Science.gov

Sample records for flexible aircraft maintenance

  1. Automation tools for flexible aircraft maintenance.

    SciTech Connect

    Prentice, William J.; Drotning, William D.; Watterberg, Peter A.; Loucks, Clifford S.; Kozlowski, David M.

    2003-11-01

    This report summarizes the accomplishments of the Laboratory Directed Research and Development (LDRD) project 26546 at Sandia, during the period FY01 through FY03. The project team visited four DoD depots that support extensive aircraft maintenance in order to understand critical needs for automation, and to identify maintenance processes for potential automation or integration opportunities. From the visits, the team identified technology needs and application issues, as well as non-technical drivers that influence the application of automation in depot maintenance of aircraft. Software tools for automation facility design analysis were developed, improved, extended, and integrated to encompass greater breadth for eventual application as a generalized design tool. The design tools for automated path planning and path generation have been enhanced to incorporate those complex robot systems with redundant joint configurations, which are likely candidate designs for a complex aircraft maintenance facility. A prototype force-controlled actively compliant end-effector was designed and developed based on a parallel kinematic mechanism design. This device was developed for demonstration of surface finishing, one of many in-contact operations performed during aircraft maintenance. This end-effector tool was positioned along the workpiece by a robot manipulator, programmed for operation by the automated planning tools integrated for this project. Together, the hardware and software tools demonstrate many of the technologies required for flexible automation in a maintenance facility.

  2. 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.

  3. Improvement of aircraft maintenance methods

    NASA Astrophysics Data System (ADS)

    Vladimirov, N. I.

    The papers presented in this volume provide an overview of recent theoretical and experimental research aimed at improving the maintenance of aircraft, developing advanced diagnostic techniques, and increasing the efficiency and safety of flight operations. Topics discussed include design characteristics of the functional systems of aircraft and prediction of their technical condition, a probability analysis of a method for diagnosing gas turbine engines on the basis of thermogasdynamic parameters, characteristics of fatigue crack growth under the service-spectrum loading of the tail boom, and the accuracy of nonparametric reliability estimates under varying operation conditions. Papers are also presented on ways of reducing the aeration of hydraulic fluids in aircraft, evaluation of the efficiency of the pilot's control activity in a flight simulator, and using control charts for the analysis of the performance of aviation specialists. (For individual items see A93-18327 to A93-18351)

  4. Human factors in aircraft maintenance and inspection

    NASA Technical Reports Server (NTRS)

    Shepherd, William T.

    1992-01-01

    The events which have led to the intensive study of aircraft structural problems have contributed in no less measure to the study of human factors which influence aircraft maintenance and inspection. Initial research emphasis on aging aircraft maintenance and inspection has since broadened to include all aircraft types. Technicians must be equally adept at repairing old and new aircraft. Their skills must include the ability to repair sheet metal and composite materials; control cable and fly-by-wire systems; round dials and glass cockpits. Their work performance is heavily influenced by others such as designers, technical writers, job card authors, schedulers, and trainers. This paper describes the activities concerning aircraft and maintenance human factors.

  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. Maintenance cost study of rotary wing aircraft

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The feasibility was studied of predicting rotary wing operation maintenance costs by using several aircraft design factors for the aircraft dynamic systems. The dynamic systems considered were engines, drives and transmissions, rotors, and flight controls. Multiple regression analysis was used to correlate aircraft design and operational factors with manhours per flight hour, and equations for each dynamic system were developed. Results of labor predictions using the equations compare favorably with actual values.

  7. 14 CFR 183.27 - Designated aircraft maintenance inspectors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Designated aircraft maintenance inspectors...: Privileges § 183.27 Designated aircraft maintenance inspectors. A designated aircraft maintenance inspector (DAMI) may approve maintenance on civil aircraft used by United States military flying clubs in...

  8. 14 CFR 183.27 - Designated aircraft maintenance inspectors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Designated aircraft maintenance inspectors...: Privileges § 183.27 Designated aircraft maintenance inspectors. A designated aircraft maintenance inspector (DAMI) may approve maintenance on civil aircraft used by United States military flying clubs in...

  9. 14 CFR 183.27 - Designated aircraft maintenance inspectors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Designated aircraft maintenance inspectors...: Privileges § 183.27 Designated aircraft maintenance inspectors. A designated aircraft maintenance inspector (DAMI) may approve maintenance on civil aircraft used by United States military flying clubs in...

  10. 14 CFR 183.27 - Designated aircraft maintenance inspectors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Designated aircraft maintenance inspectors...: Privileges § 183.27 Designated aircraft maintenance inspectors. A designated aircraft maintenance inspector (DAMI) may approve maintenance on civil aircraft used by United States military flying clubs in...

  11. 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.

  12. 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.

  13. 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 manager must establish an aircraft inspection program for each make and model program aircraft and...

  14. 14 CFR 183.27 - Designated aircraft maintenance inspectors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Designated aircraft maintenance inspectors. 183.27 Section 183.27 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF...: Privileges § 183.27 Designated aircraft maintenance inspectors. A designated aircraft maintenance...

  15. 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.

  16. 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.

  17. 14 CFR 91.1109 - Aircraft maintenance: Inspection program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Ownership Operations Program Management § 91.1109 Aircraft maintenance: Inspection program. Each program... thereof. (3) The name and address of the person responsible for scheduling the inspections required by...

  18. 14 CFR 91.1109 - Aircraft maintenance: Inspection program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Ownership Operations Program Management § 91.1109 Aircraft maintenance: Inspection program. Each program... thereof. (3) The name and address of the person responsible for scheduling the inspections required by...

  19. 14 CFR 91.1109 - Aircraft maintenance: Inspection program.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Ownership Operations Program Management § 91.1109 Aircraft maintenance: Inspection program. Each program... thereof. (3) The name and address of the person responsible for scheduling the inspections required by...

  20. 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.

  1. 14 CFR 121.701 - Maintenance log: Aircraft.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Maintenance log: Aircraft. 121.701 Section 121.701 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED...: Aircraft. (a) Each person who takes action in the case of a reported or observed failure or malfunction...

  2. 14 CFR 121.701 - Maintenance log: Aircraft.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Maintenance log: Aircraft. 121.701 Section 121.701 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED...: Aircraft. (a) Each person who takes action in the case of a reported or observed failure or malfunction...

  3. 14 CFR 121.701 - Maintenance log: Aircraft.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Maintenance log: Aircraft. 121.701 Section 121.701 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED...: Aircraft. (a) Each person who takes action in the case of a reported or observed failure or malfunction...

  4. 14 CFR 121.701 - Maintenance log: Aircraft.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Maintenance log: Aircraft. 121.701 Section 121.701 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED...: Aircraft. (a) Each person who takes action in the case of a reported or observed failure or malfunction...

  5. 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.

  6. Structural risk assessment and aircraft fleet maintenance

    NASA Technical Reports Server (NTRS)

    Smith, Herb, Jr.; Saff, C. R.; Christian, Tom F.

    1990-01-01

    In the present analysis, deterministic flaw growth analysis is used to project the failure distributions from inspection data. Inspection data is reported for each critical point in the aircraft. The data will indicate either a crack of a specific size or no crack. The crack length may be either less than, equal to, or greater than critical size for that location. Non-critical length cracks are projected to failure using the crack growth characteristics for that location to find the life when it will be at critical length. Greater-than-critical length cracks are projected back to determine the life at failure, that is, when it was at critical length. The same process is used as in the case of a non-critical crack except that the projection goes the other direction. These points, along with the critical length cracks are used to determine the failure distribution. To be able to use data from different aircraft to build a common failure distribution, a consistent life variable must be used. Aircraft life varies with the severity of the usage; therefore the number of flight hours for a particular aircraft must be modified by its usage factor to obtain a normalized life which can be compared with that from other aircraft.

  7. 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…

  8. 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.

  9. Flexible connector for use in aircraft

    NASA Technical Reports Server (NTRS)

    Wakeman, Thomas G. (Inventor); Hauser, Ambrose A. (Inventor)

    1992-01-01

    The invention concerns a connector, in an aircraft engine, for mounting a ring to a turbine rotor which the ring surrounds. The ring carries propeller blades, and the connector transmits both thrust and torque loads between the ring and the rotor, without significant deformation. However, the connector does deform in order to accommodate differential thermal growth between the ring and the rotor.

