanism. These findings suggest that the focus of attention within working memory can flexibly maintain nonterminal early and medial list representations at the expense of other list representations even when there is not additional time for processing or active maintenance. Maintenance seems to be accomplished through an attentional refreshing mechanism.

  12. Determination of the flight equipment maintenance costs of commuter airlines

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Labor and materials costs associated with maintaining and operating 12 commuter airlines carrying an average of from 42 to 1,100 passengers daily in a variety of aircraft types were studied to determine the total direct maintenance cost per flight hour for the airframe, engine, and avionics and other instruments. The distribution of maintenance costs are analyzed for two carriers, one using turboprop aircraft and the other using piston engine aircraft.

  13. Validation of an Active Gear, Flexible Aircraft Take-off and Landing analysis (AGFATL)

    NASA Technical Reports Server (NTRS)

    Mcgehee, J. R.

    1984-01-01

    The results of an analytical investigation using a computer program for active gear, flexible aircraft take off and landing analysis (AGFATL) are compared with experimental data from shaker tests, drop tests, and simulated landing tests to validate the AGFATL computer program. Comparison of experimental and analytical responses for both passive and active gears indicates good agreement for shaker tests and drop tests. For the simulated landing tests, the passive and active gears were influenced by large strut binding friction forces. The inclusion of these undefined forces in the analytical simulations was difficult, and consequently only fair to good agreement was obtained. An assessment of the results from the investigation indicates that the AGFATL computer program is a valid tool for the study and initial design of series hydraulic active control landing gear systems.

  14. Pilot modeling and closed-loop analysis of flexible aircraft in the pitch tracking task

    NASA Technical Reports Server (NTRS)

    Schmidt, D. K.

    1983-01-01

    The issue addressed in the appropriate modeling technique for pilot vehicle analysis of large flexible aircraft, when the frequency separation between the rigid-body mode and the dynamic aeroelastic modes is reduced. This situation was shown to have significant effects on pitch-tracking performance and subjective rating of the task, obtained via fixed base simulation. Further, the dynamics in these cases are not well modeled with a rigid-body-like model obtained by including only 'static elastic' effects, for example. It is shown that pilot/vehicle analysis of this data supports the hypothesis that an appropriate pilot-model structure is an optimal-control pilot model of full order. This is in contrast to the contention that a representative model is of reduced order when the subject is controlling high-order dynamics as in a flexible vehicle. The key appears to be in the correct assessment of the pilot's objective of attempting to control 'rigid-body' vehicle response, a response that must be estimated by the pilot from observations contaminated by aeroelastic dynamics. Finally, a model-based metric is shown to correlate well with the pilot's subjective ratings.

  15. The longitudinal equations of motion of a tilt prop/rotor aircraft including the effects of wing and prop/rotor blade flexibility

    NASA Technical Reports Server (NTRS)

    Curtiss, H. C., Jr.

    1976-01-01

    The equations of motion for the longitudinal dynamics of a tilting prop/rotor aircraft are developed. The analysis represents an extension of the equations of motion. The effects of the longitudinal degrees of freedom of the body (pitch, heave and horizontal velocity) are included. The results of body freedom can be added to the equations of motion for the flexible wing propeller combination.

  16. 40 CFR 141.804 - Aircraft water system operations and maintenance plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Aircraft Drinking Water Rule... must include the following requirements for procedures for disinfection and flushing of aircraft water system. (i) The air carrier must conduct disinfection and flushing of the aircraft water system in...

  17. 14 CFR 43.17 - Maintenance, preventive maintenance, and alterations performed on U.S. aeronautical products by...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... maintenance, or alteration is performed in accordance with a Bilateral Aviation Safety Agreement between the... recorded in accordance with a Bilateral Aviation Safety Agreement between the United States and Canada and... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE...

  18. 14 CFR 91.421 - Rebuilt engine maintenance records.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Rebuilt engine maintenance records. 91.421..., Preventive Maintenance, and Alterations § 91.421 Rebuilt engine maintenance records. (a) The owner or operator may use a new maintenance record, without previous operating history, for an aircraft engine...

  19. 14 CFR 91.421 - Rebuilt engine maintenance records.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Rebuilt engine maintenance records. 91.421..., Preventive Maintenance, and Alterations § 91.421 Rebuilt engine maintenance records. (a) The owner or operator may use a new maintenance record, without previous operating history, for an aircraft engine...

  20. Navy composite maintenance and repair experience

    NASA Technical Reports Server (NTRS)

    Donnellan, T. M.; Cochran, R. C.; Rosenzweig, E. L.; Trabocco, R. E.

    1992-01-01

    The Navy has been a strong proponent of composites for aircraft structure. Fleet use of composites started with the F-14 in the early 1970's and has steadily increased. This experience base provides sufficient information to allow an evaluation of the maintenance performance of polymer composites in service. A summary is presented of the Navy's experience with maintenance of composite structure. The general types of damage experienced in the fleet as well as specific examples of composite damage to aircraft is described. The impact of future designs on supportability is also discussed.

  1. Multi-objective decision-making model based on CBM for an aircraft fleet

    NASA Astrophysics Data System (ADS)

    Luo, Bin; Lin, Lin

    2018-04-01

    Modern production management patterns, in which multi-unit (e.g., a fleet of aircrafts) are managed in a holistic manner, have brought new challenges for multi-unit maintenance decision making. To schedule a good maintenance plan, not only does the individual machine maintenance have to be considered, but also the maintenance of the other individuals have to be taken into account. Since most condition-based maintenance researches for aircraft focused on solely reducing maintenance cost or maximizing the availability of single aircraft, as well as considering that seldom researches concentrated on both the two objectives: minimizing cost and maximizing the availability of a fleet (total number of available aircraft in fleet), a multi-objective decision-making model based on condition-based maintenance concentrated both on the above two objectives is established. Furthermore, in consideration of the decision maker may prefer providing the final optimal result in the form of discrete intervals instead of a set of points (non-dominated solutions) in real decision-making problem, a novel multi-objective optimization method based on support vector regression is proposed to solve the above multi-objective decision-making model. Finally, a case study regarding a fleet is conducted, with the results proving that the approach efficiently generates outcomes that meet the schedule requirements.

  2. Novel methods for aircraft corrosion monitoring

    NASA Astrophysics Data System (ADS)

    Bossi, Richard H.; Criswell, Thomas L.; Ikegami, Roy; Nelson, James; Normand, Eugene; Rutherford, Paul S.; Shrader, John E.

    1995-07-01

    Monitoring aging aircraft for hidden corrosion is a significant problem for both military and civilian aircraft. Under a Wright Laboratory sponsored program, Boeing Defense & Space Group is investigating three novel methods for detecting and monitoring hidden corrosion: (1) atmospheric neutron radiography, (2) 14 MeV neutron activation analysis and (3) fiber optic corrosion sensors. Atmospheric neutron radiography utilizes the presence of neutrons in the upper atmosphere as a source for interrogation of the aircraft structure. Passive track-etch neutron detectors, which have been previously placed on the aircraft, are evaluated during maintenance checks to assess the presence of corrosion. Neutrons generated by an accelerator are used via activation analysis to assess the presence of distinctive elements in corrosion products, particularly oxygen. By using fast (14 MeV) neutrons for the activation, portable, high intensity sources can be employed for field testing of aircraft. The third novel method uses fiber optics as part of a smart structure technology for corrosion detection and monitoring. Fiber optic corrosion sensors are placed in the aircraft at locations known to be susceptible to corrosion. Periodic monitoring of the sensors is used to alert maintenance personnel to the presence and degree of corrosion at specific locations on the aircraft. During the atmospheric neutron experimentation, we identified a fourth method referred to as secondary emission radiography (SER). This paper discusses the development of these methods.

  3. Navy Maintenance: The P-3 Aircraft Overhaul Program Can Be Improved.

    DTIC Science & Technology

    1987-06-01

    Air Sys- tems Command’s Naval Aviation Logistics Center, we obtained data on aircraft turnaround times, mobilization requirements, and aircraft over...480 561 637 P-3 Workload as a Percent of 23 22 25 27 Total FINDING Z: Aplicability of Procedural Changes To Other Aircraft. The GAO observed that the

  4. Task Analysis - Aircraft Structural Maintenance AFSC 458X2

    DTIC Science & Technology

    1989-08-01

    GAGES OR METERS 13 10 23 SELECT WEIGHT MEASURING SCALES 15 6 21 RECALL TYPES, PROPERTIES, AND CHARACTERISTICS 8 11 19 OF PLASTICS SELECT COMMON...SURFACES (K0494) 121 00480 SHOT PEEN METAL SURFACES (K0498) 123 00490 BALANCE AIRCRAFT CONTROL SURFACES 125 00500 CLEAN PLASTICS (0275) 127 00510...STORE TRANSPARENT PLASTICS IN PROPER ENVIRONMENT (J0299) 128 00520 POLISH OUT SURFACE SCRATCHES 129 00530 CUT PLASTICS 131 00540 RESEARCH AIRCRAFT

  5. Augmented reality application utility for aviation maintenance work instruction

    NASA Astrophysics Data System (ADS)

    Pourcho, John Bryan

    Current aviation maintenance work instructions do not display information effectively enough to prevent costly errors and safety concerns. Aircraft are complex assemblies of highly interrelated components that confound troubleshooting and can make the maintenance procedure difficult (Drury & Gramopadhye, 2001). The sophisticated nature of aircraft maintenance necessitates a revolutionized training intervention for aviation maintenance technicians (United States General Accounting Office, 2003). Quite simply, the paper based job task cards fall short of offering rapid access to technical data and the system or component visualization necessary for working on complex integrated aircraft systems. Possible solutions to this problem include upgraded standards for paper based task cards and the use of integrated 3D product definition used on various mobile platforms (Ropp, Thomas, Lee, Broyles, Lewin, Andreychek, & Nicol, 2013). Previous studies have shown that incorporation of 3D graphics in work instructions allow the user to more efficiently and accurately interpret maintenance information (Jackson & Batstone, 2008). For aircraft maintenance workers, the use of mobile 3D model-based task cards could make current paper task card standards obsolete with their ability to deliver relevant, synchronized information to and from the hangar. Unlike previous versions of 3D model-based definition task cards and paper task cards, which are currently used in the maintenance industry, 3D model based definition task cards have the potential to be more mobile and accessible. Utilizing augmented reality applications on mobile devices to seamlessly deliver 3D product definition on mobile devices could increase the efficiency, accuracy, and reduce the mental workload for technicians when performing maintenance tasks (Macchiarella, 2004). This proposal will serve as a literary review of the aviation maintenance industry, the spatial ability of maintenance technicians, and benefits of

  6. Improving Separation Assurance Stability Through Trajectory Flexibility Preservation

    NASA Technical Reports Server (NTRS)

    Idris, Husni; Shen, Ni; Wing, David J.

    2010-01-01

    New information and automation technologies are enabling the distribution of tasks and decisions from the service providers to the users of the air traffic system, with potential capacity and cost benefits. This distribution of tasks and decisions raises the concern that independent user actions will decrease the predictability and increase the complexity of the traffic system, hence inhibiting and possibly reversing any potential benefits. One such concern is the adverse impact of uncoordinated actions by individual aircraft on the stability of separation assurance. For example, individual aircraft performing self-separation may resolve predicted losses of separation or conflicts with some traffic, only to result in secondary conflicts with other traffic or with the same traffic later in time. In answer to this concern, this paper proposes metrics for preserving user trajectory flexibility to be used in self-separation along with other objectives. The hypothesis is that preserving trajectory flexibility will naturally reduce the creation of secondary conflicts by bringing about implicit coordination between aircraft. The impact of using these metrics on improving self-separation stability is investigated by measuring the impact on secondary conflicts. The scenarios analyzed include aircraft in en route airspace with each aircraft meeting a required time of arrival in a twenty minute time horizon while maintaining separation from the surrounding traffic and using trajectory flexibility metrics to mitigate the risk of secondary conflicts. Preliminary experiments showed promising results in that the trajectory flexibility preservation reduced the potential for secondary conflicts.

  7. 77 FR 72778 - Airworthiness Directives; Cessna Aircraft Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-06

    ... following: (1) Inspect the number of hours on the A/C compressor hour meter; and (2) Check the aircraft... following Cessna Aircraft Company Model 525 Maintenance Manual, Revision 23, dated July 1, 2012. (1) Before...-0880; Directorate Identifier 2012-CE-004-AD] RIN 2120-AA64 Airworthiness Directives; Cessna Aircraft...

  8. Piloted Simulation Assessment of the Impact of Flexible Structures on Handling Qualities of Generic Supersonic Aircraft

    NASA Technical Reports Server (NTRS)

    Stringer, Mary T.; Cowen, Brandon; Hoffler, Keith D.; Couch, Jesse C.; Ogburn, Marilyn E.; Diebler, Corey G.

    2013-01-01

    The NASA Langley Research Center Cockpit Motion Facility (CMF) was used to conduct a piloted simulation assessment of the impact of flexible structures on flying qualities. The CMF was used because of its relatively high bandwidth, six degree-of-freedom motion capability. Previous studies assessed and attempted to mitigate the effects of multiple dynamic aeroservoelastic modes (DASE). Those results indicated problems existed, but the specific cause and effect was difficult to ascertain. The goal of this study was to identify specific DASE frequencies, damping ratios, and gains that cause degradation in handling qualities. A generic aircraft simulation was developed and designed to have Cooper-Harper Level 1 handling qualities when flown without DASE models. A test matrix of thirty-six DASE modes was implemented. The modes had frequencies ranging from 1 to 3.5 Hz and were applied to each axis independently. Each mode consisted of a single axis, frequency, damping, and gain, and was evaluated individually by six subject pilots with test pilot backgrounds. Analysis completed to date suggests that a number of the DASE models evaluated degrade the handling qualities of this class of aircraft to an uncontrollable condition.

  9. General aviation avionics equipment maintenance

    NASA Technical Reports Server (NTRS)

    Parker, C. D.; Tommerdahl, J. B.

    1978-01-01

    Maintenance of general aviation avionics equipment was investigated with emphasis on single engine and light twin engine general aviation aircraft. Factors considered include the regulatory agencies, avionics manufacturers, avionics repair stations, the statistical character of the general aviation community, and owners and operators. The maintenance, environment, and performance, repair costs, and reliability of avionics were defined. It is concluded that a significant economic stratification is reflected in the maintenance problems encountered, that careful attention to installations and use practices can have a very positive impact on maintenance problems, and that new technologies and a general growth in general aviation will impact maintenance.

  10. Metabolic Syndrome and Cardio-Cerebrovascular Risk Disparities Between Pilots and Aircraft Mechanics.

    PubMed

    Kim, Myeong-Bo; Kim, Hyun-Jin; Kim, Soo-Hyeon; Lee, Suk-Ho; Lee, Se-Ho; Park, Won-Ju

    2017-09-01

    In the Republic of Korea Air Force, the health of pilots is strictly supervised, but there is comparatively not enough interest in aircraft mechanics' health. Among mechanics, who are heavily involved in military aircraft maintenance, the occurrence of sudden cardio-cerebrovascular diseases (CCVDs) is a possible risk factor during the maintenance process, which should be performed perfectly. We performed health examinations on 2123 male aircraft pilots and 1271 aircraft mechanics over 30 yr of age and determined the prevalence of metabolic syndrome (MetS), an important risk factor for CCVDs. The prevalence of MetS in the aircraft mechanics (21.3%) was significantly higher than in the pilots (12.6%), and the gap in prevalence tended to grow as age increased. Among aircraft mechanics in their 30s and 40s, the prevalence of MetS was lower than in the general population. However, the prevalence of MetS among aircraft mechanics in their 50s (36.0%) was similar to that in the general population (35.7%). Systematic health management is needed for aircraft mechanics for aviation safety and for the maintenance of military strength via the prevention of CCVDs.Kim M-B, Kim H-J, Kim S-H, Lee S-H, Lee S-H, Park W-J. Metabolic syndrome and cardio-cerebrovascular risk disparities between pilots and aircraft mechanics. Aerosp Med Hum Perform. 2017; 88(9):866-870.

  11. Dynamics and control of robotic aircraft with articulated wings

    NASA Astrophysics Data System (ADS)

    Paranjape, Aditya Avinash

    There is a considerable interest in developing robotic aircraft, inspired by birds, for a variety of missions covering reconnaissance and surveillance. Flapping wing aircraft concepts have been put forth in light of the efficiency of flapping flight at small scales. These aircraft are naturally equipped with the ability to rotate their wings about the root, a form of wing articulation. This thesis covers some problems concerning the performance, stability and control of robotic aircraft with articulated wings in gliding flight. Specifically, we are interested in aircraft without a vertical tail, which would then use wing articulation for longitudinal as well as lateral-directional control. Although the dynamics and control of articulated wing aircraft share several common features with conventional fixed wing aircraft, the presence of wing articulation presents several unique benefits as well as limitations from the perspective of performance and control. One of the objective of this thesis is to understand these features using a combination of theoretical and numerical tools. The aircraft concept envisioned in this thesis uses the wing dihedral angles for longitudinal and lateral-directional control. Aircraft with flexible articulated wings are also investigated. We derive a complete nonlinear model of the flight dynamics incorporating dynamic CG location and the changing moment of inertia. We show that symmetric dihedral configuration, along with a conventional horizontal tail, can be used to control flight speed and flight path angle independently of each other. This characteristic is very useful for initiating an efficient perching maneuver. It is shown that wing dihedral angles alone can effectively regulate sideslip during rapid turns and generate a wide range of equilibrium turn rates while maintaining a constant flight speed and regulating sideslip. We compute the turning performance limitations that arise due to the use of wing dihedral for yaw control

  12. Effect of Molecular Flexibility upon Ice Adhesion Shear Strength

    NASA Technical Reports Server (NTRS)

    Smith, Joseph G.; Wohl, Christopher J.; Kreeger, Richard E.; Palacios, Jose; Knuth, Taylor; Hadley, Kevin

    2016-01-01

    Ice formation on aircraft surfaces effects aircraft performance by increasing weight and drag leading to loss of lift. Current active alleviation strategies involve pneumatic boots, heated surfaces, and usage of glycol based de-icing fluids. Mitigation or reduction of in-flight icing by means of a passive approach may enable retention of aircraft capabilities, i.e., no reduction in lift, while reducing the aircraft weight and mechanical complexity. Under a NASA Aeronautics Research Institute Seedling activity, the effect of end group functionality and chain length upon ice adhesion shear strength (IASS) was evaluated with the results indicating that chemical functionality and chain length (i.e. molecular flexibility) affected IASS. Based on experimental and modeling results, diamine monomers incorporating molecular flexibility as either a side chain or in between diamine functionalities were prepared, incorporated into epoxy resins that were subsequently used to fabricate coatings on aluminum substrates, and tested in a simulated icing environment. The IASS was found to be lower when molecular flexibility was incorporated in the polymer chain as opposed to a side chain.

  13. 14 CFR 125.247 - Inspection programs and maintenance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance § 125.247 Inspection programs and maintenance. (a) No person may operate an airplane subject to this part unless (1... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Inspection programs and maintenance. 125...

  14. 14 CFR 125.247 - Inspection programs and maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance § 125.247 Inspection programs and maintenance. (a) No person may operate an airplane subject to this part unless (1... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Inspection programs and maintenance. 125...

  15. 14 CFR 125.247 - Inspection programs and maintenance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance § 125.247 Inspection programs and maintenance. (a) No person may operate an airplane subject to this part unless (1... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Inspection programs and maintenance. 125...

  16. 14 CFR 125.247 - Inspection programs and maintenance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance § 125.247 Inspection programs and maintenance. (a) No person may operate an airplane subject to this part unless (1... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Inspection programs and maintenance. 125...

  17. 14 CFR 125.247 - Inspection programs and maintenance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance § 125.247 Inspection programs and maintenance. (a) No person may operate an airplane subject to this part unless (1... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Inspection programs and maintenance. 125...

  18. Flexible-Wing-Based Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Ifju, Peter G.; Jenkins, David A.; Ettinger, Scott; Lian, Yong-Sheng; Shyy, Wei; Waszak, Martin R.

    2002-01-01

    This paper documents the development and evaluation of an original flexible-wing-based Micro Air Vehicle (MAV) technology that reduces adverse effects of gusty wind conditions and unsteady aerodynamics, exhibits desirable flight stability, and enhances structural durability. The flexible wing concept has been demonstrated on aircraft with wingspans ranging from 18 inches to 5 inches. Salient features of the flexible-wing-based MAV, including the vehicle concept, flexible wing design, novel fabrication methods, aerodynamic assessment, and flight data analysis are presented.

  19. Flight test results for the Daedalus and Light Eagle human powered aircraft

    NASA Technical Reports Server (NTRS)

    Sullivan, R. Bryan; Zerweckh, Siegfried H.

    1988-01-01

    The results of the flight test program of the Daedalus and Light Eagle human powered aircraft in the winter of 1987/88 are given. The results from experiments exploring the Light Eagle's rigid body and structural dynamics are presented. The interactions of these dynamics with the autopilot design are investigated. Estimates of the power required to fly the Daedalus aircraft are detailed. The system of sensors, signal conditioning boards, and data acquisition equipment used to record the flight data is also described. In order to investigate the dynamics of the aircraft, flight test maneuvers were developed to yield maximum data quality from the point of view of estimating lateral and longitudinal stability derivatives. From this data, structural flexibility and unsteady aerodynamics have been modeled in an ad hoc manner and are used to augment the equations of motion with flexibility effects. Results of maneuvers that were flown are compared with the predictions from the flexibility model. To extend the ad hoc flexibility model, a fully flexible aeroelastic model has been developed. The model is unusual in the approximate equality of many structural natural frequencies and the importance of unsteady aerodynamic effects. the Gossamer Albatross. It is hypothesized that this inverse ground effect is caused by turbulence in the Earth's boundary layer. The diameters of the largest boundary layer eddies (which represent most of the turbulent kinetic energy) are proportional to altitude; thus, closer to the ground, the energy in the boundary layer becomes concentrated in eddies of smaller and smaller diameter. Eventually the eddies become sufficiently small (approximately 0.5 cm) that they trip the laminar boundary layer on the wing. As a result, a greater percentage of the wing area is covered with turbulent flow. Consequently the aircraft's drag and the pow er required both increase as the aircraft flies closer to the ground. The results of the flight test program are

  20. Composite components on commercial aircraft

    NASA Technical Reports Server (NTRS)

    Dexter, H. B.

    1980-01-01

    Commercial aircraft manufacturers are making production commitments to composite structure for future aircraft and modifications to current production aircraft. Flight service programs with advanced composites sponsored by NASA during the past 10 years are described. Approximately 2.5 million total composite component flight hours have been accumulated since 1970 on both commercial transports and helicopters. Design concepts with significant mass savings were developed, appropriate inspection and maintenance procedures were established, and satisfactory service was achieved for the various composite components. A major NASA/U.S. industry technology program to reduce fuel consumption of commercial transport aircraft through the use of advanced composites was undertaken. Ground and flight environmental effects on the composite materials used in the flight service programs supplement the flight service evaluation.

  1. 14 CFR 21.445 - Maintenance of eligibility.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maintenance of eligibility. 21.445 Section 21.445 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Maintenance of eligibility. The DAS shall continue to meet the requirements for issue of the authorization or...

  2. 14 CFR 21.445 - Maintenance of eligibility.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maintenance of eligibility. 21.445 Section 21.445 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Maintenance of eligibility. The DAS shall continue to meet the requirements for issue of the authorization or...

  3. WEST ELEVATION OF USAIR MAINTENANCE HANGAR AT GREATER BUFFALO INTERNATIONAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    WEST ELEVATION OF USAIR MAINTENANCE HANGAR AT GREATER BUFFALO INTERNATIONAL AIRPORT. A BOEING 737-200 HAS BEEN TOWED IN FOR AN OVERNIGHT (BALANCE) CHECK. THE TAIL DOCK STANDS ARE IN POSITION AT THE REAR OF THE AIRCRAFT TO FACILITATE INSPECTION. MAINTENANCE CREWS PERFORM NIGHTLY SERVICE ON UP TO 6 AIRCRAFT. THE NORMAL SEQUENCE OF 12 ROUTINE CHECKS COVERS SEVEN BASIC AREAS: INTERIOR, EXTERIOR, WINGS, LANDING GEAR, TAIL, AUXILIARY POWER UNIT (APU), AND ENGINES. THE WORK FORCE CONSISTS OF 5 INSPECTORS, 3 LEAD MECHANICS, AND 24 MECHANICS; NIGHTLY SCHEDULES ARE COORDINATED BY A PLANNER. - Greater Buffalo International Airport, Maintenance Hangar, Buffalo, Erie County, NY

  4. Coast Guard Aircraft: Transfer of Fixed-Wing C-27J Aircraft Is Complex and Further Fleet Purchases Should Coincide with Study Results

    DTIC Science & Technology

    2015-03-01

    C-27J to the Coast Guard. This report assesses (1) the status of the transfer and risks the Coast Guard faces in fielding the transferred aircraft...had transferred 2 of the 14 C-27J aircraft it is receiving from the Air Force to its aircraft maintenance facility, with plans to field 14 fully...Coast Guard continues to receive these aircraft in the near term, the capability and cost of the Coast Guard’s fixed-wing fleet runs the risk of being

  5. 40 CFR 141.804 - Aircraft water system operations and maintenance plan.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... must include the following requirements for procedures for disinfection and flushing of aircraft water system. (i) The air carrier must conduct disinfection and flushing of the aircraft water system in... water procedures; (ii) Sample collection procedures; (iii) Disinfection and flushing procedures; (iv...

  6. Scorpion: Close Air Support (CAS) aircraft

    NASA Technical Reports Server (NTRS)

    Allen, Chris; Cheng, Rendy; Koehler, Grant; Lyon, Sean; Paguio, Cecilia

    1991-01-01

    The objective is to outline the results of the preliminary design of the Scorpion, a proposed close air support aircraft. The results obtained include complete preliminary analysis of the aircraft in the areas of aerodynamics, structures, avionics and electronics, stability and control, weight and balance, propulsion systems, and costs. A conventional wing, twin jet, twin-tail aircraft was chosen to maximize the desirable characteristics. The Scorpion will feature low speed maneuverability, high survivability, low cost, and low maintenance. The life cycle cost per aircraft will be 17.5 million dollars. The maximum takeoff weight will be 52,760 pounds. Wing loading will be 90 psf. The thrust to weight will be 0.6 lbs/lb. This aircraft meets the specified mission requirements. Some modifications have been suggested to further optimize the design.

  7. Flight Dynamics Simulation Modeling and Control of a Large Flexible Tiltrotor Aircraft

    DTIC Science & Technology

    2014-09-01

    matrix from fixed to rotating coordinate systems u longitudinal aircraft velocity, state-space control vector v elastic beam chordwise displacement /lateral...spectrum active control , including flight control systems, rotor load limiting, and vibration and noisetiltion [1]. The development of a high-order...the flutter response of fixed- wing aircraft. The B-52 CCV ( Controls Configured Vehicle) was one of the first aircraft to demonstrate benefits of active

  8. Genetic Algorithm-Guided, Adaptive Model Order Reduction of Flexible Aircrafts

    NASA Technical Reports Server (NTRS)

    Zhu, Jin; Wang, Yi; Pant, Kapil; Suh, Peter; Brenner, Martin J.

    2017-01-01

    This paper presents a methodology for automated model order reduction (MOR) of flexible aircrafts to construct linear parameter-varying (LPV) reduced order models (ROM) for aeroservoelasticity (ASE) analysis and control synthesis in broad flight parameter space. The novelty includes utilization of genetic algorithms (GAs) to automatically determine the states for reduction while minimizing the trial-and-error process and heuristics requirement to perform MOR; balanced truncation for unstable systems to achieve locally optimal realization of the full model; congruence transformation for "weak" fulfillment of state consistency across the entire flight parameter space; and ROM interpolation based on adaptive grid refinement to generate a globally functional LPV ASE ROM. The methodology is applied to the X-56A MUTT model currently being tested at NASA/AFRC for flutter suppression and gust load alleviation. Our studies indicate that X-56A ROM with less than one-seventh the number of states relative to the original model is able to accurately predict system response among all input-output channels for pitch, roll, and ASE control at various flight conditions. The GA-guided approach exceeds manual and empirical state selection in terms of efficiency and accuracy. The adaptive refinement allows selective addition of the grid points in the parameter space where flight dynamics varies dramatically to enhance interpolation accuracy without over-burdening controller synthesis and onboard memory efforts downstream. The present MOR framework can be used by control engineers for robust ASE controller synthesis and novel vehicle design.

  9. 77 FR 67584 - Air Carrier Contract Maintenance Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-13

    ...-certificated repair facilities, and the air carriers' outsourcing of maintenance. In each of those reports... maintenance outsourcing practices (Recommendation 2). \\3\\ Review of Air Carriers' Use of Aircraft Repair... (Recommendation 7). \\4\\ Air Carrier's Outsourcing Use of Non-Certificated Repair Facilities, Report No. AV-2006...

  10. Problems with aging wiring in Naval aircraft

    NASA Technical Reports Server (NTRS)

    Campbell, Frank J.

    1994-01-01

    The Navy is experiencing a severe aircraft electrical wiring maintenance problem as a result of the extensive use of an aromatic polyimide insulation that is deteriorating at a rate that was unexpected when this wire was initially selected. This problem has significantly affected readiness, reliability, and safety and has greatly increased the cost of ownership of Naval aircraft. Failures in wire harnesses have exhibited arcing and burning that will propagate drastically, to the interruption of many electrical circuits from a fault initiated by the failure of deteriorating wires. There is an urgent need for a capability to schedule aircraft rewiring in an orderly manner with a logically derived determination of which aircraft have aged to the point of absolute necessity. Excessive maintenance was demonstrated to result from the accelerated aging due to the parameters of moisture, temperature, and strain that exist in the Naval Aircraft environment. Laboratory studies have demonstrated that MIL-W-81381 wire insulation when aged at high humidities followed the classical Arrhenius thermal aging relationship. In an extension of the project a multifactor formula was developed that is now capable of predicting life under varying conditions of these service parameters. An automated test system has also been developed to analyze the degree of deterioration that has occurred in wires taken from an aircraft in order to obtain an assessment of remaining life. Since it is both physically and financially impossible to replace the wiring in all the Navy's aircraft at once, this system will permit expedient scheduling so that those aircraft that are most probable to have wiring failure problems can be overhauled first.

  11. Turboprop aircraft against terrorism: a SWOT analysis of turboprop aircraft in CAS operations

    NASA Astrophysics Data System (ADS)

    Yavuz, Murat; Akkas, Ali; Aslan, Yavuz

    2012-06-01

    Today, the threat perception is changing. Not only for countries but also for defence organisations like NATO, new threat perception is pointing terrorism. Many countries' air forces become responsible of fighting against terorism or Counter-Insurgency (COIN) Operations. Different from conventional warfare, alternative weapon or weapon systems are required for such operatioins. In counter-terrorism operations modern fighter jets are used as well as helicopters, subsonic jets, Unmanned Aircraft Systems (UAS), turboprop aircraft, baloons and similar platforms. Succes and efficiency of the use of these platforms can be determined by evaluating the conditions, the threats and the area together. Obviously, each platform has advantages and disadvantages for different cases. In this research, examples of turboprop aircraft usage against terrorism and with a more general approach, turboprop aircraft for Close Air Support (CAS) missions from all around the world are reviewed. In this effort, a closer look is taken at the countries using turboprop aircraft in CAS missions while observing the fields these aircraft are used in, type of operations, specifications of the aircraft, cost and the maintenance factors. Thus, an idea about the convenience of using these aircraft in such operations can be obtained. A SWOT analysis of turboprop aircraft in CAS operations is performed. This study shows that turboprop aircraft are suitable to be used in counter-terrorism and COIN operations in low threat environment and is cost benefical compared to jets.

  12. Taxiing, Take-Off, and Landing Simulation of the High Speed Civil Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Reaves, Mercedes C.; Horta, Lucas G.

    1999-01-01

    The aircraft industry jointly with NASA is studying enabling technologies for higher speed, longer range aircraft configurations. Higher speeds, higher temperatures, and aerodynamics are driving these newer aircraft configurations towards long, slender, flexible fuselages. Aircraft response during ground operations, although often overlooked, is a concern due to the increased fuselage flexibility. This paper discusses modeling and simulation of the High Speed Civil Transport aircraft during taxiing, take-off, and landing. Finite element models of the airframe for various configurations are used and combined with nonlinear landing gear models to provide a simulation tool to study responses to different ground input conditions. A commercial computer simulation program is used to numerically integrate the equations of motion and to compute estimates of the responses using an existing runway profile. Results show aircraft responses exceeding safe acceptable human response levels.

  13. Survey of Applications of Active Control Technology for Gust Alleviation and New Challenges for Lighter-weight Aircraft

    NASA Technical Reports Server (NTRS)

    Regan, Christopher D.; Jutte, Christine V.

    2012-01-01

    This report provides a historical survey and assessment of the state of the art in the modeling and application of active control to aircraft encountering atmospheric disturbances in flight. Particular emphasis is placed on applications of active control technologies that enable weight reduction in aircraft by mitigating the effects of atmospheric disturbances. Based on what has been learned to date, recommendations are made for addressing gust alleviation on as the trend for more structurally efficient aircraft yields both lighter and more flexible aircraft. These lighter more flexible aircraft face two significant challenges reduced separation between rigid body and flexible modes, and increased sensitivity to gust encounters due to increased wing loading and improved lift to drag ratios. The primary audience of this paper is engineering professionals new to the area of gust load alleviation and interested in tackling the multifaceted challenges that lie ahead for lighter-weight aircraft.

  14. 78 FR 17865 - Airworthiness Directives; PILATUS AIRCRAFT LTD. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ... TBO were moved from Chapter 5: Time Limits/Maintenance Checks, to Chapter 4: Structural, Component and... Directives; PILATUS AIRCRAFT LTD. Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final... all PILATUS AIRCRAFT LTD. Models PC-12, PC-12/45, and PC-12/47 airplanes. This AD results from...

  15. Integrated Model Reduction and Control of Aircraft with Flexible Wings

    NASA Technical Reports Server (NTRS)

    Swei, Sean Shan-Min; Zhu, Guoming G.; Nguyen, Nhan T.

    2013-01-01

    This paper presents an integrated approach to the modeling and control of aircraft with exible wings. The coupled aircraft rigid body dynamics with a high-order elastic wing model can be represented in a nite dimensional state-space form. Given a set of desired output covariance, a model reduction process is performed by using the weighted Modal Cost Analysis (MCA). A dynamic output feedback controller, which is designed based on the reduced-order model, is developed by utilizing output covariance constraint (OCC) algorithm, and the resulting OCC design weighting matrix is used for the next iteration of the weighted cost analysis. This controller is then validated for full-order evaluation model to ensure that the aircraft's handling qualities are met and the uttering motion of the wings suppressed. An iterative algorithm is developed in CONDUIT environment to realize the integration of model reduction and controller design. The proposed integrated approach is applied to NASA Generic Transport Model (GTM) for demonstration.

  16. Analysis of Trajectory Flexibility Preservation Impact on Traffic Complexity

    NASA Technical Reports Server (NTRS)

    Idris, Husni; El-Wakil, Tarek; Wing, David J.

    2009-01-01

    The growing demand for air travel is increasing the need for mitigation of air traffic congestion and complexity problems, which are already at high levels. At the same time new information and automation technologies are enabling the distribution of tasks and decisions from the service providers to the users of the air traffic system, with potential capacity and cost benefits. This distribution of tasks and decisions raises the concern that independent user actions will decrease the predictability and increase the complexity of the traffic system, hence inhibiting and possibly reversing any potential benefits. In answer to this concern, the authors proposed the introduction of decision-making metrics for preserving user trajectory flexibility. The hypothesis is that such metrics will make user actions naturally mitigate traffic complexity. In this paper, the impact of using these metrics on traffic complexity is investigated. The scenarios analyzed include aircraft in en route airspace with each aircraft meeting a required time of arrival in a one-hour time horizon while mitigating the risk of loss of separation with the other aircraft, thus preserving its trajectory flexibility. The experiments showed promising results in that the individual trajectory flexibility preservation induced self-separation and self-organization effects in the overall traffic situation. The effects were quantified using traffic complexity metrics, namely dynamic density indicators, which indicated that using the flexibility metrics reduced aircraft density and the potential of loss of separation.

  17. 14 CFR 91.1437 - CAMP: Authority to perform and approve maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Ownership Operations Program Management § 91.1437 CAMP: Authority to perform and approve maintenance. A program manager who maintains program aircraft under a CAMP may employ maintenance personnel, or make... maintenance. 91.1437 Section 91.1437 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF...

  18. Distributed Traffic Complexity Management by Preserving Trajectory Flexibility

    NASA Technical Reports Server (NTRS)

    Idris, Husni; Vivona, Robert A.; Garcia-Chico, Jose-Luis; Wing, David J.

    2007-01-01

    In order to handle the expected increase in air traffic volume, the next generation air transportation system is moving towards a distributed control architecture, in which groundbased service providers such as controllers and traffic managers and air-based users such as pilots share responsibility for aircraft trajectory generation and management. This paper presents preliminary research investigating a distributed trajectory-oriented approach to manage traffic complexity, based on preserving trajectory flexibility. The underlying hypotheses are that preserving trajectory flexibility autonomously by aircraft naturally achieves the aggregate objective of avoiding excessive traffic complexity, and that trajectory flexibility is increased by collaboratively minimizing trajectory constraints without jeopardizing the intended air traffic management objectives. This paper presents an analytical framework in which flexibility is defined in terms of robustness and adaptability to disturbances and preliminary metrics are proposed that can be used to preserve trajectory flexibility. The hypothesized impacts are illustrated through analyzing a trajectory solution space in a simple scenario with only speed as a degree of freedom, and in constraint situations involving meeting multiple times of arrival and resolving conflicts.

