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Sample records for helicopter handling qualities

  1. Helicopter Handling Qualities

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Helicopters are used by the military and civilian communities for a variety of tasks and must be capable of operating in poor weather conditions and at night. Accompanying extended helicopter operations is a significant increase in pilot workload and a need for better handling qualities. An overview of the status and problems in the development and specification of helicopter handling-qualities criteria is presented. Topics for future research efforts by government and industry are highlighted.

  2. The Implications of Handling Qualities in Civil Helicopter Accidents Involving Hover and Low Speed Flight

    NASA Technical Reports Server (NTRS)

    Dugan, Daniel C.; Delamer, Kevin J.

    2005-01-01

    Because of increasing accident rates in Army helicopters in hover and low speed flight, a study was made in 1999 of accidents which could be attributed to inadequate stability augmentation. A study of civil helicopter accidents from 1993-2004 was then undertaken to pursue the issue of poor handling qualities in helicopters which, in almost all cases, had no stability augmentation. The vast majority of the mishaps studied occurred during daylight in visual meteorological condition, reducing the impact of degraded visual environments (DVE) on the results. Based on the Cooper-Harper Rating Scale, the handling qualities of many of the helicopters studied could be described as having from "very objectionable" to "major" deficiencies. These costly deficiencies have resulted in unnecessary loss of life, injury, and high dollar damage. Low cost and lightweight augmentation systems for helicopters have been developed in the past and are still being investigated. They offer the potential for significant reductions in the accident rate.

  3. A compilation and analysis of helicopter handling qualities data. Volume 2: Data analysis

    NASA Technical Reports Server (NTRS)

    Heffley, R. K.

    1979-01-01

    A compilation and an analysis of helicopter handling qualities data are presented. Multiloop manual control methods are used to analyze the descriptive data, stability derivatives, and transfer functions for a six degrees of freedom, quasi static model. A compensatory loop structure is applied to coupled longitudinal, lateral and directional equations in such a way that key handling qualities features are examined directly.

  4. Handling Qualities Evaluation, OH-58A Helicopter Incorporating a Ministab 3-Axis Stability Augmentation System

    DTIC Science & Technology

    1975-02-01

    A limited handling qualities evaluation of the OH-58A helicopter incorporating the SFENA 3-axis stability augmentation system called Ministab was...Ministab stability augmentation system was manufactured by the Societe Francaise d’Equipements pour la Navigation Aerienne (SFENA) of France and made

  5. Investigation of the effects of bandwidth and time delay on helicopter roll-axis handling qualities

    NASA Technical Reports Server (NTRS)

    Pausder, Heinz-Juergen; Blanken, Chris L.

    1993-01-01

    Several years of cooperative research conducted under the U.S./German Memorandum of Understanding (MOU) in helicopter flight control has recently resulted in a successful handling qualities study. The focus of this cooperative research has been the effects on handling qualities due to time delays in combination with a high bandwidth vehicle. The jointly performed study included the use of U.S. ground-based simulation and German in-flight simulation facilities. The NASA-Ames Vertical Motion Simulator (VMS) was used to develop a high bandwidth slalom tracking task which took into consideration the constraints of the facilities. The VMS was also used to define a range of the test parameters and to perform initial handling qualities evaluations. The flight tests were conducted using DLR's variable-stability BO 105 S3 Advanced Technology Testing Helicopter System (ATTHeS). Configurations included a rate command and an attitude command response system with added time delays up to 160 milliseconds over the baseline and bandwidth values between 1.5 and 4.5 rad/sec. Sixty-six evaluations were performed in about 25 hours of flight time during ten days of testing. The results indicate a need to more tightly constrain the allowable roll axis phase delay for the Level 1 and Level 2 requirements in the U.S. Army's specification for helicopter handling qualities, ADS-33C.

  6. Piloted simulator investigation of helicopter control systems effects on handling qualities during instrument flight

    NASA Technical Reports Server (NTRS)

    Forrest, R. D.; Chen, R. T. N.; Gerdes, R. M.; Alderete, T. S.; Gee, D. R.