  10. 14 CFR 121.701 - Maintenance log: Aircraft.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Maintenance log: Aircraft. 121.701 Section 121.701 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS...

  11. 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. 91.1109 Section 91.1109 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership Operations Program Management...

  12. A Telerobotics Architecture for Aircraft Maintenance and Remanufacturing

    NASA Technical Reports Server (NTRS)

    Backes, P. G.; Zimmerman, W.; Leahy, M. B., Jr.

    1994-01-01

    The application of telerobotics to aircraft depot maintenance and remanufacturing is described and a telerobotics architecture for the application is discussed. Telerobotics will enhance process quality and could potentially decrease turn-around time and costs while moving human operatiors from hazardous work areas to safe and comfortable operator control stations.

  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. 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

  15. 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

  16. 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.

  17. 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

  18. Dynamic-Loads Analysis of Flexible Aircraft With Active Controls

    NASA Technical Reports Server (NTRS)

    Perry, B. I.; Durling, B. J.

    1982-01-01

    Integrated system of stand-along computer programs, DYLOFLEX, analyzes dynamic loads on flexible aircraft with active controls. DYLOFLEX capabilities include calculating dynamic loads due to continuous atmospheric turbulence, discrete gusts, and discrete control inputs. Each of the eight individual DYLOFLEX programs may be used alone or in conjunction with other DYLOFLEX programs.

  19. 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

  20. 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.

  1. Unsafe acts and unsafe outcomes in aircraft maintenance.

    PubMed

    Hobbs, Alan; Williamson, Ann

    2002-10-10

    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. PMID:12487688

  2. 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

  3. Flexible body dynamic stability for high performance aircraft

    NASA Technical Reports Server (NTRS)

    Goforth, E. A.; Youssef, H. M.; Apelian, C. V.; Schroeder, S. C.

    1991-01-01

    Dynamic equations which include the effects of unsteady aerodynamic forces and a flexible body structure were developed for a free flying high performance fighter aircraft. The linear and angular deformations are assumed to be small in the body reference frame, allowing the equations to be linearized in the deformation variables. Equations for total body dynamics and flexible body dynamics are formulated using the hybrid coordinate method and integrated in a state space format. A detailed finite element model of a generic high performance fighter aircraft is used to generate the mass and stiffness matrices. Unsteady aerodynamics are represented by a rational function approximation of the doublet lattice matrices. The equations simplify for the case of constant angular rate of the body reference frame, allowing the effect of roll rate to be studied by computing the eigenvalues of the system. It is found that the rigid body modes of the aircraft are greatly affected by introducing a constant roll rate, while the effect on the flexible modes is minimal for this configuration.

  4. 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.

  5. 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.

  6. The Design and Implementation of Aircraft Maintenance On-site Control System

    NASA Astrophysics Data System (ADS)

    Zhou, Guilin; Zhang, Huawei

    Based on the desire of aircraft maintenance, combined with the situation in work, this paper present the design and implementation of aircraft maintenance system based dot Net. For a partial page refresh object, AJAX is used through the system. New technology is used in a creative way and will promote innovation and transformation of the business.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 2. CONTEXT SHOWING NORTHWEST CORNER, WITH BUILDING S251 (AIRCRAFT MAINTENANCE ...

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

    2. CONTEXT SHOWING NORTHWEST CORNER, WITH BUILDING S251 (AIRCRAFT MAINTENANCE AND REPAIR SHOPS BUILDING ADDITION) IN FOREGROUND. - Loring Air Force Base, Arch Hangar, East of Arizona Road near southern end of runway, Limestone, Aroostook County, ME

  15. A dynamic data structure for flexible molecular maintenance and informatics

    PubMed Central

    Bajaj, Chandrajit; Chowdhury, Rezaul Alam; Rasheed, Muhibur

    2011-01-01

    Motivation: We present the ‘Dynamic Packing Grid’ (DPG), a neighborhood data structure for maintaining and manipulating flexible molecules and assemblies, for efficient computation of binding affinities in drug design or in molecular dynamics calculations. Results: DPG can efficiently maintain the molecular surface using only linear space and supports quasi-constant time insertion, deletion and movement (i.e. updates) of atoms or groups of atoms. DPG also supports constant time neighborhood queries from arbitrary points. Our results for maintenance of molecular surface and polarization energy computations using DPG exhibit marked improvement in time and space requirements. Availability: http://www.cs.utexas.edu/~bajaj/cvc/software/DPG.shtml Contact: bajaj@cs.utexas.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:21115440

  16. 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.

  17. Effects of job-simulated flexibility and strength-flexibility training protocols on maintenance employees engaged in manual handling operations.

    PubMed

    Guo, L; Genaidy, A; Warm, J; Karwowski, W; Hidalgo, J

    1992-09-01

    This study examined the effects of four flexibility and strength-flexibility training protocols on the dynamic strength, endurance time, and truncal flexibility of 24 maintenance employees engaged in manual material handling operations. The study was conducted over an 8-week period. Significant improvement in physical capacity was obtained through flexibility training either by a progressive increase in the holding time with fixed exercise repetition or a progressive increase repetition with fixed holding time. The flexibility and strength-flexibility training protocols exhibited similar effects on physical capacity. It was suggested that a follow-up flexibility protocol should be performed on a daily basis in order to maintain the gains obtained in flexibility during the intensive/short training programme. PMID:1505509

  18. 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

  19. 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

  20. 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.

  1. 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…

  2. 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.

  3. 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.

  4. 14 CFR 129.14 - Maintenance program and minimum equipment list requirements for U.S.-registered aircraft.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Maintenance program and minimum equipment list requirements for U.S.-registered aircraft. 129.14 Section 129.14 Aeronautics and Space FEDERAL....S.-REGISTERED AIRCRAFT ENGAGED IN COMMON CARRIAGE General § 129.14 Maintenance program and...

  5. 14 CFR 129.14 - Maintenance program and minimum equipment list requirements for U.S.-registered aircraft.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Maintenance program and minimum equipment list requirements for U.S.-registered aircraft. 129.14 Section 129.14 Aeronautics and Space FEDERAL....S.-REGISTERED AIRCRAFT ENGAGED IN COMMON CARRIAGE General § 129.14 Maintenance program and...

  6. 14 CFR 129.14 - Maintenance program and minimum equipment list requirements for U.S.-registered aircraft.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Maintenance program and minimum equipment list requirements for U.S.-registered aircraft. 129.14 Section 129.14 Aeronautics and Space FEDERAL....S.-REGISTERED AIRCRAFT ENGAGED IN COMMON CARRIAGE General § 129.14 Maintenance program and...

  7. 14 CFR 129.14 - Maintenance program and minimum equipment list requirements for U.S.-registered aircraft.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Maintenance program and minimum equipment list requirements for U.S.-registered aircraft. 129.14 Section 129.14 Aeronautics and Space FEDERAL....S.-REGISTERED AIRCRAFT ENGAGED IN COMMON CARRIAGE General § 129.14 Maintenance program and...

  8. 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…

  9. 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. PMID:20099178

  10. 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.

  11. 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.

  12. Use of augmented reality in aircraft maintenance operations

    NASA Astrophysics Data System (ADS)

    De Marchi, L.; Ceruti, A.; Testoni, N.; Marzani, A.; Liverani, A.

    2014-03-01

    This paper illustrates a Human-Machine Interface based on Augmented Reality (AR) conceived to provide to maintenance operators the results of an impact detection methodology. In particular, the implemented tool dynamically interacts with a head portable visualization device allowing the inspector to see the estimated impact position on the structure. The impact detection methodology combines the signals collected by a network of piezosensors bonded on the structure to be monitored. Then a signal processing algorithm is applied to compensate for dispersion the acquired guided waves. The compensated waveforms yield to a robust estimation of guided waves difference in distance of propagation (DDOP), used to feed hyperbolic algorithms for impact location determination. The output of the impact methodology is passed to an AR visualization technology that is meant to support the inspector during the on-field inspection/diagnosis as well as the maintenance operations. The inspector, in fact, can see interactively in real time the impact data directly on the surface of the structure. Here the proposed approach is tested on the engine cowling of a Cessna 150 general aviation airplane. Preliminary results confirm the feasibility of the method and its exploitability in maintenance practice.