  19. Peripheral neuropathy in military aircraft maintenance workers in Australia.

    PubMed

    Guest, Maya; Attia, John R; D'este, Catherine A; Boggess, May M; Brown, Anthony M; Gibson, Richard E; Tavener, Meredith A; Ross, James; Gardner, Ian; Harrex, Warren

    2011-04-01

    This study aimed to examine possible persisting peripheral neuropathy in a group who undertook fuel tank repairs on F-111 aircraft, relative to two contemporaneous comparison groups. Vibration perception threshold (VPT) was tested using biothesiometry in 614 exposed personnel, compared with two unexposed groups (513 technical trades and 403 nontrades). Regression modeling was used to examine associations, adjusting for possible confounders. We observed that 26% of participants had chronic persistent increased VPT in the great toe. In contrast, statistically significant higher VPT of the great toe was observed in the comparison groups; however, the effect was small, about 1/4 the magnitude of diabetes. Age, height, and diabetes were all significant and strong predictors in most models. This study highlights chronic persisting peripheral neuropathy in a population of aircraft maintainers.

  20. 77 FR 76842 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-31

    ... Aircraft Gas Turbine Engines and Identification Plate for Aircraft Engines AGENCY: Federal Aviation... , compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet engines with...)(v). 6. Standards for Supersonic Aircraft Turbine Engines This final rule contains carbon monoxide...

  1. Control of Next Generation Aircraft and Wind Turbines

    NASA Technical Reports Server (NTRS)

    Frost, Susan

    2010-01-01

    The first part of this talk will describe some of the exciting new next generation aircraft that NASA is proposing for the future. These aircraft are being designed to reduce aircraft fuel consumption and environmental impact. Reducing the aircraft weight is one approach that will be used to achieve these goals. A new control framework will be presented that enables lighter, more flexible aircraft to maintain aircraft handling qualities, while preventing the aircraft from exceeding structural load limits. The second part of the talk will give an overview of utility-scale wind turbines and their control. Results of collaboration with Dr. Balas will be presented, including new theory to adaptively control the turbine in the presence of structural modes, with the focus on the application of this theory to a high-fidelity simulation of a wind turbine.

  2. Aviation Maintenance Technology. General. G104 Technical Mechanics. Instructor Material.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    These instructor materials for an aviation maintenance technology course contain five instructional modules. The modules cover the following topics: performing aircraft ground handling and servicing, using hand and power tools and precision measuring instruments, identifying and selecting aircraft hardware, fabricating and installing rigid and…

  3. Durability of aircraft composite materials

    NASA Technical Reports Server (NTRS)

    Dextern, H. B.

    1982-01-01

    Confidence in the long term durability of advanced composites is developed through a series of flight service programs. Service experience is obtained by installing secondary and primary composite components on commercial and military transport aircraft and helicopters. Included are spoilers, rudders, elevators, ailerons, fairings and wing boxes on transport aircraft and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on helicopters. Materials included in the evaluation are boron/epoxy, Kevlar/epoxy, graphite/epoxy and boron/aluminum. Inspection, maintenance, and repair results for the components in service are reported. The effects of long term exposure to laboratory, flight, and outdoor environmental conditions are reported for various composite materials. Included are effects of moisture absorption, ultraviolet radiation, and aircraft fuels and fluids.

  4. Robust lateral blended-wing-body aircraft feedback control design using a parameterized LFR model and DGK-iteration

    NASA Astrophysics Data System (ADS)

    Schirrer, A.; Westermayer, C.; Hemedi, M.; Kozek, M.

    2013-12-01

    This paper shows control design results, performance, and limitations of robust lateral control law designs based on the DGK-iteration mixed-μ-synthesis procedure for a large, flexible blended wing body (BWB) passenger aircraft. The aircraft dynamics is preshaped by a low-complexity inner loop control law providing stabilization, basic response shaping, and flexible mode damping. The μ controllers are designed to further improve vibration damping of the main flexible modes by exploiting the structure of the arising significant parameter-dependent plant variations. This is achieved by utilizing parameterized Linear Fractional Representations (LFR) of the aircraft rigid and flexible dynamics. Designs with various levels of LFR complexity are carried out and discussed, showing the achieved performance improvement over the initial controller and their robustness and complexity properties.

  5. Maintenance of Airport Visual Aid Facilities

    DOT National Transportation Integrated Search

    1982-08-26

    This advisory circular provides recommended guidelines for maintenance of : airport visual aid facilities. Since the function of such facilities is to : assist in the safe and efficient movement of aircraft during landing, takeoff, : and taxiing mane...

  6. The Second Joint NASA/FAA/DOD Conference on Aging Aircraft. Pt. 1

    NASA Technical Reports Server (NTRS)

    Harris, Charles E. (Editor)

    1999-01-01

    The purpose of the Conference was to bring together world leaders in aviation safety research, aircraft design and manufacturing, fleet operation and aviation maintenance to disseminate information on current practices and advanced technologies that will assure the continued airworthiness of the aging aircraft in the military and commercial fleets. The Conference included reviews of current industry practices, assessments of future technology requirements, and status of aviation safety research. The Conference provided an opportunity for interactions among the key personnel in the research and technology development community, the original equipment manufacturers, commercial airline operators, military fleet operators, aviation maintenance, and aircraft certification and regulatory authorities. Conference participation was unrestricted and open to the international aviation community.

  7. Applications of advanced electric/electronic technology to conventional aircraft

    NASA Technical Reports Server (NTRS)

    Heimbold, R. L.

    1980-01-01

    The desirability of seven advanced technologies as applied to three commercial aircraft of 1985 to 1995 was investigated. Digital fly by wire, multiplexing, ring laser gyro, integrated avionics, all electric airplane, electric load management, and fiber optics were considered for 500 passenger, 50 passenger, and 30 passenger aircraft. The major figure of merit used was Net Value of Technology based on procurement and operating cost over the life of the aircraft. An existing computer program, ASSET, was used to resize the aircraft and evalute fuel usage and maintenance costs for each candidate configuration. Conclusions were that, for the 500 passenger aircraft, all candidates had a worthwhile payoff with the all electric airplane having a large payoff.

  8. Ultrasonic Measurement of Aircraft Strut Hydraulic Fluid Level

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G.

    2002-01-01

    An ultrasonic method is presented for non-intrusively measuring hydraulic fluid level in aircraft struts in the field quickly and easily without modifying the strut or aircraft. The technique interrogates the strut with ultrasonic waves generated and received by a removable ultrasonic transducer hand-held on the outside of the strut in a fashion that is in the presence or absence of hydraulic fluid inside the strut. This technique was successfully demonstrated on an A-6 aircraft strut on the carriage at the Aircraft Landing Dynamics Research Facility at NASA Langley Research Center. Conventional practice upon detection of strut problem symptoms is to remove aircraft from service for extensive maintenance to determine fluid level. No practical technique like the method presented herein for locating strut hydraulic fluid level is currently known to be used.

  9. Depot Maintenance: Air Force is Assessing Engine Maintenance Options for Work Currently Performed at Kelly Aviation Center

    DTIC Science & Technology

    2011-02-11

    on TF39 engines, which are typically used for C-5 Galaxy aircraft; T56 engines, which are typically used for C-130 aircraft; and fuel accessories on...conducting separate cost-benefit analyses for the TF39 and T56 engine maintenance work. Under Air Force guidance for depot-level source-of-repair selection...Force has not developed specific risk mitigation plans for the TF39 or T56 engines because it is still assessing how the work will be performed

  10. Lightning Discharges to Aircraft and Associated Meteorological Conditions

    NASA Technical Reports Server (NTRS)

    Harrison, L P

    1946-01-01

    A summary is given of information on atmospheric electrical discharges to aircraft and associated meteorological conditions. Information is given that is designed to give a fairly comprehensive view of the underlying principles of meteorology and atmospheric electricity. Of special interest to pilots are lists of procedures of flight conduct and aircraft maintenance recommended foe avoiding or minimizing the hazards of disruptive electrical discharges and other severe conditions near thunderstorms.

  11. Ride comfort control in large flexible aircraft. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Warren, M. E.

    1971-01-01

    The problem of ameliorating the discomfort of passengers on a large air transport subject to flight disturbances is examined. The longitudinal dynamics of the aircraft, including effects of body flexing, are developed in terms of linear, constant coefficient differential equations in state variables. A cost functional, penalizing the rigid body displacements and flexure accelerations over the surface of the aircraft is formulated as a quadratic form. The resulting control problem, to minimize the cost subject to the state equation constraints, is of a class whose solutions are well known. The feedback gains for the optimal controller are calculated digitally, and the resulting autopilot is simulated on an analog computer and its performance evaluated.

  12. 14 CFR 141.89 - Maintenance of personnel, facilities, and equipment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Maintenance of personnel, facilities, and... Maintenance of personnel, facilities, and equipment. The holder of a pilot school certificate or provisional... training unless: (a) Each airport, aircraft, and facility necessary for that training meets the standards...

  13. 14 CFR 141.89 - Maintenance of personnel, facilities, and equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Maintenance of personnel, facilities, and... Maintenance of personnel, facilities, and equipment. The holder of a pilot school certificate or provisional... training unless: (a) Each airport, aircraft, and facility necessary for that training meets the standards...

  14. 14 CFR 141.89 - Maintenance of personnel, facilities, and equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Maintenance of personnel, facilities, and... Maintenance of personnel, facilities, and equipment. The holder of a pilot school certificate or provisional... training unless: (a) Each airport, aircraft, and facility necessary for that training meets the standards...

  15. 14 CFR 141.89 - Maintenance of personnel, facilities, and equipment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Maintenance of personnel, facilities, and... Maintenance of personnel, facilities, and equipment. The holder of a pilot school certificate or provisional... training unless: (a) Each airport, aircraft, and facility necessary for that training meets the standards...

  16. 14 CFR 141.89 - Maintenance of personnel, facilities, and equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Maintenance of personnel, facilities, and... Maintenance of personnel, facilities, and equipment. The holder of a pilot school certificate or provisional... training unless: (a) Each airport, aircraft, and facility necessary for that training meets the standards...

  17. Cryogenics maintenance strategy

    NASA Astrophysics Data System (ADS)

    Cruzat, Fabiola

    2012-09-01

    ALMA is an interferometer composed of 66 independent systems, with specific maintenance requirements for each subsystem. To optimize the observation time and reduce downtime maintenance, requirements are very demanding. One subsystem with high maintenance efforts is cryogenics and vacuum. To organize the maintenance, the Cryogenic and Vacuum department is using and implementing different tools. These are monitoring and problem reporting systems and CMMS. This leads to different maintenance approaches: Preventive Maintenance, Corrective Maintenance and Condition Based Maintenance. In order to coordinate activities with other departments the preventive maintenance schedule is kept as flexible as systems allow. To cope with unavoidable failures, the team has to be prepared to work under any condition with the spares on time. Computerized maintenance management system (CMMS) will help to manage inventory control for reliable spare part handling, the correct record of work orders and traceability of maintenance activities. For an optimized approach the department is currently evaluating where preventive or condition based maintenance applies to comply with the individual system demand. Considering the change from maintenance contracts to in-house maintenance will help to minimize costs and increase availability of parts. Due to increased number of system and tasks the cryo team needs to grow. Training of all staff members is mandatory, in depth knowledge must be built up by doing complex maintenance activities in the Cryo group, use of advanced computerized metrology systems.

  18. Control and trajectory design of a highly flexible air vehicle with a distributed sensing architecture

    NASA Astrophysics Data System (ADS)

    Pachikara, Abraham James

    Next generational aircraft are becoming very flexible due to efforts to reduce weight and increase aerodynamic efficiency. As a result, flight control systems and trajectories that were designed with traditional rigid body assumptions may no longer become valid. When an aircraft becomes more flexible, the shape of the aircraft can deform significantly due to the aeroservoelastic dynamics. No longer are few sensors located at the CG and elsewhere will be enough to maximize performance. Instead, a full suite of sensors will be needed all throughout the aircraft to accurately measure the complete aerodynamic distribution and dynamics. First, a parametric study will be conducted to understand how flexibility impacts both the open-loop and closed-loop dynamics of a generic micro air vehicle (MAV). Once the impact of flexibility on the MAV's aeroservoelastic dynamics is well understood, an aeroservoelastic flight controller will be designed that leverages a "Fly-By-Feel" sensor architecture. A sensor architecture will be developed that uses several sensors to estimate the MAV's full aerodynamic and inertial distribution along with inertial sensors at the CG. A modal filtering approach will be used for the relevant sensor management and to extract useful modal characteristics from the sensor data. Once that is done, a controller will be designed for maneuver tracking. Once a flight controller has been designed, a set of representative motion primitives for the MAV can be developed that model how the aircraft moves for trajectory generation. Then trajectories can be developed for the flexible vehicle. Analysis will then be conducted to understand how flexibility impacts the creation of trajectories and MAV performance metrics.

  19. Overview of Innovative Aircraft Power and Propulsion Systems and Their Applications for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony; Landis, Geoffrey; Lyons, Valerie

    2003-01-01

    Planetary exploration may be enhanced by the use of aircraft for mobility. This paper reviews the development of aircraft for planetary exploration missions at NASA and reviews the power and propulsion options for planetary aircraft. Several advanced concepts for aircraft exploration, including the use of in situ resources, the possibility of a flexible all-solid-state aircraft, the use of entomopters on Mars, and the possibility of aerostat exploration of Titan, are presented.

  20. Classification of Aircraft Maneuvers for Fault Detection

    NASA Technical Reports Server (NTRS)

    Oza, Nikunj C.; Tumer, Irem Y.; Tumer, Kagan; Huff, Edward M.; Clancy, Daniel (Technical Monitor)

    2002-01-01

    Automated fault detection is an increasingly important problem in aircraft maintenance and operation. Standard methods of fault detection assume the availability of either data produced during all possible faulty operation modes or a clearly-defined means to determine whether the data is a reasonable match to known examples of proper operation. In our domain of fault detection in aircraft, the first assumption is unreasonable and the second is difficult to determine. We envision a system for online fault detection in aircraft, one part of which is a classifier that predicts the maneuver being performed by the aircraft as a function of vibration data and other available data. We explain where this subsystem fits into our envisioned fault detection system as well its experiments showing the promise of this classification subsystem.

  1. AIRCRAFT MAINTENANCE ENABLED JOINT CONCEPT FOR ENTRY OPERATIONS

    DTIC Science & Technology

    2017-04-06

    approach to manpower consolidation on a scale similar to what Rivet Workforce accomplished in the 1980s and 1990s. A consolidation based on aircraft...Logistics for the AirSea Battle,” Research (Maxwell Air Force Base , Alabama: Air Force Fellows, March 2011), 19. 36 “The Aviationist » Rapid Raptor...USAF A Research Report Submitted to the Faculty In Partial Fulfillment of the Graduation Requirements Advisor: Col Daniel Runyon 6 April 2017

  2. 78 FR 63017 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... Aircraft Gas Turbine Engines and Identification Plate for Aircraft Engines AGENCY: Federal Aviation... (NO X ), compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet... adopting the gas turbine engine test procedures of the International Civil Aviation Organization (ICAO...

  3. Fourth NASA Workshop on Computational Control of Flexible Aerospace Systems, part 2

    NASA Technical Reports Server (NTRS)

    Taylor, Lawrence W., Jr. (Compiler)

    1991-01-01

    A collection of papers presented at the Fourth NASA Workshop on Computational Control of Flexible Aerospace Systems is given. The papers address modeling, systems identification, and control of flexible aircraft, spacecraft and robotic systems.

  4. Maneuver Classification for Aircraft Fault Detection

    NASA Technical Reports Server (NTRS)

    Oza, Nikunj C.; Tumer, Irem Y.; Tumer, Kagan; Huff, Edward M.

    2003-01-01

    Automated fault detection is an increasingly important problem in aircraft maintenance and operation. Standard methods of fault detection assume the availability of either data produced during all possible faulty operation modes or a clearly-defined means to determine whether the data provide a reasonable match to known examples of proper operation. In the domain of fault detection in aircraft, identifying all possible faulty and proper operating modes is clearly impossible. We envision a system for online fault detection in aircraft, one part of which is a classifier that predicts the maneuver being performed by the aircraft as a function of vibration data and other available data. To develop such a system, we use flight data collected under a controlled test environment, subject to many sources of variability. We explain where our classifier fits into the envisioned fault detection system as well as experiments showing the promise of this classification subsystem.

  5. An artificial intelligence-based structural health monitoring system for aging aircraft

    NASA Technical Reports Server (NTRS)

    Grady, Joseph E.; Tang, Stanley S.; Chen, K. L.

    1993-01-01

    To reduce operating expenses, airlines are now using the existing fleets of commercial aircraft well beyond their originally anticipated service lives. The repair and maintenance of these 'aging aircraft' has therefore become a critical safety issue, both to the airlines and the Federal Aviation Administration. This paper presents the results of an innovative research program to develop a structural monitoring system that will be used to evaluate the integrity of in-service aerospace structural components. Currently in the final phase of its development, this monitoring system will indicate when repair or maintenance of a damaged structural component is necessary.

  6. 14 CFR 43.3 - Persons authorized to perform maintenance, preventive maintenance, rebuilding, and alterations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... certificate holder has written procedures available to the pilot to evaluate the accomplishment of the task... alterations as provided in part 121 or 135. (g) Except for holders of a sport pilot certificate, the holder of a pilot certificate issued under part 61 may perform preventive maintenance on any aircraft owned or...

  7. Architecture and Key Techniques of Augmented Reality Maintenance Guiding System for Civil Aircrafts

    NASA Astrophysics Data System (ADS)

    hong, Zhou; Wenhua, Lu

    2017-01-01

    Augmented reality technology is introduced into the maintenance related field for strengthened information in real-world scenarios through integration of virtual assistant maintenance information with real-world scenarios. This can lower the difficulty of maintenance, reduce maintenance errors, and improve the maintenance efficiency and quality of civil aviation crews. Architecture of augmented reality virtual maintenance guiding system is proposed on the basis of introducing the definition of augmented reality and analyzing the characteristics of augmented reality virtual maintenance. Key techniques involved, such as standardization and organization of maintenance data, 3D registration, modeling of maintenance guidance information and virtual maintenance man-machine interaction, are elaborated emphatically, and solutions are given.

  8. 78 FR 1728 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... scheduled maintenance, whichever occurs first, do the following. (1) Remove the oil filler plug and check... Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines AGENCY: Federal Aviation... all Thielert Aircraft Engines GmbH (TAE) TAE 125-02-99 and TAE 125-02-114 reciprocating engines. This...

  9. 34 CFR 300.230 - SEA flexibility.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 2 2014-07-01 2013-07-01 true SEA flexibility. 300.230 Section 300.230 Education... DISABILITIES Local Educational Agency Eligibility § 300.230 SEA flexibility. (a) Adjustment to State fiscal... SEA, notwithstanding §§ 300.162 through 300.163 (related to State-level nonsupplanting and maintenance...

  10. 34 CFR 300.230 - SEA flexibility.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false SEA flexibility. 300.230 Section 300.230 Education... DISABILITIES Local Educational Agency Eligibility § 300.230 SEA flexibility. (a) Adjustment to State fiscal... SEA, notwithstanding §§ 300.162 through 300.163 (related to State-level nonsupplanting and maintenance...

  11. 34 CFR 300.230 - SEA flexibility.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false SEA flexibility. 300.230 Section 300.230 Education... DISABILITIES Local Educational Agency Eligibility § 300.230 SEA flexibility. (a) Adjustment to State fiscal... SEA, notwithstanding §§ 300.162 through 300.163 (related to State-level nonsupplanting and maintenance...

  12. Effects of Structural Flexibility on Aircraft-Engine Mounts

    NASA Technical Reports Server (NTRS)

    Phillips, W. H.

    1986-01-01

    Analysis extends technique for design of widely used type of vibration-isolating mounts for aircraft engines, in which rubber mounting pads located in plane behind center of gravity of enginepropeller combination. New analysis treats problem in statics. Results of simple approach useful in providing equations for design of vibrationisolating mounts. Equations applicable in usual situation in which engine-mount structure itself relatively light and placed between large mass of engine and other heavy components of airplane.

  13. Improving Maintenance Data Collection Via Point-of- Maintenance (POMX) Implementation

    DTIC Science & Technology

    2006-03-01

    accurate documentation, (3) identifying and correcting the root causes for poor data integrity, and (4) educating the unit on the critical need for data ...the validity of the results. The data in this study were analyzed using the SAS JMP 6.0 statistical software package. The results for the tests...traditional keyboard data entry methods at a computer terminal. These terminals are typically located in the aircraft maintenance unit (AMU) facility , away

  14. Improving Maintenance Data Collection Via Point-Of-Maintenance (POMX) Implementation

    DTIC Science & Technology

    2006-03-01

    accurate documentation, (3) identifying and correcting the root causes for poor data integrity, and (4) educating the unit on the critical need for data ...the validity of the results. The data in this study were analyzed using the SAS JMP 6.0 statistical software package. The results for the tests...traditional keyboard data entry methods at a computer terminal. These terminals are typically located in the aircraft maintenance unit (AMU) facility , away

  15. NOISECHECK Procedures for Measuring Noise Exposure from Aircraft Operations

    DTIC Science & Technology

    1980-11-01

    in § afterburner , 8 min € MIL PVR, 8 min 6 80« rpm, and 20 min « idle). Aircraft Maintenance and Runup Log Procedure 1. Log every maintenance...OoMirtnat OltUnct »it« Profilt & SEL utt Eq. l Stipolt- « tnt I Fro» lorkihttt 7 NOISEFILE Sa ♦ 4 SEL Sltnt OltUnct WtSEFlLE SEL Mrtrift

  16. Soil analyses and evaluations at the impact dynamics research facility for two full-scale aircraft crash tests

    NASA Technical Reports Server (NTRS)

    Cheng, R. Y. K.

    1977-01-01

    The aircraft structural crash behavior and occupant survivability for aircraft crashes on a soil surface was studied. The results of placement, compaction, and maintenance of two soil test beds are presented. The crators formed by the aircraft after each test are described.

  17. Development of a Computerised Method of Determining Aircraft Maintenance Intervals.

    DTIC Science & Technology

    1985-09-01

    Reliability. Vol.17. 1978. pp461-464. 23. , and Shunji Osaki. "Optimum Preventive Maintenance Policies for a 2-Unit Redundant System." IEEE...Transactions on Reliability. Vol.R-23. No.2. June 1974. pp86-91. 24. _ _, and Shunji Osaki. "A Summary of Optimum Preventive Maintenance Policies for a Two-Unit

  18. The drive for Aircraft Energy Efficiency

    NASA Technical Reports Server (NTRS)

    James, R. L., Jr.; Maddalon, D. V.

    1984-01-01

    NASA's Aircraft Energy Efficiency (ACEE) program, which began in 1976, has mounted a development effort in four major transport aircraft technology fields: laminar flow systems, advanced aerodynamics, flight controls, and composite structures. ACEE has explored two basic methods for achieving drag-reducing boundary layer laminarization: the use of suction through the wing structure (via slots or perforations) to remove boundary layer turbulence, and the encouragement of natural laminar flow maintenance through refined design practices. Wind tunnel tests have been conducted for wide bodied aircraft equipped with high aspect ratio supercritical wings and winglets. Maneuver load control and pitch-active stability augmentation control systems reduce fuel consumption by reducing the drag associated with high aircraft stability margins. Composite structures yield lighter airframes that in turn call for smaller wing and empennage areas, reducing induced drag for a given payload. In combination, all four areas of development are expected to yield a fuel consumption reduction of 40 percent.

  19. Pulsed Holographic Nondestructive Testing On Aircraft

    NASA Astrophysics Data System (ADS)

    Fagot, Hubert; Smigielski, Paul; Albe, Felix; Arnaud, Jean-Louis

    1983-06-01

    An holographic camera composed of two ruby lasers was built at ISL. It provides double exposure holograms with an adjustable time interval ranging from few ns to infinity. Various aircraft structures were first tested at ISL in laboratory conditions: honeycomb panels, wings ... The industrial tests on a military aircraft in maintenance checking were performed in a hangar of the SNIAS at Saint-Nazaire: wings, trap-door of the rear landing gear, air-brake... Electromechanical shocks were used to make the structure vibrate and to allow a fast trigger of the lasers. This avoids disturbance due to ambiant noises and vibrations.

  20. Distributed Trajectory Flexibility Preservation for Traffic Complexity Mitigation

    NASA Technical Reports Server (NTRS)

    Idris, Husni; Wing, David; Delahaye, Daniel

    2009-01-01

    The growing demand for air travel is increasing the need for mitigation of air traffic congestion and complexity problems, which are already at high levels. At the same time new information and automation technologies are enabling the distribution of tasks and decisions from the service providers to the users of the air traffic system, with potential capacity and cost benefits. This distribution of tasks and decisions raises the concern that independent user actions will decrease the predictability and increase the complexity of the traffic system, hence inhibiting and possibly reversing any potential benefits. In answer to this concern, the authors propose the introduction of decision-making metrics for preserving user trajectory flexibility. The hypothesis is that such metrics will make user actions naturally mitigate traffic complexity. In this paper, the impact of using these metrics on traffic complexity is investigated. The scenarios analyzed include aircraft in en route airspace with each aircraft meeting a required time of arrival in a one-hour time horizon while mitigating the risk of loss of separation with the other aircraft, thus preserving its trajectory flexibility. The experiments showed promising results in that the individual trajectory flexibility preservation induced self-separation and self-organization effects in the overall traffic situation. The effects were quantified using traffic complexity metrics based on Lyapunov exponents and traffic proximity.

  1. Utilization of sonar technology and microcontroller towards reducing aviation hazards during ground handling of aircraft

    NASA Astrophysics Data System (ADS)

    Khanam, Mosammat Samia; Biswas, Debasish; Rashid, Mohsina; Salam, Md Abdus

    2017-12-01

    Safety is one of the most important factors in the field of aviation. Though, modern aircraft are equipped with many instruments/devices to enhance the flight safety but it is seen that accidents/incidents are never reduced to zero. Analysis of the statistical summary of Commercial Jet Airplane accidents highlights that fatal accidents that occurred worldwide from 2006 through 2015 is 11% during taxing, loading/unloading, parking and towing. Human, handling the aircrafts is one of the most important links in aircraft maintenance and hence play a significant role in aviation safety. Effort has been made in this paper to obviate human error in aviation and outline an affordable system that monitors the uneven surface &obstacles for safe "towing in" and "towing out" of an aircraft by the ground crew. The system revolves around implementation of sonar technology by microcontroller. Ultrasonic sensors can be installed on aircraft wings and tail section to identify the uneven surface &obstacles ahead and provide early warning to the maintenance ground crews.

  2. Emerging nondestructive inspection methods for aging aircraft

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Beattie, A; Dahlke, L; Gieske, J

    This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with amore » discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.« less

  3. Classification of Aircraft Maneuvers for Fault Detection

    NASA Technical Reports Server (NTRS)

    Oza, Nikunj; Tumer, Irem Y.; Tumer, Kagan; Huff, Edward M.; Koga, Dennis (Technical Monitor)

    2002-01-01

    Automated fault detection is an increasingly important problem in aircraft maintenance and operation. Standard methods of fault detection assume the availability of either data produced during all possible faulty operation modes or a clearly-defined means to determine whether the data provide a reasonable match to known examples of proper operation. In the domain of fault detection in aircraft, the first assumption is unreasonable and the second is difficult to determine. We envision a system for online fault detection in aircraft, one part of which is a classifier that predicts the maneuver being performed by the aircraft as a function of vibration data and other available data. To develop such a system, we use flight data collected under a controlled test environment, subject to many sources of variability. We explain where our classifier fits into the envisioned fault detection system as well as experiments showing the promise of this classification subsystem.

  4. Flight control electronics reliability/maintenance study

    NASA Technical Reports Server (NTRS)

    Dade, W. W.; Edwards, R. H.; Katt, G. T.; Mcclellan, K. L.; Shomber, H. A.

    1977-01-01

    Collection and analysis of data are reported that concern the reliability and maintenance experience of flight control system electronics currently in use on passenger carrying jet aircraft. Two airlines B-747 airplane fleets were analyzed to assess the component reliability, system functional reliability, and achieved availability of the CAT II configuration flight control system. Also assessed were the costs generated by this system in the categories of spare equipment, schedule irregularity, and line and shop maintenance. The results indicate that although there is a marked difference in the geographic location and route pattern between the airlines studied, there is a close similarity in the reliability and the maintenance costs associated with the flight control electronics.

  5. We have just begun to create efficient transport aircraft

    NASA Technical Reports Server (NTRS)

    Maglieri, D. J.; Dollyhigh, S. M.

    1982-01-01

    Factors affecting the cost-effectiveness and economics of the air transportation industry are reviewed. The delivery of more fuel-efficient aircraft and eventual total replacement in the 1990's by fleets of advanced aircraft are seen to offset rising fuel costs. Better airport operations are perceived to eliminate fuel-costly delays due to overcrowded runways, lack of available carriers, and maintenance of aircraft in holding patterns. Noise reduction research will lower the lawsuit costs from noise pollution, and the introduction of advanced turbofans for long, short, and medium range flights, advanced commuter planes, and advanced SSTs offering projected 50% increases in current aircraft efficiencies are seen to be limited only by the airlines' ability to provide purchase financing, rather than by a lack of available new technology.

  6. Constraint Maintenance with Preferences and Underlying Flexible Solution

    NASA Technical Reports Server (NTRS)

    Bresina, John; Jonsson, Ari; Morris, Paul; Rajan, Kanna

    2003-01-01

    This paper describes an aspect of the constraint reasoning mechanism. that is part of a ground planning system slated to be used for the Mars Exploration Rovers mission, where two rovers are scheduled to land on Mars in January of 2003. The planning system combines manual planning software from JPL with an automatic planning/scheduling system from NASA Ames Research Center, and is designed to be used in a mixed-initiative mode. Among other things, this means that after a plan has been produced, the human operator can perform extensive modifications under the supervision of the automated. system. For each modification to an activity, the automated system must adjust other activities as needed to ensure that constraints continue to be satisfied. Thus, the system must accommodate change in an interactive setting. Performance is of critical importance for interactive use. This is achieved by maintaining an underlying flexible solution to the temporal constraints, while the system presents a fixed schedule to the user. Adjustments are then a matter of constraint propagation rather than completely re-solving the problem. However, this begs the important question of which fixed schedule (among the ones sanctioned by the underlying flexible solution) should be presented to the user.Our approach uses least-change and other preferences as a prism through which the user views the flexible solution.

  7. The Second Joint NASA/FAA/DoD Conference on Aging Aircraft. Part 2

    NASA Technical Reports Server (NTRS)

    Harris, Charles E. (Editor)

    1999-01-01

    The purpose of the Conference was to bring together world leaders in aviation safety research, aircraft design and manufacturing, fleet operation and aviation maintenance to disseminate information on current practices and advanced technologies that will assure the continued airworthiness of the aging aircraft in the military and commercial fleets. The Conference included reviews of current industry practices, assessments of future technology requirements, and status of aviation safety research. The Conference provided an opportunity for interactions among the key personnel in the research and technology development community, the original equipment manufacturers, commercial airline operators, military fleet operators, aviation maintenance, and aircraft certification and regulatory authorities. Conference participation was unrestricted and open to the international aviation community. Appendix B contains the name and addresses of the 623 participants in the Conference.

  8. Coexistence Analysis of Civil Unmanned Aircraft Systems at Low Altitudes

    NASA Astrophysics Data System (ADS)

    Zhou, Yuzhe

    2016-11-01

    The requirement of unmanned aircraft systems in civil areas is growing. However, provisioning of flight efficiency and safety of unmanned aircraft has critical requirements on wireless communication spectrum resources. Current researches mainly focus on spectrum availability. In this paper, the unmanned aircraft system communication models, including the coverage model and data rate model, and two coexistence analysis procedures, i. e. the interference and noise ratio criterion and frequency-distance-direction criterion, are proposed to analyze spectrum requirements and interference results of the civil unmanned aircraft systems at low altitudes. In addition, explicit explanations are provided. The proposed coexistence analysis criteria are applied to assess unmanned aircraft systems' uplink and downlink interference performances and to support corresponding spectrum planning. Numerical results demonstrate that the proposed assessments and analysis procedures satisfy requirements of flexible spectrum accessing and safe coexistence among multiple unmanned aircraft systems.

  9. 75 FR 52482 - Airworthiness Directives; PILATUS Aircraft Ltd. Model PC-7 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-26

    ..., check the airplane maintenance records to determine if the left and/or right aileron outboard bearing... an entry is found during the airplane maintenance records check required in paragraph (f)(1) of this...-0849; Directorate Identifier 2010-CE-043-AD] RIN 2120-AA64 Airworthiness Directives; PILATUS Aircraft...

  10. PipelineDog: a simple and flexible graphic pipeline construction and maintenance tool.

    PubMed

    Zhou, Anbo; Zhang, Yeting; Sun, Yazhou; Xing, Jinchuan

    2018-05-01

    Analysis pipelines are an essential part of bioinformatics research, and ad hoc pipelines are frequently created by researchers for prototyping and proof-of-concept purposes. However, most existing pipeline management system or workflow engines are too complex for rapid prototyping or learning the pipeline concept. A lightweight, user-friendly and flexible solution is thus desirable. In this study, we developed a new pipeline construction and maintenance tool, PipelineDog. This is a web-based integrated development environment with a modern web graphical user interface. It offers cross-platform compatibility, project management capabilities, code formatting and error checking functions and an online repository. It uses an easy-to-read/write script system that encourages code reuse. With the online repository, it also encourages sharing of pipelines, which enhances analysis reproducibility and accountability. For most users, PipelineDog requires no software installation. Overall, this web application provides a way to rapidly create and easily manage pipelines. PipelineDog web app is freely available at http://web.pipeline.dog. The command line version is available at http://www.npmjs.com/package/pipelinedog and online repository at http://repo.pipeline.dog. ysun@kean.edu or xing@biology.rutgers.edu or ysun@diagnoa.com. Supplementary data are available at Bioinformatics online.

  11. [Development of Hospital Equipment Maintenance Information System].

    PubMed

    Zhou, Zhixin

    2015-11-01

    Hospital equipment maintenance information system plays an important role in improving medical treatment quality and efficiency. By requirement analysis of hospital equipment maintenance, the system function diagram is drawed. According to analysis of input and output data, tables and reports in connection with equipment maintenance process, relationships between entity and attribute is found out, and E-R diagram is drawed and relational database table is established. Software development should meet actual process requirement of maintenance and have a friendly user interface and flexible operation. The software can analyze failure cause by statistical analysis.

  12. Advanced U.S. military aircraft battery systems

    NASA Astrophysics Data System (ADS)

    Flake, Richard A.; Eskra, Michael D.

    1990-04-01

    While most USAF aircraft currently use vented Ni-Cd for dc electrical power and emergency power, as well as the powering of lights and instruments prior to engine starting, these batteries have high maintenance requirements, low reliability, and no built-in testing capability with which to check battery health prior to flight. The USAF Wright R&D Center accordingly initiated its Advanced Maintenance-Free NiCd Battery System development program in 1986, in order to develop a sealed Ni-Cd battery which would remain maintenance-free over a period of three years. Attention is being given to a high power bipolar battery design in which there are no individual cell cases or cell interconnects.

  13. 14 CFR 21.245 - Maintenance of eligibility.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maintenance of eligibility. 21.245 Section 21.245 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... requirements for issue of the authorization or shall notify the Administrator within 48 hours of any change...

  14. 14 CFR 21.245 - Maintenance of eligibility.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maintenance of eligibility. 21.245 Section 21.245 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... requirements for issue of the authorization or shall notify the Administrator within 48 hours of any change...

  15. Optimizing Maintenance Manpower for USMC F/A-18 Squadrons

    DTIC Science & Technology

    2016-06-01

    experience level, with the requirement of keeping a standard number of aircraft operationally ready. MVP results show areas of deficit, either manpower ...MAINTENANCE MANPOWER FOR USMC F/A-18 SQUADRONS by Kevin J. Goodwin June 2016 Thesis Co-Advisors: W. Matthew Carlyle Robert F. Dell Second...REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE OPTIMIZING MAINTENANCE MANPOWER FOR USMC F/A-18 SQUADRONS 5. FUNDING NUMBERS 6

  16. 77 FR 71087 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ... by making the following pen and ink changes to the Airworthiness Limitations of the maintenance.... (g) Alternative Methods of Compliance (AMOC) (1) The Manager, Boston Aircraft Certification Office...

  17. Active Structural Control for Aircraft Efficiency with the X-56A Aircraft

    NASA Technical Reports Server (NTRS)

    Ouellette, Jeffrey

    2015-01-01

    The X-56A Multi-Utility Technology Testbed is an experimental aircraft designed to study active control of flexible structures. The vehicle is easily reconfigured to allow for testing of different configurations. The vehicle is being used to study new sensor, actuator, modeling and controls technologies. These new technologies will allow for lighter vehicles and new configurations that exceed the efficiency currently achievable. A description of the vehicle and the current research efforts that it enables are presented.

  18. In situ monitoring of the integrity of bonded repair patches on aircraft and civil infrastructures

    NASA Astrophysics Data System (ADS)

    Kumar, Amrita; Roach, Dennis; Beard, Shawn; Qing, Xinlin; Hannum, Robert

    2006-03-01

    critical structures that can monitor damage can provide for improved reliability and streamlining of aircraft maintenance. Early detection of damage such as fatigue crack initiation can improve personnel safety and prolong service life. This paper presents the testing of an acousto-ultrasonic piezoelectric sensor based structural health monitoring system for real-time monitoring of fatigue cracks and disbonds in bonded repairs. The system utilizes a network of distributed miniature piezoelectric sensors/actuators embedded on a thin dielectric carrier film, to query, monitor and evaluate the condition of a structure. The sensor layers are extremely flexible and can be integrated with any type of metal or composite structure. Diagnostic signals obtained from a structure during structural monitoring are processed by a portable diagnostic unit. With appropriate diagnostic software, the signals can be analyzed to ascertain the integrity of the structure being monitored. Details on the system, its integration and examples of detection of fatigue crack and disbond growth and quantification for bonded repairs will be presented here.