    1979-01-01

    An exploratory piloted simulation was conducted to investigate the effects of the characteristics of helicopter flight control systems on instrument flight handling qualities. This joint FAA/NASA study was motivated by the need to improve instrument flight capability. A near-term objective is to assist in updating the airworthiness criteria for helicopter instrument flight. The experiment consisted of variations of single-rotor helicopter types and levels of stability and control augmentation systems (SCAS). These configurations were evaluated during an omnirange approach task under visual and instrument flight conditions. The levels of SCAS design included a simple rate damping system, collective decoupling plus rate damping, and an attitude command system with collective decoupling. A limited evaluation of stick force versus airspeed stability was accomplished. Some problems were experienced with control system mechanization which had a detrimental effect on longitudinal stability. Pilot ratings, pilot commentary, and performance data related to the task are presented.

  7. An investigation of the effects of pitch-roll (de)coupling on helicopter handling qualities

    NASA Technical Reports Server (NTRS)

    Blanken, C. L.; Pausder, H. J.; Ockier, C. J.

    1995-01-01

    An extensive investigation of the effects of pitch-roll coupling on helicopter handling qualities was performed by the U.S. Army and Deutsche Forschungsanstalt fur Luft- und Raumfahrt (DLR), using a NASA ground-based and a DLR in-flight simulator. Over 90 different coupling configurations were evaluated using a high gain roll-axis tracking task. The results show that although the current ADS-33C coupling criterion discriminates against those types of coupling typical of conventionally controlled helicopters, it is not always suited for the prediction of handling qualities of helicopters with modern control systems. Based on the observation that high frequency inputs during tracking are used to alleviate coupling, a frequency domain pitch-roll coupling criterion that uses the average coupling ratio between the bandwidth and neutral stability frequency is formulated. This criterion provides a more comprehensive coverage with respect to the different types of coupling, shows excellent consistency, and has the additional benefit that compliance testing data are obtained from the bandwidth/phase delay tests, so that no additional flight testing is needed.

  8. Effects of rotor parameter variations on handling qualities of unaugmented helicopters in simulated terrain flight

    NASA Technical Reports Server (NTRS)

    Talbot, P. D.; Dugan, D. D.; Chen, R. T. N.; Gerdes, R. M.

    1980-01-01

    A coordinated analysis and ground simulator experiment was performed to investigate the effects on single rotor helicopter handling qualities of systematic variations in the main rotor hinge restraint, hub hinge offset, pitch-flap coupling, and blade lock number. Teetering rotor, articulated rotor, and hingeless rotor helicopters were evaluated by research pilots in special low level flying tasks involving obstacle avoidance at 60 to 100 knots airspeed. The results of the experiment are in the form of pilot ratings, pilot commentary, and some objective performance measures. Criteria for damping and sensitivity are reexamined when combined with the additional factors of cross coupling due to pitch and roll rates, pitch coupling with collective pitch, and longitudinal static stability. Ratings obtained with and without motion are compared. Acceptable flying qualities were obtained within each rotor type by suitable adjustment of the hub parameters, however, pure teetering rotors were found to lack control power for the tasks. A limit for the coupling parameter L sub q/L sub p of 0.35 is suggested.

  9. The development and potential of inverse simulation for the quantitative assessment of helicopter handling qualities

    NASA Technical Reports Server (NTRS)

    Bradley, Roy; Thomson, Douglas G.

    1993-01-01

    In this paper it is proposed that inverse simulation can make a positive contribution to the study of handling qualities. It is shown that mathematical descriptions of the MTEs (Mission Task Elements) defined in ADS-33C may be used to drive an inverse simulation thereby generating, from an appropriate mathematical model, the controls and states of a subject helicopter flying it. By presenting the results of such simulations it is shown that, in the context of inverse simulation, the attitude quickness parameters given in ADS-33C are independent of vehicle configuration. An alternative quickness parameter, associated with the control displacements required to fly the MTE is proposed, and some preliminary results are presented.

  10. A pilot's assessment of helicopter handling-quality factors common to both agility and instrument flying tasks

    NASA Technical Reports Server (NTRS)

    Gerdes, R. M.

    1980-01-01

    A series of simulation and flight investigations were undertaken to evaluate helicopter flying qualities and the effects of control system augmentation for nap-of-the-Earth (NOE) agility and instrument flying tasks. Handling quality factors common to both tasks were identified. Precise attitude control was determined to be a key requirement for successful accomplishment of both tasks. Factors that degraded attitude controllability were improper levels of control sensitivity and damping, and rotor system cross coupling due to helicopter angular rate and collective pitch input. Application of rate command, attitude command, and control input decouple augmentation schemes enhanced attitude control and significantly improved handling qualities for both tasks. The NOE agility and instrument flying handling quality considerations, pilot rating philosophy, and supplemental flight evaluations are also discussed.