  13. Aviation Maintenance (Aircraft Mechanics & Aircraft & Instrument Repair Personnel). Aviation Careers Series. Revised.

    ERIC Educational Resources Information Center

    Zaharevitz, Walter

    This booklet, one in a series on aviation careers, outlines career opportunities in aviation maintenance. The booklet provides the following information about aviation maintenance jobs: nature of the work, working conditions, where the jobs are, wages and benefits, opportunities for advancement, requirements to enter the job, opportunities for…

  14. Damage detection in aircraft structures using dynamically measured static flexibility matrices

    SciTech Connect

    Robinson, N.A.; Peterson, L.D.; James, G.H.; Doebling, S.W.

    1996-02-01

    Two methods for detecting the location of structural damage in an aircraft fuselage using modal test data are presented. Both methods use the dynamically measured static flexibility matrix, which is assembled from a combination of measured modal vectors, frequencies, and driving point residual flexibilities. As a consequence, neither method requires a mode-to-mode correlation, and both avoid tedious modal discrimination and selection. The first method detects damage as a softening in the point flexibility components, which are the diagonal entries in the flexibility matrix. The second method detects damage from the disassembled elemental stiffnesses as determined using a presumed connectivity. Vibration data from a laser vibrometer is used to measure the modal mechanics of a DC9 aircraft fuselage before and after induced weakening in a longitudinal stringer. Both methods are shown to detect the location of the damage, primarily because the normal stiffness of the reinforced shell of the fuselage is localized to a few square centimeters.

  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. 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). PMID:22317657

  17. 77 FR 59873 - Airworthiness Directives; Cessna Aircraft Company Airplanes; Initial Regulatory Flexibility Analysis

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... FR 32103). That NPRM proposed to require you to install a placard that prohibits flight into known... issuance of the NPRM (76 FR 32105), June 3, 2011, as the FAA initially determined that the cost of the... Directives; Cessna Aircraft Company Airplanes; Initial Regulatory Flexibility Analysis AGENCY:...

  18. 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.

  19. 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.

  20. 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.

  1. Flight testing a highly flexible aircraft - Case study on the MIT Light Eagle

    NASA Technical Reports Server (NTRS)

    Zerweckh, S. H.; Von Flotow, A. H.; Murray, J. E.

    1988-01-01

    This paper describes the techniques developed for a flight test program of a human powered aircraft, the application of these techniques in the winter of 1987/88 and the results of the flight testing. A system of sensors, signal conditioning and data recording equipment was developed and installed in the aircraft. Flight test maneuvers which do not exceed the aircraft's limited capability were developed and refined in an iterative sequence of test flights. The test procedures were adjusted to yield maximum data quality from the point of view of estimating lateral and longitudinal stability derivatives. Structural flexibility and unsteady aerodynamics are modeled in an ad hoc manner, capturing the effects observed during the test flights. A model with flexibility-extended equations of motion is presented. Results of maneuvers that were flown are compared with the predictions of that model and analyzed. Finally the results of the flight test program are examined critically, especially with respect to future applications, and suggestions are made in order to improve maneuvers for parameter estimation of very flexible aircraft.

  2. 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…

  3. 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.

  4. 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).

  5. The passing of the shift in aircraft maintenance - a task that produces deaths.

    PubMed

    Campos, Reginaldo; Martins, Edgard; Soares, Marcelo M

    2012-01-01

    Maintenance tasks, especially in heavy maintenance, may not be completed in a single shift. Aircraft maintenance technicians often take work in progress by colleagues, and spend the incomplete work for a change of team. The need for accuracy and efficiency of information transfer in many cases, without having time to have a meeting to pass the service is a crucial aspect of maintenance work. The ideal shift change can occur normally before delivery and continues to proceed normally after delivery. Although a shift change create challenges for communication, they also offer opportunities to detect and correct errors, where the task of delivery is an opportunity to identify the problem and fix it. In this case, the task was done correctly the first round, however, a problem began when the second round took. One example is a case in which the first round have removed a defective part for replacement and let the component of aircraft at end of turn with problems. Instead of ordering and installation of an operational component, the second round was then reinstall the faulty component, not realizing he had information about the problem attached. PMID:22317554

  6. The passing of the shift in aircraft maintenance--a task that produces deaths.

    PubMed

    Campos, Reginaldo; Martins, Edgard; Soares, Marcelo

    2012-01-01

    Maintenance tasks, especially in heavy maintenance, may not be completed in a single shift. Aircraft maintenance technicians often take work in progress by colleagues, and spend the incomplete work for a change of team. The need for accuracy and efficiency of information transfer in many cases, without having time to have a meeting to pass the service is a crucial aspect of maintenance work. The ideal shift change can occur normally before delivery and continues to proceed normally after delivery. Although a shift change create challenges for communication, they also offer opportunities to detect and correct errors, where the task of delivery is an opportunity to identify the problem and fix it. In this case, the task was done correctly the first round, however, a problem began when the second round took. One example is a case in which the first round have removed a defective part for replacement and let the component of aircraft at end of turn with problems. Instead of ordering and installation of an operational component, the second round was then reinstall the faulty component, not realizing he had information about the problem attached. PMID:22316725

  7. 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.

  8. The application of TSIM software to act design and analysis on flexible aircraft

    NASA Technical Reports Server (NTRS)

    Kaynes, Ian W.

    1989-01-01

    The TSIM software is described. This is a package which uses an interactive FORTRAN-like simulation language for the simulation on nonlinear dynamic systems and offers facilities which include: mixed continuous and discrete time systems, time response calculations, numerical optimization, automatic trimming of nonlinear aircraft systems, and linearization of nonlinear equations for eigenvalues, frequency responses and power spectral response evaluation. Details are given of the application of TSIM to the analysis of aeroelastic systems under the RAE Farborough extension FLEX-SIM. The aerodynamic and structural data for the equations of motion of a flexible aircraft are prepared by a preprocessor program for incorporation in TSIM simulations. Within the simulation, the flexible aircraft model may then be selected interactively for different flight conditions and modal reduction techniques applied. The use of FLEX-SIM is demonstrated by an example of the flutter prediction for a simple aeroelastic model. By utilizing the numerical optimization facility of TSIM, it is possible to undertake identification of required parameters in the TSIM model within the simulation.

  9. 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.

  10. 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.

  11. FCAP - A new tool for the evaluation of active control technology. [Flight Control Analysis Program for flexible aircraft

    NASA Technical Reports Server (NTRS)

    Noll, R. B.; Morino, L.

    1975-01-01

    A computer program has been developed for the evaluation of flight control systems designed for flexible aircraft. This Flight Control Analysis Program (FCAP) is designed in a modular fashion to incorporate sensor, actuator, and control logic element dynamics as well as aircraft dynamics and aerodynamics for complex configurations. Formulation of the total aircraft dynamic system is accomplished in matrix form by casting the equations in state vector format. The system stability and performance are determined in either the frequency or time domain using classical analysis techniques. The aerodynamic method used also permits evaluation of the flutter characteristics of the aircraft.

  12. 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. PMID:23597959

  13. 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.

  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, 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 14 CFR 129.14 - Maintenance program and minimum equipment list requirements for U.S.-registered aircraft.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Maintenance program and minimum equipment list requirements for U.S.-registered aircraft. 129.14 Section 129.14 Aeronautics and Space FEDERAL... having geographic responsibility for the operator. The foreign operator must show, before...

  1. 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.

  2. 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.

  3. Validation of a Flexible Aircraft TakeOff and Landing Analysis /FATOLA/ computer program using flight landing data

    NASA Technical Reports Server (NTRS)

    Carden, H. D.; Mcgehee, J. R.

    1977-01-01

    A multiple-degree-of-freedom takeoff and landing analysis, Flexible Aircraft TakeOff and Landing Analysis computer program (FATOLA), was used to predict the landing behavior of a rigid-body X-24B reentry research vehicle and of a flexible-body modified-delta-wing supersonic YF-12 research aircraft. The analytical predictions were compared with flight test data for both research vehicles. Predicted time histories of vehicle motion and attitude, landing-gear strut stroke, and axial force transmitted from the landing gear to the airframe during the landing impact and rollout compared well with the actual time histories. Based on the comparisons presented, the versatility and validity of the FATOLA program for predicting landing dynamics of aircraft has been demonstrated.