  19. 75 FR 66655 - Airworthiness Directives; PILATUS Aircraft Ltd. Model PC-7 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-29

    ... December 3, 2010 (the effective date of this AD), check the airplane maintenance records to determine if... of the airplane. Do this check following paragraph 3.A. of Pilatus Aircraft Ltd. PC-7 Service... maintenance records check required in paragraph (f)(1) of this AD or it is unclear whether or not the left and...

  20. A Study of Vehicle Structural Layouts in Post-WWII Aircraft

    NASA Technical Reports Server (NTRS)

    Sensmeier, Mark D.; Samareh, Jamshid A.

    2004-01-01

    In this paper, results of a study of structural layouts of post-WWII aircraft are presented. This study was undertaken to provide the background information necessary to determine typical layouts, design practices, and industry trends in aircraft structural design. Design decisions are often predicated not on performance-related criteria, but rather on such factors as manufacturability, maintenance access, and of course cost. For this reason, a thorough understanding of current best practices in the industry is required as an input for the design optimization process. To determine these best practices and industry trends, a large number of aircraft structural cutaway illustrations were analyzed for five different aircraft categories (commercial transport jets, business jets, combat jet aircraft, single engine propeller aircraft, and twin-engine propeller aircraft). Several aspects of wing design and fuselage design characteristics are presented here for the commercial transport and combat aircraft categories. A great deal of commonality was observed for transport structure designs over a range of eras and manufacturers. A much higher degree of variability in structural designs was observed for the combat aircraft, though some discernable trends were observed as well.

  1. Hardening surveillance illumination using aircraft antennas

    NASA Astrophysics Data System (ADS)

    Donohoe, J. P.; Taylor, C. D.

    1990-06-01

    Aircraft maintenance depots and main operating bases need to be able to perform quick checks of the electromagnetic pulse (EMP) hardness of their systems without removing them from service for any length of time. Preliminary tests have shown that the onboard HF antennas of the EMP Test-Bed Aircraft (EMPTAC) may be capable of providing the HF excitation required to effectively monitor the EMP hardness of aircraft systems. The surface current and charge distributions on the EMPTAC which result from swept frequency excitation of the HF radio antennas are computed over a range of 0.5 to 100 MHz using various antenna drive configurations. The computational analysis is performed by using two separate frequency-dependent techniques: the method-of-moments technique and the physical optics approximation. These calculations are then compared with the excitation provided from an overhead plane wave and with measured data from EMPTAC tests.

  2. Aviation Maintenance Technology. Airframe. A204. Aircraft Welding. Instructor Material.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This teacher's guide is designed to aid teachers in leading students through a module on aircraft welding on airframes. The module contains four units that cover the following topics: (1) gas welding and cutting; (2) brazing and soldering; (3) shielded metal arc welding; and (4) gas tungsten arc welding. Each unit follows a standardized format…

  3. Analysis of operational limit of an aircraft: An aeroelastic approach

    NASA Astrophysics Data System (ADS)

    Hasan, Md. Mehedi; Hassan, M. D. Mehedi; Sarrowar, S. M. Bayazid; Faisal, Kh. Md.; Ahmed, Sheikh Reaz, Dr.

    2017-06-01

    In classical theory of elasticity, external loading acting on the body is independent of deformation of the body. But, in aeroelasticity, aerodynamic forces depend on the attitude of the body relative to the flow. Aircraft's are subjected to a range of static loads resulting from equilibrium or steady flight maneuvers such as coordinated level turn, steady pitch and bank rate, steady and level flight. Interaction of these loads with elastic forces of aircraft structure creates some aeroelastic phenomena. In this paper, we have summarized recent developments in the area of aeroelasticity. A numerical approach has been applied for finding divergence speed, a static aeroelastic phenomena, of a typical aircraft. This paper also involves graphical representations of constraints on load factor and bank angle during different steady flight maneuvers taking flexibility into account and comparing it with the value without flexibility. Effect of wing skin thickness, spar web thickness and position of flexural axis of wing on this divergence speed as well as load factor and bank angle has also been observed using MATLAB.

  4. Structural health monitoring methodology for aircraft condition-based maintenance

    NASA Astrophysics Data System (ADS)

    Saniger, Jordi; Reithler, Livier; Guedra-Degeorges, Didier; Takeda, Nobuo; Dupuis, Jean Pierre

    2001-06-01

    Reducing maintenance costs while keeping a constant level of safety is a major issue for Air Forces and airlines. The long term perspective is to implement condition based maintenance to guarantee a constant safety level while decreasing maintenance costs. On this purpose, the development of a generalized Structural Health Monitoring System (SHMS) is needed. The objective of such a system is to localize the damages and to assess their severity, with enough accuracy to allow low cost corrective actions. The present paper describes a SHMS based on acoustic emission technology. This choice was driven by its reliability and wide use in the aerospace industry. The described SHMS uses a new learning methodology which relies on the generation of artificial acoustic emission events on the structure and an acoustic emission sensor network. The calibrated acoustic emission events picked up by the sensors constitute the knowledge set that the system relies on. With this methodology, the anisotropy of composite structures is taken into account, thus avoiding the major cause of errors of classical localization methods. Moreover, it is adaptive to different structures as it does not rely on any particular model but on measured data. The acquired data is processed and the event's location and corrected amplitude are computed. The methodology has been demonstrated and experimental tests on elementary samples presented a degree of accuracy of 1cm.

  5. Opportunities for development of advanced large cargo aircraft

    NASA Technical Reports Server (NTRS)

    Whitehead, A. H., Jr.

    1976-01-01

    A critical review of the history, current state of the art, and future prospects for cargo aircraft systems indicates that three of the major advantages of air cargo are rapid delivery, ability to bridge geographical boundaries, and capability to provide a flexible market response. Foreseeable advances in large aircraft development offer even greater profit potential by increasing the payload ton-miles per pound of fuel. Intermodal containers and handling systems and computerized control and billing may be key ingredients. Details of a NASA program for large aircraft systems technology are outlined, which includes systems studies, research and technology investigations, and determination of the need for critical flight experiments. Innovative advanced technologies and configuration concepts are discussed. Numerous illustrations supplement the text.

  6. 76 FR 31457 - Airworthiness Directives; Diamond Aircraft Industries GmbH Model DA 42 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... Airworthiness Directives; Diamond Aircraft Industries GmbH Model DA 42 Airplanes AGENCY: Federal Aviation... reportedly found on DA 42 Main Landing Gear (MLG) Damper-to-Trailing Arm joints during standard maintenance... DA 42 Main Landing Gear (MLG) Damper-to-Trailing Arm joints during standard maintenance. Depending on...

  7. Study of aircraft in intraurban transportation systems, San Francisco Bay area

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The nine-county San Francisco Bay area is examined in two time periods (1975-1980 and 1985-1990) as a scenario for analyzing the characteristics of an intraurban, commuter-oriented aircraft transportation system. Aircraft have dominated the long-haul passenger market for some time, but efforts to penetrate the very-short-haul intraurban market have met with only token success. Yet, the characteristics of an aircraft transportation system-speed and flexibility-are very much needed to solve the transportation ills of our major urban areas. This study attempts to determine if the aircraft can contribute toward solving the transportation problems of major metropolitan areas and be economically viable in such an environment.

  8. Revision of certification standards for aviation maintenance personnel

    NASA Technical Reports Server (NTRS)

    Vipond, Leslie K.

    1992-01-01

    Part 65, Subparts D and E, of the Federal Aviation Regulations (FAR) identify the certification requirements for aviation mechanics and aviation repairmen. The training, experience, privileges, ratings, recordkeeping, and currency requirements for aviation maintenance personnel are also addressed by those parts of the FAR. The recent emergence of the aging fleet problem and the introduction of new technologies, aircraft, engines, and aeronautical products has caused certain portions of these rules to become obsolete. Further, international political arrangements, such as bilateral airworthiness and maintenance agreements, International Civil Aviation Organization (ICAO) standards, certain international agreements for maintenance personnel training, and mechanic certificate reciprocity, have all impacted on the current regulatory policy.

  9. Benefits and limitations of composites in carrier-based aircraft

    NASA Technical Reports Server (NTRS)

    Mcerlean, Donald P.

    1992-01-01

    There are many unique aspects of Navy air missions that lead to the differentiation between the design and performance of ship and shore-based aircraft. The major aspects are discussed from which essentially all Navy aircraft design requirements derive. (1) Navy aircraft operate from carriers at sea imposes a broad spectrum of physical conditions, constraints, and requirements ranging from the harsh sea environment, the space limitations of a carrier, takeoff and landing requirements as well as for endurance at long distances from the carrier. (2) Because the carrier and its airwing are intended to be capable of responding to a broad range of contingencies, mission flexibility is essential (maximum weapon carriage, rapid reconfiguration, multiple mission capability). (3) The embarked aircraft provides the long range defense of the battle group against air, surface and subsurface launched antiship missiles. (4) The carrier and its aircraft must operate independently and outside of normal supply lines. Taking into account these aspects, the use of composite materials in the design and performance of naval aircraft is outlined, also listing advantages and disadvantages.

  10. Aging Aircraft Transparencies: AN Italian Air Force Fleet Case History

    NASA Astrophysics Data System (ADS)

    Caucci, D.; Aiello, L.; Bagnoli, F.; Bernabei, M.

    2008-08-01

    Aircraft acrylic transparencies are structural components that must withstand flight and ground loads. Crazing occurrence, known as Environmental Stress Cracking (ESC), causes their substitution during aircraft maintenance operations. This form of aging is mainly a physical phenomenon due to the interaction of transparencies base material with an active liquid and leads craze formation at lower stress that would be required in air. In this paper, an extensive phenomenon of network ESC occurred on transparencies of many aircrafts operating in the same fleet was investigated. Cover application while parking was found to be the critical aspect in crazing appearance, thus acting as physical shield for condensed water and heat transferring.

  11. The NASA Earth Research-2 (ER-2) Aircraft: A Flying Laboratory for Earth Science Studies

    NASA Technical Reports Server (NTRS)

    Navarro, Robert

    2007-01-01

    The National Aeronautics and Space Administration Dryden Flight Research Center, Edwards, California, has two Lockheed Martin Corporation (Bethesda, Maryland) Earth Research-2 (ER2) aircraft that serve as high-altitude and long-range flying laboratories. The ER-2 aircraft has been successfully utilized to conduct scientific studies of stratospheric and tropospheric chemistry, land-use mapping, disaster assessment, preliminary testing and calibration and validation of satellite sensors. The research missions for the ER-2 aircraft are planned, implemented, and managed by the Dryden Flight Research Center Science Mission Directorate. Maintenance and instrument payload integration is conducted by Dryden personnel. The ER-2 aircraft provides experimenters with a wide array of payload accommodations areas with suitable environment control with required electrical and mechanical interfaces. Missions may be flown out of Dryden or from remote bases worldwide, according to research requirements. The NASA ER-2 aircraft is utilized by a variety of customers, including U.S. Government agencies, civilian organizations, universities, and state governments. The combination of the ER-2 aircraft s range, endurance, altitude, payload power, payload volume and payload weight capabilities complemented by a trained maintenance and operations team provides an excellent and unique platform system to the science community and other customers.

  12. Reliability and Maintainability model (RAM) user and maintenance manual. Part 2

    NASA Technical Reports Server (NTRS)

    Ebeling, Charles E.

    1995-01-01

    This report documents the procedures for utilizing and maintaining the Reliability and Maintainability Model (RAM) developed by the University of Dayton for the NASA Langley Research Center (LaRC). The RAM model predicts reliability and maintainability (R&M) parameters for conceptual space vehicles using parametric relationships between vehicle design and performance characteristics and subsystem mean time between maintenance actions (MTBM) and manhours per maintenance action (MH/MA). These parametric relationships were developed using aircraft R&M data from over thirty different military aircraft of all types. This report describes the general methodology used within the model, the execution and computational sequence, the input screens and data, the output displays and reports, and study analyses and procedures. A source listing is provided.

  13. Generalized Operations Simulation Environment for Aircraft Maintenance Training

    DTIC Science & Technology

    2004-04-01

    Operations Simulation Environment ( GOSE ) project is a collaborative effort between AETC and AFRL to develop common, cost-effective, generalized VR training...maintenance training domain since it provided an opportunity to build on the VEST architecture. Development of GOSE involves re-engineering VEST as a scalable...modular, immersive VR training system comprised of PC-based hardware and software. GOSE initiatives include: (a) formalize training needs across

  14. Improving the Aircraft Design Process Using Web-Based Modeling and Simulation

    NASA Technical Reports Server (NTRS)

    Reed, John A.; Follen, Gregory J.; Afjeh, Abdollah A.; Follen, Gregory J. (Technical Monitor)

    2000-01-01

    Designing and developing new aircraft systems is time-consuming and expensive. Computational simulation is a promising means for reducing design cycle times, but requires a flexible software environment capable of integrating advanced multidisciplinary and multifidelity analysis methods, dynamically managing data across heterogeneous computing platforms, and distributing computationally complex tasks. Web-based simulation, with its emphasis on collaborative composition of simulation models, distributed heterogeneous execution, and dynamic multimedia documentation, has the potential to meet these requirements. This paper outlines the current aircraft design process, highlighting its problems and complexities, and presents our vision of an aircraft design process using Web-based modeling and simulation.

  15. Improving the Aircraft Design Process Using Web-based Modeling and Simulation

    NASA Technical Reports Server (NTRS)

    Reed, John A.; Follen, Gregory J.; Afjeh, Abdollah A.

    2003-01-01

    Designing and developing new aircraft systems is time-consuming and expensive. Computational simulation is a promising means for reducing design cycle times, but requires a flexible software environment capable of integrating advanced multidisciplinary and muitifidelity analysis methods, dynamically managing data across heterogeneous computing platforms, and distributing computationally complex tasks. Web-based simulation, with its emphasis on collaborative composition of simulation models, distributed heterogeneous execution, and dynamic multimedia documentation, has the potential to meet these requirements. This paper outlines the current aircraft design process, highlighting its problems and complexities, and presents our vision of an aircraft design process using Web-based modeling and simulation.

  16. Handling qualities of large flexible control-configured aircraft

    NASA Technical Reports Server (NTRS)

    Swaim, R. L.

    1979-01-01

    The approach to an analytical study of flexible airplane longitudinal handling qualities was to parametrically vary the natural frequencies of two symmetric elastic modes to induce mode interactions with the rigid body dynamics. Since the structure of the pilot model was unknown for such dynamic interactions, the optimal control pilot modeling method is being applied and used in conjunction with pilot rating method.

  17. Effect of broadened-specification fuels on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1979-01-01

    A wide variety of studies on the potential effects of broadened-specification fuels on future aircraft engines and fuel systems are summarized. The compositions and characteristics of aircraft fuels that may be derived from current and future crude-oil sources are described, and the most critical properties that may effect aircraft engines and fuel systems are identified and discussed. The problems that are most likely to be encountered because of changes in selected fuel properties are explored; and the related effects on engine performance, component durability and maintenance, and aircraft fuel-system performance are examined. The ability of current technology to accept possible future fuel specification changes is assessed and selected technological advances that can reduce the severity of the potential problems are illustrated.

  18. Effect of broadened-specification fuels on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1979-01-01

    A wide variety of studies on the potential effects of broadened-specification fuels on future aircraft engines and fuel systems are summarized. The compositions and characteristics of aircraft fuels that may be derived from current and future crude-oil sources are described, and the most critical properties that may affect aircraft engines and fuel systems are identified and discussed. The problems that are most likely to be encountered because of changes in selected fuel properties are described; and the related effects on engine performance, component durability and maintenance, and aircraft fuel-system performance are discussed. The ability of current technology to accept possible future fuel-specification changes is discussed, and selected technological advances that can reduce the severity of the potential problems are illustrated.

  19. Multidisciplinary Design Optimization of A Highly Flexible Aeroservoelastic Wing

    NASA Astrophysics Data System (ADS)

    Haghighat, Sohrab

    A multidisciplinary design optimization framework is developed that integrates control system design with aerostructural design for a highly-deformable wing. The objective of this framework is to surpass the existing aircraft endurance limits through the use of an active load alleviation system designed concurrently with the rest of the aircraft. The novelty of this work is two fold. First, a unified dynamics framework is developed to represent the full six-degree-of-freedom rigid-body along with the structural dynamics. It allows for an integrated control design to account for both manoeuvrability (flying quality) and aeroelasticity criteria simultaneously. Secondly, by synthesizing the aircraft control system along with the structural sizing and aerodynamic shape design, the final design has the potential to exploit synergies among the three disciplines and yield higher performing aircraft. A co-rotational structural framework featuring Euler--Bernoulli beam elements is developed to capture the wing's nonlinear deformations under the effect of aerodynamic and inertial loadings. In this work, a three-dimensional aerodynamic panel code, capable of calculating both steady and unsteady loadings is used. Two different control methods, a model predictive controller (MPC) and a 2-DOF mixed-norm robust controller, are considered in this work to control a highly flexible aircraft. Both control techniques offer unique advantages that make them promising for controlling a highly flexible aircraft. The control system works towards executing time-dependent manoeuvres along with performing gust/manoeuvre load alleviation. The developed framework is investigated for demonstration in two design cases: one in which the control system simply worked towards achieving or maintaining a target altitude, and another where the control system is also performing load alleviation. The use of the active load alleviation system results in a significant improvement in the aircraft performance

  20. Maintenance Work, Maintenance Skills: The Case of a Major Water Company in the UK.

    ERIC Educational Resources Information Center

    Cooke, Fang Lee

    2002-01-01

    A case study of a British water company found that technological change had only a moderate impact on technical skills but increased the need for diagnostic and information technology skills for the maintenance of electronic equipment. Organizational restructuring increased requirements for functional flexibility and interpersonal skills.…

  1. The Aerosonde Robotic Aircraft: A New Paradigm for Environmental Observations.

    NASA Astrophysics Data System (ADS)

    Holland, G. J.; Webster, P. J.; Curry, J. A.; Tyrell, G.; Gauntlett, D.; Brett, G.; Becker, J.; Hoag, R.; Vaglienti, W.

    2001-05-01

    The Aerosonde is a small robotic aircraft designed for highly flexible and inexpensive operations. Missions are conducted in a completely robotic mode, with the aircraft under the command of a ground controller who monitors the mission. Here we provide an update on the Aerosonde development and operations and expand on the vision for the future, including instrument payloads, observational strategies, and platform capabilities. The aircraft was conceived in 1992 and developed to operational status in 1995-98, after a period of early prototyping. Continuing field operations and development since 1998 have led to the Aerosonde Mark 3, with ~2000 flight hours completed. A defined development path through to 2002 will enable the aircraft to become increasingly more robust with increased flexibility in the range and type of operations that can be achieved. An Aerosonde global reconnaissance facility is being developed that consists of launch and recovery sites dispersed around the globe. The use of satellite communications and internet technology enables an operation in which all aircraft around the globe are under the command of a single center. During operation, users will receive data at their home institution in near-real time via the virtual field environment, allowing the user to update the mission through interaction with the global command center. Sophisticated applications of the Aerosonde will be enabled by the development of a variety of interchangeable instrument payloads and the operation of Smart Aerosonde Clusters that allow a cluster of Aerosondes to interact intelligently in response to the data being collected.

  2. 75 FR 26885 - Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A, B, and C Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-13

    ... states that this ``check'' should be performed in accordance with the maintenance manual. Because we have... Airworthiness Directives; Sikorsky Aircraft Corporation Model S- 76A, B, and C Helicopters AGENCY: Federal... directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S-76A, B, and C helicopters that requires...

  3. Effects of simulated turbulence on aircraft handling qualities

    NASA Technical Reports Server (NTRS)

    Jacobson, I. D.; Joshi, D. S.

    1977-01-01

    The influence of simulated turbulence on aircraft handling qualities is presented. Pilot opinions of the handling qualities of a light general aviation aircraft were evaluated in a motion-base simulator using a simulated turbulence environment. A realistic representation of turbulence disturbances is described in terms of rms intensity and scale length and their random variations with time. The time histories generated by the proposed turbulence models showed characteristics which are more similar to real turbulence than the frequently-used Gaussian turbulence model. The proposed turbulence models flexibly accommodate changes in atmospheric conditions and are easily implemented in flight simulator studies.

  4. The Development and Deployment of a Maintenance Operations Safety Survey.

    PubMed

    Langer, Marie; Braithwaite, Graham R

    2016-11-01

    Based on the line operations safety audit (LOSA), two studies were conducted to develop and deploy an equivalent tool for aircraft maintenance: the maintenance operations safety survey (MOSS). Safety in aircraft maintenance is currently measured reactively, based on the number of audit findings, reportable events, incidents, or accidents. Proactive safety tools designed for monitoring routine operations, such as flight data monitoring and LOSA, have been developed predominantly for flight operations. In Study 1, development of MOSS, 12 test peer-to-peer observations were collected to investigate the practicalities of this approach. In Study 2, deployment of MOSS, seven expert observers collected 56 peer-to-peer observations of line maintenance checks at four stations. Narrative data were coded and analyzed according to the threat and error management (TEM) framework. In Study 1, a line check was identified as a suitable unit of observation. Communication and third-party data management were the key factors in gaining maintainer trust. Study 2 identified that on average, maintainers experienced 7.8 threats (operational complexities) and committed 2.5 errors per observation. The majority of threats and errors were inconsequential. Links between specific threats and errors leading to 36 undesired states were established. This research demonstrates that observations of routine maintenance operations are feasible. TEM-based results highlight successful management strategies that maintainers employ on a day-to-day basis. MOSS is a novel approach for safety data collection and analysis. It helps practitioners understand the nature of maintenance errors, promote an informed culture, and support safety management systems in the maintenance domain. © 2016, Human Factors and Ergonomics Society.

  5. The Development and Deployment of a Maintenance Operations Safety Survey

    PubMed Central

    Langer, Marie; Braithwaite, Graham R.

    2016-01-01

    Objective: Based on the line operations safety audit (LOSA), two studies were conducted to develop and deploy an equivalent tool for aircraft maintenance: the maintenance operations safety survey (MOSS). Background: Safety in aircraft maintenance is currently measured reactively, based on the number of audit findings, reportable events, incidents, or accidents. Proactive safety tools designed for monitoring routine operations, such as flight data monitoring and LOSA, have been developed predominantly for flight operations. Method: In Study 1, development of MOSS, 12 test peer-to-peer observations were collected to investigate the practicalities of this approach. In Study 2, deployment of MOSS, seven expert observers collected 56 peer-to-peer observations of line maintenance checks at four stations. Narrative data were coded and analyzed according to the threat and error management (TEM) framework. Results: In Study 1, a line check was identified as a suitable unit of observation. Communication and third-party data management were the key factors in gaining maintainer trust. Study 2 identified that on average, maintainers experienced 7.8 threats (operational complexities) and committed 2.5 errors per observation. The majority of threats and errors were inconsequential. Links between specific threats and errors leading to 36 undesired states were established. Conclusion: This research demonstrates that observations of routine maintenance operations are feasible. TEM-based results highlight successful management strategies that maintainers employ on a day-to-day basis. Application: MOSS is a novel approach for safety data collection and analysis. It helps practitioners understand the nature of maintenance errors, promote an informed culture, and support safety management systems in the maintenance domain. PMID:27411354

  6. Flexible Wing Base Micro Aerial Vehicles: Composite Materials for Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Ifju, Peter G.; Ettinger, Scott; Jenkins, David; Martinez, Luis

    2002-01-01

    This paper will discuss the development of the University of Florida's Micro Air Vehicle concept. A series of flexible wing based aircraft that possess highly desirable flight characteristics were developed. Since computational methods to accurately model flight at the low Reynolds numbers associated with this scale are still under development, our effort has relied heavily on trial and error. Hence a time efficient method was developed to rapidly produce prototype designs. The airframe and wings are fabricated using a unique process that incorporates carbon fiber composite construction. Prototypes can be fabricated in around five man-hours, allowing many design revisions to be tested in a short period of time. The resulting aircraft are far more durable, yet lighter, than their conventional counterparts. This process allows for thorough testing of each design in order to determine what changes were required on the next prototype. The use of carbon fiber allows for wing flexibility without sacrificing durability. The construction methods developed for this project were the enabling technology that allowed us to implement our designs. The resulting aircraft were the winning entries in the International Micro Air Vehicle Competition for the past two years. Details of the construction method are provided in this paper along with a background on our flexible wing concept.

  7. An Overview of Virtual Acoustic Simulation of Aircraft Flyover Noise

    NASA Technical Reports Server (NTRS)

    Rizzi, Stephen A.

    2013-01-01

    Methods for testing human subject response to aircraft flyover noise have greatly advanced in recent years as a result of advances in simulation technology. Capabilities have been developed which now allow subjects to be immersed both visually and aurally in a three-dimensional, virtual environment. While suitable for displaying recorded aircraft noise, the true potential is found when synthesizing aircraft flyover noise because it allows the flexibility and freedom to study sounds from aircraft not yet flown. A virtual acoustic simulation method is described which is built upon prediction-based source noise synthesis, engineering-based propagation modeling, and empirically-based receiver modeling. This source-path-receiver paradigm allows complete control over all aspects of flyover auralization. With this capability, it is now possible to assess human response to flyover noise by systematically evaluating source noise reductions within the context of a system level simulation. Examples of auralized flyover noise and movie clips representative of an immersive aircraft flyover environment are made in the presentation.

  8. Sensitivity of disease parameters to flexible budesonide/formoterol treatment in an allergic rat model.

    PubMed

    Brange, Charlotte; Smailagic, Amir; Jansson, Anne-Helene; Middleton, Brian; Miller-Larsson, Anna; Taylor, John D; Silberstein, David S; Lal, Harbans

    2009-02-01

    Clinical studies show that flexible dosing (maintenance and symptom-driven dose adjustments) of budesonide and formoterol (BUD/FORM) improves control of asthma exacerbations as compared to fixed maintenance dosing protocols (maintenance therapy) even when the latter utilize higher BUD/FORM doses. This suggests that dose-response relationships for certain pathobiologic mechanisms in asthma shift over time. Here, we have conducted animal studies to address this issue. (1) To test in an animal asthma-like model whether it is possible to achieve the same or greater pharmacological control over bronchoconstriction and airway/lung inflammation, and with less total drug used, by flexible BUD/FORM dosing (upward adjustment of doses) in association with allergen challenges. (2) To determine whether the benefit requires adjustment of both drug components. Rats sensitized on days 0 and 7 were challenged intratracheally with ovalbumin on days 14 and 21. On days 13-21, rats were treated intratracheally with fixed maintenance or flexible BUD/FORM combinations. On day 22, rats were challenged with methacholine and lungs were harvested for analysis. A flexible BUD/FORM dosing regimen (using 3.3 times less total drug than the fixed maintenance high dose regimen), delivered the same or greater reductions of excised lung gas volume (a measure of gas trapped in lung by bronchoconstriction) and lung weight (a measure of inflammatory oedema). When either BUD or FORM alone was increased on days of challenge, the benefit of the flexible dose upward adjustment was lost. Flexible dosing of the BUD/FORM combination improves the pharmacological inhibition of allergen-induced bronchoconstriction and an inflammatory oedema in an allergic asthma-like rat model.

  9. Aircraft Segmentation in SAR Images Based on Improved Active Shape Model

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Xiong, B.; Kuang, G.

    2018-04-01

    In SAR image interpretation, aircrafts are the important targets arousing much attention. However, it is far from easy to segment an aircraft from the background completely and precisely in SAR images. Because of the complex structure, different kinds of electromagnetic scattering take place on the aircraft surfaces. As a result, aircraft targets usually appear to be inhomogeneous and disconnected. It is a good idea to extract an aircraft target by the active shape model (ASM), since combination of the geometric information controls variations of the shape during the contour evolution. However, linear dimensionality reduction, used in classic ACM, makes the model rigid. It brings much trouble to segment different types of aircrafts. Aiming at this problem, an improved ACM based on ISOMAP is proposed in this paper. ISOMAP algorithm is used to extract the shape information of the training set and make the model flexible enough to deal with different aircrafts. The experiments based on real SAR data shows that the proposed method achieves obvious improvement in accuracy.

  10. Informed maintenance for next generation space transportation systems

    NASA Astrophysics Data System (ADS)

    Fox, Jack J.

    2001-02-01

    Perhaps the most substantial single obstacle to progress of space exploration and utilization of space for human benefit is the safety & reliability and the inherent cost of launching to, and returning from, space. The primary influence in the high costs of current launch systems (the same is true for commercial and military aircraft and most other reusable systems) is the operations, maintenance and infrastructure portion of the program's total life cycle costs. Reusable Launch Vehicle (RLV) maintenance and design have traditionally been two separate engineering disciplines with often conflicting objectives-maximizing ease of maintenance versus optimizing performance, size and cost. Testability analysis, an element of Informed Maintenance (IM), has been an ad hoc, manual effort, in which maintenance engineers attempt to identify an efficient method of troubleshooting for the given product, with little or no control over product design. Therefore, testability deficiencies in the design cannot be rectified. It is now widely recognized that IM must be engineered into the product at the design stage itself, so that an optimal compromise is achieved between system maintainability and performance. The elements of IM include testability analysis, diagnostics/prognostics, automated maintenance scheduling, automated logistics coordination, paperless documentation and data mining. IM derives its heritage from complimentary NASA science, space and aeronautic enterprises such as the on-board autonomous Remote Agent Architecture recently flown on NASA's Deep Space 1 Probe as well as commercial industries that employ quick turnaround operations. Commercial technologies and processes supporting NASA's IM initiatives include condition based maintenance technologies from Boeing's Commercial 777 Aircraft and Lockheed-Martin's F-22 Fighter, automotive computer diagnostics and autonomous controllers that enable 100,000 mile maintenance free operations, and locomotive monitoring

  11. Informed maintenance for next generation reusable launch systems

    NASA Astrophysics Data System (ADS)

    Fox, Jack J.; Gormley, Thomas J.

    2001-03-01

    Perhaps the most substantial single obstacle to progress of space exploration and utilization of space for human benefit is the safety & reliability and the inherent cost of launching to, and returning from, space. The primary influence in the high costs of current launch systems (the same is true for commercial and military aircraft and most other reusable systems) is the operations, maintenance and infrastructure portion of the program's total life cycle costs. Reusable Launch Vehicle (RLV) maintenance and design have traditionally been two separate engineering disciplines with often conflicting objectives - maximizing ease of maintenance versus optimizing performance, size and cost. Testability analysis, an element of Informed Maintenance (IM), has been an ad hoc, manual effort, in which maintenance engineers attempt to identify an efficient method of troubleshooting for the given product, with little or no control over product design. Therefore, testability deficiencies in the design cannot be rectified. It is now widely recognized that IM must be engineered into the product at the design stage itself, so that an optimal compromise is achieved between system maintainability and performance. The elements of IM include testability analysis, diagnostics/prognostics, automated maintenance scheduling, automated logistics coordination, paperless documentation and data mining. IM derives its heritage from complimentary NASA science, space and aeronautic enterprises such as the on-board autonomous Remote Agent Architecture recently flown on NASA's Deep Space 1 Probe as well as commercial industries that employ quick turnaround operations. Commercial technologies and processes supporting NASA's IM initiatives include condition based maintenance technologies from Boeing's Commercial 777 Aircraft and Lockheed-Martin's F-22 Fighter, automotive computer diagnostics and autonomous controllers that enable 100,000 mile maintenance free operations, and locomotive monitoring

  12. Operational Interventions to Maintenance Error

    NASA Technical Reports Server (NTRS)

    Kanki, Barbara G.; Walter, Diane; Dulchinos, VIcki

    1997-01-01

    A significant proportion of aviation accidents and incidents are known to be tied to human error. However, research of flight operational errors has shown that so-called pilot error often involves a variety of human factors issues and not a simple lack of individual technical skills. In aircraft maintenance operations, there is similar concern that maintenance errors which may lead to incidents and accidents are related to a large variety of human factors issues. Although maintenance error data and research are limited, industry initiatives involving human factors training in maintenance have become increasingly accepted as one type of maintenance error intervention. Conscientious efforts have been made in re-inventing the team7 concept for maintenance operations and in tailoring programs to fit the needs of technical opeRAtions. Nevertheless, there remains a dual challenge: 1) to develop human factors interventions which are directly supported by reliable human error data, and 2) to integrate human factors concepts into the procedures and practices of everyday technical tasks. In this paper, we describe several varieties of human factors interventions and focus on two specific alternatives which target problems related to procedures and practices; namely, 1) structured on-the-job training and 2) procedure re-design. We hope to demonstrate that the key to leveraging the impact of these solutions comes from focused interventions; that is, interventions which are derived from a clear understanding of specific maintenance errors, their operational context and human factors components.

  13. Aging Aircraft Fleets: Structural and Other Subsystem Aspects (le Vieillissement des flottes d’avions militaires : aspects structures et autres sous-systemes)

    DTIC Science & Technology

    2001-03-01

    Science and Technology” – Vol. 7, Plenum Press (New York, 1980), 53-175. 7-1 Human Factors in Aircraft Inspection Colin G. Drury State University of...Page intentionnellement blanche 15-1 Human Factors in Aircraft Maintenance Colin G. Drury State University of New York at Buffalo Department of...c) changing mission requirements, (d) the specter of runaway maintenance costs , (e) concern about safety, (f) impairment of fleet readiness and (g

  14. A Generic Inner-Loop Control Law Structure for Six-Degree-of-Freedom Conceptual Aircraft Design

    NASA Technical Reports Server (NTRS)

    Cox, Timothy H.; Cotting, M. Christopher

    2005-01-01

    A generic control system framework for both real-time and batch six-degree-of-freedom simulations is presented. This framework uses a simplified dynamic inversion technique to allow for stabilization and control of any type of aircraft at the pilot interface level. The simulation, designed primarily for the real-time simulation environment, also can be run in a batch mode through a simple guidance interface. Direct vehicle-state acceleration feedback is required with the simplified dynamic inversion technique. The estimation of surface effectiveness within real-time simulation timing constraints also is required. The generic framework provides easily modifiable control variables, allowing flexibility in the variables that the pilot commands. A direct control allocation scheme is used to command aircraft effectors. Primary uses for this system include conceptual and preliminary design of aircraft, when vehicle models are rapidly changing and knowledge of vehicle six-degree-of-freedom performance is required. A simulated airbreathing hypersonic vehicle and simulated high-performance fighter aircraft are used to demonstrate the flexibility and utility of the control system.

  15. A Generic Inner-Loop Control Law Structure for Six-Degree-of-Freedom Conceptual Aircraft Design

    NASA Technical Reports Server (NTRS)

    Cox, Timothy H.; Cotting, Christopher

    2005-01-01

    A generic control system framework for both real-time and batch six-degree-of-freedom (6-DOF) simulations is presented. This framework uses a simplified dynamic inversion technique to allow for stabilization and control of any type of aircraft at the pilot interface level. The simulation, designed primarily for the real-time simulation environment, also can be run in a batch mode through a simple guidance interface. Direct vehicle-state acceleration feedback is required with the simplified dynamic inversion technique. The estimation of surface effectiveness within real-time simulation timing constraints also is required. The generic framework provides easily modifiable control variables, allowing flexibility in the variables that the pilot commands. A direct control allocation scheme is used to command aircraft effectors. Primary uses for this system include conceptual and preliminary design of aircraft, when vehicle models are rapidly changing and knowledge of vehicle 6-DOF performance is required. A simulated airbreathing hypersonic vehicle and simulated high-performance fighter aircraft are used to demonstrate the flexibility and utility of the control system.

  16. Eclipse program C-141A aircraft

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This photograph shows the Air Force C-141A that was used in the Eclipse project as a tow vehicle. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wind loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  17. 14 CFR Appendix A to Part 91 - Category II Operations: Manual, Instruments, Equipment, and Maintenance

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... authorization for the type aircraft checked. (3) A schedule that provides for the performance of bench checks..., Equipment, and Maintenance A Appendix A to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Maintenance 1. Category II Manual (a) Application for approval. An applicant for approval of a Category II...

  18. 14 CFR Appendix A to Part 91 - Category II Operations: Manual, Instruments, Equipment, and Maintenance

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... authorization for the type aircraft checked. (3) A schedule that provides for the performance of bench checks..., Equipment, and Maintenance A Appendix A to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Maintenance 1. Category II Manual (a) Application for approval. An applicant for approval of a Category II...

  19. 14 CFR Appendix A to Part 91 - Category II Operations: Manual, Instruments, Equipment, and Maintenance

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... authorization for the type aircraft checked. (3) A schedule that provides for the performance of bench checks..., Equipment, and Maintenance A Appendix A to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Maintenance 1. Category II Manual (a) Application for approval. An applicant for approval of a Category II...

  20. 14 CFR Appendix A to Part 91 - Category II Operations: Manual, Instruments, Equipment, and Maintenance

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... authorization for the type aircraft checked. (3) A schedule that provides for the performance of bench checks..., Equipment, and Maintenance A Appendix A to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Maintenance 1. Category II Manual (a) Application for approval. An applicant for approval of a Category II...

  1. 14 CFR Appendix A to Part 91 - Category II Operations: Manual, Instruments, Equipment, and Maintenance

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... authorization for the type aircraft checked. (3) A schedule that provides for the performance of bench checks..., Equipment, and Maintenance A Appendix A to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Maintenance 1. Category II Manual (a) Application for approval. An applicant for approval of a Category II...