  11. The effects of pilot stress factors on handling quality assessments during US/German helicopter agility flight tests

    NASA Technical Reports Server (NTRS)

    Pausder, H. J.; Gerdes, R. M.

    1982-01-01

    Flight tests were conducted with two helicopters to study and evaluate the effects of helicopter characteristics and pilot and task demands on performance in nap-of-the-Earth flight. Different, low-level slalom courses were set up and were flown by three pilots with different levels of flight experience. A pilot rating questionnaire was used to obtain redundant information and to gain more insight into factors that influence pilot ratings. The flight test setups and procedures are described, and the pilot ratings are summarized and interpreted in close connection with the analyzed test data. Pilot stress is discussed. The influence of demands on the pilot, of the helicopter characteristics, and of other stress factors are outlined with particular emphasis on how these factors affect handling-qualities assessment.

  12. A piloted simulator investigation of augmentation systems to improve helicopter nap-of-the-earth handling qualities

    NASA Technical Reports Server (NTRS)

    Chen, R. T. N.; Talbot, P. D.; Gerdes, R. M.; Dugan, D. C.

    1978-01-01

    A piloted simulation study assessed various levels of stability and control augmentation designed to improve the handling qualities of several helicopters in nap-of-the-earth (NOE) flight. Five basic single rotor helicopters - one teetering, two articulated, and two hingeless - which were found to have a variety of major deficiencies in a previous fixed-based simulator study were selected as baseline configurations. The stability and control augmentation systems (SCAS) include simple control augmentation systems (CAS) to decouple pitch and yaw responses due to collective input and to quicken the pitch and roll control responses; SCAS of rate command type designed to optimize the sensitivity and damping and to decouple the pitch-roll due to aircraft angular rate; and attitude command type SCAS. Pilot ratings and commentary are presented as well as performance data related to the task. SCAS control usage and their gain levels associated with specific rotor type are also discussed.

  13. A compilation and analysis of helicopter handling qualities data. Volume 1: Data compilation

    NASA Technical Reports Server (NTRS)

    Heffley, R. K.; Jewell, W. F.; Lehman, J. M.; Vanwinkle, R. A.

    1979-01-01

    A collection of basic descriptive data, stability derivatives and transfer functions for six degrees of freedom, quasi-static model is introduced. The data are arranged in a common, compact format for each of the five helicopters represented. The vehicles studied include the BO-105, AH-1h, and the CH53D.

  14. An experimental evaluation of the Sternberg task as a workload metric for helicopter Flight Handling Qualities (FHQ) research

    NASA Technical Reports Server (NTRS)

    Hemingway, J. C.

    1984-01-01

    The objective was to determine whether the Sternberg item-recognition task, employed as a secondary task measure of spare mental capacity for flight handling qualities (FHQ) simulation research, could help to differentiate between different flight-control conditions. FHQ evaluations were conducted on the Vertical Motion Simulator at Ames Research Center to investigate different primary flight-control configurations, and selected stability and control augmentation levels for helicopters engaged in low-level flight regimes. The Sternberg task was superimposed upon the primary flight-control task in a balanced experimental design. The results of parametric statistical analysis of Sternberg secondary task data failed to support the continued use of this task as a measure of pilot workload. In addition to the secondary task, subjects provided Cooper-Harper pilot ratings (CHPR) and responded to workload questionnaire. The CHPR data also failed to provide reliable statistical discrimination between FHQ treatment conditions; some insight into the behavior of the secondary task was gained from the workload questionnaire data.

  15. A real-time blade element helicopter simulation for handling qualities analysis

    NASA Technical Reports Server (NTRS)

    Du Val, Ronald W.

    1989-01-01

    A simulation model which utilizes parallel processing platforms is described in terms of its contributions to improved real-time helicopter simulation. The FLIGHTLAB parallel processing environment is explained, and the relative advantages of the blade element and rotor map models for rigid and elastic articulated blades are discussed. A UH-60 simulation is conducted by means of a rigid model with 14 degrees of freedom, as well as an elastic model with 26 degrees of freedom, to compare trim conditions, longitudinal static margins, and longitudinal and lateral frequency responses. The FLIGHTLAB system is shown to facilitate restructuring for parallel processing as well as the systematic comparison of a variety of models. The system can facilitate the comparison of rigid and elastic blade element rotor models at NASA-Ames and other research facilities.