  4. 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.

  5. 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

  6. 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.

  7. 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. PMID:24879637

  8. 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. PMID:27108198

  9. 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.

  10. 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.

  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. 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

  13. Flexibility.

    ERIC Educational Resources Information Center

    Humphrey, L. Dennis

    1981-01-01

    Flexibility is an important aspect of all sports and recreational activities. Flexibility can be developed and maintained by stretching exercises. Exercises designed to develop flexibility in ankle joints, knees, hips, and the lower back are presented. (JN)

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. 14 CFR 91.1443 - CAMP: Airworthiness release or aircraft maintenance log entry.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... in the program manager's manual; (2) Include a certification that— (i) The work was performed in accordance with the requirements of the program manager's manual; (ii) All items required to be inspected... maintenance, or alterations performed by a repair station certificated under the provisions of part 145...

  19. 40 CFR 141.804 - Aircraft water system operations and maintenance plan.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... carrier operations and maintenance program (14 CFR part 43, 14 CFR part 91, 14 CFR part 121). (b) Each... (FDA) regulations (21 CFR part 1240, subpart E). (2) Procedures for disinfection and flushing. The plan... points in accordance with Food and Drug Administration (FDA) regulations (21 CFR part 1240, subpart...

  20. 40 CFR 141.804 - Aircraft water system operations and maintenance plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... carrier operations and maintenance program (14 CFR part 43, 14 CFR part 91, 14 CFR part 121). (b) Each... (FDA) regulations (21 CFR part 1240, subpart E). (2) Procedures for disinfection and flushing. The plan... points in accordance with Food and Drug Administration (FDA) regulations (21 CFR part 1240, subpart...

  1. 40 CFR 141.804 - Aircraft water system operations and maintenance plan.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... carrier operations and maintenance program (14 CFR part 43, 14 CFR part 91, 14 CFR part 121). (b) Each... (FDA) regulations (21 CFR part 1240, subpart E). (2) Procedures for disinfection and flushing. The plan... points in accordance with Food and Drug Administration (FDA) regulations (21 CFR part 1240, subpart...

  2. 40 CFR 141.804 - Aircraft water system operations and maintenance plan.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... carrier operations and maintenance program (14 CFR part 43, 14 CFR part 91, 14 CFR part 121). (b) Each... (FDA) regulations (21 CFR part 1240, subpart E). (2) Procedures for disinfection and flushing. The plan... points in accordance with Food and Drug Administration (FDA) regulations (21 CFR part 1240, subpart...

  3. 40 CFR 141.804 - Aircraft water system operations and maintenance plan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... carrier operations and maintenance program (14 CFR part 43, 14 CFR part 91, 14 CFR part 121). (b) Each... (FDA) regulations (21 CFR part 1240, subpart E). (2) Procedures for disinfection and flushing. The plan... points in accordance with Food and Drug Administration (FDA) regulations (21 CFR part 1240, subpart...

  4. 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.

  5. Effect of structural flexibility on the design of vibration-isolating mounts for aircraft engines

    NASA Technical Reports Server (NTRS)

    Phillips, W. H.

    1984-01-01

    Previous analyses of the design of vibration-isolating mounts for a rear-mounted engine to decouple linear and rotational oscillations are extended to take into account flexibility of the engine-mount structure. Equations and curves are presented to allow the design of mount systems and to illustrate the results for a range of design conditions.

  6. 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.

  7. Cognitive Flexibility in Preschoolers: The Role of Representation Activation and Maintenance

    ERIC Educational Resources Information Center

    Chevalier, Nicolas; Blaye, Agnes

    2008-01-01

    Preschoolers' lack of cognitive flexibility has often been attributed to perseverative processing. This study investigates alternative potential sources of difficulty such as deficits in activating previously ignored information and in maintaining currently relevant information. In Experiment 1, a new task tapping attentional switching was…

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after... FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION § 43.7 Persons authorized to approve aircraft, airframes, aircraft...

  9. 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.

  10. Standard test method for corrosion of low-embrittling cadmium plate by aircraft maintenance chemicals. ASTM standard

    SciTech Connect

    1989-02-01

    This test method is under the jurisdiction of ASTM Committee F-7 on Aerospace and Aircraft and is the direct responsibility of Subcommittee F07.07 on Qualification Testing of Aircraft Cleaning Materials. Current edition approved Nov. 17, 1988. Published February 1989 and reapproved 1998.

  11. Functional maintenance and structural flexibility of microbial communities perturbed by simulated intense rainfall in a pilot-scale membrane bioreactor.

    PubMed

    Sato, Yuya; Hori, Tomoyuki; Navarro, Ronald R; Habe, Hiroshi; Ogata, Atsushi

    2016-07-01

    Intense rainfall is one of the most serious and common natural events, causing the excessive inflow of rainwater into wastewater treatment plants. However, little is known about the impacts of rainwater dilution on the structure and function of the sludge microorganisms. Here, high-throughput sequencing of 16S ribosomal RNA (rRNA) genes was implemented to describe the microbial community dynamics during the simulated intense rainfall situation (event i) in which approximately 45 % of the sludge biomass was artificially overflowed by massive water supply in a pilot-scale membrane bioreactor. Thereafter, we investigated the functional and structural responses of the perturbed microbial communities to subsequent conditional changes, i.e., an increase in organic loading rate from 225 to 450 mg chemical oxygen demand (COD) l(-1) day(-1) (event ii) and an addition of a microbiota activator (event iii). Due to the event i, the COD removal declined to 78.2 %. This deterioration coincided with the decreased microbial diversity and the proliferation of the oligotrophic Aquabacterium sp. During the succeeding events ii and iii, the sludge biomass increased and the COD removal became higher (86.5-97.4 %). With the apparent recovery of the reactor performance, microbial communities became diversified and the compositions dynamically changed. Notably, various bacterial micropredators were highly enriched under the successive conditions, most likely being involved in the flexible reorganization of microbial communities. These results indicate that the activated sludge harbored functionally redundant microorganisms that were able to thrive and proliferate along with the conditional changes, thereby contributing to the functional maintenance of the membrane bioreactor. PMID:27020291

  12. [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. PMID:27213653

  13. Prismatic sealed nickel-cadmium batteries utilizing fiber structured electrodes. II - Applications as a maintenance free aircraft battery

    NASA Astrophysics Data System (ADS)

    Anderman, Menahem; Benczur-Urmossy, Gabor; Haschka, Friedrich

    Test data on prismatic sealed Ni-Cd batteries utilizing fiber structured electrodes (sealed FNC) is discussed. It is shown that, under a voltage limited charging scheme, the charge acceptance of the sealed FNC battery is far superior to that of the standard vented aircraft Ni-Cd batteries. This results in the sealed FNC battery maintaining its capacity over several thousand cycles without any need for electrical conditioning or water topping. APU start data demonstrate superior power capabilities over existing technologies. Performance at low temperature is presented. Abuse test results reveal a safe fail mechanism even under severe electrical abuse.

  14. A flexible computer aid for conceptual design based on constraint propagation and component-modeling. [of aircraft in three dimensions

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1988-01-01

    The Rubber Airplane program, which combines two symbolic processing techniques with a component-based database of design knowledge, is proposed as a computer aid for conceptual design. Using object-oriented programming, programs are organized around the objects and behavior to be simulated, and using constraint propagation, declarative statements designate mathematical relationships among all the equation variables. It is found that the additional level of organizational structure resulting from the arrangement of the design information in terms of design components provides greater flexibility and convenience.

  15. 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 the flight in the aircraft records. (c) The aircraft does not have to be flown as required...

  16. Aircraft Environmental System Mechanic, 2-9. Block IV--Utility Systems and Flight Line Maintenance. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This publication contains a teaching guide and student instructional materials for conducting a high school or adult vocational education course to train persons to perform duties as an aircraft environmental systems mechanic. The instructional design for this course is self-paced and/or small group-paced. Instructor materials contained in the…

  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. 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.