  2. Multi-Objective Flight Control for Drag Minimization and Load Alleviation of High-Aspect Ratio Flexible Wing Aircraft

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan; Ting, Eric; Chaparro, Daniel; Drew, Michael; Swei, Sean

    2017-01-01

    As aircraft wings become much more flexible due to the use of light-weight composites material, adverse aerodynamics at off-design performance can result from changes in wing shapes due to aeroelastic deflections. Increased drag, hence increased fuel burn, is a potential consequence. Without means for aeroelastic compensation, the benefit of weight reduction from the use of light-weight material could be offset by less optimal aerodynamic performance at off-design flight conditions. Performance Adaptive Aeroelastic Wing (PAAW) technology can potentially address these technical challenges for future flexible wing transports. PAAW technology leverages multi-disciplinary solutions to maximize the aerodynamic performance payoff of future adaptive wing design, while addressing simultaneously operational constraints that can prevent the optimal aerodynamic performance from being realized. These operational constraints include reduced flutter margins, increased airframe responses to gust and maneuver loads, pilot handling qualities, and ride qualities. All of these constraints while seeking the optimal aerodynamic performance present themselves as a multi-objective flight control problem. The paper presents a multi-objective flight control approach based on a drag-cognizant optimal control method. A concept of virtual control, which was previously introduced, is implemented to address the pair-wise flap motion constraints imposed by the elastomer material. This method is shown to be able to satisfy the constraints. Real-time drag minimization control is considered to be an important consideration for PAAW technology. Drag minimization control has many technical challenges such as sensing and control. An initial outline of a real-time drag minimization control has already been developed and will be further investigated in the future. A simulation study of a multi-objective flight control for a flight path angle command with aeroelastic mode suppression and drag

  3. Using virtual reality technology for aircraft visual inspection training: presence and comparison studies.

    PubMed

    Vora, Jeenal; Nair, Santosh; Gramopadhye, Anand K; Duchowski, Andrew T; Melloy, Brian J; Kanki, Barbara

    2002-11-01

    The aircraft maintenance industry is a complex system consisting of several interrelated human and machine components. Recognizing this, the Federal Aviation Administration (FAA) has pursued human factors related research. In the maintenance arena the research has focused on the aircraft inspection process and the aircraft inspector. Training has been identified as the primary intervention strategy to improve the quality and reliability of aircraft inspection. If training is to be successful, it is critical that we provide aircraft inspectors with appropriate training tools and environment. In response to this need, the paper outlines the development of a virtual reality (VR) system for aircraft inspection training. VR has generated much excitement but little formal proof that it is useful. However, since VR interfaces are difficult and expensive to build, the computer graphics community needs to be able to predict which applications will benefit from VR. To address this important issue, this research measured the degree of immersion and presence felt by subjects in a virtual environment simulator. Specifically, it conducted two controlled studies using the VR system developed for visual inspection task of an aft-cargo bay at the VR Lab of Clemson University. Beyond assembling the visual inspection virtual environment, a significant goal of this project was to explore subjective presence as it affects task performance. The results of this study indicated that the system scored high on the issues related to the degree of presence felt by the subjects. As a next logical step, this study, then, compared VR to an existing PC-based aircraft inspection simulator. The results showed that the VR system was better and preferred over the PC-based training tool.

  4. Rolling dry-coupled transducers for ultrasonic inspections of aging aircraft structures

    NASA Astrophysics Data System (ADS)

    Komsky, Igor N.

    2004-07-01

    Some advanced aircraft materials or coatings are porous or otherwise sensitive to the application of water, gel, or some other ultrasonic couplants. To overcome the problems associated with the liquid coupling medium, dry-coupled rolling modules were developed at Northwestern University for the transmission of both longitudinal and transverse ultrasonic waves at frequencies up to 10 MHz. Dry-coupled ultrasonic modules contain solid core internal stators and solid or flexible external rotors with the flexible polymer substrates. Two types of the dry-coupled modules are under development. Cylindrical base transducer modules include solid core cylindrical rotors with flexible polymer substrates that rotate around the stators with ultrasonic elements. Dry-coupled modules with elongated bases contain solid core stators and flexible track-like polymer substrates that rotate around the stators as rotors of the modules. The elongated base modules have larger contact interfaces with the inspection surface in comparison with the cylindrical base modules. Some designs of the dry-coupled rolling modules contain several ultrasonic elements with different incident angles or a variable angle unit for rapid adjustments of incident angles. The prototype dry-coupled rolling modules were integrated with the portable ultrasonic inspection systems and tested on a number of Boeing aircraft structures.

  5. Common software and interface for different helmet-mounted display (HMD) aircraft symbology sets

    NASA Astrophysics Data System (ADS)

    Mulholland, Fred F.

    2000-06-01

    Different aircraft in different services and countries have their own set of symbology they want displayed on their HMD. Even as flight symbolgy is standardized, there will still be some differences for types of aircraft, different weapons, different sensors, and different countries. As an HMD supplier, we want to provide a system that can be used across all these applications with no changes in the system, including no changes in the software. This HMD system must also provide the flexibility to accommodate new symbology as it is developed over the years, again, with no change in the HMD software. VSI has developed their HMD software to accommodate F-15, F- 16, F-18, and F-22 symbology sets for the Joint Helmet Mounted Cueing System. It also has the flexibility to accommodate the aircraft types and services of the Joint Strike Fighter: Conventional Takeoff and Landing variant for the USAF, Carrier-based Variant for the USN, and the Short Takeoff and Vertical Landing variant for the USMC and U.K. Royal Navy and Air Force. The key to this flexibility is the interface definition. The interface parameters are established at power-on with the download of an interface definition data set. This data set is used to interpret symbology commands from the aircraft OFP during operation and provide graphic commands to the HMD software. This presentation will define the graphics commands, provide an example of how the interface definition data set is defined, and then show how symbology commands produce a display.

  6. Interface concerns of ejector integration in V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Lowry, R. B.

    1979-01-01

    A number of areas which have in the past contributed to weight, complexity, and thrust losses in the ejector-powered V/STOL vehicle were identified. Most of these interfaces taken singly do not represent a severe compromise to the vehicle; however, the bottom line is that the sum of compromises and the subsequent effects on performance, flight operations and maintenance have rendered the ejector V/STOL aircraft unattractive. In addition to some of the unique ejector/aircraft integration problems, the vehicle by virtue of having a V/STOL capability, is compromised in other areas. To be successful and acceptable, the advantages must outweight the disadvantages and simplicity with minimum penalties must be the rule. It is concluded that more emphasis must be placed on the ejector/aircraft interface for the concept to be successful.

  7. Applying Lean to the F-15 Maintenance Process for the Royal Saudi Air Force

    DTIC Science & Technology

    2014-03-01

    Royal Saudi Air Force. The research focuses on improving the F-15 maintenance process in the Royal Saudi Air Force’s Maintenance Squadrons. The F-15...and on the aircraft age condition, the researcher concludes it is time to get rid of some obstacles and use new management techniques to resolve the...processes? Research Focus This research is focusing on the Royal Saudi Air Force F-15 maintenance process. Because of the time and

  8. Application of decomposition techniques to the preliminary design of a transport aircraft

    NASA Technical Reports Server (NTRS)

    Rogan, J. E.; Mcelveen, R. P.; Kolb, M. A.

    1986-01-01

    A multifaceted decomposition of a nonlinear constrained optimization problem describing the preliminary design process for a transport aircraft has been made. Flight dynamics, flexible aircraft loads and deformations, and preliminary structural design subproblems appear prominently in the decomposition. The use of design process decomposition for scheduling design projects, a new system integration approach to configuration control, and the application of object-centered programming to a new generation of design tools are discussed.

  9. Impact of future fuel properties on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Grobman, J. S.

    1978-01-01

    From current projections of the availability of high-quality petroleum crude oils, it is becoming increasingly apparent that the specifications for hydrocarbon jet fuels may have to be modified. The problems that are most likely to be encountered as a result of these modifications relate to engine performance, component durability and maintenance, and aircraft fuel-system performance. The effect on engine performance will be associated with changes in specific fuel consumption, ignition at relight limits, at exhaust emissions. Durability and maintenance will be affected by increases in combustor liner temperatures, carbon deposition, gum formation in fuel nozzles, and erosion and corrosion of turbine blades and vanes. Aircraft fuel-system performance will be affected by increased deposits in fuel-system heat exchangers and changes in the pumpability and flowability of the fuel. The severity of the potential problems is described in terms of the fuel characteristics most likely to change in the future. Recent data that evaluate the ability of current-technology aircraft to accept fuel specification changes are presented, and selected technological advances that can reduce the severity of the problems are described and discussed.

  10. Performance and safety aspects of the XV-15 tilt rotor research aircraft

    NASA Technical Reports Server (NTRS)

    Wernicke, K. G.

    1977-01-01

    Aircraft performance is presented illustrating the flexibility and capability of the XV-15 to conduct its planned proof-of-concept flight research in the areas of dynamics, stability and control, and aerodynamics. Additionally, the aircraft will demonstrate mission-type performance typical of future operational aircraft. The aircraft design is described and discussed with emphasis on the safety and fail-operate features of the aircraft and its systems. Two or more levels of redundancy are provided in the dc and ac electrical systems, hydraulics, conversion, flaps, landing gear extension, SCAS, and force-feel. RPM is maintained by a hydro-electrical blade pitch governor that consists of a primary and standby governor with a cockpit wheel control for manual backup. The two engines are interconnected for operation on a single engine. In the event of total loss of power, the aircraft can enter autorotation starting from the airplane as well as the helicopter mode of flight.

  11. Feasibility study of a 270V dc flat cable aircraft electrical power distributed system

    NASA Astrophysics Data System (ADS)

    Musga, M. J.; Rinehart, R. J.

    1982-01-01

    This report documents the efforts of a one man-year feasibility study to evaluate the usage of flat conductors in place of conventional round wires for a 270 volt direct current aircraft power distribution system. This study consisted of designing electrically equivalent power distribution harnesses in flat conductor configurations for a currently operational military aircraft. Harness designs were established for installation in aircraft airframes which are: (1) All metal, or (2) All composite, or (3) a mixture of both. Flat cables have greater surface areas for heat transfer allowing higher current densities and therefore lighter weight conductors, than with round wires. Flat cables are less susceptible to electromagnetic effects. However, these positive factors are partially offset by installation and maintenance difficulties. This study concludes that the extent of these difficulties can be adequately limited with appropriate modification to present installation and maintenance practices. A comparative analysis of the flat and the round conductor power distribution harnesses was made for weight, cost, maintenance and reliability. The knowledge gained from the design and comparative analysis phases was used to generate design criteria for flat power cable harnesses and to identify and prioritize flat cable harness components and associated production tooling which require development.

  12. Flight demonstration of a self repairing flight control system in a NASA F-15 fighter aircraft

    NASA Technical Reports Server (NTRS)

    Urnes, James M.; Stewart, James; Eslinger, Robert

    1990-01-01

    Battle damage causing loss of control capability can compromise mission objectives and even result in aircraft loss. The Self Repairing Flight Control System (SRFCS) flight development program directly addresses this issue with a flight control system design that measures the damage and immediately refines the control system commands to preserve mission potential. The system diagnostics process detects in flight the type of faults that are difficult to isolate post flight, and thus cause excessive ground maintenance time and cost. The control systems of fighter aircraft have the control power and surface displacement to maneuver the aircraft in a very large flight envelope with a wide variation in airspeed and g maneuvering conditions, with surplus force capacity available from each control surface. Digital flight control processors are designed to include built-in status of the control system components, as well as sensor information on aircraft control maneuver commands and response. In the event of failure or loss of a control surface, the SRFCS utilizes this capability to reconfigure control commands to the remaining control surfaces, thus preserving maneuvering response. Correct post-flight repair is the key to low maintainability support costs and high aircraft mission readiness. The SRFCS utilizes the large data base available with digital flight control systems to diagnose faults. Built-in-test data and sensor data are used as inputs to an Onboard Expert System process to accurately identify failed components for post-flight maintenance action. This diagnostic technique has the advantage of functioning during flight, and so is especially useful in identifying intermittent faults that are present only during maneuver g loads or high hydraulic flow requirements. A flight system was developed to test the reconfiguration and onboard maintenance diagnostics concepts on a NASA F-15 fighter aircraft.

  13. Thin, Light, Flexible Heaters Save Time and Energy

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Icing Branch at NASA's Glenn Research Center uses the Center's Icing Research Tunnel (IRT) and Icing Research Aircraft to research methods for evaluating and simulating the growth of ice on aircraft, the effects that ice may have on aircraft in flight, and the development and effectiveness of various ice protection and detection systems. EGC Enterprises Inc. (EGC), of Chardon, Ohio, used the IRT to develop thermoelectric thin-film heater technology to address in-flight icing on aircraft wings. Working with researchers at Glenn and the original equipment manufacturers of aircraft parts, the company tested various thin, flexible, durable, lightweight, and efficient heaters. Development yielded a thin-film heater technology that can be used in many applications in addition to being an effective deicer for aircraft. This new thermoelectric heater was dubbed the QoFoil Rapid Response Thin-Film Heater, or QoFoil, for short. The product meets all criteria for in-flight use and promises great advances in thin-film, rapid response heater technology for a broad range of industrial applications. Primary advantages include time savings, increased efficiency, and improved temperature uniformity. In addition to wing deicing, EGC has begun looking at the material's usefulness for applications including cooking griddles, small cabinet heaters, and several laboratory uses.

  14. Carrier Based Air Logistics Study: Maintenance Analysis.

    DTIC Science & Technology

    1982-01-01

    MONITORING AGENCY NAME & ADDRESS(If dIierent loan Controling 01116.) 1S. SECURITY CLASS. (of Od. report) gel Unclassified IS&. DECL ASSI IlCATION/ OOWNGRAOIN...Management System AECL Avionics Equipment Configuration List AIMD Aircraft Intermediate Maintenance Department ASO Aviation Supply Office ASW...implementation. Component-specific data, and indentured[2] relationships between components extracted from the Aviation Supply Office ( ASO ) weapon

  15. Air quality and ocular discomfort aboard commercial aircraft.

    PubMed

    Backman, H; Haghighat, F

    2000-10-01

    Aircraft cabin air quality has been a subject of recent public health interest. Aircraft environments are designed according to standards to ensure the comfort and well-being of the occupants. The upper and lower limits of humidity set by ASHRAE standards are based on the maintenance of acceptable thermal conditions established solely on comfort considerations, including thermal sensation, skin wetness, skin dryness, dry eyes and ocular discomfort. The purpose of this study is to investigate the influence of air (carbon dioxide level, relative humidity, and temperature) aboard commercial aircraft on ocular discomfort and dry eye of aircraft personnel and passengers. Measurements of indoor air quality were performed in 15 different aircraft at different times and altitudes. Forty-two measurements of carbon dioxide, temperature, and humidity were performed with portable air samplers every 5 minutes. Passenger loads did not exceed 137 passengers. Thermal comfort rarely met ASHRAE standards. Low humidity levels and high carbon dioxide levels were found on the Airbus 320. The DC-9 had the highest humidity level and the Boeing-767 had the lowest carbon dioxide level. Air quality was poorest on the Airbus 320 aircraft. This poor level of air quality may cause intolerance to contact lenses, dry eyes, and may be a health hazard to both passengers and crew members. Improved ventilation and aircraft cabin micro-environments need to be made for the health and comfort of the occupants.

  16. Comparison of Requirements for Composite Structures for Aircraft and Space Applications

    NASA Technical Reports Server (NTRS)

    Raju, Ivatury S.; Elliot, Kenny B.; Hampton, Roy W.; Knight, Norman F., Jr.; Aggarwal, Pravin; Engelstad, Stephen P.; Chang, James B.

    2010-01-01

    In this report, the aircraft and space vehicle requirements for composite structures are compared. It is a valuable exercise to study composite structural design approaches used in the airframe industry and to adopt methodology that is applicable for space vehicles. The missions, environments, analysis methods, analysis validation approaches, testing programs, build quantities, inspection, and maintenance procedures used by the airframe industry, in general, are not transferable to spaceflight hardware. Therefore, while the application of composite design approaches from aircraft and other industries is appealing, many aspects cannot be directly utilized. Nevertheless, experiences and research for composite aircraft structures may be of use in unexpected arenas as space exploration technology develops, and so continued technology exchanges are encouraged.

  17. Eclipse program C-141A aircraft

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This photograph shows the Air Force C-141A that was used in the Eclipse project as a tow vehicle. The project used a QF-106 interceptor aircraft to simulate a future orbiter, which would be towed to a high altitude and released to fire its own engines and carry a payload into space. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  18. Adaptive Failure Compensation for Aircraft Flight Control Using Engine Differentials: Regulation

    NASA Technical Reports Server (NTRS)

    Yu, Liu; Xidong, Tang; Gang, Tao; Joshi, Suresh M.

    2005-01-01

    The problem of using engine thrust differentials to compensate for rudder and aileron failures in aircraft flight control is addressed in this paper in a new framework. A nonlinear aircraft model that incorporates engine di erentials in the dynamic equations is employed and linearized to describe the aircraft s longitudinal and lateral motion. In this model two engine thrusts of an aircraft can be adjusted independently so as to provide the control flexibility for rudder or aileron failure compensation. A direct adaptive compensation scheme for asymptotic regulation is developed to handle uncertain actuator failures in the linearized system. A design condition is specified to characterize the system redundancy needed for failure compensation. The adaptive regulation control scheme is applied to the linearized model of a large transport aircraft in which the longitudinal and lateral motions are coupled as the result of using engine thrust differentials. Simulation results are presented to demonstrate the effectiveness of the adaptive compensation scheme.

  19. Application of decomposition techniques to the preliminary design of a transport aircraft

    NASA Technical Reports Server (NTRS)

    Rogan, J. E.; Kolb, M. A.

    1987-01-01

    A nonlinear constrained optimization problem describing the preliminary design process for a transport aircraft has been formulated. A multifaceted decomposition of the optimization problem has been made. Flight dynamics, flexible aircraft loads and deformations, and preliminary structural design subproblems appear prominently in the decomposition. The use of design process decomposition for scheduling design projects, a new system integration approach to configuration control, and the application of object-centered programming to a new generation of design tools are discussed.

  20. Flexible aerogel composite for mechanical stability and process of fabrication

    DOEpatents

    Coronado, Paul R.; Poco, John F.

    2000-01-01

    A flexible aerogel and process of fabrication. An aerogel solution is mixed with fibers in a mold and allowed to gel. The gel is then processed by supercritical extraction, or by air drying, to produce a flexible aerogel formed to the shape of the mold. The flexible aerogel has excellent thermal and acoustic properties, and can be utilized in numerous applications, such as for energy absorption, insulation (temperature and acoustic), to meet the contours of aircraft shapes, and where space is limited since an inch of aerogel is a 4-5 times better insulator than an inch of fiberglass. The flexible aerogel may be of an inorganic (silica) type or an organic (carbon) type, but containing fibers, such as glass or carbon fibers.

  1. Flexible aerogel composite for mechanical stability and process of fabrication

    DOEpatents

    Coronado, Paul R.; Poco, John F.

    1999-01-01

    A flexible aerogel and process of fabrication. An aerogel solution is mixed with fibers in a mold and allowed to gel. The gel is then processed by supercritical extraction, or by air drying, to produce a flexible aerogel formed to the shape of the mold. The flexible aerogel has excellent thermal and acoustic properties, and can be utilized in numerous applications, such as for energy absorption, insulation (temperature and acoustic), to meet the contours of aircraft shapes, and where space is limited since an inch of aerogel is a 4-5 times better insulator than an inch of fiberglass. The flexible aerogel may be of an inorganic (silica) type or an organic (carbon) type, but containing fibers, such as glass or carbon fibers.

  2. Aeroelastic Modeling of Elastically Shaped Aircraft Concept via Wing Shaping Control for Drag Reduction

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan; James Urnes, Sr.

    2012-01-01

    Lightweight aircraft design has received a considerable attention in recent years as a means for improving cruise efficiency. Reducing aircraft weight results in lower lift requirements which directly translate into lower drag, hence reduced engine thrust requirements during cruise. The use of lightweight materials such as advanced composite materials has been adopted by airframe manufacturers in current and future aircraft. Modern lightweight materials can provide less structural rigidity while maintaining load-carrying capacity. As structural flexibility increases, aeroelastic interactions with aerodynamic forces and moments become an increasingly important consideration in aircraft design and aerodynamic performance. Furthermore, aeroelastic interactions with flight dynamics can result in issues with vehicle stability and control. Abstract This paper describes a recent aeroelastic modeling effort for an elastically shaped aircraft concept (ESAC). The aircraft model is based on the rigid-body generic transport model (GTM) originally developed at NASA Langley Research Center. The ESAC distinguishes itself from the GTM in that it is equipped with highly flexible wing structures as a weight reduction design feature. More significantly, the wings are outfitted with a novel control effector concept called variable camber continuous trailing edge (VCCTE) flap system for active control of wing aeroelastic deflections to optimize the local angle of attack of wing sections for improved aerodynamic efficiency through cruise drag reduction and lift enhancement during take-off and landing. The VCCTE flap is a multi-functional and aerodynamically efficient device capable of achieving high lift-to-drag ratios. The flap system is comprised of three chordwise segments that form the variable camber feature of the flap and multiple spanwise segments that form a piecewise continuous trailing edge. By configuring the flap camber and trailing edge shape, drag reduction could be

  3. The Effect of Functional Flow Diagrams on the Technical System Understanding of Apprentice Aircraft Maintenance Mechanics.

    ERIC Educational Resources Information Center

    Johnson, Scott D.; Satchwell, Richard E.

    A quasiexperimental study involved 18 male students enrolled in an aircraft systems course at the University of Illinois. The control group of 10 students studied 39 schematic diagrams of aircraft systems. The treatment group of eight students studied the same schematic diagrams plus conceptual diagrams of the systems. Otherwise, the instruction…

  4. Study of advanced rotary combustion engines for commuter aircraft

    NASA Technical Reports Server (NTRS)

    Berkowitz, M.; Jones, C.; Myers, D.

    1983-01-01

    Performance, weight, size, and maintenance data for advanced rotary aircraft engines suitable for comparative commuter aircraft system evaluation studies of alternate engine candidates are provided. These are turbocharged, turbocompounded, direct injected, stratified charge rotary engines. Hypothetical engines were defined (an RC4-74 at 895 kW and an RC6-87 at 1490 kW) based on the technologies and design approaches used in the highly advanced engine of a study of advanced general aviation rotary engines. The data covers the size range of shaft power from 597 kW (800 hp) to 1865 kW (2500 hp) and is in the form of drawings, tables, curves and written text. These include data on internal geometry and configuration, installation information, turbocharging and turbocompounding arrangements, design features and technologies, engine cooling, fuels, scaling for weight size BSFC and heat rejection for varying horsepower, engine operating and performance data, and TBO and maintenance requirements. The basic combustion system was developed and demonstrated; however the projected power densities and performance efficiencies require increases in engine internal pressures, thermal loading, and rotative speed.

  5. System level airworthiness tool: A comprehensive approach to small unmanned aircraft system airworthiness

    NASA Astrophysics Data System (ADS)

    Burke, David A.

    One of the pillars of aviation safety is assuring sound engineering practices through airworthiness certification. As Unmanned Aircraft Systems (UAS) grow in popularity, the need for airworthiness standards and verification methods tailored for UAS becomes critical. While airworthiness practices for large UAS may be similar to manned aircraft, it is clear that small UAS require a paradigm shift from the airworthiness practices of manned aircraft. Although small in comparison to manned aircraft these aircraft are not merely remote controlled toys. Small UAS may be complex aircraft flying in the National Airspace System (NAS) over populated areas for extended durations and beyond line of sight of the operators. A comprehensive systems engineering framework for certifying small UAS at the system level is needed. This work presents a point based tool that evaluates small UAS by rewarding good engineering practices in design, analysis, and testing. The airworthiness requirements scale with vehicle size and operational area, while allowing flexibility for new technologies and unique configurations.

  6. Real-time strategy game training: emergence of a cognitive flexibility trait.

    PubMed

    Glass, Brian D; Maddox, W Todd; Love, Bradley C

    2013-01-01

    Training in action video games can increase the speed of perceptual processing. However, it is unknown whether video-game training can lead to broad-based changes in higher-level competencies such as cognitive flexibility, a core and neurally distributed component of cognition. To determine whether video gaming can enhance cognitive flexibility and, if so, why these changes occur, the current study compares two versions of a real-time strategy (RTS) game. Using a meta-analytic Bayes factor approach, we found that the gaming condition that emphasized maintenance and rapid switching between multiple information and action sources led to a large increase in cognitive flexibility as measured by a wide array of non-video gaming tasks. Theoretically, the results suggest that the distributed brain networks supporting cognitive flexibility can be tuned by engrossing video game experience that stresses maintenance and rapid manipulation of multiple information sources. Practically, these results suggest avenues for increasing cognitive function.

  7. Real-Time Strategy Game Training: Emergence of a Cognitive Flexibility Trait

    PubMed Central

    Glass, Brian D.; Maddox, W. Todd; Love, Bradley C.

    2013-01-01

    Training in action video games can increase the speed of perceptual processing. However, it is unknown whether video-game training can lead to broad-based changes in higher-level competencies such as cognitive flexibility, a core and neurally distributed component of cognition. To determine whether video gaming can enhance cognitive flexibility and, if so, why these changes occur, the current study compares two versions of a real-time strategy (RTS) game. Using a meta-analytic Bayes factor approach, we found that the gaming condition that emphasized maintenance and rapid switching between multiple information and action sources led to a large increase in cognitive flexibility as measured by a wide array of non-video gaming tasks. Theoretically, the results suggest that the distributed brain networks supporting cognitive flexibility can be tuned by engrossing video game experience that stresses maintenance and rapid manipulation of multiple information sources. Practically, these results suggest avenues for increasing cognitive function. PMID:23950921

  8. Eclipse program QF-106 aircraft in flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This photo shows one of the QF-106s used in the Eclipse project in flight. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  9. Simulations for the Test Flight of an Experimental HALE Aircraft

    DTIC Science & Technology

    2011-06-01

    as a plant representation for HALE aircraft control design. It focuses on a reduced number of states to represent the complex nonlinear problem...Atkins, Ella M., Shearer, Christopher M. and Nathan A. Pitcher . “X-HALE: A Very Flexible UAV for Nonlinear Aeroelastic Tests.” (AIAA 2010-2715), April

  10. RTJ-303: Variable geometry, oblique wing supersonic aircraft

    NASA Technical Reports Server (NTRS)

    Antaran, Albert; Belete, Hailu; Dryzmkowski, Mark; Higgins, James; Klenk, Alan; Rienecker, Lisa

    1992-01-01

    This document is a preliminary design of a High Speed Civil Transport (HSCT) named the RTJ-303. It is a 300 passenger, Mach 1.6 transport with a range of 5000 nautical miles. It features four mixed-flow turbofan engines, variable geometry oblique wing, with conventional tail-aft control surfaces. The preliminary cost analysis for a production of 300 aircraft shows that flyaway cost would be 183 million dollars (1992) per aircraft. The aircraft uses standard jet fuel and requires no special materials to handle aerodynamic heating in flight because the stagnation temperatures are approximately 130 degrees Fahrenheit in the supersonic cruise condition. It should be stressed that this aircraft could be built with today's technology and does not rely on vague and uncertain assumptions of technology advances. Included in this report are sections discussing the details of the preliminary design sequence including the mission to be performed, operational and performance constraints, the aircraft configuration and the tradeoffs of the final choice, wing design, a detailed fuselage design, empennage design, sizing of tail geometry, and selection of control surfaces, a discussion on propulsion system/inlet choice and their position on the aircraft, landing gear design including a look at tire selection, tip-over criterion, pavement loading, and retraction kinematics, structures design including load determination, and materials selection, aircraft performance, a look at stability and handling qualities, systems layout including location of key components, operations requirements maintenance characteristics, a preliminary cost analysis, and conclusions made regarding the design, and recommendations for further study.

  11. Test results of smart aircraft fastener for KC-135 structural integrity

    NASA Astrophysics Data System (ADS)

    Schoess, Jeffrey N.; Seifert, Greg

    1998-07-01

    Hidden and inaccessible corrosion in aircraft structures is the number one logistics problem for the US Air Force, with an estimated maintenance cost in excess of $LR 1.0B per year in 1990-equivalent dollars. The Smart Aircraft Fastener Evaluation (SAFE) system was developed to provide early warning detection of corrosion-related symptoms in hidden locations of aircraft structures. The SAFE system incorporates an in situ measurement approach that measures and autonomously records several environmental conditions within a Hi-Lok aircraft fastener that could cause corrosion. The SAFE system integrates a miniature electrochemical microsensor array and a time-of-wetness sensor with an ultra low power 8-bit microcontroller and 4- Mbyte solid-state FLASH archival memory to measure evidence of active corrosion. A summary of the technical approach and a detailed analysis of the KC-135 lap joint test coupon results are presented.

  12. NASA Electric Aircraft Test Bed (NEAT) Development Plan - Design, Fabrication, Installation

    NASA Technical Reports Server (NTRS)

    Dyson, Rodger W.

    2016-01-01

    As large airline companies compete to reduce emissions, fuel, noise, and maintenance costs, it is expected that more of their aircraft systems will shift from using turbofan propulsion, pneumatic bleed power, and hydraulic actuation, to instead using electrical motor propulsion, generator power, and electrical actuation. This requires new flight-weight and flight-efficient powertrain components, fault tolerant power management, and electromagnetic interference mitigation technologies. Moreover, initial studies indicate some combination of ambient and cryogenic thermal management and relatively high bus voltages when compared to state of practice will be required to achieve a net system benefit. Developing all these powertrain technologies within a realistic aircraft architectural geometry and under realistic operational conditions requires a unique electric aircraft testbed. This report will summarize existing testbed capabilities located in the U.S. and details the development of a unique complementary testbed that industry and government can utilize to further mature electric aircraft technologies.

  13. Flexible HVAC System for Lab or Classroom.

    ERIC Educational Resources Information Center

    Friedan, Jonathan

    2001-01-01

    Discusses an effort to design a heating, ventilation, and air conditioning system flexible enough to accommodate an easy conversion of classrooms to laboratories and dry labs to wet labs. The design's energy efficiency and operations and maintenance are examined. (GR)

  14. Engine-induced structural-borne noise in a general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Unruh, J. F.; Scheidt, D. C.; Pomerening, D. J.

    1979-01-01

    Structural borne interior noise in a single engine general aviation aircraft was studied to determine the importance of engine induced structural borne noise and to determine the necessary modeling requirements for the prediction of structural borne interior noise. Engine attached/detached ground test data show that engine induced structural borne noise is a primary interior noise source for the single engine test aircraft, cabin noise is highly influenced by responses at the propeller tone, and cabin acoustic resonances can influence overall noise levels. Results from structural and acoustic finite element coupled models of the test aircraft show that wall flexibility has a strong influence on fundamental cabin acoustic resonances, the lightweight fuselage structure has a high modal density, and finite element analysis procedures are appropriate for the prediction of structural borne noise.

  15. Analysis of EA-18G Growler Engine Maintenance at Naval Air Station Whidbey Island, WA

    DTIC Science & Technology

    2013-06-01

    maintenance. A. NAVAL AVIATION MAINTENANCE PROGRAM The aviation maintenance community considers the NAMP its bible . “The NAMP applies to all...will increase to 114, which is the total number of aircraft at the completion of the acquisition process in year 2018 (increasing by 12 per year...until 2018 where eight will complete the acquisition)  The cost of the F414-GE-400 engine is about 3.7 million dollars. B. CALCULATING THE ENGINE Aₒ

  16. Modular C3 Interface Analysis (Flexible Intraconnect). Volume 1, Part 1

    DTIC Science & Technology

    1980-04-01

    was prepared in parallel with a separate Flexible^ Intraconnect design definition study conducted by Hughes Aircraft Company under F19628-77-O-0261...reported herein consists of Task I, Task II, and Task III of Phase I of an on-going study being conducted by the Air Force to develop a Flexible...Intraconnect for tactical C^ tivity. equipment connec- As evidenced by the quantity of analyses performed and docu- mented during the period of this study

  17. Study of aircraft in intraurban transportation systems, San Francisco Bay area

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The nine-county San Francisco Bay area is examined in two time periods (1975-1980 and 1985-1990) as a scenario for analyzing the characteristics of an intraurban, commuter-oriented aircraft transportation system. Aircraft have dominated the long-haul passenger market for some time, but efforts to penetrate the very-short-haul intraurban market have met with only token success. Yet, the characteristics of an aircraft transportation system, speed and flexibility, are very much needed to solve the transportation ills of our major urban areas. The aircraft intraurban system is a technically feasible alternative to ground transportation systems. Although requiring some subsidy, it becomes socially viable where substantial commuter traffic exists at ranges of 10 to 15 mi or more and where topographic features constrain ground travel. The general problem areas of community noise, air traffic congestion, ground transportation interface, pollution, and safety appear to have workable solutions.

  18. Analytical Fuselage and Wing Weight Estimation of Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Chambers, Mark C.; Ardema, Mark D.; Patron, Anthony P.; Hahn, Andrew S.; Miura, Hirokazu; Moore, Mark D.

    1996-01-01

    A method of estimating the load-bearing fuselage weight and wing weight of transport aircraft based on fundamental structural principles has been developed. This method of weight estimation represents a compromise between the rapid assessment of component weight using empirical methods based on actual weights of existing aircraft, and detailed, but time-consuming, analysis using the finite element method. The method was applied to eight existing subsonic transports for validation and correlation. Integration of the resulting computer program, PDCYL, has been made into the weights-calculating module of the AirCraft SYNThesis (ACSYNT) computer program. ACSYNT has traditionally used only empirical weight estimation methods; PDCYL adds to ACSYNT a rapid, accurate means of assessing the fuselage and wing weights of unconventional aircraft. PDCYL also allows flexibility in the choice of structural concept, as well as a direct means of determining the impact of advanced materials on structural weight. Using statistical analysis techniques, relations between the load-bearing fuselage and wing weights calculated by PDCYL and corresponding actual weights were determined.

  19. High-order computational fluid dynamics tools for aircraft design

    PubMed Central

    Wang, Z. J.

    2014-01-01

    Most forecasts predict an annual airline traffic growth rate between 4.5 and 5% in the foreseeable future. To sustain that growth, the environmental impact of aircraft cannot be ignored. Future aircraft must have much better fuel economy, dramatically less greenhouse gas emissions and noise, in addition to better performance. Many technical breakthroughs must take place to achieve the aggressive environmental goals set up by governments in North America and Europe. One of these breakthroughs will be physics-based, highly accurate and efficient computational fluid dynamics and aeroacoustics tools capable of predicting complex flows over the entire flight envelope and through an aircraft engine, and computing aircraft noise. Some of these flows are dominated by unsteady vortices of disparate scales, often highly turbulent, and they call for higher-order methods. As these tools will be integral components of a multi-disciplinary optimization environment, they must be efficient to impact design. Ultimately, the accuracy, efficiency, robustness, scalability and geometric flexibility will determine which methods will be adopted in the design process. This article explores these aspects and identifies pacing items. PMID:25024419

  20. Verification of the CFD simulation system SAUNA for complex aircraft configurations

    NASA Astrophysics Data System (ADS)

    Shaw, Jonathon A.; Peace, Andrew J.; May, Nicholas E.; Pocock, Mark F.

    1994-04-01

    This paper is concerned with the verification for complex aircraft configurations of an advanced CFD simulation system known by the acronym SAUNA. A brief description of the complete system is given, including its unique use of differing grid generation strategies (structured, unstructured or both) depending on the geometric complexity of the addressed configuration. The majority of the paper focuses on the application of SAUNA to a variety of configurations from the military aircraft, civil aircraft and missile areas. Mesh generation issues are discussed for each geometry and experimental data are used to assess the accuracy of the inviscid (Euler) model used. It is shown that flexibility and accuracy are combined in an efficient manner, thus demonstrating the value of SAUNA in aerodynamic design.

  1. Impairment of color vision in aircraft maintenance workers.

    PubMed

    Guest, Maya; D'Este, Catherine; Attia, John; Boggess, May; Brown, Anthony; Tavener, Meredith; Gibson, Richard; Gardner, Ian; Harrex, Warren; Ross, James

    2011-10-01

    The purpose of the study was to examine possible persisting effects to color vision in a group from the Royal Australian Air Force who had exposure to formulations containing neurotoxins during F-111 fuel tank maintenance, relative to two contemporaneous comparison groups. Color vision was tested in 512 exposed personnel, 458 technical-trade comparisons, and 330 non-technical comparisons using the Ishihara test plates and the Lanthony D-15 Desaturated Color disk arrangement test. Participants were excluded if they failed the Ishihara test as this indicates congenital color blindness. From the Lanthony results, the type of color deficient vision (CDV) was diagnosed, and additionally, the Bowman's color confusion index (CCI) was calculated. Regression models were used to examine whether there was an association between color vision deficiencies and F-111 fuel tank maintenance, adjusting for possible confounders. The CCI ranged from 1 to 2.8 (median 1.2, quartiles 1.1, 1.4) in the 2,600 eyes tested. Forty five percent of all participants had blue-yellow CDV in at least one eye. Deficiencies of this nature are caused by environmental exposures. Logistic regression demonstrated statistically significant differences in CCI category in the exposed group versus technical group (odds ratio 1.7: 95% CI 1.3-2.0) and a blue-yellow confusion in the exposed group versus technical group (odds ratio 1.4: 95% CI 1.1-1.7). No differences were observed between the exposed group and the non-technical group. The results indicate reduced color discrimination among the exposed subjects compared to one of two control groups. The findings may be due to previous exposure to solvents among the air force personnel.

  2. Follow on Researches for X-56A Aircraft at NASA Dryden Flight Research Center (Progress Report)

    NASA Technical Reports Server (NTRS)

    Pak, Chan-Gi

    2012-01-01

    A lot of composite materials are used for the modern aircraft to reduce its weight. Aircraft aeroservoelastic models are typically characterized by significant levels of model parameter uncertainty due to composite manufacturing process. Small modeling errors in the finite element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of X-56A aircraft is the flight demonstration of active flutter suppression, and therefore in this study, the identification of the primary and secondary modes is based on the flutter analysis of X-56A aircraft. It should be noted that for all three Mach number cases rigid body modes and mode numbers seven and nine are participated 89.1 92.4 % of the first flutter mode. Modal participation of the rigid body mode and mode numbers seven and nine for the second flutter mode are 94.6 96.4%. Rigid body mode and the first two anti-symmetric modes, eighth and tenth modes, are participated 93.2 94.6% of the third flutter mode. Therefore, rigid body modes and the first four flexible modes of X-56A aircraft are the primary modes during the model tuning procedure. The ground vibration test-validated structural dynamic finite element model of the X-56A aircraft is to obtain in this study. The structural dynamics finite element model of X-56A aircraft is improved using the parallelized big-bang big-crunch algorithm together with a hybrid optimization technique.