  16. A helicopter handling-qualities study of the effects of engine response characteristics, height-control dynamics, and excess power on nap-of-the-Earth operations

    NASA Technical Reports Server (NTRS)

    Corliss, L. D.

    1982-01-01

    The helicopter configuration with an rpm-governed gas-turbine engine was examined. A wide range of engine response time, vehicle damping and sensitivity, and excess power levels was studied. The data are compared with the existing handling-qualities specifications, MIL-F-83300 and AGARD 577, and in general show a need for higher minimums when performing such NOE maneuvers as a dolphin and bob-up task.

  17. Helicopter mathematical models and control law development for handling qualities research

    NASA Technical Reports Server (NTRS)

    Chen, Robert T. N.; Lebacqz, J. Victor; Aiken, Edwin W.; Tischler, Mark B.

    1988-01-01

    Progress made in joint NASA/Army research concerning rotorcraft flight-dynamics modeling, design methodologies for rotorcraft flight-control laws, and rotorcraft parameter identification is reviewed. Research into these interactive disciplines is needed to develop the analytical tools necessary to conduct flying qualities investigations using both the ground-based and in-flight simulators, and to permit an efficient means of performing flight test evaluation of rotorcraft flying qualities for specification compliance. The need for the research is particularly acute for rotorcraft because of their mathematical complexity, high order dynamic characteristics, and demanding mission requirements. The research in rotorcraft flight-dynamics modeling is pursued along two general directions: generic nonlinear models and nonlinear models for specific rotorcraft. In addition, linear models are generated that extend their utilization from 1-g flight to high-g maneuvers and expand their frequency range of validity for the design analysis of high-gain flight control systems. A variety of methods ranging from classical frequency-domain approaches to modern time-domain control methodology that are used in the design of rotorcraft flight control laws is reviewed. Also reviewed is a study conducted to investigate the design details associated with high-gain, digital flight control systems for combat rotorcraft. Parameter identification techniques developed for rotorcraft applications are reviewed.

  18. A piloted simulator investigation of static stability and stability/control augmentation effects on helicopter handling qualities for instrument approach

    NASA Technical Reports Server (NTRS)

    Lebacqz, J. V.; Forrest, R. D.

    1980-01-01

    A ground simulator experiment was conducted on the Flight Simulator for Advanced Aircraft at Ames Research Center to investigate the influence of several static stability and stability/control augmentation design parameters on helicopter flying qualities during terminal area operations in instrument conditions. Effects of light turbulence were included. Two levels of static stability in each rotational axis (pitch, roll, yaw) were examined for a hingeless rotor configuration. The variations in pitch and roll were: (1) stable and (2) neutral static stability; in yaw there were two stable levels. Four types of stability/control augmentation were also examined for the lower level of static stability in each axis. This latter investigation covered three helicopter rotor types: hingeless, articulated, and teetering. Four pilots performed a total of 105 evaluations of these parameters for a representative VOR instrument approach task. Pilot rating results indicate the acceptability of neutral static stability longitudinally and laterally and the need for pitch-roll attitude augmentation to achieve a satisfactory system.

  19. Rotorcraft handling-qualities design criteria development

    NASA Technical Reports Server (NTRS)

    Aiken, Edwin W.; Lebacqz, J. Victor; Chen, Robert T. N.; Key, David L.

    1988-01-01

    Joint NASA/Army efforts at the Ames Research Center to develop rotorcraft handling-qualities design criteria began in earnest in 1975. Notable results were the UH-1H VSTOLAND variable stability helicopter, the VFA-2 camera-and-terrain-board simulator visual system, and the generic helicopter real-time mathematical model, ARMCOP. An initial series of handling-qualities studies was conducted to assess the effects of rotor design parameters, interaxis coupling, and various levels of stability and control augmentation. The ability to conduct in-flight handling-qualities research was enhanced by the development of the NASA/Army CH-47 variable-stability helicopter. Research programs conducted using this vehicle include vertical-response investigations, hover augmentation systems, and the effects of control-force characteristics. The handling-qualities data base was judged to be sufficient to allow an update of the military helicopter handling-qualities specification, MIL-H-8501. These efforts, including not only the in-house experimental work but also contracted research and collaborative programs performed under the auspices of various international agreements. The report concludes by reviewing the topics that are currently most in need of work, and the plans for addressing these topics.

  20. Space shuttle handling qualities

    NASA Technical Reports Server (NTRS)

    Gilbert, D. W.