  19. Aircraft wiring program status report

    NASA Technical Reports Server (NTRS)

    Beach, Rex

    1995-01-01

    In this Naval Air Warfare Center (NAWC) Aircraft Division status report, the general and wire and cable component activities, the systems engineering activities, the aircraft wiring lead maintenance activities, the NAVAIR/NASA interface activities, and the Base Realignment and Closure (BRAC) Commission recommendations are presented.

  20. 14 CFR 135.419 - Approved aircraft inspection program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Approved aircraft inspection program. 135... 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....

  1. 14 CFR 135.419 - Approved aircraft inspection program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Approved aircraft inspection program. 135... 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....

  2. 14 CFR 135.419 - Approved aircraft inspection program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Approved aircraft inspection program. 135... 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....

  3. Designing with Maintenance in Mind.

    ERIC Educational Resources Information Center

    Hoffman, Kisty

    2002-01-01

    When planning for a new facility, consideration of maintenance needs is crucial to successful design. Designing for maintenance needs involves considering such factors as the durability of materials used, the cost and lifecycle of the materials, and the flexibility of the maintenance staff. Stresses the importance of including key members of the…

  4. 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.

  5. 14 CFR 91.1437 - CAMP: Authority to perform and approve maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... program manager who maintains program aircraft under a CAMP may employ maintenance personnel, or make... maintenance manual. Unless properly certificated, the program manager may not perform or approve...

  6. Emergency in-flight egress for general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1981-01-01

    A NASA program for development of an inflight egress system for the left (pilot) door of general aviation aircraft is described. The pyrotechnic release door was felt to be necessary because of pilot difficulty in reaching the right door when subjected to spin/stall centrifugal effects. A flexible, linear shaped charged of hexanitrostibene II and a lanyard actuated detonator are discussed, along with mock-up tests and instrumentation. The egress system was designed for minimum structural impact, mimimum pilot initiation procedures, low weight, and no egress interference, and to provide sufficient force to blow off the door, have low required maintenance, and high reliability. Results of 68 tests are reviewed, noting the inclusion of a screen to keep glass fragments from spraying the cabin. Certification was achieved, and uses in the F-111 and B-1 aircraft are noted.

  7. 14 CFR 43.3 - Persons authorized to perform maintenance, preventive maintenance, rebuilding, and alterations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Persons authorized to perform maintenance, preventive maintenance, rebuilding, and alterations. 43.3 Section 43.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION § 43.3...

  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

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or component parts for return to service after maintenance, preventive maintenance, rebuilding, or alteration. 43.7 Section 43.7 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT...

  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. 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.

  11. 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…

  12. Walk-through survey report: HVLV (high velocity low volume) control technology for aircraft bonded wing and radome maintenance at Air Force Logistics Command, McClellan Air Force Base, Sacramento, California

    SciTech Connect

    Hollett, B.A.

    1983-08-01

    A walk through survey was conducted at the Sacramento Air Logistics Center, McClellan Air Force Base, California, on June 13, 1983, to evaluate the use of High Velocity Low Volume (HVLV) technology in the aircraft-maintenance industry. The HVLV system consisted of 65 ceiling drops in the bonded honeycomb shop where grinding and sanding operations created glass fiber and resin dusts. Preemployment and periodic physical examinations were required. Workers were required to wear disposable coveralls, and disposable dust masks were available. Workers walked through decontamination air jet showers before leaving the area to change clothes. Environmental monitoring revealed no significant dust exposures when the HVLV system was in use. Performance of the exhaust system on the eight-inch-diameter nose cone sanding operation was good, but the three-inch-diameter tools were too large and the shrouds too cumbersome for use on many hand-finishing tasks. The author concludes that the HVLV system is partially successful but requires additional shroud design. Further development of small tool shrouds is recommended.

  13. Composite components on commercial aircraft

    NASA Technical Reports Server (NTRS)

    Dexter, H. B.

    1980-01-01

    Flight experience gained with numerous composite aircraft structures is discussed. Both commercial transports and helicopters are included. Design concepts with significant mass savings and appropriate inspection and maintenance procedures are among the factors considered. Also, a major NASA/U.S. industry technology program to reduce fuel consumption of commercial transport aircraft through the use of advanced composites is described, including preliminary results. Ground and flight environmental effects on the composite materials used in the flight service programs are also discussed.

  14. 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...

  15. 14 CFR 91.421 - Rebuilt engine maintenance records.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 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...

  16. 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...

  17. 14 CFR 91.415 - Changes to aircraft inspection programs.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Changes to aircraft inspection programs. 91..., Preventive Maintenance, and Alterations § 91.415 Changes to aircraft inspection programs. (a) Whenever the Administrator finds that revisions to an approved aircraft inspection program under § 91.409(f)(4) or §...

  18. 14 CFR 91.415 - Changes to aircraft inspection programs.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Changes to aircraft inspection programs. 91..., Preventive Maintenance, and Alterations § 91.415 Changes to aircraft inspection programs. (a) Whenever the Administrator finds that revisions to an approved aircraft inspection program under § 91.409(f)(4) or §...

  19. Aircraft Control-Position Indicator

    NASA Technical Reports Server (NTRS)

    Dennis, D. V.

    1985-01-01

    Aircraft control-position indicator cockpit-mounted instrument that displays positions of elevator and ailerons to pilot. Display is cruciform array of lights: horizontal row of amber lights and vertical row of green lights representing aileron and elevator positions, respectively. Display used extensively in spin testing and has been trouble-free, with no maintenance required after about 30 hours of operation.

  20. Aircraft Noise

    NASA Astrophysics Data System (ADS)

    Michel, Ulf; Dobrzynski, Werner; Splettstoesser, Wolf; Delfs, Jan; Isermann, Ullrich; Obermeier, Frank

    Aircraft industry is exposed to increasing public pressure aiming at a continuing reduction of aircraft noise levels. This is necessary to both compensate for the detrimental effect on noise of the expected increase in air traffic and improve the quality of living in residential areas around airports.

  1. Aircraft Design

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H. (Inventor); Uden, Edward (Inventor)

    2016-01-01

    The present invention is an aircraft wing design that creates a bell shaped span load, which results in a negative induced drag (induced thrust) on the outer portion of the wing; such a design obviates the need for rudder control of an aircraft.

  2. Improved portable lighting for visual aircraft inspection

    SciTech Connect

    Shagam, R.N.; Lerner, J.; Shie, R.

    1995-04-01

    The most common tool used by aircraft inspectors is the personal flashlight. While it is compact and very portable, it is generally typified by poor beam quality which can interfere with the ability for an inspector to detect small defects and anomalies, such as cracks and corrosion sites, which may be indicators of major structural problems. A Light Shaping Diffuser{trademark} (LSD) installed in a stock flashlight as a replacement to the lens can improve the uniformity of an average flashlight and improve the quality of the inspection. Field trials at aircraft maintenance facilities have demonstrated general acceptance of the LSD by aircraft inspection and maintenance personnel.

  3. Improved portable lighting for visual aircraft inspection

    NASA Astrophysics Data System (ADS)

    Shagam, Richard N.; Lerner, Jeremy M.; Shie, Rick

    1995-07-01

    The most common tool used by aircraft inspectors is the personal flashlight. While it is compact and very portable, it is generally typified by poor beam quality which can interfere with the ability for an inspector to detect small defects and anomalies, such as cracks and corrosion sites, which may be indicators of major structural problems. A Light Shaping Diffuser TM (LSD) installed in a stock flashlight as a replacement to the lens can improve the uniformity of an average flashlight and improve the quality of the inspection. Field trials at aircraft maintenance facilities have demonstrated general acceptance of the LSD by aircraft inspection and maintenance personnel.

  4. 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...

  5. 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...

  6. 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...

  7. Ryan Flexwing aircraft under test

    NASA Technical Reports Server (NTRS)

    1962-01-01

    A flexible wing aircraft built by Ryan, was flown in the Full Scale Tunnel. The researcher posing as the pilot is John W. Paulson, Assistant Head of the Full Scale Tunnel. Photograph published in Sixty Years of Aeronautical Research 1917-1977, by David A. Anderton - NASA publication (page 60).