  3. Performance of preventive maintenance treatments for flexible pavements in Texas.

    DOT National Transportation Integrated Search

    2017-03-01

    This report documents the work performed in the first year of the Texas Department of TxDOT Project 0-6878. : The main objective of this project is to quantify the effectiveness of various popular preventive maintenance : (PM) treatments under varyin...

  4. Artificial intelligence and its impact on combat aircraft

    NASA Technical Reports Server (NTRS)

    Ott, Lawrence M.; Abbot, Kathy; Kleider, Alfred; Moon, D.; Retelle, John

    1987-01-01

    As the threat becomes more sophisticated and weapon systems more complex to meet the threat, the need for machines to assist the pilot in the assessment of information becomes paramount. This is particularly true in real-time, high stress situations. The advent of artificial intelligence (AI) technology offers the opportunity to make quantum advances in the application of machine technology. However, if AI systems are to find their way into combat aircraft, they must meet certain criteria. The systems must be responsive, reliable, easy to use, flexible, and understandable. These criteria are compared with the current status used in a combat airborne application. Current AI systems deal with nonreal time applications and require significant user interaction. On the other hand, aircraft applications require real time, minimum human interaction systems. In order to fill the gap between where technology is now and where it must be for aircraft applications, considerable government research is ongoing in NASA, DARPA, and three services. The ongoing research is briefly summarized. Finally, recognizing that AI technology is in its embryonic stage, and the aircraft needs are very demanding, a number of issues arise. These issues are delineated and findings are provided where appropriate.

  5. The air transportation industry birthplace of reliability-centered maintenance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Matteson, T.D.

    1996-08-01

    The 1980s and 1970s provided a timely opportunity for examining and radically changing the process called {open_quotes}preventive maintenance{close_quotes} as it is applied to the aircraft used for scheduled air transportation. The Federal Aviation Administration and four major airlines, United, American, Pan American and Trans World, were the {open_quotes}principals{close_quotes} in that process. While United`s work with the FAA on the Boeing 737 had opened the door a crack, the Boeing 747 presented a major opportunity to radically improve the process for maintenance program design. That program was guided by the results of United`s analyses of failure data from operations of severalmore » fleets, each larger than 100 aircraft, and the concurrent experience of American, Pan American and Trans World. That knowledge provided the insights necessary to support an entirely different approach to maintenance program design. As a result, while United`s existing maintenance program required scheduled overhaul of 339 items on each DC-8, it required overhaul of only 8 items on the B-7471 Although the initial thrust of that work focused on components of active systems, there was concurrent work focused on items whose principal function was to carry the loads associated with operations. That program focused on the classification of structurally-significant items and their classification as {open_quotes}safe life{close_quotes} or {open_quotes}damage tolerant{close_quote} to determine what periodic replacements or repeated inspections were required. That work came to the attention of the Department of Defense which supported preparation of the book-length report by F. Stanley Nowlan and Howard F. Heap at United Airlines entitled {open_quote}Reliability-Centered maintenance{close_quotes}.« less

  6. Recent developments in aircraft protection systems for laser guide star operations

    NASA Astrophysics Data System (ADS)

    Stomski, Paul J.; Murphy, Thomas W.; Campbell, Randy

    2012-07-01

    The astronomical community's use of high power laser guide star adaptive optics (LGS-AO) systems presents a potential hazard to aviation. Historically, the most common and trusted means of protecting aircraft and their occupants has been the use of safety observers (aka spotters) armed with shut-off switches. These safety observers watch for aircraft at risk and terminate laser propagation before the aircraft can be adversely affected by the laser. Efforts to develop safer and more cost-effective automated aircraft protection systems for use by the astronomical community have been inhibited by both technological and regulatory challenges. This paper discusses recent developments in these two areas. Specifically, with regard to regulation and guidance we discuss the 2011 release of AS-6029 by the SAE as well as the potential impact of RTCA DO-278A. With regard to the recent developments in the technology used to protect aircraft from laser illumination, we discuss the novel Transponder Based Aircraft Detection (TBAD) system being installed at W. M. Keck Observatory (WMKO). Finally, we discuss our strategy for evaluating TBAD compliance with the regulations and for seeking appropriate approvals for LGS operations at WMKO using a fully automated, flexibly configured, multi-tier aircraft protection system incorporating this new technology.

  7. The Demand for Single Engine Piston Aircraft,

    DTIC Science & Technology

    1987-08-01

    Other promising variables included Student Pilots and - Maintenance and overhaul costs. None of the national economic " variables tested was effective ...publicity and are presumed to exist 1everywhere. *O 2-11 . ., Today’s deregulated airline envi ronrrient has had opposing effects on the use of small aircraft...delivered. Foreign producers have learned to compete effectively in these segments of the U.S. marketplace. one can assume they could do the same in

  8. Initial flight qualification and operational maintenance of X-29A flight software

    NASA Technical Reports Server (NTRS)

    Earls, Michael R.; Sitz, Joel R.

    1989-01-01

    A discussion is presented of some significant aspects of the initial flight qualification and operational maintenance of the flight control system softward for the X-29A technology demonstrator. Flight qualification and maintenance of complex, embedded flight control system software poses unique problems. The X-29A technology demonstrator aircraft has a digital flight control system which incorporates functions generally considered too complex for analog systems. Organizational responsibilities, software assurance issues, tools, and facilities are discussed.

  9. Small unmanned aircraft systems for remote sensing and Earth science research

    NASA Astrophysics Data System (ADS)

    Hugenholtz, Chris H.; Moorman, Brian J.; Riddell, Kevin; Whitehead, Ken

    2012-06-01

    To understand and predict Earth-surface dynamics, scientists often rely on access to the latest remote sensing data. Over the past several decades, considerable progress has been made in the development of specialized Earth observation sensors for measuring a wide range of processes and features. Comparatively little progress has been made, however, in the development of new platforms upon which these sensors can be deployed. Conventional platforms are still almost exclusively restricted to piloted aircraft and satellites. For many Earth science research questions and applications these platforms do not yet have the resolution or operational flexibility to provide answers affordably. The most effective remote sensing data match the spatiotemporal scale of the process or feature of interest. An emerging technology comprising unmanned aircraft systems (UAS), also known as unmanned aerial vehicles (UAV), is poised to offer a viable alternative to conventional platforms for acquiring high-resolution remote sensing data with increased operational flexibility, lower cost, and greater versatility (Figure 1).

  10. 77 FR 36341 - Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ...EPA is adopting several new aircraft engine emission standards for oxides of nitrogen (NOX), compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet engines with rated thrusts greater than 26.7 kilonewtons (kN). We also are adopting certain other requirements for gas turbine engines that are subject to exhaust emission standards as follows. First, we are clarifying when the emission characteristics of a new turbofan or turbojet engine model have become different enough from its existing parent engine design that it must conform to the most current emission standards. Second, we are establishing a new reporting requirement for manufacturers of gas turbine engines that are subject to any exhaust emission standard to provide us with timely and consistent emission- related information. Third, and finally, we are establishing amendments to aircraft engine test and emissions measurement procedures. EPA actively participated in the United Nations' International Civil Aviation Organization (ICAO) proceedings in which most of these requirements were first developed. These regulatory requirements have largely been adopted or are actively under consideration by its member states. By adopting such similar standards, therefore, the United States maintains consistency with these international efforts.

  11. Multi-Channel, Constant-Current Power Source for Aircraft Applications

    DTIC Science & Technology

    2017-03-01

    Special considerations impacting this design were minimizing volume, maintaining system power quality, and providing electrical fault protection...applications. Electrical loads, such as lighting, de-icing heaters, and actuators may be operated from this compact power conversion unit. Because of the...nature of aircraft systems, two of the most important design considerations are the maintenance of electrical power quality and minimization of weight

  12. Rotor blade construction for circulation control aircraft

    NASA Technical Reports Server (NTRS)

    Carter, Sr., Donald R. (Inventor); Sedlak, Matthew (Inventor); Krauss, Timothy A. (Inventor)

    1986-01-01

    A circulation control aircraft rotor blade having a spanwise Coanda surface 16 and a plurality of spanwise extending flexible composite material panels 18 cooperating with the surface to define slots for the discharge of compressed air from within the blade with each panel having first flexure means 60 associated with screw adjustments 36 for establishing a slot opening preload and second flexure means 62 associated with screw adjustments 38 for establishing a slot maximum opening.

  13. Flexible micro flow sensor for micro aerial vehicles

    NASA Astrophysics Data System (ADS)

    Zhu, Rong; Que, Ruiyi; Liu, Peng

    2017-12-01

    This article summarizes our studies on micro flow sensors fabricated on a flexible polyimide circuit board by a low-cost hybrid process of thin-film deposition and circuit printing. The micro flow sensor has merits of flexibility, structural simplicity, easy integrability with circuits, and good sensing performance. The sensor, which adheres to an object surface, can detect the surface flow around the object. In our study, we install the fabricated micro flow sensors on micro aerial vehicles (MAVs) to detect the surface flow variation around the aircraft wing and deduce the aerodynamic parameters of the MAVs in flight. Wind tunnel experiments using the sensors integrated with the MAVs are also conducted.

  14. 77 FR 38463 - Issuance of Special Airworthiness Certificates for Light-Sport Category Aircraft

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    ... standards for LSA design, manufacturing, continued airworthiness, and maintenance. It also made... aviation authorities on any issues affecting the design, production, continued airworthiness, or other... assessment of the special light-sport aircraft (SLSA) manufacturing industry, the FAA is issuing this notice...

  15. Flexible Blades for Wind Turbines

    NASA Astrophysics Data System (ADS)

    Collins, Madeline Carlisle; Macphee, David; Harris, Caleb

    2016-11-01

    Previous research has shown that windmills with flexible blades are more efficient than those with rigid blades. Flexibility offers passive pitch control, preferable to active pitch control which is costly and requires maintenance. Flexible blades morph such that the blade more closely resembles its design point at part load and over load. The lift-to-drag ratios on individual blades was investigated. A mold was designed and machined from an acrylic slab for the casting of blades with a NACA 0012 cross section. A flexible blade was cast from silicone and a rigid blade was cast from polyurethane. Each of these blades was tested in a wind tunnel, cantilever mounted, spanning the whole test section. The angle of attack was varied by rotating the mount. All tests were performed at the same wind speed. A load cell within the mount measured forces on the blade, from which the lift and drag forces were calculated. The stall point for the flexible blade occurred later than for the rigid blade, which agrees with previous research. Lift-to-drag ratios were larger for the flexible blade at all angles of attack tested. Flexible blades seem to be a viable option for passive pitch control. Future research will include different airfoil cross sections, wind speeds, and blade materials. Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

  16. High Reliability Engine Control Demonstrated for Aircraft Engines

    NASA Technical Reports Server (NTRS)

    Guo, Ten-Huei

    1999-01-01

    For a dual redundant-control system, which is typical for short-haul aircraft, if a failure is detected in a control sensor, the engine control is transferred to a safety mode and an advisory is issued for immediate maintenance action to replace the failed sensor. The safety mode typically results in severely degraded engine performance. The goal of the High Reliability Engine Control (HREC) program was to demonstrate that the neural-network-based sensor validation technology can safely operate an engine by using the nominal closed-loop control during and after sensor failures. With this technology, engine performance could be maintained, and the sensor could be replaced as a conveniently scheduled maintenance action.

  17. Aircraft Transparency Failure and Logistical Cost Analysis. Volume I. Program Summary

    DTIC Science & Technology

    1978-12-01

    Hours liv LIST OF ABBREVIATIONS (Continued) SFMC Field Maintenance Cost FMEA Failure Modes and Effect Analysis SFMS Field Maintenance Squadron FSN...3, CH-53, AND UH -1 Figure 3. Study Aircraft 10 I. 1. WINDSHIELDS 2. CANOPIES 3. WINDOWS INTERACTIVE SUPPORT SYSTEMS 1. ANTI-ICING 2. DEFOGGING 3...52,947 13,761 UH /TH-1F, 1P 73,431 73,640 Total helicopters 339,690 113,492 2.99 Bombers B-S2G 138,348 64,431 B-S2P 93,000 36,936 B-57 34,527 19,552

  18. Impact of future fuel properties on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Grobman, J. S.

    1978-01-01

    The effect of modifications in hydrocarbon jet fuels specifications on engine performance, component durability and maintenance, and aircraft fuel system performance is discussed. Specific topics covered include: specific fuel consumption; ignition at relight limits; exhaust emissions; combustor liner temperatures; carbon deposition; gum formation in fuel nozzles, erosion and corrosion of turbine blades and vanes; deposits in fuel system heat exchangers; and pumpability and flowability of the fuel. Data that evaluate the ability of current technology aircraft to accept fuel specification changes are presented, and selected technological advances that can reduce the severity of the problems are described and discussed.

  19. Actively Controlled Landing Gear for Aircraft Vibration Reduction

    NASA Technical Reports Server (NTRS)

    Horta, Lucas G.; Daugherty, Robert H.; Martinson, Veloria J.

    1999-01-01

    Concepts for long-range air travel are characterized by airframe designs with long, slender, relatively flexible fuselages. One aspect often overlooked is ground induced vibration of these aircraft. This paper presents an analytical and experimental study of reducing ground-induced aircraft vibration loads using actively controlled landing gears. A facility has been developed to test various active landing gear control concepts and their performance. The facility uses a NAVY A6-intruder landing gear fitted with an auxiliary hydraulic supply electronically controlled by servo valves. An analytical model of the gear is presented including modifications to actuate the gear externally and test data is used to validate the model. The control design is described and closed-loop test and analysis comparisons are presented.

  20. Evaluation of all-electric secondary power for transport aircraft

    NASA Technical Reports Server (NTRS)

    Murray, W. E.; Feiner, L. J.; Flores, R. R.

    1992-01-01

    This report covers a study by Douglas Aircraft Company (DAC) of electrical power systems for advanced transport aircraft based upon an all-electric design concept. The concept would eliminate distributed hydraulic and pneumatic secondary power systems, and feature an expanded secondary electrical power system redesigned to supply power to the loads customarily supplied by hydraulic or pneumatic power. The initial study was based on an advanced 20-kHz electrical power transmission and distribution system, using a system architecture supplied by NASA-Lewis Research Center for twin-engine aircraft with many advanced power conversion concepts. NASA-LeRC later requested DAC to refocus the study on 400-Hz secondary power distribution. Subsequent work was based on a three-engine MD-11 aircraft, selected by DAC as a baseline system design that would provide data for the comparative cost/benefit analysis. The study concluded that the 20-kHz concept produced many expected benefits, and that the all-electric trijet weight savings on hardware redesign would be 2,304 pounds plus a 2.1-percent fuel reduction and resized for a total weight reduction of 11,000 pounds. Cost reductions for a fleet of 800 aircraft in a 15-year production program were estimated at $76.71 million for RDT&E; $2.74 million per aircrat for production; $9.84 million for nonrecurring expenses; $120,000 per aircraft for product support; and $300,000 per aircraft per year for operating and maintenance costs, giving a present value of $1.914 billion saved or a future value of $10.496 billion saved.

  1. Eclipse program F-106 aircraft in flight, front view

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Shot of the QF-106 aircraft in flight with the landing gear deployed. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  2. Evaluation of all-electric secondary power for transport aircraft

    NASA Astrophysics Data System (ADS)

    Murray, W. E.; Feiner, L. J.; Flores, R. R.

    1992-01-01

    This report covers a study by Douglas Aircraft Company (DAC) of electrical power systems for advanced transport aircraft based upon an all-electric design concept. The concept would eliminate distributed hydraulic and pneumatic secondary power systems, and feature an expanded secondary electrical power system redesigned to supply power to the loads customarily supplied by hydraulic or pneumatic power. The initial study was based on an advanced 20-kHz electrical power transmission and distribution system, using a system architecture supplied by NASA-Lewis Research Center for twin-engine aircraft with many advanced power conversion concepts. NASA-LeRC later requested DAC to refocus the study on 400-Hz secondary power distribution. Subsequent work was based on a three-engine MD-11 aircraft, selected by DAC as a baseline system design that would provide data for the comparative cost/benefit analysis. The study concluded that the 20-kHz concept produced many expected benefits, and that the all-electric trijet weight savings on hardware redesign would be 2,304 pounds plus a 2.1-percent fuel reduction and resized for a total weight reduction of 11,000 pounds. Cost reductions for a fleet of 800 aircraft in a 15-year production program were estimated at $76.71 million for RDT&E $2.74 million per aircrat for production; $9.84 million for nonrecurring expenses; $120,000 per aircraft for product support; and $300,000 per aircraft per year for operating and maintenance costs, giving a present value of $1.914 billion saved or a future value of $10.496 billion saved.

  3. The F-18 High Alpha Research Vehicle: A High-Angle-of-Attack Testbed Aircraft

    NASA Technical Reports Server (NTRS)

    Regenie, Victoria; Gatlin, Donald; Kempel, Robert; Matheny, Neil

    1992-01-01

    The F-18 High Alpha Research Vehicle is the first thrust-vectoring testbed aircraft used to study the aerodynamics and maneuvering available in the poststall flight regime and to provide the data for validating ground prediction techniques. The aircraft includes a flexible research flight control system and full research instrumentation. The capability to control the vehicle at angles of attack up to 70 degrees is also included. This aircraft was modified by adding a pitch and yaw thrust-vectoring system. No significant problems occurred during the envelope expansion phase of the program. This aircraft has demonstrated excellent control in the wing rock region and increased rolling performance at high angles of attack. Initial pilot reports indicate that the increased capability is desirable although some difficulty in judging the size and timing of control inputs was observed. The aircraft, preflight ground testing and envelope expansion flight tests are described.

  4. Reduction of Maintenance Error Through Focused Interventions

    NASA Technical Reports Server (NTRS)

    Kanki, Barbara G.; Walter, Diane; Rosekind, Mark R. (Technical Monitor)

    1997-01-01

    It is well known that a significant proportion of aviation accidents and incidents are tied to human error. In flight operations, research of operational errors has shown that so-called "pilot error" often involves a variety of human factors issues and not a simple lack of individual technical skills. In aircraft maintenance operations, there is similar concern that maintenance errors which may lead to incidents and accidents are related to a large variety of human factors issues. Although maintenance error data and research are limited, industry initiatives involving human factors training in maintenance have become increasingly accepted as one type of maintenance error intervention. Conscientious efforts have been made in re-inventing the "team" concept for maintenance operations and in tailoring programs to fit the needs of technical operations. Nevertheless, there remains a dual challenge: to develop human factors interventions which are directly supported by reliable human error data, and to integrate human factors concepts into the procedures and practices of everyday technical tasks. In this paper, we describe several varieties of human factors interventions and focus on two specific alternatives which target problems related to procedures and practices; namely, 1) structured on-the-job training and 2) procedure re-design. We hope to demonstrate that the key to leveraging the impact of these solutions comes from focused interventions; that is, interventions which are derived from a clear understanding of specific maintenance errors, their operational context and human factors components.

  5. OpenMDAO: Framework for Flexible Multidisciplinary Design, Analysis and Optimization Methods

    NASA Technical Reports Server (NTRS)

    Heath, Christopher M.; Gray, Justin S.

    2012-01-01

    The OpenMDAO project is underway at NASA to develop a framework which simplifies the implementation of state-of-the-art tools and methods for multidisciplinary design, analysis and optimization. Foremost, OpenMDAO has been designed to handle variable problem formulations, encourage reconfigurability, and promote model reuse. This work demonstrates the concept of iteration hierarchies in OpenMDAO to achieve a flexible environment for supporting advanced optimization methods which include adaptive sampling and surrogate modeling techniques. In this effort, two efficient global optimization methods were applied to solve a constrained, single-objective and constrained, multiobjective version of a joint aircraft/engine sizing problem. The aircraft model, NASA's nextgeneration advanced single-aisle civil transport, is being studied as part of the Subsonic Fixed Wing project to help meet simultaneous program goals for reduced fuel burn, emissions, and noise. This analysis serves as a realistic test problem to demonstrate the flexibility and reconfigurability offered by OpenMDAO.

  6. Wireless microsensors for health monitoring of aircraft structures

    NASA Astrophysics Data System (ADS)

    Varadan, Vijay K.

    2003-01-01

    navigation system and other microsensors for health monitoring and condition-based maintenance of structures, drag sensing and control of aircraft, strain and deflection of structures and systems, ice sensing on aircraft, remote temperature and humidity measurement of propellant in munitions, chemical sensing, etc. are discussed.

  7. VASCOMP 2. The V/STOL aircraft sizing and performance computer program. Volume 6: User's manual, revision 3

    NASA Technical Reports Server (NTRS)

    Schoen, A. H.; Rosenstein, H.; Stanzione, K.; Wisniewski, J. S.

    1980-01-01

    This report describes the use of the V/STOL Aircraft Sizing and Performance Computer Program (VASCOMP II). The program is useful in performing aircraft parametric studies in a quick and cost efficient manner. Problem formulation and data development were performed by the Boeing Vertol Company and reflects the present preliminary design technology. The computer program, written in FORTRAN IV, has a broad range of input parameters, to enable investigation of a wide variety of aircraft. User oriented features of the program include minimized input requirements, diagnostic capabilities, and various options for program flexibility.

  8. Damage-mitigating control of aircraft for high performance and life extension

    NASA Astrophysics Data System (ADS)

    Caplin, Jeffrey

    1998-12-01

    A methodology is proposed for the synthesis of a Damage-Mitigating Control System for a high-performance fighter aircraft. The design of such a controller involves consideration of damage to critical points of the structure, as well as the performance requirements of the aircraft. This research is interdisciplinary, and brings existing knowledge in the fields of unsteady aerodynamics, structural dynamics, fracture mechanics, and control theory together to formulate a new approach towards aircraft flight controller design. A flexible wing model is formulated using the Finite Element Method, and the important mode shapes and natural frequencies are identified. The Doublet Lattice Method is employed to develop an unsteady flow model for computation of the unsteady aerodynamic loads acting on the wing due to rigid-body maneuvers and structural deformation. These two models are subsequently incorporated into a pre-existing nonlinear rigid-body aircraft flight-dynamic model. A family of robust Damage-Mitigating Controllers is designed using the Hinfinity-optimization and mu-synthesis method. In addition to weighting the error between the ideal performance and the actual performance of the aircraft, weights are also placed on the strain amplitude at the root of each wing. The results show significant savings in fatigue life of the wings while retaining the dynamic performance of the aircraft.

  9. Using Intelligent Simulation to Enhance Human Performance in Aircraft Maintenance

    NASA Technical Reports Server (NTRS)

    Johnson, William B.; Norton, Jeffrey E.

    1992-01-01

    Human factors research and development investigates the capabilities and limitations of the human within a system. Of the many variables affecting human performance in the aviation maintenance system, training is among the most important. The advent of advanced technology hardware and software has created intelligent training simulations. This paper describes one advanced technology training system under development for the Federal Aviation Administration.

  10. Static Aeroelastic Scaling and Analysis of a Sub-Scale Flexible Wing Wind Tunnel Model

    NASA Technical Reports Server (NTRS)

    Ting, Eric; Lebofsky, Sonia; Nguyen, Nhan; Trinh, Khanh

    2014-01-01

    This paper presents an approach to the development of a scaled wind tunnel model for static aeroelastic similarity with a full-scale wing model. The full-scale aircraft model is based on the NASA Generic Transport Model (GTM) with flexible wing structures referred to as the Elastically Shaped Aircraft Concept (ESAC). The baseline stiffness of the ESAC wing represents a conventionally stiff wing model. Static aeroelastic scaling is conducted on the stiff wing configuration to develop the wind tunnel model, but additional tailoring is also conducted such that the wind tunnel model achieves a 10% wing tip deflection at the wind tunnel test condition. An aeroelastic scaling procedure and analysis is conducted, and a sub-scale flexible wind tunnel model based on the full-scale's undeformed jig-shape is developed. Optimization of the flexible wind tunnel model's undeflected twist along the span, or pre-twist or wash-out, is then conducted for the design test condition. The resulting wind tunnel model is an aeroelastic model designed for the wind tunnel test condition.

  11. Micro- and nano-NDE systems for aircraft: great things in small packages

    NASA Astrophysics Data System (ADS)

    Malas, James C.; Kropas-Hughes, Claudia V.; Blackshire, James L.; Moran, Thomas; Peeler, Deborah; Frazier, W. G.; Parker, Danny

    2003-07-01

    Recent advancements in small, microscopic NDE sensor technologies will revolutionize how aircraft maintenance is done, and will significantly improve the reliability and airworthiness of current and future aircraft systems. A variety of micro/nano systems and concepts are being developed that will enable whole new capabilities for detecting and tracking structural integrity damage. For aging aircraft systems, the impact of micro-NDE sensor technologies will be felt immediately, with dramatic reductions in labor for maintenance, and extended useable life of critical components being two of the primary benefits. For the fleet management of future aircraft systems, a comprehensive evaluation and tracking of vehicle health throughout its entire life cycle will be needed. Indeed, micro/nano NDE systems will be instrumental in realizing this futuristic vision. Several major challenges will need to be addressed, however, before micro- and nano-NDE systems can effectively be implemented, and this will require interdisciplinary research approaches, and a systematic engineering integration of the new technologies into real systems. Future research will need to emphasize systems engineering approaches for designing materials and structures with in-situ inspection and prognostic capabilities. Recent advances in 1) embedded / add-on micro-sensors, 2) computer modeling of nondestructive evaluation responses, and 3) wireless communications are important steps toward this goal, and will ultimately provide previously unimagined opportunities for realizing whole new integrated vehicle health monitoring capabilities. The future use of micro/nano NDE technologies as vehicle health monitoring tools will have profound implications, and will provide a revolutionary way of doing NDE in the near and distant future.

  12. Adaptive Positive Position Feedback Control of Flexible Aircraft Structures Using Piezoelectric Actuators

    DTIC Science & Technology

    2014-03-27

    2 1.3 NASA F/A-18 investigating high AOA vortex generation [1] . . . . . . . . . . 3 1.4 F-15 with vortex formations in front...AOA angle of attack HW hot wire NASA National Aeronautics and Space Administration LANTIRN Low Altitude Navigation and Targeting Infrared for Night...National Aeronautics and Space Administration ( NASA ) investigation into the interaction of vortices generated at high AOA and aircraft structure

  13. Daedalus Project's Light Eagle - Human powered aircraft

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The Michelob Light Eagle is seen here in flight over Rogers Dry Lake at the NASA Dryden Flight Research Center, Edwards, California. The Light Eagle and Daedalus human powered aircraft were testbeds for flight research conducted at Dryden between January 1987 and March 1988. These unique aircraft were designed and constructed by a group of students, professors, and alumni of the Massachusetts Institute of Technology within the context of the Daedalus project. The construction of the Light Eagle and Daedalus aircraft was funded primarily by the Anheuser Busch and United Technologies Corporations, respectively, with additional support from the Smithsonian Air and Space Museum, MIT, and a number of other sponsors. To celebrate the Greek myth of Daedalus, the man who constructed wings of wax and feathers to escape King Minos, the Daedalus project began with the goal of designing, building and testing a human-powered aircraft that could fly the mythical distance, 115 km. To achieve this goal, three aircraft were constructed. The Light Eagle was the prototype aircraft, weighing 92 pounds. On January 22, 1987, it set a closed course distance record of 59 km, which still stands. Also in January of 1987, the Light Eagle was powered by Lois McCallin to set the straight distance, the distance around a closed circuit, and the duration world records for the female division in human powered vehicles. Following this success, two more aircraft were built, the Daedalus 87 and Daedalus 88. Each aircraft weighed approximately 69 pounds. The Daedalus 88 aircraft was the ship that flew the 199 km from the Iraklion Air Force Base on Crete in the Mediterranean Sea, to the island of Santorini in 3 hours, 54 minutes. In the process, the aircraft set new records in distance and endurance for a human powered aircraft. The specific areas of flight research conducted at Dryden included characterizing the rigid body and flexible dynamics of the Light Eagle, investigating sensors for an

  14. History of the KC-10A Aircraft Acquisition

    DTIC Science & Technology

    1988-04-01

    in other research reports or educational pursuits contingent upon the following stipulations: - Reproduction rights do not extend to any copyrighted...MAC, AFLC, and others) would create data for flight, maintenance, and technical data manuals, and evaluate human engineering factors. This testing...productio); ond deli.erme:; ra.. a fa:st rate and the acquisition program began to phase out.. The, total fleot gjrew to 52 aircraft, and del ivf , ics of th:ý

  15. Maintenance on the Advanced Colloids Experiment Module

    NASA Image and Video Library

    2018-04-16

    iss055e035366 (April 16, 2018) --- NASA astronaut Ricky Arnold performs maintenance on the Advanced Colloids Experiment Module located inside the Light Microscopy Module which is a modified commercial, highly flexible, state-of-the-art light imaging microscope facility that provides researchers with powerful diagnostic hardware and software in microgravity.

  16. Commercial-Aircraft Protection System

    NASA Astrophysics Data System (ADS)

    Case, Russell L., Jr.; Wolff, Peter H.

    2004-09-01

    Recent world events have identified needs for a commercial aircraft defense system against Man-Portable Air Defense Systems (MANPADS), such as SA-7 and Stinger shoulder launched surface-to-air missiles. Technical challenges include target detection, identification and countermeasures. Political and societal challenges include cost, time to deployment, ground and air safety, and reliability. These challenges, as well as many others, have been met and overcome with the development of Thor Systems' Commercial-Aircraft Protection System (C-APS). C-APS makes use of commercial technology such as radar and infrared sensors with a laser-based countermeasure. Unlike adapted military systems, C-APS detects the threat long before the military versions by employing a 360 degree hemispherical scan, identifying the threat with an infrared sensor and employing a directed laser to not only deflect the target but to permanently disable its seeker. Enhanced capabilities include multiple threat elimination and closed-loop technology for kill verification. All of this is accomplished with development costs less than half that required to convert military technology, manufacturing costs significantly less than competitive products, and a maintenance cycle coincident with standard FAA requirements, which are significantly longer than current systems.

  17. The Joint Strike Fighter (JSF) PHM and the Autonomic Logistic Concept: Potential Impact on Aging Aircraft Problems

    DTIC Science & Technology

    2003-02-01

    and highly intelligent aircraft. A major tenet of this discussion will be that robust information sources provided by the PHM system can and will be...and maintainable (R+M) designed intelligent aircraft which encompasses a comprehensive Prognostics and Health Management (PHM) capability to enhance...hydraulic pump has a 90% chance of failing within the next 10 flight hours. This way, maintenance personnel will be able to make intelligent ,.informed

  18. The all-electric aircraft - A systems view and proposed NASA research Programs

    NASA Technical Reports Server (NTRS)

    Spitzer, C. R.

    1984-01-01

    It is expected that all-electric aircraft, whether military or commercial, will exhibit reduced weight, acquisition cost and fuel consumption, an expanded flight envelope and improved survivability and reliability, simpler maintenance, and reduced support equipment. Also noteworthy are dramatic improvements in mission adaptability, based on the degree to which control system performance relies on easily exchanged software. Flight-critical secondary power and control systems whose malfunction would mean loss of an aircraft pose failure detection and design methodology problems, however, that have only begun to be addressed. NASA-sponsored research activities concerned with these problems and prospective benefits are presently discussed.

  19. Structural Load Alleviation Applied to Next Generation Aircraft and Wind Turbines

    NASA Technical Reports Server (NTRS)

    Frost, Susan

    2011-01-01

    Reducing the environmental impact of aviation is a goal of the Subsonic Fixed Wing Project under the Fundamental Aeronautics Program of NASAs Aeronautics Research Mission Directorate. Environmental impact of aviation is being addressed by novel aircraft configurations and materials that reduce aircraft weight and increase aerodynamic efficiency. NASA is developing tools to address the challenges of increased airframe flexibility created by wings constructed with reduced structural material and novel light-weight materials. This talk will present a framework and demonstration of a flight control system using optimal control allocation with structural load feedback and constraints to achieve safe aircraft operation. As wind turbines age, they become susceptible to many forms of blade degradation. Results will be presented on work in progress that uses adaptive contingency control for load mitigation in a wind turbine simulation with blade damage progression modeled.

  20. Walter C. Williams Research Aircraft Integration Facility (RAIF)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    in the Thermostructural Laboratory, now also resides in the ITF. In preparing a research aircraft for flight testing, it is vital to measure its structural frequencies and mode shapes and compare results to the models used in design analysis. The final function performed in the ITF is routine aircraft maintenance. This includes preflight and post-flight instrumentation checks and the servicing of hydraulics, avionics, and engines necessary on any research aircraft. Aircraft are not merely moved to the ITF for automated testing purposes but are housed there throughout their flight test programs.

  1. 77 FR 59873 - Airworthiness Directives; Cessna Aircraft Company Airplanes; Initial Regulatory Flexibility Analysis

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... should be flown into known icing. However, the original certification basis for these airplanes did not incorporate Amendment 7 (May 3, 1962) of CAR 3, requiring manufacturers to provide a placard specifying the... aircraft is limited by the equipment installed (CAR 3 Sec. 3.772). As a result, with operational deicing...

  2. X-HALE: A Very Flexible UAV for Nonlinear Aeroelastic Tests

    DTIC Science & Technology

    2010-04-01

    Theseus (right) showing large wing deflections (Courtesy NASA Dryden) Figure 2. Three different “Sensorcraft” configurations1 More...Shearer, C. M., Coupled Nonlinear Flight Dynamics, Aeroelasticity, and Control of Very Flexible Aircraft, Ph.D. thesis , The University of Michigan... Thesis , Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, 2003. 24. Cesnik, C.E.S. and Ortega-Morales, M

  3. Genesis of a flexible turning center

    NASA Astrophysics Data System (ADS)

    Sanclemente, Paul; French, Robert D.

    GE - Aircraft Engines has designed, built, and is operating a flexible turning center for jet engine hardware. Although the plant is in the forefront of manufacturing technology development, it was intended from the start to be a production facility. So while there was much to learn from being involved in all phases of the project, meeting production schedules was, and is, key to its success. This paper reviews the early history of the project and ends with a view of its recent production status.

  4. Study of aircraft in intraurban transportation systems, volume 3

    NASA Technical Reports Server (NTRS)

    Stout, E. G.; Kesling, P. H.; Matteson, D. E.; Sherwood, D. E.; Tuck, W. R., Jr.; Vaughn, L. A.

    1971-01-01

    An investigation of three aircraft concepts, deflected slipstream STOL, helicopter VTOL, and fixed wing STOL, is presented. An attempt was made to determine the best concept for the intraurban transportation system. Desirability of the concept was based on ease of maintenance, development timing, reliability, operating costs, and the noise produced. Indications are that the deflected slipstream STOL is best suited for intraurban transportation. Tables and graphs are included.

  5. The Guardian: Preliminary design of a close air support aircraft

    NASA Technical Reports Server (NTRS)

    Haag, Jonathan; Huber, David; Mcinerney, Kelly; Mulligan, Greg; Pessin, David; Seelos, Michael

    1991-01-01

    One design is presented of a Close Air Support (CAS) aircraft. It is a canard wing, twin engine, twin vertical tail aircraft that has the capability to cruise at 520 knots. The Guardian contains state of the art flight control systems. Specific highlights of the Guardian include: (1) low cost (the acquisition cost per airplane is $13.6 million for a production of 500 airplanes); (2) low maintenance (it was designed to be easily maintainable in unprepared fields); and (3) high versatility (it can perform a wide range of missions). Along with being a CAS aircraft, it is capable of long ferry missions, battlefield interdiction, maritime attack, and combat rescue. The Guardian is capable of a maximum ferry of 3800 nm, can takeoff in a distance of 1700 ft, land in a ground roll distance of 1644 ft. It has a maximum takeoff weight of 48,753 lbs, and is capable of carrying up to 19,500 lbs of ordinance.

  6. [The algorithm for the medical maintenance of the aircraft personnel suffering from chronic sensorineural impairment of hearing].

    PubMed

    Pankova, V B; Skryabina, L Yu; Barkhatova, O A

    2016-01-01

    The present study was designed to systematize the causes underlying the development of chronic sensorineural impairment of hearing in the aircraft personnel engaged in commercial aviation of the Russian Federation. A detailed clinical and audiological picture of chronic sensorineural loss of hearing in the aircraft personnel is presented with special reference to the criteria accepted in the civil aviationfor the evaluation of professional suitability and occupational selection in terms of hearing conditions. The study has demonstrated the paramount importance of the aviation medical expertise for the flight safety control in civil aviation. We analyzed the results of the audiological examination of the aircraft personnel suffering from chronic sensorineural impairment of hearing and proposed the algorithm for the rehabilitation of such subjects taking into consideration the stage of the chronic process.

  7. 14 CFR 91.1443 - CAMP: Airworthiness release or aircraft maintenance log entry.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... certificated mechanic. (c) Notwithstanding paragraph (b)(3) of this section, after maintenance, preventive... its manual that the signature of an authorized certificated mechanic or repairman constitutes that...

  8. 14 CFR 91.1443 - CAMP: Airworthiness release or aircraft maintenance log entry.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... certificated mechanic. (c) Notwithstanding paragraph (b)(3) of this section, after maintenance, preventive... its manual that the signature of an authorized certificated mechanic or repairman constitutes that...

  9. 14 CFR 91.1443 - CAMP: Airworthiness release or aircraft maintenance log entry.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... certificated mechanic. (c) Notwithstanding paragraph (b)(3) of this section, after maintenance, preventive... its manual that the signature of an authorized certificated mechanic or repairman constitutes that...

  10. 14 CFR 91.1443 - CAMP: Airworthiness release or aircraft maintenance log entry.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... certificated mechanic. (c) Notwithstanding paragraph (b)(3) of this section, after maintenance, preventive... its manual that the signature of an authorized certificated mechanic or repairman constitutes that...