    1985-01-01

    The initial Orbiter handling qualities requirements, their effect on the vehicle design, and how it all turned out through the first six orbital missions are reviewed. Specific areas consisting of hand controller considerations and the wheelie problem are discussed. The requirements for the pitch axis subsonic flight control system are reviewed. Results of recent simulator evaluations to compare the existing system at landing with several other configurations are presented.

  1. Handling Qualities Optimization for Rotorcraft Conceptual Design

    NASA Technical Reports Server (NTRS)

    Lawrence, Ben; Theodore, Colin R.; Berger, Tom

    2016-01-01

    Over the past decade, NASA, under a succession of rotary-wing programs has been moving towards coupling multiple discipline analyses in a rigorous consistent manner to evaluate rotorcraft conceptual designs. Handling qualities is one of the component analyses to be included in a future NASA Multidisciplinary Analysis and Optimization framework for conceptual design of VTOL aircraft. Similarly, the future vision for the capability of the Concept Design and Assessment Technology Area (CD&A-TA) of the U.S Army Aviation Development Directorate also includes a handling qualities component. SIMPLI-FLYD is a tool jointly developed by NASA and the U.S. Army to perform modeling and analysis for the assessment of flight dynamics and control aspects of the handling qualities of rotorcraft conceptual designs. An exploration of handling qualities analysis has been carried out using SIMPLI-FLYD in illustrative scenarios of a tiltrotor in forward flight and single-main rotor helicopter at hover. Using SIMPLI-FLYD and the conceptual design tool NDARC integrated into a single process, the effects of variations of design parameters such as tail or rotor size were evaluated in the form of margins to fixed- and rotary-wing handling qualities metrics as well as the vehicle empty weight. The handling qualities design margins are shown to vary across the flight envelope due to both changing flight dynamic and control characteristics and changing handling qualities specification requirements. The current SIMPLI-FLYD capability and future developments are discussed in the context of an overall rotorcraft conceptual design process.

  2. An evaluation of helicopter noise and vibration ride qualities criteria

    NASA Technical Reports Server (NTRS)

    Hammond, C. E.; Hollenbaugh, D. D.; Clevenson, S. A.; Leatherwood, J. D.

    1981-01-01

    Two methods of quantifying helicopter ride quality; absorbed power for vibration only and the NASA ride comfort model for both noise and vibration are discussed. Noise and vibration measurements were obtained on five operational US Army helicopters. The data were converted to both absorbed power and DISC's (discomfort units used in the NASA model) for specific helicopter flight conditions. Both models indicate considerable variation in ride quality between the five helicopters and between flight conditions within each helicopter.

  3. Helicopter Strakes

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Langley Research Center has done extensive research into the effectiveness of tail boom strakes on conventional tail rotor helicopters. (A strake is a "spoiler" whose purpose is to alter the airflow around an aerodynamic body.) By placing strakes on a tail boom, the air loading can be changed, thrust and power requirements of the tail rotor can be reduced, and helicopter low speed flight handling qualities are improved. This research led to the incorporation of tail boom strakes on three production-type commercial helicopters manufactured by McDonnell Douglas Helicopter Company.

  4. Orion Entry Handling Qualities Assessments

    NASA Technical Reports Server (NTRS)

    Bihari, B.; Tiggers, M.; Strahan, A.; Gonzalez, R.; Sullivan, K.; Stephens, J. P.; Hart, J.; Law, H., III; Bilimoria, K.; Bailey, R.

    2011-01-01

    The Orion Command Module (CM) is a capsule designed to bring crew back from the International Space Station (ISS), the moon and beyond. The atmospheric entry portion of the flight is deigned to be flown in autopilot mode for nominal situations. However, there exists the possibility for the crew to take over manual control in off-nominal situations. In these instances, the spacecraft must meet specific handling qualities criteria. To address these criteria two separate assessments of the Orion CM s entry Handling Qualities (HQ) were conducted at NASA s Johnson Space Center (JSC) using the Cooper-Harper scale (Cooper & Harper, 1969). These assessments were conducted in the summers of 2008 and 2010 using the Advanced NASA Technology Architecture for Exploration Studies (ANTARES) six degree of freedom, high fidelity Guidance, Navigation, and Control (GN&C) simulation. This paper will address the specifics of the handling qualities criteria, the vehicle configuration, the scenarios flown, the simulation background and setup, crew interfaces and displays, piloting techniques, ratings and crew comments, pre- and post-fight briefings, lessons learned and changes made to improve the overall system performance. The data collection tools, methods, data reduction and output reports will also be discussed. The objective of the 2008 entry HQ assessment was to evaluate the handling qualities of the CM during a lunar skip return. A lunar skip entry case was selected because it was considered the most demanding of all bank control scenarios. Even though skip entry is not planned to be flown manually, it was hypothesized that if a pilot could fly the harder skip entry case, then they could also fly a simpler loads managed or ballistic (constant bank rate command) entry scenario. In addition, with the evaluation set-up of multiple tasks within the entry case, handling qualities ratings collected in the evaluation could be used to assess other scenarios such as the constant bank angle