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Structural integrity in aircraft.

    NASA Technical Reports Server (NTRS)

    Hardrath, H. F.

    1973-01-01

    The paper reviews briefly the current design philosophies for achieving long, efficient, and reliable service in aircraft structures. The strengths and weaknesses of these design philosophies and their demonstrated records of success are discussed. The state of the art has not been developed to the point where designing can be done without major test inspection and maintenance programs. A broad program of research is proposed through which a viable computerized design scheme will be provided during the next decade. The program will organize and correlate existing knowledge on fatigue and fracture behavior, identify gaps in this knowledge, and guide specific research to upgrade design capabilities.

  13. Aircraft recognition and pose estimation

    NASA Astrophysics Data System (ADS)

    Hmam, Hatem; Kim, Jijoong

    2000-05-01

    This work presents a geometry based vision system for aircraft recognition and pose estimation using single images. Pose estimation improves the tracking performance of guided weapons with imaging seekers, and is useful in estimating target manoeuvres and aim-point selection required in the terminal phase of missile engagements. After edge detection and straight-line extraction, a hierarchy of geometric reasoning algorithms is applied to form line clusters (or groupings) for image interpretation. Assuming a scaled orthographic projection and coplanar wings, lateral symmetry inherent in the airframe provides additional constraints to further reject spurious line clusters. Clusters that accidentally pass all previous tests are checked against the original image and are discarded. Valid line clusters are then used to deduce aircraft viewing angles. By observing that the leading edges of wings of a number of aircraft of interest are within 45 to 65 degrees from the symmetry axis, a bounded range of aircraft viewing angles can be found. This generic property offers the advantage of not requiring the storage of complete aircraft models viewed from all aspects, and can handle aircraft with flexible wings (e.g. F111). Several aircraft images associated with various spectral bands (i.e. visible and infra-red) are finally used to evaluate the system's performance.

  14. Modal Filtering for Control of Flexible Aircraft

    NASA Technical Reports Server (NTRS)

    Suh, Peter M.; Mavris, Dimitri N.

    2013-01-01

    Modal regulators and deformation trackers are designed for an open-loop fluttering wing model. The regulators are designed with modal coordinate and accelerometer inputs respectively. The modal coordinates are estimated with simulated fiber optics. The robust stability of the closed-loop systems is compared in a structured singular-value vector analysis. Performance is evaluated and compared in a gust alleviation and flutter suppression simulation. For the same wing and flight condition two wing-shape-tracking control architectures are presented, which achieve deformation control at any point on the wing.

  15. 14 CFR 43.3 - Persons authorized to perform maintenance, preventive maintenance, rebuilding, and alterations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... alterations. Link to an amendment published at 74 FR 53394, October 16, 2009. Link to an amendment published... maintain, rebuild, alter, or perform preventive maintenance on an aircraft, airframe, aircraft engine, propeller, appliance, or component part to which this part applies. Those items, the performance of which...

  16. Composite components on commercial aircraft

    NASA Technical Reports Server (NTRS)

    Dexter, H. B.

    1980-01-01

    The paper considers the use of composite components in commercial aircraft. NASA has been active in sponsoring flight service programs with advanced composites for the last 10 years, with 2.5 million total composite component hours accumulated since 1970 on commercial transports and helicopters with no significant degradation in residual strength of composite components. Design, inspection, and maintenance procedures have been developed; a major NASA/US industry technology program has been developed to reduce fuel consumption of commercial transport aircraft through the use of advanced composites.

  17. 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. PMID:24745557

  18. STOL Aircraft

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Michael E. Fisher, President of AeroVisions International, has introduced the Culex light twin engine aircraft which offers economy of operation of a single engine plane, the ability to fly well on one engine, plus the capability of flying from short, unimproved fields of takeoff and landing distances less than 35 feet. Key element of design is an airfoil developed by Langley. Culex was originally intended to be factory built aircraft for special utility markets. However, it is now offered as a build-it-yourself kit plane.

  19. Aeroelastic stability of forward swept composite winged aircraft

    NASA Technical Reports Server (NTRS)

    Weisshaar, T. A.

    1983-01-01

    This paper reviews the author's past and present aeroelastic stability and performance studies related to forward swept, composite wing aircraft. The influence of laminate elastic bend/twist coupling upon wing divergence, lateral control, and lift effectiveness will be illustrated by means of closed-form solutions, numerical analysis and simple wind-tunnel experiments. In addition, results of analyses of a freely flying flexible FSW aircraft are discussed to indicate the possible effects of the flexible forward swept wing on aircraft dynamic stability. These studies show, both theoretically and experimentally, that, if the aircraft is not carefully designed, a phenomenon referred to as body freedom flutter may appear.

  20. Aircraft cybernetics

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The use of computers for aircraft control, flight simulation, and inertial navigation is explored. The man-machine relation problem in aviation is addressed. Simple and self-adapting autopilots are described and the assets and liabilities of digital navigation techniques are assessed.

  1. Preventative Maintenance.

    ERIC Educational Resources Information Center

    Migliorino, James

    Boards of education must be convinced that spending money up front for preventive maintenance will, in the long run, save districts' tax dollars. A good program of preventive maintenance can minimize disruption of service; reduce repair costs, energy consumption, and overtime; improve labor productivity and system equipment reliability; handle…

  2. Software Maintenance.

    ERIC Educational Resources Information Center

    Cannon, Glenn; Jobe, Holly

    Proper cleaning and storage of audiovisual aids is outlined in this brief guide. Materials and equipment needed for first line maintenance are listed, as well as maintenance procedures for records, audio and video tape, film, filmstrips, slides, realia, models, prints, graphics, maps, and overhead transparencies. A 15-item quiz on software…

  3. Maintenance Downtime

    Atmospheric Science Data Center

    2013-07-10

    ... will be unavailable March 5, 2013 8:00 am to 5:00 pm due to database maintenance. Date(s):  Tuesday, March 5, 2013 ... will be unavailable March 5, 2013 8:00 am to 5:00 pm due to database maintenance. ...

  4. Maintenance Budgeting.

    ERIC Educational Resources Information Center

    Smith, J. McCree

    Three methods for the preparation of maintenance budgets are discussed--(1) a traditional method, inconclusive and obsolete, based on gross square footage, (2) the formula approach method based on building classification (wood-frame, masonry-wood, masonry-concrete) with maintenance cost factors for each type plus custodial service rates by type of…

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 5. SOUTHWEST CORNER, SHOWING WEST ELEVATION WITH BUILDING 8251 (AIRCRAFT ...

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

    5. SOUTHWEST CORNER, SHOWING WEST ELEVATION WITH BUILDING 8251 (AIRCRAFT MAINTENANCE AND REPAIR SHOPS BUILDING ADDITION) AT LEFT. - Loring Air Force Base, Arch Hangar, East of Arizona Road near southern end of runway, Limestone, Aroostook County, ME

  10. 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.

  11. Eclipse program QF-106 aircraft

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This photo shows two QF-106 aircraft that were used for the Eclipse project, both parked at the Mojave Airport in Mojave, California. 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.

  12. 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.

  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. 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.

  15. Civil Applications For New V/STOL and STOL Aircraft

    NASA Technical Reports Server (NTRS)

    Albers, James A.; Zuk, John

    1990-01-01

    New designs offer benefits in congested urban areas and remote regions. Report explores potential uses in civil aviation of advanced rotorcraft, vertical/short-takeoff-and-landing (V/STOL) aircraft, and short-takeoff-and-landing (STOL) aircraft. Future opportunities overcome formidable geographic barriers and lack of major airport facilities, bringing fast, flexible transportation to remote areas. Aircraft relieves congestion at airports in densely populated areas by utilizing pads and short runways without interfering with large-air-carrier traffic.

  16. Flexible Scheduling.

    ERIC Educational Resources Information Center

    Davis, Harold S.; Bechard, Joseph E.

    A flexible schedule allows teachers to change group size, group composition, and class length according to the purpose of the lesson. This pamphlet presents various "master" schedules for flexible scheduling: (1) Simple block schedules, (2) back-to-back schedules, (3) interdisciplinary schedules, (4) school-wide block schedules, (5) open-lab…

  17. Flexibility Program

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    These brief guidelines for a muscular flexibility program state that the purpose of such a program is to increase the range of motion in order to avoid injuries and eliminate awkwardness in physical activities. A flexibility program is described as an extension of the warm-up period and should be an ongoing, permanent effort to lengthen muscles. A…

  18. 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.