  11. 14 CFR 91.1443 - CAMP: Airworthiness release or aircraft maintenance log entry.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... certificated mechanic. (c) Notwithstanding paragraph (b)(3) of this section, after maintenance, preventive... its manual that the signature of an authorized certificated mechanic or repairman constitutes that...

  12. CREW CHIEF: A computer graphics simulation of an aircraft maintenance technician

    NASA Technical Reports Server (NTRS)

    Aume, Nilss M.

    1990-01-01

    Approximately 35 percent of the lifetime cost of a military system is spent for maintenance. Excessive repair time is caused by not considering maintenance during design. Problems are usually discovered only after a mock-up has been constructed, when it is too late to make changes. CREW CHIEF will reduce the incidence of such problems by catching design defects in the early design stages. CREW CHIEF is a computer graphic human factors evaluation system interfaced to commercial computer aided design (CAD) systems. It creates a three dimensional man model, either male or female, large or small, with various types of clothing and in several postures. It can perform analyses for physical accessibility, strength capability with tools, visual access, and strength capability for manual materials handling. The designer would produce a drawing on his CAD system and introduce CREW CHIEF in it. CREW CHIEF's analyses would then indicate places where problems could be foreseen and corrected before the design is frozen.

  13. NASA DC-8 Ground Support Technician Joe Niquette performs routine maintenance on the DC-8 aircraft in Punta Arenas, Chile

    NASA Image and Video Library

    2004-03-17

    NASA DC-8 Ground Support Technician Joe Niquette performs routine maintenance on the DC-8 aircraft at Carlos Ibanez del Campo International Airport in Punta Arenas, Chile. AirSAR 2004 is a three-week expedition by an international team of scientists that is using an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central and South America with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. In South America and Antarctica, AirSAR will collect imagery and data to help determine the contribution of Southern Hemisphere glaciers to sea level rise due to climate change. In Patagonia, researchers found this contribution had more than doubled from 1995 to 2000, compared to the previous 25 years. AirSAR data will make it possible to determine whether that trend is decreasing, continuing or accelerating. AirSAR will also provide reliable information on ice shelf thickness to measure the contribution of the glaciers to sea level.

  14. NASA Dryden DC-8 maintenance crew members inspect the aircraft prior to take-off for an AirSAR 2004 flight

    NASA Image and Video Library

    2004-03-06

    NASA Dryden DC-8 maintenance crew members inspect the aircraft prior to take-off. L-R; Scott Silver, Paul Ristrim and Mike Lakowski. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that uses an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central America with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. The radar, developed by NASA's Jet Propulsion Laboratory, can penetrate clouds and also collect data at night. Its high-resolution sensors operate at multiple wavelengths and modes, allowing AirSAR to see beneath treetops, through thin sand, and dry snow pack. AirSAR's 2004 campaign is a collaboration of many U.S. and Central American institutions and scientists, including NASA; the National Science Foundation; the Smithsonian Institution; National Geographic; Conservation International; the Organization of Tropical Studies; the Central American Commission for Environment and Development; and the Inter-American Development Bank.

  15. A Generic Guidance and Control Structure for Six-Degree-of-Freedom Conceptual Aircraft Design

    NASA Technical Reports Server (NTRS)

    Cotting, M. Christopher; Cox, Timothy H.

    2005-01-01

    A control system framework is presented for both real-time and batch six-degree-of-freedom simulation. This framework allows stabilization and control with multiple command options, from body rate control to waypoint guidance. Also, pilot commands can be used to operate the simulation in a pilot-in-the-loop environment. This control system framework is created by using direct vehicle state feedback with nonlinear dynamic inversion. A direct control allocation scheme is used to command aircraft effectors. Online B-matrix estimation is used in the control allocation algorithm for maximum algorithm flexibility. Primary uses for this framework include conceptual design and early preliminary design of aircraft, where vehicle models change rapidly and a knowledge of vehicle six-degree-of-freedom performance is required. A simulated airbreathing hypersonic vehicle and a simulated high performance fighter are controlled to demonstrate the flexibility and utility of the control system.

  16. Forecasting the impact of virtual environment technology on maintenance training

    NASA Technical Reports Server (NTRS)

    Schlager, Mark S.; Boman, Duane; Piantanida, Tom; Stephenson, Robert

    1993-01-01

    To assist NASA and the Air Force in determining how and when to invest in virtual environment (VE) technology for maintenance training, we identified possible roles for VE technology in such training, assessed its cost-effectiveness relative to existing technologies, and formulated recommendations for a research agenda that would address instructional and system development issues involved in fielding a VE training system. In the first phase of the study, we surveyed VE developers to forecast capabilities, maturity, and estimated costs for VE component technologies. We then identified maintenance tasks and their training costs through interviews with maintenance technicians, instructors, and training developers. Ten candidate tasks were selected from two classes of maintenance tasks (seven aircraft maintenance and three space maintenance) using five criteria developed to identify types of tasks most likely to benefit from VE training. Three tasks were used as specific cases for cost-benefit analysis. In formulating research recommendations, we considered three aspects of feasibility: technological considerations, cost-effectiveness, and anticipated R&D efforts. In this paper, we describe the major findings in each of these areas and suggest research efforts that we believe will help achieve the goal of a cost-effective VE maintenance training system by the next decade.

  17. Test and Evaluation of Ultrasonic Additive Manufacturing (UAM) for a Large Aircraft Maintenance Shelter (LAMS) Baseplate

    DTIC Science & Technology

    2015-03-26

    TEST AND EVALUATION OF ULTRASONIC ADDITIVE MANUFACTURING (UAM) FOR A LARGE AREA MAINTENANCE...States Government. AFIT-ENV-MS-15-M-158 TEST AND EVALUATION OF ULTRASONIC ADDITIVE MANUFACTURING FOR A LARGE AREA MAINTENANCE SHELTER...Civil Engineer (CE) operations. This research replicates a Large Area Maintenance Shelter (LAMS) baseplate design for ultrasonic additive

  18. Optical Fiber Sensors for Aircraft Structural Health Monitoring

    PubMed Central

    García, Iker; Zubia, Joseba; Durana, Gaizka; Aldabaldetreku, Gotzon; Illarramendi, María Asunción; Villatoro, Joel

    2015-01-01

    Aircraft structures require periodic and scheduled inspection and maintenance operations due to their special operating conditions and the principles of design employed to develop them. Therefore, structural health monitoring has a great potential to reduce the costs related to these operations. Optical fiber sensors applied to the monitoring of aircraft structures provide some advantages over traditional sensors. Several practical applications for structures and engines we have been working on are reported in this article. Fiber Bragg gratings have been analyzed in detail, because they have proved to constitute the most promising technology in this field, and two different alternatives for strain measurements are also described. With regard to engine condition evaluation, we present some results obtained with a reflected intensity-modulated optical fiber sensor for tip clearance and tip timing measurements in a turbine assembled in a wind tunnel. PMID:26134107

  19. Optical Fiber Sensors for Aircraft Structural Health Monitoring.

    PubMed

    García, Iker; Zubia, Joseba; Durana, Gaizka; Aldabaldetreku, Gotzon; Illarramendi, María Asunción; Villatoro, Joel

    2015-06-30

    Aircraft structures require periodic and scheduled inspection and maintenance operations due to their special operating conditions and the principles of design employed to develop them. Therefore, structural health monitoring has a great potential to reduce the costs related to these operations. Optical fiber sensors applied to the monitoring of aircraft structures provide some advantages over traditional sensors. Several practical applications for structures and engines we have been working on are reported in this article. Fiber Bragg gratings have been analyzed in detail, because they have proved to constitute the most promising technology in this field, and two different alternatives for strain measurements are also described. With regard to engine condition evaluation, we present some results obtained with a reflected intensity-modulated optical fiber sensor for tip clearance and tip timing measurements in a turbine assembled in a wind tunnel.

  20. Adapting Strategic Aircraft Assets to a Changing World: Technology Insertion to Provide Flexibility

    DTIC Science & Technology

    1994-09-01

    Distributed Processing ............................ 67 Unembedded Expansions ............................ 71 Concepts for, and Impacts on, Preflight...capabilities through the use of unembedded expansions to the existing avionics complex. But, before we explore these technology insertion concepts, we must... Unembedded Expansions The final hardware technology insertion area focuses on the concept of expanding the aircraft’s capabilities by inserting, or perhaps

  1. Aircraft empennage structural detail design

    NASA Technical Reports Server (NTRS)

    Meholic, Greg; Brown, Rhonda; Hall, Melissa; Harvey, Robert; Singer, Michael; Tella, Gustavo

    1993-01-01

    This project involved the detailed design of the aft fuselage and empennage structure, vertical stabilizer, rudder, horizontal stabilizer, and elevator for the Triton primary flight trainer. The main design goals under consideration were to illustrate the integration of the control systems devices used in the tail surfaces and their necessary structural supports as well as the elevator trim, navigational lighting system, electrical systems, tail-located ground tie, and fuselage/cabin interface structure. Accommodations for maintenance, lubrication, adjustment, and repairability were devised. Weight, fabrication, and (sub)assembly goals were addressed. All designs were in accordance with the FAR Part 23 stipulations for a normal category aircraft.

  2. Manx: Close air support aircraft preliminary design

    NASA Technical Reports Server (NTRS)

    Amy, Annie; Crone, David; Hendrickson, Heidi; Willis, Randy; Silva, Vince

    1991-01-01

    The Manx is a twin engine, twin tailed, single seat close air support design proposal for the 1991 Team Student Design Competition. It blends advanced technologies into a lightweight, high performance design with the following features: High sensitivity (rugged, easily maintained, with night/adverse weather capability); Highly maneuverable (negative static margin, forward swept wing, canard, and advanced avionics result in enhanced aircraft agility); and Highly versatile (design flexibility allows the Manx to contribute to a truly integrated ground team capable of rapid deployment from forward sites).

  3. Flexibility and Sharing of Childcare Duties in Black Families.

    ERIC Educational Resources Information Center

    Wilson, Melvin N.; And Others

    1990-01-01

    The findings of a survey of 64 Black families do not support the hypothesis of role flexibility and sharing in Black households. The mothers in the sample, 78 percent of whom were employed, were primarily responsible for household maintenance and child rearing. (DM)

  4. Aircraft Structural Design Handbook for Lower Cost Maintenance and Repair

    DTIC Science & Technology

    1977-03-01

    Structure Repair and Maintenance program under Air Force contract F33615-74-C-3101, Project No. 1368, Task No. 136802. The work was performed by...Interchangeability 6.4.5.3 Work Area Consideration 6.5 Life Cycle Cost Impact Considerati ons 6.5.1 Introduction 6.5.2 Objective 6.5.3 Life Cycle Cost...engine sonic vibration, ^auses working of the vane assemblies and their inboard and outboard attach members resulting in fatigue cracks. The constant

  5. Air Force Air Refueling: The KC-X Aircraft Acquisition Program

    DTIC Science & Technology

    2008-08-04

    7 Boom vs . Probe and Drogue Air Refueling . . . . . . . . . . . . . . . . . . . . . . 7 Capacity vs ...consideration must be given to a few key attributes. For example, a tanker aircraft’s method of dispensing fuel – flying boom vs . probe and drogue – is a key...flight, which can add considerable flexibility to certain air operations. Boom vs . Probe and Drogue Air Refueling.32 Aircraft can be equipped to be

  6. Maximum Likelihood Estimation with Emphasis on Aircraft Flight Data

    NASA Technical Reports Server (NTRS)

    Iliff, K. W.; Maine, R. E.

    1985-01-01

    Accurate modeling of flexible space structures is an important field that is currently under investigation. Parameter estimation, using methods such as maximum likelihood, is one of the ways that the model can be improved. The maximum likelihood estimator has been used to extract stability and control derivatives from flight data for many years. Most of the literature on aircraft estimation concentrates on new developments and applications, assuming familiarity with basic estimation concepts. Some of these basic concepts are presented. The maximum likelihood estimator and the aircraft equations of motion that the estimator uses are briefly discussed. The basic concepts of minimization and estimation are examined for a simple computed aircraft example. The cost functions that are to be minimized during estimation are defined and discussed. Graphic representations of the cost functions are given to help illustrate the minimization process. Finally, the basic concepts are generalized, and estimation from flight data is discussed. Specific examples of estimation of structural dynamics are included. Some of the major conclusions for the computed example are also developed for the analysis of flight data.

  7. Schweizer RU-38A Twin-Condor: covert surveillance aircraft

    NASA Astrophysics Data System (ADS)

    O'Toole, Michael J.; Schweizer, Paul H.

    1997-11-01

    The world order has changed and with it, governments are now faced with waging a new type of `ware.' Regional instability, drug trafficking, environmental issues, international terrorism, and illegal immigration are examples of escalating problems that cross international boundaries and threaten the security of nations. The first and most important element in coping with these illegal activities is the ability to detect and monitor events in a timely and secure fashion. Conventional means of gathering intelligence such as large airborne collection systems and satellites lack the flexibility, dwell times, and cost effectiveness to meet many of today's needs. There is a growing requirement for airborne platforms that can covertly perform surveillance missions during either day or night and in a cost effective manner. To meet this need, Schweizer Aircraft has recently developed the RU-38A twin-engine surveillance aircraft. This paper discusses the evolution and principle design concepts of this aircraft and how its unique performance enables the RU-38A to achieve new levels of surveillance capability.

  8. Nondestructive inspection of bonded composite doublers for aircraft

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Roach, D.; Moore, D.; Walkington, P.

    1996-12-31

    One major thrust in FAA`s National Aging Aircraft Research Program is to foster new technologies in civil aircraft maintenance. Recent DOD and other government developments in using bonded composite doublers on metal structures support the need for validation of such doubler applications on US certificated airplanes. In this study, a specific composite application was chosen on an L-1011 aircraft. Primary inspection requirements for these doublers include identifying disbonds between composite laminate and aluminum parent material, and delaminations in the composite laminate. Surveillance of cracks or corrosion in the parent aluminum material beneath the double is also a concern. No singlemore » NDI method can inspect for every flaw type, therefore we need to know NDI capabilities and limitations. This paper reports on a series of NDI tests conducted on laboratory test structures and on a fuselage section from a retired L-1011. Application of ultrasonics, x-ray, and eddy current to composite doublers and results from test specimens loaded to provide a changing flaw profile, are presented in this paper. Development of appropriate inspection calibration standards are also discussed.« less

  9. 14 CFR 91.1411 - Continuous airworthiness maintenance program use by fractional ownership program manager.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... program use by fractional ownership program manager. 91.1411 Section 91.1411 Aeronautics and Space FEDERAL... airworthiness maintenance program use by fractional ownership program manager. Fractional ownership program... through 91.1443. Any program manager who elects to maintain the program aircraft using a continuous...

  10. Aviation Maintenance Technology. General. G103 Fundamentals of Regulations, Publications, and Records. Instructor Material.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    These instructor materials for an aviation maintenance technology course contain three instructional modules. The modules cover the following topics: selecting and using regulations, publications, and records; documenting aircraft records; and exercising mechanic's privileges and limitations. Each module contains some or all of these nine basic…

  11. Comparison of Requirements for Composite Structures for Aircraft and Space Applications

    NASA Technical Reports Server (NTRS)

    Raju, Ivatury S.; Elliott, Kenny B.; Hampton, Roy W.; Knight, Norman F., Jr.; Aggarwal, Pravin; Engelstad, Stephen P.; Chang, James B.

    2010-01-01

    In this paper, the aircraft and space vehicle requirements for composite structures are compared. It is a valuable exercise to study composite structural design approaches used in the airframe industry, and to adopt methodology that is applicable for space vehicles. The missions, environments, analysis methods, analysis validation approaches, testing programs, build quantities, inspection, and maintenance procedures used by the airframe industry, in general, are not transferable to spaceflight hardware. Therefore, while the application of composite design approaches from other industries is appealing, many aspects cannot be directly utilized. Nevertheless, experiences and research for composite aircraft structures may be of use in unexpected arenas as space exploration technology develops, and so continued technology exchanges are encouraged.

  12. A Simulation Based Approach for Contingency Planning for Aircraft Turnaround Operation System Activities in Airline Hubs

    NASA Technical Reports Server (NTRS)

    Adeleye, Sanya; Chung, Christopher

    2006-01-01

    Commercial aircraft undergo a significant number of maintenance and logistical activities during the turnaround operation at the departure gate. By analyzing the sequencing of these activities, more effective turnaround contingency plans may be developed for logistical and maintenance disruptions. Turnaround contingency plans are particularly important as any kind of delay in a hub based system may cascade into further delays with subsequent connections. The contingency sequencing of the maintenance and logistical turnaround activities were analyzed using a combined network and computer simulation modeling approach. Experimental analysis of both current and alternative policies provides a framework to aid in more effective tactical decision making.

  13. Development and validation of a general purpose linearization program for rigid aircraft models

    NASA Technical Reports Server (NTRS)

    Duke, E. L.; Antoniewicz, R. F.

    1985-01-01

    A FORTRAN program that provides the user with a powerful and flexible tool for the linearization of aircraft models is discussed. The program LINEAR numerically determines a linear systems model using nonlinear equations of motion and a user-supplied, nonlinear aerodynamic model. The system model determined by LINEAR consists of matrices for both the state and observation equations. The program has been designed to allow easy selection and definition of the state, control, and observation variables to be used in a particular model. Also, included in the report is a comparison of linear and nonlinear models for a high performance aircraft.

  14. Configuration selection for a 450-passenger ultraefficient 2020 aircraft

    NASA Astrophysics Data System (ADS)

    Paulus, D.; Salmon, T.; Mohr, B.; Roessler, C.; Petersson, Ӧ.; Stroscher, F.; Baier, H.; Hornung, M.

    2013-12-01

    This paper describes the configuration selection process in the FP7 project ACFA (Active Control for Flexible Aircraft) 2020 in view of the Advisory Council for Aeronautics Research in Europe (ACARE) aims. The design process challenges and the comparison of a blended wing body (BWB) aircraft with a wide body carry-through wing box (CWB) configuration are described in detail. Furthermore, the interactions between the conceptual design and structural design using multidisciplinary design optimization (MDO) to rapidly generate and adapt structural models to design changes and provide early feedback of mass and center of gravity values for these nontraditional configurations are discussed. Comparison of the two concepts determined that the developed all-lifting BWB airframe has the potential for a significant reduced fuel consumption compared to the CWB.

  15. Texas flexible pavements and overlays : year 5 report - complete data documentation.

    DOT National Transportation Integrated Search

    2017-05-01

    Proper calibration and validation of pavement design and performance models to Texas conditions is : essential for cost-effective flexible pavement design, performance predictions, and maintenance/rehab : strategies. The veracity of the calibration o...

  16. A Study of Transparent Plastics for use on Aircraft, Special Report

    NASA Technical Reports Server (NTRS)

    Axilrod, Benjamin M.; Kline, Gordon M.

    1937-01-01

    Various transparent organic plastics, including both commercially available and experimental materials, have been examined to determine their suitability for use as flexible windshields on aircraft, The properties which have been studied include light transmission, haziness, distortion, resistance to weathering, scratch and indentation hardness, impact strength, dimensional stability, resistance to water and various cleaning fluids, bursting strength at normal and low temperatures, and flammability.

  17. Development of Advanced Methods of Structural and Trajectory Analysis for Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Ardema, Mark D.

    1996-01-01

    In this report the author describes: (1) development of advanced methods of structural weight estimation, and (2) development of advanced methods of flight path optimization. A method of estimating the load-bearing fuselage weight and wing weight of transport aircraft based on fundamental structural principles has been developed. This method of weight estimation represents a compromise between the rapid assessment of component weight using empirical methods based on actual weights of existing aircraft and detailed, but time-consuming, analysis using the finite element method. The method was applied to eight existing subsonic transports for validation and correlation. Integration of the resulting computer program, PDCYL, has been made into the weights-calculating module of the AirCraft SYNThesis (ACSYNT) computer program. ACSYNT bas traditionally used only empirical weight estimation methods; PDCYL adds to ACSYNT a rapid, accurate means of assessing the fuselage and wing weights of unconventional aircraft. PDCYL also allows flexibility in the choice of structural concept, as well as a direct means of determining the impact of advanced materials on structural weight.

  18. Air Vehicle Integration and Technology Research (AVIATR). Task Order 0003: Condition-Based Maintenance Plus Structural Integrity (CBM+SI) Demonstration (September 2011 to March 2012)

    DTIC Science & Technology

    2012-03-01

    the potential maintenance plans are compared via the TPMs , which are related to the cost of ownership of the fleet and to aircraft availability. 7...due to maintenance of the wing system is reported because this measure has a straightforward interpretation. This TPM is referred to as Fleet DT...3.2.2. Maintenance Parameters The F-15 Program has indicated that, in practice , maintenance actions are generally performed on multiples of 200 FH. For

  19. Design Methodology for Multi-Element High-Lift Systems on Subsonic Civil Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Pepper, R. S.; vanDam, C. P.

    1996-01-01

    The choice of a high-lift system is crucial in the preliminary design process of a subsonic civil transport aircraft. Its purpose is to increase the allowable aircraft weight or decrease the aircraft's wing area for a given takeoff and landing performance. However, the implementation of a high-lift system into a design must be done carefully, for it can improve the aerodynamic performance of an aircraft but may also drastically increase the aircraft empty weight. If designed properly, a high-lift system can improve the cost effectiveness of an aircraft by increasing the payload weight for a given takeoff and landing performance. This is why the design methodology for a high-lift system should incorporate aerodynamic performance, weight, and cost. The airframe industry has experienced rapid technological growth in recent years which has led to significant advances in high-lift systems. For this reason many existing design methodologies have become obsolete since they are based on outdated low Reynolds number wind-tunnel data and can no longer accurately predict the aerodynamic characteristics or weight of current multi-element wings. Therefore, a new design methodology has been created that reflects current aerodynamic, weight, and cost data and provides enough flexibility to allow incorporation of new data when it becomes available.

  20. Fire blocking systems for aircraft seat cushions

    NASA Technical Reports Server (NTRS)

    Parker, J. A.; Kourtides, D. A. (Inventor)

    1984-01-01

    A configuration and method for reducing the flammability of bodies of organic materials that thermally decompose to give flammable gases comprises covering the body with a flexible matrix that catalytically cracks the flammable gases to less flammable species. Optionally, the matrix is covered with a gas impermeable outer layer. In a preferred embodiment, the invention takes the form of an aircraft seat in which the body is a poly(urethane) seat cushion, the matrix is an aramid fabric or felt and the outer layer is an aluminum film.

  1. Retrospective cohort mortality study of workers at an aircraft maintenance facility. I. Epidemiological results.

    PubMed

    Spirtas, R; Stewart, P A; Lee, J S; Marano, D E; Forbes, C D; Grauman, D J; Pettigrew, H M; Blair, A; Hoover, R N; Cohen, J L

    1991-08-01

    A retrospective cohort study of 14,457 workers at an aircraft maintenance facility was undertaken to evaluate mortality associated with exposures in their workplace. The purpose was to determine whether working with solvents, particularly trichloroethylene, posed any excess risk of mortality. The study group consisted of all civilian employees who worked for at least one year at Hill Air Force Base, Utah, between 1 January 1952 and 31 December 1956. Work histories were obtained from records at the National Personnel Records Centre, St. Louis, Missouri, and the cohort was followed up for ascertainment of vital state until 31 December 1982. Observed deaths among white people were compared with the expected number of deaths, based on the Utah white population, and adjusted for age, sex, and calendar period. Significant deficits occurred for mortality from all causes (SMR 92, 95% confidence interval (95% CI) 90-95), all malignant neoplasms (SMR 90, 95% CI 83-97), ischaemic heart disease (SMR 93, 95% CI 88-98), non-malignant respiratory disease (SMR 87, 95% CI 76-98), and accidents (SMR 61, 95% CI 52-70). Mortality was raised for multiple myeloma (MM) in white women (SMR 236, 95% CI 87-514), non-Hodgkin's lymphoma (NHL) in white women (SMR 212, 95% CI 102-390), and cancer of the biliary passages and liver in white men dying after 1980 (SMR 358, 95% CI 116-836). Detailed analysis of the 6929 employees occupationally exposed to trichloroethylene, the most widely used solvent at the base during the 1950s and 1960s, did not show any significant or persuasive association between several measures of exposure to trichloroethylene and any excess of cancer. Women employed in departments in which fabric cleaning and parachute repair operations were performed had more deaths than expected from MM and NHL. The inconsistent mortality patterns by sex, multiple and overlapping exposures, and small numbers made it difficult to ascribe these excesses to any particular substance

  2. Flexible and composite structures for premium pavements. Volume 2, Design manual

    DOT National Transportation Integrated Search

    1980-11-01

    This design manual presents the results of a detailed study to identify and design flexible and composite pavement configurations which will perform as premium or "zero-maintenance" pavements. This manual includes identification and classification of...

  3. Robust, Flexible and Lightweight Dielectric Barrier Discharge Actuators Using Nanofoams/Aerogels

    NASA Technical Reports Server (NTRS)

    Siochi, Emilie J. (Inventor); Sauti, Godfrey (Inventor); Wilkinson, Stephen P. (Inventor); Guo, Haiquan N. (Inventor); Xu, Tian-Bing (Inventor); Meador, Mary Ann B. (Inventor)

    2015-01-01

    Robust, flexible, lightweight, low profile enhanced performance dielectric barrier discharge actuators (plasma actuators) based on aerogels/nanofoams with controlled pore size and size distribution as well as pore shape. The plasma actuators offer high body force as well as high force to weight ratios (thrust density). The flexibility and mechanical robustness of the actuators allows them to be shaped to conform to the surface to which they are applied. Carbon nanotube (CNT) based electrodes serve to further decrease the weight and profile of the actuators while maintaining flexibility while insulating nano-inclusions in the matrix enable tailoring of the mechanical properties. Such actuators are required for flow control in aeronautics and moving machinery such as wind turbines, noise abatement in landing gear and rotary wing aircraft and other applications.

  4. Human factors issues in aircraft maintenance and inspection : "information exchange and communications".

    DOT National Transportation Integrated Search

    1990-11-01

    The Federal Aviation Administration sponsored a 2-day meeting in December 1989 as part of a continuing program to address issues of human factors and personnel performance in aviation maintenance and inspection. This meeting focused on issues of "inf...

  5. NASA DC-8 Ground Support Technicians Mark Corlew and Mike Lakowski perform routine maintenance on the aircraft in Punta Arenas, Chile

    NASA Image and Video Library

    2004-03-17

    NASA DC-8 Ground Support Technicians Mark Corlew and Mike Lakowski perform routine maintenance on the aircraft at Carlos Ibanez del Campo International Airport in Punta Arenas, Chile. AirSAR 2004 is a three-week expedition by an international team of scientists that is using an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central and South America with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. In South America and Antarctica, AirSAR will collect imagery and data to help determine the contribution of Southern Hemisphere glaciers to sea level rise due to climate change. In Patagonia, researchers found this contribution had more than doubled from 1995 to 2000, compared to the previous 25 years. AirSAR data will make it possible to determine whether that trend is decreasing, continuing or accelerating. AirSAR will also provide reliable information on ice shelf thickness to measure the contribution of the glaciers to sea level.

  6. Concept of a programmable maintenance processor applicable to multiprocessing systems

    NASA Technical Reports Server (NTRS)

    Glover, Richard D.

    1988-01-01

    A programmable maintenance processor concept applicable to multiprocessing systems has been developed at the NASA Ames Research Center's Dryden Flight Research Facility. This stand-alone-processor is intended to provide support for system and application software testing as well as hardware diagnostics. An initial machanization has been incorporated into the extended aircraft interrogation and display system (XAIDS) which is multiprocessing general-purpose ground support equipment. The XAIDS maintenance processor has independent terminal and printer interfaces and a dedicated magnetic bubble memory that stores system test sequences entered from the terminal. This report describes the hardware and software embodied in this processor and shows a typical application in the check-out of a new XAIDS.

  7. Aircraft family design using enhanced collaborative optimization

    NASA Astrophysics Data System (ADS)

    Roth, Brian Douglas

    commonality, but of appropriate fidelity for aircraft conceptual design. The thesis also introduces a new aircraft family concept. Unlike most families, the intent is not necessarily to produce all family members. Rather, the family includes members for immediate production and members that address potential future market conditions and/or environmental regulations. The result is a set of designs that yield a small performance penalty today in return for significant future flexibility to produce family members that respond to new market conditions and environmental regulations.

  8. The Eliminator: A design of a close air support aircraft

    NASA Technical Reports Server (NTRS)

    Hendrix, Mandy; Hoang, TY; Kokolios, Alex; Selyem, Sharon; Wardell, Mark; Winterrowd, David

    1991-01-01

    The Eliminator is the answer to the need for an affordable, maintainable, survivable, high performance close air support aircraft primarily for the United States, but with possible export sales to foreign customers. The Eliminator is twin turbofan, fixed wing aircraft with high mounted canards and low mounted wings. It is designed for high subsonic cruise and an attack radius of 250 nautical miles. Primarily it would carry 20 500 pound bombs as its main ordnance , but is versatile enough to carry a variety of weapons configurations to perform several different types of missions. It carries state of the art navigation and targeting systems to deliver its payload with pinpoint precision and is designed for maximum survivability of the crew and aircraft for a safe return and quick turnaround. It can operate from fields as short as 1800 ft. with easy maintenance for dispersed operation during hostile situations. It is designed for exceptional maneuverability and could be used in a variety of roles from air-to-air operations to anti-submarine warfare and maritime patrol duties.

  9. A Feasibility Study of Expanding the F404 Aircraft Engine Repair Capability at the Aircraft Intermediate Maintenance Department

    DTIC Science & Technology

    1993-06-01

    1 A. OBJECTIVES ............. .... .................. 1 B. HISTORY ................... .................... 2 C...utilization, and any additional manpower requirements at the "selected" AIMD’s. B. HISTORY Until late 1991 both NADEP JAX and NADEP North Island (NORIS...TRIANGULAR OR ALL LOG NORMAL DISTRIBUTIONS FOR SERVICE TIMES AT AIND CECIL FIELD maintenance/ Triangular Log Normal MAZDA Difference Differe•ce Supply

  10. Flying After Conducting an Aircraft Excessive Cabin Leakage Test.

    PubMed

    Houston, Stephen; Wilkinson, Elizabeth

    2016-09-01

    Aviation medical specialists should be aware that commercial airline aircraft engineers may undertake a 'dive equivalent' operation while conducting maintenance activities on the ground. We present a worked example of an occupational risk assessment to determine a minimum safe preflight surface interval (PFSI) for an engineer before flying home to base after conducting an Excessive Cabin Leakage Test (ECLT) on an unserviceable aircraft overseas. We use published dive tables to determine the minimum safe PFSI. The estimated maximum depth acquired during the procedure varies between 10 and 20 fsw and the typical estimated bottom time varies between 26 and 53 min for the aircraft types operated by the airline. Published dive tables suggest that no minimum PFSI is required for such a dive profile. Diving tables suggest that no minimum PFSI is required for the typical ECLT dive profile within the airline; however, having conducted a risk assessment, which considered peak altitude exposure during commercial flight, the worst-case scenario test dive profile, the variability of interindividual inert gas retention, and our existing policy among other occupational groups within the airline, we advised that, in the absence of a bespoke assessment of the particular circumstances on the day, the minimum PFSI after conducting ECLT should be 24 h. Houston S, Wilkinson E. Flying after conducting an aircraft excessive cabin leakage test. Aerosp Med Hum Perform. 2016; 87(9):816-820.

  11. Aviation Maintenance Technology. Airframe. A203. Aircraft Fabric Covering, Painting, and Finishing. Instructor Material.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This teacher's guide is designed to aid teachers in leading students through a module on airframe building and repair, including fabric covering, painting, and finishing. The module contains two units that cover the following topics: (1) inspecting, testing, and installing aircraft fabric coverings and (2) applying dope, paint, and trim. Each unit…

  12. Human factors evaluation of the work environment of operators engaged in the inspection and repair of aging aircraft.

    DOT National Transportation Integrated Search

    1992-01-01

    Site evaluations of air carriers and repair stations conducting inspections and heavy maintenance on PART 121 aging aircraft were conducted during 1989-90 under the FAA's Office of Flight Standards Aging Fleet Evaluation Program. This report presents...

  13. Application of reliability-centered-maintenance to BWR ECCS motor operator valve performance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feltus, M.A.; Choi, Y.A.

    1993-01-01

    This paper describes the application of reliability-centered maintenance (RCM) methods to plant probabilistic risk assessment (PRA) and safety analyses for four boiling water reactor emergency core cooling systems (ECCSs): (1) high-pressure coolant injection (HPCI); (2) reactor core isolation cooling (RCIC); (3) residual heat removal (RHR); and (4) core spray systems. Reliability-centered maintenance is a system function-based technique for improving a preventive maintenance program that is applied on a component basis. Those components that truly affect plant function are identified, and maintenance tasks are focused on preventing their failures. The RCM evaluation establishes the relevant criteria that preserve system function somore » that an RCM-focused approach can be flexible and dynamic.« less

  14. The Ashore Infrastructure Requirments Needed to Support Mobile Maintenance Facilities (MMF) for Intermediate Maintenance on the Next Generation Aircraft Carrier (CVNX)

    DTIC Science & Technology

    1999-12-01

    GENERATION AIRCRAFT CARRIER (CVNX) 6. AUTHOR(S) Watt, Michael R. 5. FUNDING NUMBERS Contract Number 7. PERFORMING ORGANIZATION NAME(S) AND...ADDRESS(ES) Naval Postgraduate School Monterey, CA 93943-5000 PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING / MONITORING AGENCY NAME(S) AND... ORGANIZATION OF STUDY 5 H. BACKGROUND INFORMATION 9 A. CURRENT MILITARY USERS OF MOBILE FACILITIES 10 1. United States Marine Corps (USMC) 11 2

  15. Applying Best Practices to Military Commercial-Derivative Aircraft Engine Sustainment: Assessment of Using Parts Manufacturer Approval (PMA) Parts and Designated Engineering Representative (DER) Repairs

    DTIC Science & Technology

    2016-01-01

    Company HPT high-pressure turbine LPT low-pressure turbine MARPA Modification and Replacement Parts Association MRO maintenance , repair, and overhaul...Corporation R® is a registered trademark. Cover image: A KC-10 F103 (CF6-50) engine at the MTU Vancouver facility (courtesy of MTU Maintenance Canada Ltd...representative (DER) repairs to decrease the cost of their aircraft engine maintenance . These parts and repairs are provided by third-party companies and

  16. Creating a Test-Validated Finite-Element Model of the X-56A Aircraft Structure

    NASA Technical Reports Server (NTRS)

    Pak, Chan-Gi; Truong, Samson

    2014-01-01

    Small modeling errors in a finite-element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of the X-56A Multi-Utility Technology Testbed aircraft is the flight demonstration of active flutter suppression and, therefore, in this study, the identification of the primary and secondary modes for the structural model tuning based on the flutter analysis of the X-56A aircraft. The ground-vibration test-validated structural dynamic finite-element model of the X-56A aircraft is created in this study. The structural dynamic finite-element model of the X-56A aircraft is improved using a model-tuning tool. In this study, two different weight configurations of the X-56A aircraft have been improved in a single optimization run. Frequency and the cross-orthogonality (mode shape) matrix were the primary focus for improvement, whereas other properties such as c.g. location, total weight, and off-diagonal terms of the mass orthogonality matrix were used as constraints. The end result was an improved structural dynamic finite-element model configuration for the X-56A aircraft. Improved frequencies and mode shapes in this study increased average flutter speeds of the X-56A aircraft by 7.6% compared to the baseline model.

  17. Control of nonlinear flexible space structures

    NASA Astrophysics Data System (ADS)

    Shi, Jianjun

    With the advances made in computer technology and efficiency of numerical algorithms over last decade, the MPC strategies have become quite popular among control community. However, application of MPC or GPC to flexible space structure control has not been explored adequately in the literature. The work presented in this thesis primarily focuses on application of GPC to control of nonlinear flexible space structures. This thesis is particularly devoted to the development of various approximate dynamic models, design and assessment of candidate controllers, and extensive numerical simulations for a realistic multibody flexible spacecraft, namely, Jupiter Icy Moons Orbiter (JIMO)---a Prometheus class of spacecraft proposed by NASA for deep space exploratory missions. A stable GPC algorithm is developed for Multi-Input-Multi-Output (MIMO) systems. An end-point weighting (penalty) is used in the GPC cost function to guarantee the nominal stability of the closed-loop system. A method is given to compute the desired end-point state from the desired output trajectory. The methodologies based on Fake Algebraic Riccati Equation (FARE) and constrained nonlinear optimization, are developed for synthesis of state weighting matrix. This makes this formulation more practical. A stable reconfigurable GPC architecture is presented and its effectiveness is demonstrated on both aircraft as well as spacecraft model. A representative in-orbit maneuver is used for assessing the performance of various control strategies using various design models. Different approximate dynamic models used for analysis include linear single body flexible structure, nonlinear single body flexible structure, and nonlinear multibody flexible structure. The control laws evaluated include traditional GPC, feedback linearization-based GPC (FLGPC), reconfigurable GPC, and nonlinear dissipative control. These various control schemes are evaluated for robust stability and robust performance in the presence of

  18. A mathematical model for Vertical Attitude Takeoff and Landing (VATOL) aircraft simulation. Volume 3: User's manual for VATOL simulation program

    NASA Technical Reports Server (NTRS)

    Fortenbaugh, R. L.

    1980-01-01

    Instructions for using Vertical Attitude Takeoff and Landing Aircraft Simulation (VATLAS), the digital simulation program for application to vertical attitude takeoff and landing (VATOL) aircraft developed for installation on the NASA Ames CDC 7600 computer system are described. The framework for VATLAS is the Off-Line Simulation (OLSIM) routine. The OLSIM routine provides a flexible framework and standardized modules which facilitate the development of off-line aircraft simulations. OLSIM runs under the control of VTOLTH, the main program, which calls the proper modules for executing user specified options. These options include trim, stability derivative calculation, time history generation, and various input-output options.