  5. Development of Handling Qualities Criteria for Rotorcraft with Externally Slung Loads

    NASA Technical Reports Server (NTRS)

    Hoh, Roger H.; Heffley, Robert K.; Mitchell, David G.

    2006-01-01

    Piloted simulations were performed on the NASA-Ames Vertical Motion Simulator (VMS) to explore handling qualities issues for large cargo helicopters, particularly focusing on external slung load operations. The purpose of this work was based upon the need to include handling qualities criteria for cargo helicopters in an upgrade to the U.S. Army's rotorcraft handling qualities specification, Aeronautical Design Standard-33 (ADS-33E-PRF). From the VMS results, handling qualities criteria were developed fro cargo helicopters carrying external slung loads in the degraded visual environment (DVE). If satisfied, these criteria provide assurance that the handling quality rating (HQR) will be 4 or better for operations in the DVE, and with a load mass ratio of 0.33 or less. For lighter loads, flying qualities were found to be less dependent on the load geometry and therefore the significance of the criteria is less. For heavier loads, meeting the criteria ensures the best possible handling qualities, albeit Level 2 for load mass ratios greater than 0.33.

  6. Handling Qualities Influences on Civil Tiltrotor Terminal Operating Procedure Development

    NASA Technical Reports Server (NTRS)

    Decker, William A.; Simmons, Rickey C.; Tucker, George E.; Aiken, Edwin W. (Technical Monitor)

    1994-01-01

    The potential for tiltrotor aircraft as civil transports has been well recognized. Realization of that potential requires development of operating procedures tailored to take advantage of the tiltrotor's capabilities, including thrust vectoring independent of body pitch attitude and good low-speed control. While the tiltrotor shares flight characteristics with both fixed wing airplanes and helicopters, it must convert between those flight modes, typically within the context of precise terminal operations. A series of piloted simulation experiments has been conducted on the NASA Ames Research Center Vertical Motion Simulator (VMS) to investigate the influence of tiltrotor cockpit design features on developing certification and operating criteria for civil tiltrotor transports. Handling qualities evaluations have shaped cockpit design guidelines and operating procedure development for a civil tiltrotor. In particular, four topics demonstrate the interplay of handling qualities and operations profile in the development of terminal operating procedures and cockpit or control equipment for a civil tiltrotor: conversion (airplane to helicopter mode), final approach path angle, operating profile speeds and speed changes (particularly under instrument conditions), and one engine inoperative operational considerations.

  7. Directional handling qualities requirements for nap of the earth (NOE) tasks

    NASA Technical Reports Server (NTRS)

    Bivens, C. C.

    1985-01-01

    A piloted simulator experiment has been conducted to ascertain the directional axis handling requirements of hover and below 40-kt tasks of a scout/attack helicopter, with attention to such light helicopter configurations as those being considered for the 'LHX' program. Two types of yaw stability and control augmentation system were implemented: one consisted of a washed-out yaw rate feedback and shaped control unit, while the other involved a yaw rate command heading-hold system. Experiment results indicate that rotorcraft configurations with high directional gust sensitivity require greater minimum yaw damping to maintain satisfactory handling qualities in nap of the earth flight. Yaw damping and control response are critical handling qualities parameters in air-to-air target acquisition and tracking.

  8. Evaluation of ride quality prediction methods for operational military helicopters

    NASA Technical Reports Server (NTRS)

    Leatherwood, J. D.; Clevenson, S. A.; Hollenbaugh, D. D.

    1984-01-01

    The results of a simulator study conducted to compare and validate various ride quality prediction methods for use in assessing passenger/crew ride comfort within helicopters are presented. Included are results quantifying 35 helicopter pilots' discomfort responses to helicopter interior noise and vibration typical of routine flights, assessment of various ride quality metrics including the NASA ride comfort model, and examination of possible criteria approaches. Results of the study indicated that crew discomfort results from a complex interaction between vibration and interior noise. Overall measures such as weighted or unweighted root-mean-square acceleration level and A-weighted noise level were not good predictors of discomfort. Accurate prediction required a metric incorporating the interactive effects of both noise and vibration. The best metric for predicting crew comfort to the combined noise and vibration environment was the NASA discomfort index.