  19. Aircraft landing using GPS

    NASA Astrophysics Data System (ADS)

    Lawrence, David Gary

    The advent of the Global Positioning System (GPS) is revolutionizing the field of navigation. Commercial aviation has been particularly influenced by this worldwide navigation system. From ground vehicle guidance to aircraft landing applications, GPS has the potential to impact many areas of aviation. GPS is already being used for non-precision approach guidance; current research focuses on its application to more critical regimes of flight. To this end, the following contributions were made: (1) Development of algorithms and a flexible software architecture capable of providing real-time position solutions accurate to the centimeter level with high integrity. This architecture was used to demonstrate 110 automatic landings of a Boeing 737. (2) Assessment of the navigation performance provided by two GPS-based landing systems developed at Stanford, the Integrity Beacon Landing System, and the Wide Area Augmentation System. (3) Preliminary evaluation of proposed enhancements to traditional techniques for GPS positioning, specifically, dual antenna positioning and pseudolite augmentation. (4) Introduction of a new concept for positioning using airport pseudolites. The results of this research are promising, showing that GPS-based systems can potentially meet even the stringent requirements of a Category III (zero visibility) landing system. Although technical and logistical hurdles still exist, it is likely that GPS will soon provide aircraft guidance in all phases of flight, including automatic landing, roll-out, and taxi.

  20. Educating with Aircraft Models

    ERIC Educational Resources Information Center

    Steele, Hobie

    1976-01-01

    Described is utilization of aircraft models, model aircraft clubs, and model aircraft magazines to promote student interest in aerospace education. The addresses for clubs and magazines are included. (SL)

  1. Privatizing Maintenance.

    ERIC Educational Resources Information Center

    Hounsell, Dan

    1996-01-01

    Schools and other government facilities want to see whether privatization of maintenance can provide services as efficiently and at less cost than inhouse workers. Privatization proponents say that everyone will benefit the most if the bidding process involves competition. Offers examples from the Memphis City Schools and the Union Public Schools…

  2. 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.

  3. 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.

  4. 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.

  5. Emerging nondestructive inspection methods for aging aircraft

    SciTech Connect

    Beattie, A; Dahlke, L; Gieske, J

    1994-01-01

    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 a 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.

  6. 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.

  7. 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.

  8. [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. PMID:27066680

  9. 14 CFR 91.1441 - CAMP: Transfer of maintenance records.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false CAMP: Transfer of maintenance records. 91... Ownership Operations Program Management § 91.1441 CAMP: Transfer of maintenance records. When a U.S.-registered fractional ownership program aircraft maintained under a CAMP is removed from the list of...

  10. 14 CFR 91.1441 - CAMP: Transfer of maintenance records.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false CAMP: Transfer of maintenance records. 91... Ownership Operations Program Management § 91.1441 CAMP: Transfer of maintenance records. When a U.S.-registered fractional ownership program aircraft maintained under a CAMP is removed from the list of...

  11. 14 CFR 91.1441 - CAMP: Transfer of maintenance records.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false CAMP: Transfer of maintenance records. 91... Ownership Operations Program Management § 91.1441 CAMP: Transfer of maintenance records. When a U.S.-registered fractional ownership program aircraft maintained under a CAMP is removed from the list of...

  12. 14 CFR 91.1441 - CAMP: Transfer of maintenance records.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false CAMP: Transfer of maintenance records. 91... Ownership Operations Program Management § 91.1441 CAMP: Transfer of maintenance records. When a U.S.-registered fractional ownership program aircraft maintained under a CAMP is removed from the list of...

  13. 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.

  14. Periodontal maintenance.

    PubMed

    Tan, A E S

    2009-09-01

    The main goal of periodontal therapy is to establish an oral environment compatible with periodontal health by the physical disruption of the plaque biofilm and adjunctive chemical means if required. Implicit in this objective is the ongoing requirement of detection and interception of new and recurrent disease, which continues at selected intervals for the life of the dentition after the initial ("active") phase of periodontal treatment. This concept of ongoing periodontal maintenance therapy has been embraced as the mandatory requirement for favourable periodontal outcomes based on institutional clinical trials and in practice-based studies in various parts of the world. This review examines the ramifications of periodontal maintenance therapy based upon a multi-level assessment of logistic issues and risk factors at three levels: (1) The patient level - treatment time; patient attendance compliance; and homecare measures, antiseptics/antibiotics and smoking. (2) The level of the individual tooth - tooth loss; and evaluation of success versus survival. (3) The level of each tooth surface ("site") - probing depth, loss of attachment and bleeding on probing; and changes in clinical attachment levels. In spite of the diversity of studies conducted, there is agreement on the efficacy of periodontal maintenance therapy when compared with studies on untreated populations and in treated cases that were not maintained. PMID:19737263

  15. 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.

  16. World commercial aircraft accidents

    SciTech Connect

    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 accident 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.

  17. 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.

  18. Flexible cystoscopy.

    PubMed

    Kennedy, T J; Preminger, G M

    1988-08-01

    Flexible fiberoptic technology was first applied to cystoscopy in 1973, with greatly increased usage since 1982. Most procedures formerly performed with rigid cystoscopes can be done using flexible cystoscopes with minimal or no anesthesia. Patient positioning and precystocopy preparation and draping are simplified with the flexible fiberoptic instruments. Complete examination of the urethra and bladder can be performed with a single-lens system and with the patient in a variety of positions. Fiberoptic cystoscopy is limited in patients who are bleeding or have blood clots in their bladders. Withdrawal of irrigant or bladder drainage is cumbersome, and the fiberoptic image is currently not of the same caliber as that of the rigid-lens systems. Fiberoptic cystoscopy has become the procedure of choice for many urologists for ureteral stenting prior to extracorporeal shock-wave lithotripsy. With the advent of lithotripters that require no anesthesia, this application is likely to broaden. Future applications of flexible cystoscopy may include a flexible videocystoscope for use in diagnostic and therapeutic procedures. PMID:3407042

  19. 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

  20. Piping Flexibility

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A NASA computer program aids Hudson Engineering Corporation, Houston, Texas, in the design and construction of huge petrochemical processing plants like the one shown, which is located at Ju'aymah, Saudi Arabia. The pipes handling the flow of chemicals are subject to a variety of stresses, such as weight and variations in pressure and temperature. Hudson Engineering uses a COSMIC piping flexibility analysis computer program to analyze stresses and unsure the necessary strength and flexibility of the pipes. This program helps the company realize substantial savings in reduced engineering time.

  1. Application of fuzzy linear programming to maintenance scheduling

    SciTech Connect

    Noor, S.F.; McDonald, J.R.

    1995-10-01

    In this paper initially, methods of fuzzy linear programming are discussed, which is then followed by an explanation of fuzzy 0-1 programming and finally the authors show how this method is applied to maintenance scheduling of a series of generators. Fuzzy linear 0-1 programming may be used for maintenance scheduling of generating units, this makes it possible to represent some of the maintenance constraints in flexible form and hence better suited to the requirements of maintenance personnel.

  2. Vibrational Effects of Turbopump Housing Flexibility

    NASA Technical Reports Server (NTRS)

    Fenwick, J. R.; Tarn, R. B.

    1986-01-01

    Methods of computer simulation of turbopump vibrations described in report. For aircraft and aerospace service, high-speed, high-performance turbomachinery should be as light in weight as possible. Certain amount of mass needed in turbomachine housing for stiffness. Report addresses question of how much extra weight is necessary. Analyses shows under certain conditions, flexible housing more stable than rigid one.

  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. 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. 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. PORTFOLIO OF POTENTIAL STRATEGIES IN AERONAUTIC MAINTENANCE

    SciTech Connect

    Rolet, S.