  19. Twist Model Development and Results from the Active Aeroelastic Wing F/A-18 Aircraft

    NASA Technical Reports Server (NTRS)

    Lizotte, Andrew M.; Allen, Michael J.

    2007-01-01

    Understanding the wing twist of the active aeroelastic wing (AAW) F/A-18 aircraft is a fundamental research objective for the program and offers numerous benefits. In order to clearly understand the wing flexibility characteristics, a model was created to predict real-time wing twist. A reliable twist model allows the prediction of twist for flight simulation, provides insight into aircraft performance uncertainties, and assists with computational fluid dynamic and aeroelastic issues. The left wing of the aircraft was heavily instrumented during the first phase of the active aeroelastic wing program allowing deflection data collection. Traditional data processing steps were taken to reduce flight data, and twist predictions were made using linear regression techniques. The model predictions determined a consistent linear relationship between the measured twist and aircraft parameters, such as surface positions and aircraft state variables. Error in the original model was reduced in some cases by using a dynamic pressure-based assumption. This technique produced excellent predictions for flight between the standard test points and accounted for nonlinearities in the data. This report discusses data processing techniques and twist prediction validation, and provides illustrative and quantitative results.

  20. Twist Model Development and Results From the Active Aeroelastic Wing F/A-18 Aircraft

    NASA Technical Reports Server (NTRS)

    Lizotte, Andrew; Allen, Michael J.

    2005-01-01

    Understanding the wing twist of the active aeroelastic wing F/A-18 aircraft is a fundamental research objective for the program and offers numerous benefits. In order to clearly understand the wing flexibility characteristics, a model was created to predict real-time wing twist. A reliable twist model allows the prediction of twist for flight simulation, provides insight into aircraft performance uncertainties, and assists with computational fluid dynamic and aeroelastic issues. The left wing of the aircraft was heavily instrumented during the first phase of the active aeroelastic wing program allowing deflection data collection. Traditional data processing steps were taken to reduce flight data, and twist predictions were made using linear regression techniques. The model predictions determined a consistent linear relationship between the measured twist and aircraft parameters, such as surface positions and aircraft state variables. Error in the original model was reduced in some cases by using a dynamic pressure-based assumption and by using neural networks. These techniques produced excellent predictions for flight between the standard test points and accounted for nonlinearities in the data. This report discusses data processing techniques and twist prediction validation, and provides illustrative and quantitative results.

  1. High-Fidelity Multidisciplinary Design Optimization of Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Martins, Joaquim R. R. A.; Kenway, Gaetan K. W.; Burdette, David; Jonsson, Eirikur; Kennedy, Graeme J.

    2017-01-01

    To evaluate new airframe technologies we need design tools based on high-fidelity models that consider multidisciplinary interactions early in the design process. The overarching goal of this NRA is to develop tools that enable high-fidelity multidisciplinary design optimization of aircraft configurations, and to apply these tools to the design of high aspect ratio flexible wings. We develop a geometry engine that is capable of quickly generating conventional and unconventional aircraft configurations including the internal structure. This geometry engine features adjoint derivative computation for efficient gradient-based optimization. We also added overset capability to a computational fluid dynamics solver, complete with an adjoint implementation and semiautomatic mesh generation. We also developed an approach to constraining buffet and started the development of an approach for constraining utter. On the applications side, we developed a new common high-fidelity model for aeroelastic studies of high aspect ratio wings. We performed optimal design trade-o s between fuel burn and aircraft weight for metal, conventional composite, and carbon nanotube composite wings. We also assessed a continuous morphing trailing edge technology applied to high aspect ratio wings. This research resulted in the publication of 26 manuscripts so far, and the developed methodologies were used in two other NRAs. 1

  2. A Small Aircraft Transportation System (SATS) Demand Model

    NASA Technical Reports Server (NTRS)

    Long, Dou; Lee, David; Johnson, Jesse; Kostiuk, Peter; Yackovetsky, Robert (Technical Monitor)

    2001-01-01

    The Small Aircraft Transportation System (SATS) demand modeling is a tool that will be useful for decision-makers to analyze SATS demands in both airport and airspace. We constructed a series of models following the general top-down, modular principles in systems engineering. There are three principal models, SATS Airport Demand Model (SATS-ADM), SATS Flight Demand Model (SATS-FDM), and LMINET-SATS. SATS-ADM models SATS operations, by aircraft type, from the forecasts in fleet, configuration and performance, utilization, and traffic mixture. Given the SATS airport operations such as the ones generated by SATS-ADM, SATS-FDM constructs the SATS origin and destination (O&D) traffic flow based on the solution of the gravity model, from which it then generates SATS flights using the Monte Carlo simulation based on the departure time-of-day profile. LMINET-SATS, an extension of LMINET, models SATS demands at airspace and airport by all aircraft operations in US The models use parameters to provide the user with flexibility and ease of use to generate SATS demand for different scenarios. Several case studies are included to illustrate the use of the models, which are useful to identify the need for a new air traffic management system to cope with SATS.

  3. Optimal maintenance of a multi-unit system under dependencies

    NASA Astrophysics Data System (ADS)

    Sung, Ho-Joon

    same end-goals as Reliability Centered Maintenance (RCM). RCM was first introduced to the aircraft industry in an attempt to bridge the gap between the empirically-driven and theory-driven approaches to establishing optimal maintenance policies. Under RCM, qualitative processes that enable the prioritizing of functions based on the criticality and influence would be combined with mathematical modeling to obtain the optimal maintenance policies. Where this thesis work deviates from RCM is its proposal to directly apply quantitative processes to model the reliability measures in optimal maintenance problem. First, Monte Carlo (MC) simulation, in conjunction with a pre-determined Design of Experiments (DOE) table, can be used as a numerical means of obtaining the corresponding discrete simulated outcomes of the reliability measures based on the combination of decision variables (e.g., periodic preventive maintenance interval, trigger age for opportunistic maintenance, etc.). These discrete simulation results can then be regressed as Response Surface Equations (RSEs) with respect to the decision variables. Such an approach to represent the reliability measures with continuous surrogate functions (i.e., the RSEs) not only enables the application of the numerical optimization technique to solve for optimal maintenance policies, but also obviates the need to make mathematical assumptions or impose over-simplifications on the structure of a multi-unit system for the sake of mathematical tractability. The applicability of the proposed methodology to a real-world optimal maintenance problem is showcased through its application to a Time Limited Dispatch (TLD) of Full Authority Digital Engine Control (FADEC) system. In broader terms, this proof-of-concept exercise can be described as a constrained optimization problem, whose objective is to identify the optimal system inspection interval that guarantees a certain level of availability for a multi-unit system. A variety of

  4. Interaction of Aircraft Wakes From Laterally Spaced Aircraft

    NASA Technical Reports Server (NTRS)

    Proctor, Fred H.

    2009-01-01

    Large Eddy Simulations are used to examine wake interactions from aircraft on closely spaced parallel paths. Two sets of experiments are conducted, with the first set examining wake interactions out of ground effect (OGE) and the second set for in ground effect (IGE). The initial wake field for each aircraft represents a rolled-up wake vortex pair generated by a B-747. Parametric sets include wake interactions from aircraft pairs with lateral separations of 400, 500, 600, and 750 ft. The simulation of a wake from a single aircraft is used as baseline. The study shows that wake vortices from either a pair or a formation of B-747 s that fly with very close lateral spacing, last longer than those from an isolated B-747. For OGE, the inner vortices between the pair of aircraft, ascend, link and quickly dissipate, leaving the outer vortices to decay and descend slowly. For the IGE scenario, the inner vortices ascend and last longer, while the outer vortices decay from ground interaction at a rate similar to that expected from an isolated aircraft. Both OGE and IGE scenarios produce longer-lasting wakes for aircraft with separations less than 600 ft. The results are significant because concepts to increase airport capacity have been proposed that assume either aircraft formations and/or aircraft pairs landing on very closely spaced runways.

  5. LINEAR - DERIVATION AND DEFINITION OF A LINEAR AIRCRAFT MODEL

    NASA Technical Reports Server (NTRS)

    Duke, E. L.

    1994-01-01

    The Derivation and Definition of a Linear Model program, LINEAR, provides the user with a powerful and flexible tool for the linearization of aircraft aerodynamic models. LINEAR was developed to provide a standard, documented, and verified tool to derive linear models for aircraft stability analysis and control law design. Linear system models define the aircraft system in the neighborhood of an analysis point and are determined by the linearization of the nonlinear equations defining vehicle dynamics and sensors. LINEAR numerically determines a linear system model using nonlinear equations of motion and a user supplied linear or nonlinear aerodynamic model. The nonlinear equations of motion used are six-degree-of-freedom equations with stationary atmosphere and flat, nonrotating earth assumptions. LINEAR is capable of extracting both linearized engine effects, such as net thrust, torque, and gyroscopic effects and including these effects in the linear system model. The point at which this linear model is defined is determined either by completely specifying the state and control variables, or by specifying an analysis point on a trajectory and directing the program to determine the control variables and the remaining state variables. The system model determined by LINEAR consists of matrices for both the state and observation equations. The program has been designed to provide easy selection of state, control, and observation variables to be used in a particular model. Thus, the order of the system model is completely under user control. Further, the program provides the flexibility of allowing alternate formulations of both the state and observation equations. Data describing the aircraft and the test case is input to the program through a terminal or formatted data files. All data can be modified interactively from case to case. The aerodynamic model can be defined in two ways: a set of nondimensional stability and control derivatives for the flight point of

  6. Aircraft Fuel, Hydraulic and Pneumatic Systems (Course Outlines), Aviation Mechanics 3 (Air Frame): 9067.01.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to familiarize the student with the operation, inspection, and repair of aircraft fuel, hydraulic, and pneumatic systems. It is designed to help the trainee master the knowledge and skills necessary to become an aviation airframe mechanic. The aviation airframe maintenance technician…

  7. Creating a Test Validated Structural Dynamic Finite Element Model of the X-56A Aircraft

    NASA Technical Reports Server (NTRS)

    Pak, Chan-Gi; Truong, Samson

    2014-01-01

    Small modeling errors in the finite element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of the Multi Utility Technology Test-bed, X-56A aircraft, is the flight demonstration of active flutter suppression, and therefore in this study, the identification of the primary and secondary modes for the structural model tuning based on the flutter analysis of the X-56A aircraft. The ground vibration test-validated structural dynamic finite element model of the X-56A aircraft is created in this study. The structural dynamic finite element model of the X-56A aircraft is improved using a model tuning tool. In this study, two different weight configurations of the X-56A aircraft have been improved in a single optimization run. Frequency and the cross-orthogonality (mode shape) matrix were the primary focus for improvement, while other properties such as center of gravity location, total weight, and offdiagonal terms of the mass orthogonality matrix were used as constraints. The end result was a more improved and desirable structural dynamic finite element model configuration for the X-56A aircraft. Improved frequencies and mode shapes in this study increased average flutter speeds of the X-56A aircraft by 7.6% compared to the baseline model.

  8. Follow on Research for Multi-Utility Technology Test Bed Aircraft at NASA Dryden Flight Research Center (FY13 Progress Report)

    NASA Technical Reports Server (NTRS)

    Pak, Chan-Gi

    2013-01-01

    Modern aircraft employ a significant fraction of their weight in composite materials to reduce weight and improve performance. Aircraft aeroservoelastic models are typically characterized by significant levels of model parameter uncertainty due to the composite manufacturing process. Small modeling errors in the finite element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of Multi Utility Technology Test-bed (MUTT) aircraft is the flight demonstration of active flutter suppression, and therefore in this study, the identification of the primary and secondary modes for the structural model tuning based on the flutter analysis of MUTT aircraft. The ground vibration test-validated structural dynamic finite element model of the MUTT aircraft is created in this study. The structural dynamic finite element model of MUTT aircraft is improved using the in-house Multi-disciplinary Design, Analysis, and Optimization tool. In this study, two different weight configurations of MUTT aircraft have been improved simultaneously in a single model tuning procedure.

  9. The History of the XV-15 Tilt Rotor Research Aircraft: From Concept to Flight

    NASA Technical Reports Server (NTRS)

    Maisel, Martin D.; Giulianetti, Demo J.; Dugan, Daniel C.

    2000-01-01

    This monograph is a testament to the efforts of many people overcoming multiple technical challenges encountered while developing the XV-15 tilt rotor research aircraft. The Ames involvement with the tilt rotor aircraft began in 1957 with investigations of the performance and dynamic behavior of the Bell XV-3 tilt rotor aircraft. At that time, Ames Research Center was known as the Ames Aeronautical Laboratory of the National Advisory Committee for Aeronautics (NACA). As we approach the new millennium, and after more than 40 years of effort and the successful completion of our initial goals, it is appropriate to reflect on the technical accomplishments and consider the future applications of this unique aircraft class, the tilt rotor. The talented engineers, technicians, managers, and leaders at Ames have worked hard with their counterparts in the U.S. rotorcraft industry to overcome technology barriers and to make the military and civil tilt rotor aircraft safer, environmentally acceptable, and more efficient. The tilt rotor aircraft combines the advantages of vertical takeoff and landing capabilities, inherent to the helicopter, with the forward speed and range of a fixed wing turboprop airplane. Our studies have shown that this new vehicle type can provide the aviation transportation industry with the flexibility for highspeed, long-range flight, coupled with runway-independent operations, thus having a significant potential to relieve airport congestion. We see the tilt rotor aircraft as an element of the solution to this growing air transport problem.

  10. Retrospective cohort mortality study of workers at an aircraft maintenance facility. I. Epidemiological results.

    PubMed Central

    Spirtas, R; Stewart, P A; Lee, J S; Marano, D E; Forbes, C D; Grauman, D J; Pettigrew, H M; Blair, A; Hoover, R N; Cohen, J L

    1991-01-01

    A retrospective cohort study of 14,457 workers at an aircraft maintenance facility was undertaken to evaluate mortality associated with exposures in their workplace. The purpose was to determine whether working with solvents, particularly trichloroethylene, posed any excess risk of mortality. The study group consisted of all civilian employees who worked for at least one year at Hill Air Force Base, Utah, between 1 January 1952 and 31 December 1956. Work histories were obtained from records at the National Personnel Records Centre, St. Louis, Missouri, and the cohort was followed up for ascertainment of vital state until 31 December 1982. Observed deaths among white people were compared with the expected number of deaths, based on the Utah white population, and adjusted for age, sex, and calendar period. Significant deficits occurred for mortality from all causes (SMR 92, 95% confidence interval (95% CI) 90-95), all malignant neoplasms (SMR 90, 95% CI 83-97), ischaemic heart disease (SMR 93, 95% CI 88-98), non-malignant respiratory disease (SMR 87, 95% CI 76-98), and accidents (SMR 61, 95% CI 52-70). Mortality was raised for multiple myeloma (MM) in white women (SMR 236, 95% CI 87-514), non-Hodgkin's lymphoma (NHL) in white women (SMR 212, 95% CI 102-390), and cancer of the biliary passages and liver in white men dying after 1980 (SMR 358, 95% CI 116-836). Detailed analysis of the 6929 employees occupationally exposed to trichloroethylene, the most widely used solvent at the base during the 1950s and 1960s, did not show any significant or persuasive association between several measures of exposure to trichloroethylene and any excess of cancer. Women employed in departments in which fabric cleaning and parachute repair operations were performed had more deaths than expected from MM and NHL. The inconsistent mortality patterns by sex, multiple and overlapping exposures, and small numbers made it difficult to ascribe these excesses to any particular substance

  11. AIR NATIONAL GUARD C-130H AIRCRAFT MAINTENANCE OFFICER MANNING: IS THERE A BETTER OPTION

    DTIC Science & Technology

    2016-10-01

    7 Section V: Result of Analysis...was put into how to reorganize existing aircraft manpower and without creating additional cost or manpower requirements. Through careful analysis it...38-201 Determining Manpower Requirements states, “National Guard Bureau (NGB)/A1MR will build Unit Manning Documents (UMD) in accordance with

  12. 76 FR 45011 - Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ...This action proposes several new NOX emission standards, compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet engines with rated thrusts greater than 26.7 kilonewtons (kN). We also are proposing certain other requirements for gas turbine engines that are subject to exhaust emission standards. First, we are proposing to clarify when the emission characteristics of a new turbofan or turbojet engine model have become different enough from its existing parent engine design that it must conform to the most current emission standards. Second, we are proposing a new reporting requirement for manufacturers of gas turbine engines that are subject to any exhaust emission standard to provide us with timely and consistent emission-related information. Third, and finally, we are proposing amendments to aircraft engine test and emissions measurement procedures. EPA actively participated in the United Nation's International Civil Aviation Organization (ICAO) proceedings in which most of these proposed requirements were first developed. These proposed regulatory requirements have largely been adopted or are actively under consideration by its member states. By adopting such similar standards, therefore, the United States will maintain consistency with these international efforts.

  13. A simulation study of the flight dynamics of elastic aircraft. Volume 2: Data

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.; Davidson, John B.; Schmidt, David K.

    1987-01-01

    The simulation experiment described addresses the effects of structural flexibility on the dynamic characteristics of a generic family of aircraft. The simulation was performed using the NASA Langley VMS simulation facility. The vehicle models were obtained as part of this research project. The simulation results include complete response data and subjective pilot ratings and comments and so allow a variety of analyses. The subjective ratings and analysis of the time histories indicate that increased flexibility can lead to increased tracking errors, degraded handling qualities, and changes in the frequency content of the pilot inputs. These results, furthermore, are significantly affected by the visual cues available to the pilot.

  14. Aircraft

    DOEpatents

    Hibbs, Bart D.; Lissaman, Peter B. S.; Morgan, Walter R.; Radkey, Robert L.

    1998-01-01

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gasses for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well.

  15. Aircraft

    DOEpatents

    Hibbs, B.D.; Lissaman, P.B.S.; Morgan, W.R.; Radkey, R.L.

    1998-09-22

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gases for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well. 31 figs.

  16. Flexible fabrication systems in practice - Investigation of the operational behavior

    NASA Astrophysics Data System (ADS)

    Buedenbender, Winfried; Scheller, Thomas

    1987-10-01

    The operational behavior of flexible fabrication systems (FSS) is analyzed using two actual cases. It is found that fabrication using FSS has attained a certain standard. The technical availability and the actual use of FSS depends to a large extent on the qualifications and performance of the service and maintenance personnel.

  17. Cockpit automation

    NASA Technical Reports Server (NTRS)

    Wiener, Earl L.

    1988-01-01

    The aims and methods of aircraft cockpit automation are reviewed from a human-factors perspective. Consideration is given to the mixed pilot reception of increased automation, government concern with the safety and reliability of highly automated aircraft, the formal definition of automation, and the ground-proximity warning system and accidents involving controlled flight into terrain. The factors motivating automation include technology availability; safety; economy, reliability, and maintenance; workload reduction and two-pilot certification; more accurate maneuvering and navigation; display flexibility; economy of cockpit space; and military requirements.

  18. Analyses and tests of the B-1 aircraft structural mode control system

    NASA Technical Reports Server (NTRS)

    Wykes, J. H.; Byar, T. R.; Macmiller, C. J.; Greek, D. C.

    1980-01-01

    Analyses and flight tests of the B-1 structural mode control system (SMCS) are presented. Improvements in the total dynamic response of a flexible aircraft and the benefits to ride qualities, handling qualities, crew efficiency, and reduced dynamic loads on the primary structures, were investigated. The effectiveness and the performance of the SMCS, which uses small aerodynamic surfaces at the vehicle nose to provide damping to the structural modes, were evaluated.

  19. Flexible and composite structures for premium pavements. Volume 1, Development of design procedure

    DOT National Transportation Integrated Search

    1980-11-01

    This document provides results of a detailed study to identify flexible and composite structures which will perform as zero-maintenance pavements. To accomplish this, the report identifies the major distress types which have seriously limited the mai...

  20. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Manufacture of new aircraft, aircraft... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  1. Development of fire resistant, nontoxic aircraft interior materials

    NASA Technical Reports Server (NTRS)

    Haley, G.; Silverman, B.; Tajima, Y.

    1976-01-01

    All available newly developed nonmetallic polymers were examined for possible usage in developing fire resistant, nontoxic nonmetallic parts or assemblies for aircraft interiors. Specifically, feasibility for the development of clear films for new decorative laminates, compression moldings, injection molded parts, thermoformed plastic parts, and flexible foams were given primary considerations. Preliminary data on the flame resistant characteristics of the materials were obtained. Preliminary toxicity data were generated from samples of materials submitted from the contractor. Preliminary data on the physical characteristics of various thermoplastic materials to be considered for either compression molded, injection molded, or thermoformed parts were obtained.

  2. 41 CFR 102-33.170 - What standards must we establish or require (contractually, where applicable) for maintenance of...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What standards must we establish or require (contractually, where applicable) for maintenance of our Government aircraft? 102-33.170 Section 102-33.170 Public Contracts and Property Management Federal Property Management...

  3. Integrated propulsion/energy transfer control systems for lift-fan V/STOL aircraft. [reduction of total propulsion system and control system installation requirements

    NASA Technical Reports Server (NTRS)

    Deckert, W. H.; Rolls, L. S.

    1974-01-01

    An integrated propulsion/control system for lift-fan transport aircraft is described. System behavior from full-scale experimental and piloted simulator investigations are reported. The lift-fan transport is a promising concept for short-to-medium haul civil transportation and for other missions. The lift-fan transport concept features high cruise airspeed, favorable ride qualities, small perceived noise footprints, high utilization, transportation system flexibility, and adaptability to VTOL, V/STOL, or STOL configurations. The lift-fan transport has high direct operating costs in comparison to conventional aircraft, primarily because of propulsion system and aircraft low-speed control system installation requirements. An integrated lift-fan propulsion system/aircraft low-speed control system that reduces total propulsion system and control system installation requirements is discussed.

  4. Aircraft Materials, Processes, Cleaning and Corrosion Control (Course Outline), Aviation Mechanics 1 (Power and Frame): 9073.01.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to familiarize the beginning student with the basic concepts common to aircraft materials and processes, together with the requirements of proper cleaning and corrosion control as outlined by the Federal Aviation Agency. The aviation airframe and powerplant maintenance technician is…

  5. Flutter suppression control law synthesis for the Active Flexible Wing model

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek; Perry, Boyd, III; Noll, Thomas E.

    1989-01-01

    The Active Flexible Wing Project is a collaborative effort between the NASA Langley Research Center and Rockwell International. The objectives are the validation of methodologies associated with mathematical modeling, flutter suppression control law development and digital implementation of the control system for application to flexible aircraft. A flutter suppression control law synthesis for this project is described. The state-space mathematical model used for the synthesis included ten flexible modes, four control surface modes and rational function approximation of the doublet-lattice unsteady aerodynamics. The design steps involved developing the full-order optimal control laws, reducing the order of the control law, and optimizing the reduced-order control law in both the continuous and the discrete domains to minimize stochastic response. System robustness was improved using singular value constraints. An 8th order robust control law was designed to increase the symmetric flutter dynamic pressure by 100 percent. Preliminary results are provided and experiences gained are discussed.

  6. Learner-Centered Instruction (LCI): Volume IV, The Simulated Maintenance Task Environment (SMTE): A Job Specific Simulator.

    ERIC Educational Resources Information Center

    Rifkin, Kenneth I.; And Others

    The purpose of the simulated maintenance task environment is to provide a means for training and job performance testing of the flight line weapon control systems mechanic/technician for the F-111A aircraft. It provides practice in flight line equipment checkout, troubleshooting, and removal and replacement of line replaceable units in the…

  7. Optical fiber cabling technologies for flexible access network

    NASA Astrophysics Data System (ADS)

    Tanji, Hisashi

    2008-07-01

    Fiber-to-the-home (FTTH) outside plant infrastructure should be so designed and constructed as to flexibly deal with increasing subscribers and system evolution to be expected in the future, taking minimization of total cost (CAPEX and OPEX) into consideration. With this in mind, fiber access architectures are reviewed and key technologies on optical fiber and cable for supporting flexible access network are presented. Low loss over wide wavelength (low water peak) and bend-insensitive single mode fiber is a future proof solution. Enhanced separable ribbon facilitates mid-span access to individual fibers in a cable installed, improving fiber utilizing efficiency and flexibility of distribution design. It also contributes to an excellent low PMD characteristic which could be required for video RF overlay system or high capacity long reach metro-access convergence network in the future. Bend-insensitive fiber based cabling technique including field installable connector greatly improves fiber/cable handling in installation and maintenance work.

  8. Engine Company Evaluation of Feasibility of Aircraft Retrofit Water-Injected Turbomachines

    NASA Technical Reports Server (NTRS)

    Becker, Arthur

    2006-01-01

    This study supports the NASA Glenn Research Center and the U.S. Air Force Research Laboratory in their efforts to evaluate the effect of water injection on aircraft engine performance and emissions. In this study, water is only injected during the takeoff and initial climb phase of a flight. There is no water injection during engine start or ground operations, nor during climb, cruise, descent, or landing. This study determined the maintenance benefit of water injection during takeoff and initial climb and evaluated the feasibility of retrofitting a current production engine, the PW4062 (Pratt & Whitney, East Hartford, CT), with a water injection system. Predicted NO(x) emissions based on a 1:1 water-tofuel ratio are likely to be reduced between 30 to 60 percent in Environmental Protection Agency parameter (EPAP). The maintenance cost benefit for an idealized combustor water injection system installed on a PW4062 engine in a Boeing 747-400ER aircraft (The Boeing Company, Chicago, IL) is computed to be $22 per engine flight hour (EFH). Adding water injection as a retrofit kit would cost up to $375,000 per engine because of the required modifications to the fuel system and addition of the water supply system. There would also be significant nonrecurring costs associated with the development and certification of the system that may drive the system price beyond affordability.

  9. A Meta-Analysis Of Corrosion Studies for Maritime Patrol and Reconnaissance Aircraft (MPRA)

    DTIC Science & Technology

    2016-09-01

    performed onsite. Aircraft rating was based upon the presence and/or extent of paint adhesion, paint cracking , clean ability, fluid damage, oxidation...because of corrosion control maintenance. No significant issues were observed related to paint cracking , fluid damage, corrosion, and clean ability of...HEXAMETHYLENEDIISOCYANATE 822-06-0 83194 X-310A; POLYURETHANE CATALYST XYLENE 1330-20-7 82649 X-530; HS EPOXY ENAMEL CURING SOLUTION BUTANOL 71-36-3

  10. Use of active control technology to improve ride qualities of large transport aircraft

    NASA Technical Reports Server (NTRS)

    Cohen, G. C.; Cotter, C. J.; Taylor, D. L.

    1976-01-01

    Analyses, construction and flight testing of two systems: Beta-vane and Modal Suppression Augmentation System (MSAS), which were developed to suppress gust induced lateral accelerations of large aircraft, are described. The 747 transport was used as the test vehicle. The purpose of the Beta-vane system is to reduce acceleration levels at the dutch roll frequency whereas the function of the MSAS system is to reduce accelerations due to flexible body motions caused by turbulence. Data from flight test, with both systems engaged shows a 50 to 70 percent reduction in lateral aft body acceleration levels. Furthermore, it is suggested that present day techniques used for developing dynamic equations of motion in the flexible mode region are limited.

  11. Manpower Forecasts and Planned Maintenance Personnel Skill Level Changes

    DTIC Science & Technology

    1980-08-01

    McDonnell Aircraft Company performed a study to determine the relationship between subsystem design characteristics * training costs, training difficulties...I~ea)I.JJ ~* N 2u,~J~: a I# 3AU JIUA ’M aa uvJ~d~ I AWNaILa~ aa-; Jjau..rii Luu Ca 4 0 * a’ - -~e o ititti a I saa ’ -- I - 1 4 J b4𔃻 -,f JIL 1 .aa...one hundred man years of effort and several civilian companies an well as Air Force resources. The flexibility and detail available *in this programming

  12. World commercial aircraft accidents

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kimura, C.Y.

    1993-01-01

    This report is a compilation of all accidents world-wide involving aircraft in commercial service which resulted in the loss of the airframe or one or more fatality, or both. This information has been gathered in order to present a complete inventory of commercial aircraft accidents. Events involving military action, sabotage, terrorist bombings, hijackings, suicides, and industrial ground accidents are included within this list. Included are: accidents involving world commercial jet aircraft, world commercial turboprop aircraft, world commercial pistonprop aircraft with four or more engines and world commercial pistonprop aircraft with two or three engines from 1946 to 1992. Each accidentmore » is presented with information in the following categories: date of the accident, airline and its flight numbers, type of flight, type of aircraft, aircraft registration number, construction number/manufacturers serial number, aircraft damage, accident flight phase, accident location, number of fatalities, number of occupants, cause, remarks, or description (brief) of the accident, and finally references used. The sixth chapter presents a summary of the world commercial aircraft accidents by major aircraft class (e.g. jet, turboprop, and pistonprop) and by flight phase. The seventh chapter presents several special studies including a list of world commercial aircraft accidents for all aircraft types with 100 or more fatalities in order of decreasing number of fatalities, a list of collision accidents involving commercial aircrafts, and a list of world commercial aircraft accidents for all aircraft types involving military action, sabotage, terrorist bombings, and hijackings.« less

  13. NASA Langley Atmospheric Science Data Center (ASDC) Experience with Aircraft Data

    NASA Astrophysics Data System (ADS)

    Perez, J.; Sorlie, S.; Parker, L.; Mason, K. L.; Rinsland, P.; Kusterer, J.

    2011-12-01

    Over the past decade the NASA Langley ASDC has archived and distributed a variety of aircraft mission data sets. These datasets posed unique challenges for archiving from the rigidity of the archiving system and formats to the lack of metadata. The ASDC developed a state-of-the-art data archive and distribution system to serve the atmospheric sciences data provider and researcher communities. The system, called Archive - Next Generation (ANGe), is designed with a distributed, multi-tier, serviced-based, message oriented architecture enabling new methods for searching, accessing, and customizing data. The ANGe system provides the ease and flexibility to ingest and archive aircraft data through an ad hoc workflow or to develop a new workflow to suit the providers needs. The ASDC will describe the challenges encountered in preparing aircraft data for archiving and distribution. The ASDC is currently providing guidance to the DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) Earth Venture-1 project on developing collection, granule, and browse metadata as well as supporting the ADAM (Airborne Data For Assessing Models) site.

  14. Design of a control configured tanker aircraft

    NASA Technical Reports Server (NTRS)

    Walker, S. A.

    1976-01-01

    The benefits that accrue from using control configured vehicle (CCV) concepts were examined along with the techniques for applying these concepts to an advanced tanker aircraft design. Reduced static stability (RSS) and flutter mode control (FMC) were the two primary CCV concepts used in the design. The CCV tanker was designed to the same mission requirements specified for a conventional tanker design. A seven degree of freedom mathematical model of the flexible aircraft was derived and used to synthesize a lateral stability augmentation system (SAS), a longitudinal control augmentation system (CAS), and a FMC system. Fatigue life and cost analyses followed the control system synthesis, after which a comparative evaluation of the CCV and conventional tankers was made. This comparison indicated that the CCV weight and cost were lower but that, for this design iteration, the CCV fatigue life was shorter. Also, the CCV crew station acceleration was lower, but the acceleration at the boom operator station was higher relative to the corresponding conventional tanker. Comparison of the design processes used in the CCV and conventional design studies revealed that they were basically the same.

  15. Graphene-Based Ultra-Light Batteries for Aircraft

    NASA Technical Reports Server (NTRS)

    Calle, Carlos I.; Kaner, Richard B.

    2014-01-01

    Develop a graphene-based ultracapacitor prototype that is flexible, thin, lightweight, durable, low cost, and safe and that will demonstrate the feasibility for use in aircraft center dot These graphene-based devices store charge on graphene sheets and take advantage of the large accessible surface area of graphene (2,600 m2/g) to increase the electrical energy that can be stored. center dot The proposed devices should have the electrical storage capacity of thin-film-ion batteries but with much shorter charge/discharge cycle times as well as longer lives center dot The proposed devices will be carbon-based and so will not have the same issues with flammability or toxicity as the standard lithium-based storage cells There are two main established methods for the storage and delivery of electrical energy: center dot Batteries - Store energy with electrochemical reactions - High energy densities - Slow charge/discharge cycles - Used in applications requiring large amounts of energy ? aircraft center dot Electrochemical capacitors - Store energy in electrochemical double layers - Fast charge/discharge cycles - Low energy densities - Used in electronics devices - Large capacitors are used in truck engine cranking

  16. Structural analysis of Aircraft fuselage splice joint

    NASA Astrophysics Data System (ADS)

    Udaya Prakash, R.; Kumar, G. Raj; Vijayanandh, R.; Senthil Kumar, M.; Ramganesh, T.

    2016-09-01

    In Aviation sector, composite materials and its application to each component are one of the prime factors of consideration due to the high strength to weight ratio, design flexibility and non-corrosive so that the composite materials are widely used in the low weight constructions and also it can be treated as a suitable alternative to metals. The objective of this paper is to estimate and compare the suitability of a composite skin joint in an aircraft fuselage with different joints by simulating the displacement, normal stress, vonmises stress and shear stress with the help of numerical solution methods. The reference Z-stringer component of this paper is modeled by CATIA and numerical simulation is carried out by ANSYS has been used for splice joint presents in the aircraft fuselage with three combinations of joints such as riveted joint, bonded joint and hybrid joint. Nowadays the stringers are using to avoid buckling of fuselage skin, it has joined together by rivets and they are connected end to end by splice joint. Design and static analysis of three-dimensional models of joints such as bonded, riveted and hybrid are carried out and results are compared.

  17. Effects of a Stretching Development and Maintenance Program on Hamstring Extensibility in Schoolchildren: A Cluster-Randomized Controlled Trial

    PubMed Central

    Mayorga-Vega, Daniel; Merino-Marban, Rafael; Manzano-Lagunas, Jorge; Blanco, Humberto; Viciana, Jesús

    2016-01-01

    The main purpose of the present study was to examine the effects of a physical education-based stretching development and maintenance program on hamstring extensibility in schoolchildren. A sample of 150 schoolchildren aged 7-10 years old from a primary school participated in the present study (140 participants were finally included). The six classes balanced by grade were cluster randomly assigned to the experimental group 1 (n = 51), experimental group 2 (n = 51) or control group (n = 49) (i.e., a cluster randomized controlled trial design was used). During the physical education classes, the students from the experimental groups 1 and 2 performed a four-minute stretching program twice a week for nine weeks (first semester). Then, after a five-week period of detraining coinciding with the Christmas holidays, the students from the experimental groups 1 and 2 completed another stretching program twice a week for eleven weeks (second semester). The students from the experimental group 1 continued performing the stretching program for four minutes while those from the experimental group 2 completed a flexibility maintenance program for only one minute. The results of the two-way analysis of variance showed that the physical education-based stretching development program significantly improved the students’ hamstring extensibility (p < 0.001), as well as that these gains obtained remained after the stretching maintenance program (p < 0.001). Additionally, statistically significant differences between the two experimental groups were not found (p > 0.05). After a short-term stretching development program, a physical education-based stretching maintenance program of only one-minute sessions twice a week is effective in maintaining hamstring extensibility among schoolchildren. This knowledge could help and guide teachers to design programs that allow a feasible and effective development and maintenance of students’ flexibility in the physical education setting. Key

  18. Infrared Scanning For Electrical Maintenance

    NASA Astrophysics Data System (ADS)

    Eisenbath, Steven E.

    1983-03-01

    Given the technological age that we have now entered, the purpose of this paper is to relate how infrared scanning can be used for an electrical preventative maintenance program. An infrared scanner is able to produce an image because objects give off infrared radiation in relationship to their temperature. Most electrical problems will show up as an increase in temperature, thereby making the infrared scanner a useful preventative maintenance tool. Because of the sensitivity of most of the scanners, .1 to .2 of a degree, virtually all electrical problems can be pinpointed long before they become a costly failure. One of the early uses of infrared scanning was to check the power company's electrical distribution system. Most of this was performed via aircraft or truck mounted scanning devices which necessitated its semi-permanent mounting. With the advent of small hand held infrared imagers, along with more portability of the larger systems, infrared scanning has gained more popularity in checking electrical distribution systems. But the distribution systems are now a scaled down model, mainly the in-plant electrical systems. By in-plant, I mean any distribution of electricity; once it leaves the power company's grid. This can be in a hospital, retail outlet, warehouse or manufacturing facility.

  19. Integrated Aerodynamic and Control System Design of Oblique Wing Aircraft. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Morris, Stephen James

    1990-01-01

    An efficient high speed aircraft design must achieve a high lift to drag ratio at transonic and supersonic speeds. In 1952 Dr. R. T. Jones proved that for any flight Mach number minimum drag at a fixed lift is achieved by an elliptic wing planform with an appropriate oblique sweep angle. Since then, wind tunnel tests and numerical flow models have confirmed that the compressibility drag of oblique wing aircraft is lower than similar symmetrical sweep designs. At oblique sweep angles above thirty degrees the highly asymmetric planform gives rise to aerodynamic and inertia couplings which affect stability and degrade the aircraft's handling qualities. In the case of the NASA-Rockwell Oblique Wing Research Aircraft, attempts to improve the handling qualities by implementing a stability augmentation system have produced unsatisfactory results because of an inherent lack of controllability in the proposed design. The present work focuses on improving the handling qualities of oblique wing aircraft by including aerodynamic configuration parameters as variables in the control system synthesis to provide additional degrees of freedom with which to further decouple the aircraft's response. Handling qualities are measured using a quadratic cost function identical to that considered in optimal control problems, but the controller architecture is not restricted to full state feedback. An optimization procedure is used to simultaneously solve for the aircraft configuration and control gains which maximize a handling qualities measure, while meeting imposed constraints on trim. In some designs wing flexibility is also modeled and reduced order controllers are implemented. Oblique wing aircraft synthesized by this integrated design method show significant improvement in handling qualities when compared to the originally proposed closed loop aircraft. The integrated design synthesis method is then extended to show how handling qualities may be traded for other types of mission

  20. Flexible and Secure Computer-Based Assessment Using a Single Zip Disk

    ERIC Educational Resources Information Center

    Ko, C. C.; Cheng, C. D.