  9. Handling Qualities Implications for Crewed Spacecraft Operations

    NASA Technical Reports Server (NTRS)

    Bailey, Randall E.; Jackson, E. Bruce; Arthur, J. J.

    2012-01-01

    Abstract Handling qualities embody those qualities or characteristics of an aircraft that govern the ease and precision with which a pilot is able to perform the tasks required in support of an aircraft role. These same qualities are as critical, if not more so, in the operation of spacecraft. A research, development, test, and evaluation process was put into effect to identify, understand, and interpret the engineering and human factors principles which govern the pilot-vehicle dynamic system as they pertain to space exploration missions and tasks. Toward this objective, piloted simulations were conducted at the NASA Langley Research Center and Ames Research Center for earth-orbit proximity operations and docking and lunar landing. These works provide broad guidelines for the design of spacecraft to exhibit excellent handling characteristics. In particular, this work demonstrates how handling qualities include much more than just stability and control characteristics of a spacecraft or aircraft. Handling qualities are affected by all aspects of the pilot-vehicle dynamic system, including the motion, visual and aural cues of the vehicle response as the pilot performs the required operation or task. A holistic approach to spacecraft design, including the use of manual control, automatic control, and pilot intervention/supervision is described. The handling qualities implications of design decisions are demonstrated using these pilot-in-the-loop evaluations of docking operations and lunar landings.

  10. Handling qualities effects of display latency

    NASA Technical Reports Server (NTRS)

    King, David W.

    1993-01-01

    Display latency is the time delay between aircraft response and the corresponding response of the cockpit displays. Currently, there is no explicit specification for allowable display lags to ensure acceptable aircraft handling qualities in instrument flight conditions. This paper examines the handling qualities effects of display latency between 70 and 400 milliseconds for precision instrument flight tasks of the V-22 Tiltrotor aircraft. Display delay effects on the pilot control loop are analytically predicted through a second order pilot crossover model of the V-22 lateral axis, and handling qualities trends are evaluated through a series of fixed-base piloted simulation tests. The results show that the effects of display latency for flight path tracking tasks are driven by the stability characteristics of the attitude control loop. The data indicate that the loss of control damping due to latency can be simply predicted from knowledge of the aircraft's stability margins, control system lags, and required control bandwidths. Based on the relationship between attitude control damping and handling qualities ratings, latency design guidelines are presented. In addition, this paper presents a design philosophy, supported by simulation data, for using flight director display augmentation to suppress the effects of display latency for delays up to 300 milliseconds.

  11. Analysis of aircraft longitudinal handling qualities

    NASA Technical Reports Server (NTRS)

    Hess, R. A.

    1981-01-01

    The optimal control model (OCM) of the human pilot is applied to the study of aircraft handling qualities. Attention is focused primarily on longitudinal tasks. The modeling technique differs from previous applications of the OCM in that considerable effort is expended in simplifying the pilot/vehicle analysis. After briefly reviewing the OCM, a technique for modeling the pilot controlling higher order systems is introduced. Following this, a simple criterion for determining the susceptibility of an aircraft to pilot induced oscillations (PIO) is formulated. Finally, a model-based metric for pilot rating prediction is discussed. The resulting modeling procedure provides a relatively simple, yet unified approach to the study of a variety of handling qualities problems.

  12. An Investigation of Large Aircraft Handling Qualities

    NASA Astrophysics Data System (ADS)

    Joyce, Richard D.

    An analytical technique for investigating transport aircraft handling qualities is exercised in a study using models of two such vehicles, a Boeing 747 and Lockheed C-5A. Two flight conditions are employed for climb and directional tasks, and a third included for a flare task. The analysis technique is based upon a "structural model" of the human pilot developed by Hess. The associated analysis procedure has been discussed previously in the literature, but centered almost exclusively on the characteristics of high-performance fighter aircraft. The handling qualities rating level (HQRL) and pilot induced oscillation tendencies rating level (PIORL) are predicted for nominal configurations of the aircraft and for "damaged" configurations where actuator rate limits are introduced as nonlinearites. It is demonstrated that the analysis can accommodate nonlinear pilot/vehicle behavior and do so in the context of specific flight tasks, yielding estimates of handling qualities, pilot-induced oscillation tendencies and upper limits of task performance. A brief human-in-the-loop tracking study was performed to provide a limited validation of the pilot model employed.