    2010-02-22

    EADS divisions aim more and more at developing services associated to their platforms. EADS divisions, like Airbus and Eurocopter, are investigating on services associated to their platforms in order to add them value. One possible service consists in structural maintenance operation assistance, especially for NDT operations performed by the customer. EADS Innovation Works envisages three different and complementary enhanced structural maintenance categories. Enhanced NDT improves standard NDT operation environment. This is made possible by the existence of 'smart' NDT tools that are computer based and therefore able to support other functions. These functions range from local smart data processing and display to remote expert assisted operation. Passive Sensor Network relies on sensors permanently installed on aircraft structure. Interrogation of sensors is performed on ground and off line (while structure is not loaded except by its own weight). It can be done at arbitrary times in order to determine structure health. The aim is to give easy access to some hidden ''hot spots,'' to reduce human factor in structure health assessment and optimize maintenance. Structural Health Monitoring goes a step beyond Passive Sensor Network, because interrogation units are on board the aircraft and may be connected to aircraft network. It allows to use on-line techniques such as adapted acoustic emission and to automatically raise an alarm when a defect appears in the structure. This paper presents these different ways of improving structural maintenance operations in service, with their respective advantages and limitations.

  7. 41 CFR 102-36.345 - May we dispose of excess Flight Safety Critical Aircraft Parts (FSCAP)?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Flight Safety Critical Aircraft Parts (FSCAP)? 102-36.345 Section 102-36.345 Public Contracts and... Requires Special Handling Aircraft and Aircraft Parts § 102-36.345 May we dispose of excess Flight Safety... appropriate Criticality Code on the SF 120, and ensure that all available historical and maintenance...

  8. 41 CFR 102-36.345 - May we dispose of excess Flight Safety Critical Aircraft Parts (FSCAP)?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Flight Safety Critical Aircraft Parts (FSCAP)? 102-36.345 Section 102-36.345 Public Contracts and... Requires Special Handling Aircraft and Aircraft Parts § 102-36.345 May we dispose of excess Flight Safety... appropriate Criticality Code on the SF 120, and ensure that all available historical and maintenance...

  9. 41 CFR 102-36.345 - May we dispose of excess Flight Safety Critical Aircraft Parts (FSCAP)?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Flight Safety Critical Aircraft Parts (FSCAP)? 102-36.345 Section 102-36.345 Public Contracts and... Requires Special Handling Aircraft and Aircraft Parts § 102-36.345 May we dispose of excess Flight Safety... appropriate Criticality Code on the SF 120, and ensure that all available historical and maintenance...

  10. 41 CFR 102-36.345 - May we dispose of excess Flight Safety Critical Aircraft Parts (FSCAP)?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Flight Safety Critical Aircraft Parts (FSCAP)? 102-36.345 Section 102-36.345 Public Contracts and... Requires Special Handling Aircraft and Aircraft Parts § 102-36.345 May we dispose of excess Flight Safety... appropriate Criticality Code on the SF 120, and ensure that all available historical and maintenance...

  11. 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.

  12. Innovations in Aircraft Design

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Boeing 777 carries with it basic and applied research, technology, and aerodynamic knowledge honed at several NASA field centers. Several Langley Research Center innovations instrumental to the development of the aircraft include knowledge of how to reduce engine and other noise for passengers and terminal residents, increased use of lightweight aerospace composite structures for increased fuel efficiency and range, and wind tunnel tests confirming the structural integrity of 777 wing-airframe integration. Test results from Marshall Space Flight Center aimed at improving the performance of the Space Shuttle engines led to improvements in the airplane's new, more efficient jet engines. Finally, fostered by Ames Research Center, the Boeing 777 blankets that protect areas of the plane from high temperatures and fire have a lineage to Advanced Flexible Reusable Surface Insulation used on certain areas of the Space Shuttle. According to Boeing Company estimates, the 777 has captured three-quarters of new orders for airplanes in its class since the program was launched.

  13. AIRCRAFT DEPAINTING TECHNOLOGY

    EPA Science Inventory

    Chemical paint strippers historically used for aircraft contained toxic and hazardous components; aircraft depainting operations are a major source of hazardous waste generation in DOD. Federal and state agencies have begun to restrict using these hazardous materials and Governme...

  14. 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

    ... Regulations System (Continued) FEDERAL MANAGEMENT REGULATION PERSONAL PROPERTY 33-MANAGEMENT OF GOVERNMENT AIRCRAFT Managing Government Aircraft and Aircraft Parts Maintenance § 102-33.170 What standards must we... ICAP guides that have been accepted by the FAA); or (5) Your agency's self-prescribed programs....

  15. Aircraft noise problems

    NASA Astrophysics Data System (ADS)

    1981-01-01

    The problems related to aircraft noise were studied. Physical origin (sound), human reaction (noise), quantization of noise and sound sources of aircraft noise are discussed. Noise abatement at the source, technical, fleet-political and air traffic measures are explained. The measurements and future developments are also discussed. The position of Lufthansa as regards aircraft noise problems is depicted.

  16. Unmanned aircraft systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. 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.

  18. Interactive aircraft flight control and aeroelastic stabilization

    NASA Technical Reports Server (NTRS)

    Weisshaar, T. A.; Schmidt, D. K.

    1984-01-01

    The potential benefits and costs of optimizing both the structural stiffness and the active control of aircraft in a rational manner are investigated. The ultimate goal is to arrive at a unified treatment of structural and active control design for the stability augmentation of flexible aircraft. An exhaustive literature evaluation in the area of passive tailoring for aircraft performance is undertaken. A mathematical technique to be used for aeroservoelastic tailoring studies is described. Two analytical models, one elementary, the other sophisticated, are developed to illustrate the potential for aeroservoelastic tailoring. Both models have essential features of real world hardware, yet the physical understanding is not buried in a myriad of detail. These models are also described.

  19. Aircraft landing gear systems

    NASA Technical Reports Server (NTRS)

    Tanner, John A. (Editor)

    1990-01-01

    Topics presented include the laboratory simulation of landing gear pitch-plane dynamics, a summary of recent aircraft/ground vehicle friction measurement tests, some recent aircraft tire thermal studies, and an evaluation of critical speeds in high-speed aircraft. Also presented are a review of NASA antiskid braking research, titanium matrix composite landing gear development, the current methods and perspective of aircraft flotation analysis, the flow rate and trajectory of water spray produced by an aircraft tire, and spin-up studies of the Space Shuttle Orbiter main gear tire.

  20. Performance of rotating-wing aircraft

    NASA Technical Reports Server (NTRS)

    Hohenemser, K

    1938-01-01

    Up to the present there has been no coordinated presentation from which the influence of the constants essential for the performance of rotating-wing aircraft could be obtained in a systematic manner. The attempt at such a survey is made in the following, whereby nonessential factors, such as effect of blade form, blade profile, blade number, and blade twist on the performances are disregarded. Even the torsional flexibility of the blades is overlooked.

  1. 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.

  2. Maintenance Business Plans.

    ERIC Educational Resources Information Center

    Adams, Matt

    2002-01-01

    Discusses maintenance business plans, statements which provide accountability for facilities maintenance organizations' considerable budgets. Discusses the plan's components: statement of plan objectives, macro and detailed description of the facility assets, maintenance function descriptions, description of key performance indicators, milestone…

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. FLEXIBLE COUPLING

    DOEpatents

    Babelay, E.F.

    1962-02-13

    A flexible shaft coupling for operation at speeds in excess of 14,000 rpm is designed which requires no lubrication. A driving sleeve member and a driven sleeve member are placed in concentric spaced relationship. A torque force is transmitted to the driven member from the driving member through a plurality of nylon balls symmetrically disposed between the spaced sleeves. The balls extend into races and recesses within the respective sleeve members. The sleeve members have a suitable clearance therebetween and the balls have a suitable radial clearance during operation of the coupling to provide a relatively loose coupling. These clearances accommodate for both parallel and/or angular misalignments and avoid metal-tometal contact between the sleeve members during operation. Thus, no lubrication is needed, and a minimum of vibrations is transmitted between the sleeve members. (AEC)

  8. 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.

  9. 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.

  10. Quantitative thermal imaging of aircraft structures

    NASA Astrophysics Data System (ADS)

    Cramer, K. Elliott; Howell, Patricia A.; Syed, Hazari I.

    1995-03-01

    technique. A recent application of this technology to aircraft repairs using boron/epoxy patches is shown illustrating the flexibility of the technology.