    2008-01-01

    Electronic examination systems, which include Internet-based system, require extremely complicated installation, configuration and maintenance of software as well as hardware. In this paper, we present the design and development of a flexible, easy-to-use and secure examination system (e-Test), in which any commonly used computer can be used as a…

  1. Real-time and integrated measurement of potential human exposure to particle-bound polycyclic aromatic hydrocarbons (PAHs) from aircraft exhaust.

    PubMed Central

    Childers, J W; Witherspoon, C L; Smith, L B; Pleil, J D

    2000-01-01

    We used real-time monitors and low-volume air samplers to measure the potential human exposure to airborne polycyclic aromatic hydrocarbon (PAH) concentrations during various flight-related and ground-support activities of C-130H aircraft at an Air National Guard base. We used three types of photoelectric aerosol sensors (PASs) to measure real-time concentrations of particle-bound PAHs in a break room, downwind from a C-130H aircraft during a four-engine run-up test, in a maintenance hangar, in a C-130H aircraft cargo bay during cargo-drop training, downwind from aerospace ground equipment (AGE), and in a C-130H aircraft cargo bay during engine running on/off (ERO) loading and backup exercises. Two low-volume air samplers were collocated with the real-time monitors for all monitoring events except those in the break room and during in-flight activities. Total PAH concentrations in the integrated-air samples followed a general trend: downwind from two AGE units > ERO-loading exercise > four-engine run-up test > maintenance hangar during taxi and takeoff > background measurements in maintenance hangar. Each PAH profile was dominated by naphthalene, the alkyl-substituted naphthalenes, and other PAHs expected to be in the vapor phase. We also found particle-bound PAHs, such as fluoranthene, pyrene, and benzo[a]pyrene in some of the sample extracts. During flight-related exercises, total PAH concentrations in the integrated-air samples were 10-25 times higher than those commonly found in ambient air. Real-time monitor mean responses generally followed the integrated-air sample trends. These monitors provided a semiquantitative temporal profile of ambient PAH concentrations and showed that PAH concentrations can fluctuate rapidly from a baseline level < 20 to > 4,000 ng/m(3) during flight-related activities. Small handheld models of the PAS monitors exhibited potential for assessing incidental personal exposure to particle-bound PAHs in engine exhaust and for serving as

  2. Raptors and aircraft

    USGS Publications Warehouse

    Smith, D.G.; Ellis, D.H.; Johnson, T.H.; Glinski, Richard L.; Pendleton, Beth Giron; Moss, Mary Beth; LeFranc, Maurice N.=; Millsap, Brian A.; Hoffman, Stephen W.

    1988-01-01

    Less than 5% of all bird strikes of aircraft are by raptor species, but damage to airframe structure or jet engine dysfunction are likely consequences. Beneficial aircraft-raptor interactions include the use of raptor species to frighten unwanted birds from airport areas and the use of aircraft to census raptor species. Many interactions, however, modify the raptor?s immediate behavior and some may decrease reproduction of sensitive species. Raptors may respond to aircraft stimuli by exhibiting alarm, increased heart rate, flushing or fleeing and occasionally by directly attacking intruding aircraft. To date, most studies reveal that raptor responses to aircraft are brief and do not limit reproduction; however, additional study is needed.

  3. Lyapunov-based control of limit cycle oscillations in uncertain aircraft systems

    NASA Astrophysics Data System (ADS)

    Bialy, Brendan

    Store-induced limit cycle oscillations (LCO) affect several fighter aircraft and is expected to remain an issue for next generation fighters. LCO arises from the interaction of aerodynamic and structural forces, however the primary contributor to the phenomenon is still unclear. The practical concerns regarding this phenomenon include whether or not ordnance can be safely released and the ability of the aircrew to perform mission-related tasks while in an LCO condition. The focus of this dissertation is the development of control strategies to suppress LCO in aircraft systems. The first contribution of this work (Chapter 2) is the development of a controller consisting of a continuous Robust Integral of the Sign of the Error (RISE) feedback term with a neural network (NN) feedforward term to suppress LCO behavior in an uncertain airfoil system. The second contribution of this work (Chapter 3) is the extension of the development in Chapter 2 to include actuator saturation. Suppression of LCO behavior is achieved through the implementation of an auxiliary error system that features hyperbolic functions and a saturated RISE feedback control structure. Due to the lack of clarity regarding the driving mechanism behind LCO, common practice in literature and in Chapters 2 and 3 is to replicate the symptoms of LCO by including nonlinearities in the wing structure, typically a nonlinear torsional stiffness. To improve the accuracy of the system model a partial differential equation (PDE) model of a flexible wing is derived (see Appendix F) using Hamilton's principle. Chapters 4 and 5 are focused on developing boundary control strategies for regulating the bending and twisting deformations of the derived model. The contribution of Chapter 4 is the construction of a backstepping-based boundary control strategy for a linear PDE model of an aircraft wing. The backstepping-based strategy transforms the original system to a exponentially stable system. A Lyapunov-based stability

  4. Millimeter-Wave Localizers for Aircraft-to-Aircraft Approach Navigation

    NASA Technical Reports Server (NTRS)

    Tang, Adrian J.

    2013-01-01

    Aerial refueling technology for both manned and unmanned aircraft is critical for operations where extended aircraft flight time is required. Existing refueling assets are typically manned aircraft, which couple to a second aircraft through the use of a refueling boom. Alignment and mating of the two aircraft continues to rely on human control with use of high-resolution cameras. With the recent advances in unmanned aircraft, it would be highly advantageous to remove/reduce human control from the refueling process, simplifying the amount of remote mission management and enabling new operational scenarios. Existing aerial refueling uses a camera, making it non-autonomous and prone to human error. Existing commercial localizer technology has proven robust and reliable, but not suited for aircraft-to-aircraft approaches like in aerial refueling scenarios since the resolution is too coarse (approximately one meter). A localizer approach system for aircraft-to-aircraft docking can be constructed using the same modulation with a millimeterwave carrier to provide high resolution. One technology used to remotely align commercial aircraft on approach to a runway are ILS (instrument landing systems). ILS have been in service within the U.S. for almost 50 years. In a commercial ILS, two partially overlapping beams of UHF (109 to 126 MHz) are broadcast from an antenna array so that their overlapping region defines the centerline of the runway. This is called a localizer system and is responsible for horizontal alignment of the approach. One beam is modulated with a 150-Hz tone, while the other with a 90-Hz tone. Through comparison of the modulation depths of both tones, an autopilot system aligns the approaching aircraft with the runway centerline. A similar system called a glide-slope (GS) exists in the 320-to-330MHz band for vertical alignment of the approach. While this technology has been proven reliable for millions of commercial flights annually, its UHF nature limits

  5. Flexible body control of the airborne telescope SOFIA

    NASA Astrophysics Data System (ADS)

    Kaercher, Hans J.

    2002-07-01

    Airborne telescopes have, compared with earthbound or space telescopes, by far the most worse environment during operations. They must not only deal with aircraft vibrations, but also with large temperature differences and aero-acoustic loads including standing waves. System simulations are particularly useful for verifying the design performance in this environment. They should include the behavior of the overall opto-mechanical system, the environmental loads and the pointing control system itself. SOFIA - the "Stratospheric Observatory for Infrared Astronomy" - is a 2,7 m infrared telescope in an open cavity of a Boeing 747 aircraft. At present the telescope is under construction in the MAN premises in Augsburg. Simulations during the design phase of the telescope showed, that there are resonance effects in the telescope excited by the cavity acoustics. The excitations disturb the pointing behavior above the allowances. This paper describes, how the overall system was simulated, how the resonance modes will be compensated by "flexible body control", and how the pointing control system will be finally optimized during test flights in an pointing improvement phase.

  6. Mediators of weight loss and weight loss maintenance in middle-aged women.

    PubMed

    Teixeira, Pedro J; Silva, Marlene N; Coutinho, Sílvia R; Palmeira, António L; Mata, Jutta; Vieira, Paulo N; Carraça, Eliana V; Santos, Teresa C; Sardinha, Luís B

    2010-04-01

    Long-term behavioral self-regulation is the hallmark of successful weight control. We tested mediators of weight loss and weight loss maintenance in middle-aged women who participated in a randomized controlled 12-month weight management intervention. Overweight and obese women (N = 225, BMI = 31.3 +/- 4.1 kg/m(2)) were randomly assigned to a control or a 1-year group intervention designed to promote autonomous self-regulation of body weight. Key exercise, eating behavior, and body image variables were assessed before and after the program, and tested as mediators of weight loss (12 months, 86% retention) and weight loss maintenance (24 months, 81% retention). Multiple mediation was employed and an intention-to-treat analysis conducted. Treatment effects were observed for all putative mediators (Effect size: 0.32-0.79, P < 0.01 vs. controls). Weight change was -7.3 +/- 5.9% (12-month) and -5.5 +/- 5.0% (24-month) in the intervention group and -1.7 +/- 5.0% and -2.2 +/- 7.5% in controls. Change in most psychosocial variables was associated with 12-month weight change, but only flexible cognitive restraint (P < 0.01), disinhibition (P < 0.05), exercise self-efficacy (P < 0.001), exercise intrinsic motivation (P < 0.01), and body dissatisfaction (P < 0.05) predicted 24-month weight change. Lower emotional eating, increased flexible cognitive restraint, and fewer exercise barriers mediated 12-month weight loss (R(2) = 0.31, P < 0.001; effect ratio: 0.37), but only flexible restraint and exercise self-efficacy mediated 24-month weight loss (R(2) = 0.17, P < 0.001; effect ratio: 0.89). This is the first study to evaluate self-regulation mediators of weight loss and 2-year weight loss maintenance, in a large sample of overweight women. Results show that lowering emotional eating and adopting a flexible dietary restraint pattern are critical for sustained weight loss. For long-term success, interventions must also be effective in promoting exercise intrinsic motivation and

  7. How Accurately do Leading and Lagging Indictors Predict F-16 Aircraft Availability (AA)

    DTIC Science & Technology

    2016-08-01

    Predictions AU/ACSC/2016 vi PREFACE As the F-16 fleet continues to age, and budgets continue to shrink , United States Air Force (USAF... shrinking budgets, it is imperative for maintenance leaders to use all tools available to them to improve the amount of aircraft available for operations...remarkable considering the overall F-16 fleet shrinking at a steady pace (see table 2 for information). AA is one of the most critical factors that

  8. Adaptive smart wing design for military aircraft: requirements, concepts, and payoffs

    NASA Astrophysics Data System (ADS)

    Kudva, Jayanth N.; Appa, Kari; Van Way, Craig B.; Lockyer, Allen J.

    1995-05-01

    New developments in smart structures and materials have made it possible to revisit earlier work in adaptive and flexible wing technology, and remove some of the limitations for technology transition to next-generation aircraft. Research performed by Northrop Grumman, under internal funding, has led to a new program sponsored by ARPA to investigate the application of smart structures and materials technologies to twist and adapt and aircraft wing. Conceptual designs are presented based on state-of-the-art materials, including shape memory alloys, piezoelectrics, and fiber optic sensors for incorporation in a proposed smart wing design. Plans are described to demonstrate proof-of-concept on a prototype 1/10 scale -18 model that will be tested in a wind tunnel for final validation. Highlights of the proposed program are summarized with respect to program objectives, requirements, key concept design features, demonstration testing, and smart wing technology payoffs and risks.

  9. Subscale Flight Testing for Aircraft Loss of Control: Accomplishments and Future Directions

    NASA Technical Reports Server (NTRS)

    Cox, David E.; Cunningham, Kevin; Jordan, Thomas L.

    2012-01-01

    Subscale flight-testing provides a means to validate both dynamic models and mitigation technologies in the high-risk flight conditions associated with aircraft loss of control. The Airborne Subscale Transport Aircraft Research (AirSTAR) facility was designed to be a flexible and efficient research facility to address this type of flight-testing. Over the last several years (2009-2011) it has been used to perform 58 research flights with an unmanned, remotely-piloted, dynamically-scaled airplane. This paper will present an overview of the facility and its architecture and summarize the experimental data collected. All flights to date have been conducted within visual range of a safety observer. Current plans for the facility include expanding the test volume to altitudes and distances well beyond visual range. The architecture and instrumentation changes associated with this upgrade will also be presented.

  10. Occupational Competencies. A Study of the Vocational-Technical Education Needs of the Manufacturing and Aviation Maintenance Industries.

    ERIC Educational Resources Information Center

    National Council on Vocational Education, Washington, DC.

    This report focuses on two areas in which the United States has traditionally been a world leader--manufacturing and aircraft maintenance. It shows that both have been affected drastically in recent years by technological change and that both will have to employ highly skilled workers in the coming decade. The report emphasizes the following…

  11. The effect of fatigue cracks on fastener flexibility, load distribution, and fatigue crack growth

    NASA Astrophysics Data System (ADS)

    Whitman, Zachary Layne

    Fatigue cracks typically occur at stress risers such as geometry changes and holes. This type of failure has serious safety and economic repercussions affecting structures such as aircraft. The need to prevent catastrophic failure due to fatigue cracks and other discontinuities has led to durability and damage tolerant methodologies influencing the design of aircraft structures. Holes in a plate or sheet filled with a fastener are common fatigue critical locations in aircraft structure requiring damage tolerance analysis (DTA). Often, the fastener is transferring load which leads to a loading condition involving both far-field stresses such as tension and bending, and localized bearing at the hole. The difference between the bearing stress and the tensile field at the hole is known as load transfer. The ratio of load transfer as well as the magnitude of the stresses plays a significant part in how quickly a crack will progress to failure. Unfortunately, the determination of load transfer in a complex joint is far from trivial. Many methods exist in the open literature regarding the analysis of splices, doublers and attachment joints to determine individual fastener loads. These methods work well for static analyses but greater refinement is needed for crack growth analysis. The first fastener in a splice or joint is typically the most critical but different fastener flexibility equations will all give different results. The constraint of the fastener head and shop end, along with the type of fastener, affects the stiffness or flexibility of the fastener. This in turn will determine the load that the fastener will transfer within a given fastener pattern. However, current methods do not account for the change in flexibility at a fastener as the crack develops. It is put forth that a crack does indeed reduce the stiffness of a fastener by changing its constraint, thus lessening the load transfer. A crack growth analysis utilizing reduced load transfer will result in

  12. LPV Modeling of a Flexible Wing Aircraft Using Modal Alignment and Adaptive Gridding Methods

    NASA Technical Reports Server (NTRS)

    Al-Jiboory, Ali Khudhair; Zhu, Guoming; Swei, Sean Shan-Min; Su, Weihua; Nguyen, Nhan T.

    2017-01-01

    One of the earliest approaches in gain-scheduling control is the gridding based approach, in which a set of local linear time-invariant models are obtained at various gridded points corresponding to the varying parameters within the flight envelop. In order to ensure smooth and effective Linear Parameter-Varying control, aligning all the flexible modes within each local model and maintaining small number of representative local models over the gridded parameter space are crucial. In addition, since the flexible structural models tend to have large dimensions, a tractable model reduction process is necessary. In this paper, the notion of s-shifted H2- and H Infinity-norm are introduced and used as a metric to measure the model mismatch. A new modal alignment algorithm is developed which utilizes the defined metric for aligning all the local models over the entire gridded parameter space. Furthermore, an Adaptive Grid Step Size Determination algorithm is developed to minimize the number of local models required to represent the gridded parameter space. For model reduction, we propose to utilize the concept of Composite Modal Cost Analysis, through which the collective contribution of each flexible mode is computed and ranked. Therefore, a reduced-order model is constructed by retaining only those modes with significant contribution. The NASA Generic Transport Model operating at various flight speeds is studied for verification purpose, and the analysis and simulation results demonstrate the effectiveness of the proposed modeling approach.

  13. Studying impact damage on carbon-fiber reinforced aircraft composite panels with sonicir

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Han Xiaoyan; Zhang Ding; He Qi

    2011-06-23

    Composites are becoming more important materials in commercial aircraft structures such as the fuselage and wings with the new B787 Dreamliner from Boeing which has the target to utilize 50% by weight of composite materials. Carbon-fiber reinforced composites are the material of choice in aircraft structures. This is due to their light weight and high strength (high strength-to-weight ratio), high specific stiffness, tailorability of properties, design flexibility etc. Especially, by reducing the aircraft's body weight by using such lighter structures, the cost of fuel can be greatly reduced with the high jet fuel price for commercial airlines. However, these compositesmore » are prone to impact damage and the damage may occur without any observable sign on the surface, yet resulting in delaminations and disbonds that may occur well within the layers. We are studying the impact problem with carbon-fiber reinforced composite panels and developing SonicIR for this application as a fast and wide-area NDE technology. In this paper, we present our results in studying composite structures including carbon-fiber reinforced composite materials, and preliminary quantitative studies on delamination type defect depth identification in the panels.« less

  14. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  15. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  16. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  17. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  18. Hypersonic aircraft design

    NASA Technical Reports Server (NTRS)

    Alkamhawi, Hani; Greiner, Tom; Fuerst, Gerry; Luich, Shawn; Stonebraker, Bob; Wray, Todd

    1990-01-01

    A hypersonic aircraft is designed which uses scramjets to accelerate from Mach 6 to Mach 10 and sustain that speed for two minutes. Different propulsion systems were considered and it was decided that the aircraft would use one full scale turbofan-ramjet. Two solid rocket boosters were added to save fuel and help the aircraft pass through the transonic region. After considering aerodynamics, aircraft design, stability and control, cooling systems, mission profile, and landing systems, a conventional aircraft configuration was chosen over that of a waverider. The conventional design was chosen due to its landing characteristics and the relative expense compared to the waverider. Fuel requirements and the integration of the engine systems and their inlets are also taken into consideration in the final design. A hypersonic aircraft was designed which uses scramjets to accelerate from Mach 6 to Mach 10 and sustain that speed for two minutes. Different propulsion systems were considered and a full scale turbofan-ramjet was chosen. Two solid rocket boosters were added to save fuel and help the aircraft pass through the transonic reqion. After the aerodynamics, aircraft design, stability and control, cooling systems, mission profile, landing systems, and their physical interactions were considered, a conventional aircraft configuration was chosen over that of a waverider. The conventional design was chosen due to its landing characteristics and the relative expense compared to the waverider. Fuel requirements and the integration of the engine systems and their inlets were also considered in the designing process.

  19. In-flight control and communication architecture of the GLORIA imaging limb sounder on atmospheric research aircraft

    NASA Astrophysics Data System (ADS)

    Kretschmer, E.; Bachner, M.; Blank, J.; Dapp, R.; Ebersoldt, A.; Friedl-Vallon, F.; Guggenmoser, T.; Gulde, T.; Hartmann, V.; Lutz, R.; Maucher, G.; Neubert, T.; Oelhaf, H.; Preusse, P.; Schardt, G.; Schmitt, C.; Schönfeld, A.; Tan, V.

    2015-06-01

    The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA), a Fourier-transform-spectrometer-based limb spectral imager, operates on high-altitude research aircraft to study the transit region between the troposphere and the stratosphere. It is one of the most sophisticated systems to be flown on research aircraft in Europe, requiring constant monitoring and human intervention in addition to an automation system. To ensure proper functionality and interoperability on multiple platforms, a flexible control and communication system was laid out. The architectures of the communication system as well as the protocols used are reviewed. The integration of this architecture in the automation process as well as the scientific campaign flight application context are discussed.

  20. In-flight control and communication architecture of the GLORIA imaging limb-sounder on atmospheric research aircraft

    NASA Astrophysics Data System (ADS)

    Kretschmer, E.; Bachner, M.; Blank, J.; Dapp, R.; Ebersoldt, A.; Friedl-Vallon, F.; Guggenmoser, T.; Gulde, T.; Hartmann, V.; Lutz, R.; Maucher, G.; Neubert, T.; Oelhaf, H.; Preusse, P.; Schardt, G.; Schmitt, C.; Schönfeld, A.; Tan, V.

    2015-02-01

    The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA), a Fourier transform spectrometer based limb spectral imager, operates on high-altitude research aircraft to study the transit region between the troposphere and the stratosphere. It is one of the most sophisticated systems to be flown on research aircraft in Europe, requiring constant monitoring and human intervention in addition to an automation system. To ensure proper functionality and interoperability on multiple platforms, a flexible control and communication system was laid out. The architectures of the communication system as well as the protocols used are reviewed. The integration of this architecture in the automation process as well as the scientific campaign flight application context are discussed.

  1. Autonomous Operations Planner: A Flexible Platform for Research in Flight-Deck Support for Airborne Self-Separation

    NASA Technical Reports Server (NTRS)

    Karr, David A.; Vivona, Robert A.; DePascale, Stephen M.; Wing, David J.

    2012-01-01

    The Autonomous Operations Planner (AOP), developed by NASA, is a flexible and powerful prototype of a flight-deck automation system to support self-separation of aircraft. The AOP incorporates a variety of algorithms to detect and resolve conflicts between the trajectories of its own aircraft and traffic aircraft while meeting route constraints such as required times of arrival and avoiding airspace hazards such as convective weather and restricted airspace. This integrated suite of algorithms provides flight crew support for strategic and tactical conflict resolutions and conflict-free trajectory planning while en route. The AOP has supported an extensive set of experiments covering various conditions and variations on the self-separation concept, yielding insight into the system s design and resolving various challenges encountered in the exploration of the concept. The design of the AOP will enable it to continue to evolve and support experimentation as the self-separation concept is refined.

  2. Fiber optic shape sensing for monitoring of flexible structures

    NASA Astrophysics Data System (ADS)

    Lally, Evan M.; Reaves, Matt; Horrell, Emily; Klute, Sandra; Froggatt, Mark E.

    2012-04-01

    Recent advances in materials science have resulted in a proliferation of flexible structures for high-performance civil, mechanical, and aerospace applications. Large aspect-ratio aircraft wings, composite wind turbine blades, and suspension bridges are all designed to meet critical performance targets while adapting to dynamic loading conditions. By monitoring the distributed shape of a flexible component, fiber optic shape sensing technology has the potential to provide valuable data during design, testing, and operation of these smart structures. This work presents a demonstration of such an extended-range fiber optic shape sensing technology. Three-dimensional distributed shape and position sensing is demonstrated over a 30m length using a monolithic silica fiber with multiple optical cores. A novel, helicallywound geometry endows the fiber with the capability to convert distributed strain measurements, made using Optical Frequency-Domain Reflectometry (OFDR), to a measurement of curvature, twist, and 3D shape along its entire length. Laboratory testing of the extended-range shape sensing technology shows

  3. User's manual for LINEAR, a FORTRAN program to derive linear aircraft models

    NASA Technical Reports Server (NTRS)

    Duke, Eugene L.; Patterson, Brian P.; Antoniewicz, Robert F.

    1987-01-01

    This report documents a FORTRAN program that provides a powerful and flexible tool for the linearization of aircraft models. The program LINEAR numerically determines a linear system model using nonlinear equations of motion and a user-supplied nonlinear aerodynamic model. The system model determined by LINEAR consists of matrices for both state and observation equations. The program has been designed to allow easy selection and definition of the state, control, and observation variables to be used in a particular model.

  4. Propulsion controlled aircraft computer

    NASA Technical Reports Server (NTRS)

    Cogan, Bruce R. (Inventor)

    2010-01-01

    A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

  5. Aeroservoelastic wind-tunnel investigations using the Active Flexible Wing Model: Status and recent accomplishments

    NASA Technical Reports Server (NTRS)

    Noll, Thomas E.; Perry, Boyd, III; Tiffany, Sherwood H.; Cole, Stanley R.; Buttrill, Carey S.; Adams, William M., Jr.; Houck, Jacob A.; Srinathkumar, S.; Mukhopadhyay, Vivek; Pototzky, Anthony S.

    1989-01-01

    The status of the joint NASA/Rockwell Active Flexible Wing Wind-Tunnel Test Program is described. The objectives are to develop and validate the analysis, design, and test methodologies required to apply multifunction active control technology for improving aircraft performance and stability. Major tasks include designing digital multi-input/multi-output flutter-suppression and rolling-maneuver-load alleviation concepts for a flexible full-span wind-tunnel model, obtaining an experimental data base for the basic model and each control concept and providing comparisons between experimental and analytical results to validate the methodologies. The opportunity is provided to improve real-time simulation techniques and to gain practical experience with digital control law implementation procedures.

  6. Unmanned aircraft systems

    USDA-ARS?s Scientific Manuscript database

    Unmanned platforms have become increasingly more common in recent years for acquiring remotely sensed data. These aircraft are referred to as Unmanned Airborne Vehicles (UAV), Remotely Piloted Aircraft (RPA), Remotely Piloted Vehicles (RPV), or Unmanned Aircraft Systems (UAS), the official term used...

  7. Development and design of flexible Fowler flaps for an adaptive wing

    NASA Astrophysics Data System (ADS)

    Monner, Hans P.; Hanselka, Holger; Breitbach, Elmar J.

    1998-06-01

    Civil transport airplanes fly with fixed geometry wings optimized only for one design point described by altitude, Mach number and airplane weight. These parameters vary continuously during flight, to which means the wing geometry seldom is optimal. According to aerodynamic investigations a chordwide variation of the wing camber leads to improvements in operational flexibility, buffet boundaries and performance resulting in reduction of fuel consumption. A spanwise differential camber variation allows to gain control over spanwise lift distributions reducing wing root bending moments. This paper describes the design of flexible Fowler flaps for an adaptive wing to be used in civil transport aircraft that allows both a chordwise as well as spanwise differential camber variation during flight. Since both lower and upper skins are flexed by active ribs, the camber variation is achieved with a smooth contour and without any additional gaps.

  8. Active local control of propeller-aircraft run-up noise.

    PubMed

    Hodgson, Murray; Guo, Jingnan; Germain, Pierre

    2003-12-01

    Engine run-ups are part of the regular maintenance schedule at Vancouver International Airport. The noise generated by the run-ups propagates into neighboring communities, disturbing the residents. Active noise control is a potentially cost-effective alternative to passive methods, such as enclosures. Propeller aircraft generate low-frequency tonal noise that is highly compatible with active control. This paper presents a preliminary investigation of the feasibility and effectiveness of controlling run-up noise from propeller aircraft using local active control. Computer simulations for different configurations of multi-channel active-noise-control systems, aimed at reducing run-up noise in adjacent residential areas using a local-control strategy, were performed. These were based on an optimal configuration of a single-channel control system studied previously. The variations of the attenuation and amplification zones with the number of control channels, and with source/control-system geometry, were studied. Here, the aircraft was modeled using one or two sources, with monopole or multipole radiation patterns. Both free-field and half-space conditions were considered: for the configurations studied, results were similar in the two cases. In both cases, large triangular quiet zones, with local attenuations of 10 dB or more, were obtained when nine or more control channels were used. Increases of noise were predicted outside of these areas, but these were minimized as more control channels were employed. By combining predicted attenuations with measured noise spectra, noise levels after implementation of an active control system were estimated.

  9. Advanced Maintenance Simulation by Means of Hand-Based Haptic Interfaces

    NASA Astrophysics Data System (ADS)

    Nappi, Michele; Paolino, Luca; Ricciardi, Stefano; Sebillo, Monica; Vitiello, Giuliana

    Aerospace industry has been involved in virtual simulation for design and testing since the birth of virtual reality. Today this industry is showing a growing interest in the development of haptic-based maintenance training applications, which represent the most advanced way to simulate maintenance and repair tasks within a virtual environment by means of a visual-haptic approach. The goal is to allow the trainee to experiment the service procedures not only as a workflow reproduced at a visual level but also in terms of the kinaesthetic feedback involved with the manipulation of tools and components. This study, conducted in collaboration with aerospace industry specialists, is aimed to the development of an immersive virtual capable of immerging the trainees into a virtual environment where mechanics and technicians can perform maintenance simulation or training tasks by directly manipulating 3D virtual models of aircraft parts while perceiving force feedback through the haptic interface. The proposed system is based on ViRstperson, a virtual reality engine under development at the Italian Center for Aerospace Research (CIRA) to support engineering and technical activities such as design-time maintenance procedure validation, and maintenance training. This engine has been extended to support haptic-based interaction, enabling a more complete level of interaction, also in terms of impedance control, and thus fostering the development of haptic knowledge in the user. The user’s “sense of touch” within the immersive virtual environment is simulated through an Immersion CyberForce® hand-based force-feedback device. Preliminary testing of the proposed system seems encouraging.

  10. Competencies development and self-assessment in maintenance management e-training

    NASA Astrophysics Data System (ADS)

    Papathanassiou, Nikos; Pistofidis, Petros; Emmanouilidis, Christos

    2013-10-01

    The maintenance management function requires staff to possess a truly multidisciplinary set of skills. This includes competencies from engineering and information technology to health and safety, management and finance, while also taking into account the normative and legislative issues. This body of knowledge is rarely readily available within a single university course. The potential of e-learning in this field is significant, as it is a flexible and less costly alternative to conventional training. Furthermore, trainees can follow their own pace, as their available time is often a commodity. This article discusses the development of tools to support competencies development and self-assessment in maintenance management. Based on requirements arising from professional bodies' guidelines and a user survey, the developed tools implement a dedicated maintenance management training curriculum. The results from pilot testing on academic and industrial user groups are discussed and user evaluations are linked with specific e-learning design issues.

  11. Reduced order model of a blended wing body aircraft configuration

    NASA Astrophysics Data System (ADS)

    Stroscher, F.; Sika, Z.; Petersson, O.

    2013-12-01

    This paper describes the full development process of a numerical simulation model for the ACFA2020 (Active Control for Flexible 2020 Aircraft) blended wing body (BWB) configuration. Its requirements are the prediction of aeroelastic and flight dynamic response in time domain, with relatively small model order. Further, the model had to be parameterized with regard to multiple fuel filling conditions, as well as flight conditions. High efforts have been conducted in high-order aerodynamic analysis, for subsonic and transonic regime, by several project partners. The integration of the unsteady aerodynamic databases was one of the key issues in aeroelastic modeling.

  12. Transducer Modules for Dry-Coupled Ultrasonic Inspection of Aircraft Structures

    NASA Astrophysics Data System (ADS)

    Komsky, Igor N.

    2004-02-01

    Several types of transducer modules have been developed at Northwestern University to overcome the problems that are associated with the application of liquid or gel couplants. The modules deploy polymer films to transmit the ultrasound through a dry interface. These films are very flexible, so even with a low pressure they can be adapted to the irregular inspection surfaces. The dry-coupled transducer modules may be used for transmission and reception of both longitudinal and transverse ultrasonic waves in the MHz frequency range. The prototype modules have been integrated with the portable ultrasonic inspection units and tested on a number of aircraft structures.

  13. Future Data Communication Architectures for Safety Critical Aircraft Cabin Systems

    NASA Astrophysics Data System (ADS)

    Berkhahn, Sven-Olaf

    2012-05-01

    The cabin of modern aircraft is subject to increasing demands for fast reconfiguration and hence flexibility. These demands require studies for new network architectures and technologies of the electronic cabin systems, which consider also weight and cost reductions as well as safety constraints. Two major approaches are in consideration to reduce the complex and heavy wiring harness: the usage of a so called hybrid data bus technology, which enables the common usage of the same data bus for several electronic cabin systems with different safety and security requirements and the application of wireless data transfer technologies for electronic cabin systems.

  14. Probing Emissions of Military Cargo Aircraft: Description of a Joint Field Measurement Program

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cheng, Mengdawn; Corporan, E.; DeWitt, M.

    2008-01-01

    Direct emissions of NOx, volatile organic compounds, and particulate matter (PM) by aircraft contribute to the pollutant levels found in the atmosphere. Aircraft emissions can be injected at the ground level or directly at the high altitude in flight. Conversion of the precursor gases into secondary PM is one of the pathways for the increased atmospheric PM. Atmospheric PM interacts with solar radiation altering atmospheric radiation balance and potentially contributing to global and regional climate changes. Also, direct emissions of air toxics, ozone precursors and PM from aircraft in and around civilian airports and military air bases can worsen localmore » air quality in non-attainment and/or maintenance areas. These emissions need to be quantified. However, the current EPA methods for particle emission measurements from such sources, modified Method 5 and Conditional Test Method 039, are gravimetric-based, and it is anticipated that these methods will not be suitable for current and future generations of aircraft turbine engines, whose particle mass emissions are low. To evaluate measurement approaches for military aircraft emissions, two complementary projects were initiated in 2005. A joint field campaign between these two programs was executed during the first week of October 2005 at the Kentucky Air National Guard (KYANG) base in Louisville, KY. This campaign represented the first in a series of field studies for each program funded by the DoD Strategic Environmental Research and Development Program (SERDP) and provided the basis for cross-comparison of the sampling approaches and measurement techniques employed by the respective program teams. This paper describes the overall programmatic of the multi-year SERDP aircraft emissions research and presents a summary of the results from the joint field campaign.« less

  15. Small transport aircraft technology

    NASA Technical Reports Server (NTRS)

    Williams, L. J.

    1983-01-01

    Information on commuter airline trends and aircraft developments is provided to upgrade the preliminary findings of a NASA-formed small transport aircraft technology (STAT) team, established to determine whether the agency's research and development programs could help commuter aircraft manufacturers solve technical problems related to passenger acceptance and use of 19- to 50-passenger aircraft. The results and conclusions of the full set of completed STAT studies are presented. These studies were performed by five airplane manufacturers, five engine manufacturers, and two propeller manufacturers. Those portions of NASA's overall aeronautics research and development programs which are applicable to commuter aircraft design are summarized. Areas of technology that might beneficially be expanded or initiated to aid the US commuter aircraft manufacturers in the evolution of improved aircraft for the market are suggested.

  16. Airborne Subscale Transport Aircraft Research Testbed: Aircraft Model Development

    NASA Technical Reports Server (NTRS)

    Jordan, Thomas L.; Langford, William M.; Hill, Jeffrey S.

    2005-01-01

    The Airborne Subscale Transport Aircraft Research (AirSTAR) testbed being developed at NASA Langley Research Center is an experimental flight test capability for research experiments pertaining to dynamics modeling and control beyond the normal flight envelope. An integral part of that testbed is a 5.5% dynamically scaled, generic transport aircraft. This remotely piloted vehicle (RPV) is powered by twin turbine engines and includes a collection of sensors, actuators, navigation, and telemetry systems. The downlink for the plane includes over 70 data channels, plus video, at rates up to 250 Hz. Uplink commands for aircraft control include over 30 data channels. The dynamic scaling requirement, which includes dimensional, weight, inertial, actuator, and data rate scaling, presents distinctive challenges in both the mechanical and electrical design of the aircraft. Discussion of these requirements and their implications on the development of the aircraft along with risk mitigation strategies and training exercises are included here. Also described are the first training (non-research) flights of the airframe. Additional papers address the development of a mobile operations station and an emulation and integration laboratory.

  17. Aircraft Electric Secondary Power

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed.

  18. OXC management and control system architecture with scalability, maintenance, and distributed managing environment

    NASA Astrophysics Data System (ADS)

    Park, Soomyung; Joo, Seong-Soon; Yae, Byung-Ho; Lee, Jong-Hyun

    2002-07-01

    In this paper, we present the Optical Cross-Connect (OXC) Management Control System Architecture, which has the scalability and robust maintenance and provides the distributed managing environment in the optical transport network. The OXC system we are developing, which is divided into the hardware and the internal and external software for the OXC system, is made up the OXC subsystem with the Optical Transport Network (OTN) sub layers-hardware and the optical switch control system, the signaling control protocol subsystem performing the User-to-Network Interface (UNI) and Network-to-Network Interface (NNI) signaling control, the Operation Administration Maintenance & Provisioning (OAM&P) subsystem, and the network management subsystem. And the OXC management control system has the features that can support the flexible expansion of the optical transport network, provide the connectivity to heterogeneous external network elements, be added or deleted without interrupting OAM&P services, be remotely operated, provide the global view and detail information for network planner and operator, and have Common Object Request Broker Architecture (CORBA) based the open system architecture adding and deleting the intelligent service networking functions easily in future. To meet these considerations, we adopt the object oriented development method in the whole developing steps of the system analysis, design, and implementation to build the OXC management control system with the scalability, the maintenance, and the distributed managing environment. As a consequently, the componentification for the OXC operation management functions of each subsystem makes the robust maintenance, and increases code reusability. Also, the component based OXC management control system architecture will have the flexibility and scalability in nature.

  19. Why aircraft disinsection?

    PubMed

    Gratz, N G; Steffen, R; Cocksedge, W

    2000-01-01

    A serious problem is posed by the inadvertent transport of live mosquitoes aboard aircraft arriving from tropical countries where vector-borne diseases are endemic. Surveys at international airports have found many instances of live insects, particularly mosquitoes, aboard aircraft arriving from countries where malaria and arboviruses are endemic. In some instances mosquito species have been established in countries in which they have not previously been reported. A serious consequence of the transport of infected mosquitoes aboard aircraft has been the numerous cases of "airport malaria" reported from Europe, North America and elsewhere. There is an important on-going need for the disinsection of aircraft coming from airports in tropical disease endemic areas into nonendemic areas. The methods and materials available for use in aircraft disinsection and the WHO recommendations for their use are described.

  20. Psychological factors associated with weight loss maintenance: theory-driven practice for nurse practitioners.

    PubMed

    Valek, Rebecca M; Greenwald, Beverly J; Lewis, Carolyn C

    2015-04-01

    The authors discuss the psychological factors associated with weight loss maintenance and the use of Pender's health promotion model as a guide for the construction of clinical interventions to address these factors. The psychological factors include internal drive for weight maintenance, ongoing self-monitoring, long-term flexibility, positive mood and emotions, appropriate goals, and management of external stimuli. Nurse practitioners can help combat obesity trends through caring for patients in a holistic manner. Periodic psychological needs-assessments for patients who desire to maintain weight loss may further promote long-term success in weight management. © The Author(s) 2015.