  13. Design and Flight Test of a Cable Angle Feedback Control System for Improving Helicopter Slung Load Operations at Low Speed

    DTIC Science & Technology

    2014-04-01

    piloted handling qualities of the helicopter are degraded by the presence of the slung load . This dissertation investigates the dynamics, handling...qualities requirements, and control aspects of the helicopter /slung load system that contribute to the performance of piloted slung load operations. A...the nature of controlling a two-body dynamic system: helicopter and slung load . The pilot must maneuver the helicopter effectively in order to fly to

  14. Ultra-heavy vertical lift system: The Heli-Stat. [helicopter - airship combination for materials handling

    NASA Technical Reports Server (NTRS)

    Piasecki, F. N.

    1975-01-01

    A hybrid VTOL airship which is combined with helicopters is evaluated. The static lift of the airship supports approximately the full empty weight of the entire assembly. The helicopter rotors furnish the lift to support the payload as well as the propulsion and control about all axes. Thus existing helicopters, with no new technology required, can be made to lift payloads of ten times the capacity of each one alone, and considerably more than that of any airship built so far. A vehicle is described which has a 75-ton payload, based on four existing CH-53D helicopters and an airship of 3,600,000 cu. ft. The method of interconnection is described along with discussion of control, instrumentation, drive system and critical design conditions. The vertical lift and positioning capabilities of this vehicle far exceed any other means available today, yet can be built with a minimum of risk, development cost and time.

  15. Directional handling qualities requirements for nap-of-the-earth tasks

    NASA Technical Reports Server (NTRS)

    Bivens, C. C.

    1986-01-01

    A piloted similator experiment designed to investigate directional axis handling qualities requirements for low-speed and hover tasks conducted by a scout/attack helicopter is described. Included were the directional characteristics of various candidate light helicopter family (LHX) configurations. The test also focused on conventional single main/tail rotor configurations where the first-order effects that contribute to the loss of tail rotor control experienced by the OH-58 series aircraft were modeled. Two types of yaw stability and control augmentation systems were implemented: washed-out yaw rate feedback and shaped control input, and a yaw rate command, heading-hold system. The results of the experiment indicate that rotorcraft configurations with high directional gust sensitivity require more yaw damping to maintain satisfactory handling qualities during nap-of-the-earth (NOE) flying tasks. It was also determined that both yaw damping and control response are critical handling qualities parameters in performing the air-to-air target acquisition and tracking task. The lack of substantial yaw damping and larger values of gust sensitivity increased the possibility of loss of directional control at low airspeeds for the tail rotor configurations.

  16. Tests Of Helicopter Control System

    NASA Technical Reports Server (NTRS)

    Hilbert, Kathryn B.; Lebacqz, J. Victor; Hindson, William S.

    1988-01-01

    Advanced control systems being developed for rotorcraft. Report discusses aspects of development of multivariable, explicit-model-following control system for CH-47B fly-by-wire helicopter. Project part of recent trend toward use of highly-augmented, high-gain flight-control systems to assist pilots of military helicopters in performance of demanding tasks and to improve handling qualities of aircraft.

  17. Studies of the Lateral-Directional Flying Qualities of a Tandem Helicopter in Forward Flight

    NASA Technical Reports Server (NTRS)

    Amer, Kenneth B; Tapscott, Robert J

    1954-01-01

    An investigation of the lateral-directional flying qualities of a tandem-rotor helicopter in forward flight was undertaken to determine desirable goals for helicopter lateral-directional flying qualities and possible methods of achieving these goals in the tandem-rotor helicopter. Comparison between directional stability as measured in flight and rotor-off model tests in a wind tunnel shows qualitative agreement and, hence, indicates such wind-tunnel test, despite the absence of the rotors, to be one effective method of studying means of improving the directional stability of the tandem helicopter. Flight-test measurements of turns and oscillations, in conjunction with analytical studies, suggest possible practical methods of achieving the goals of satisfactory turn and oscillatory characteristics in the tandem helicopter.

  18. Results of an A109 simulation validation and handling qualities study

    NASA Technical Reports Server (NTRS)

    Eshow, Michelle M.; Orlandi, Diego; Bonaita, Giovanni; Barbieri, Sergio

    1989-01-01

    The results for the validation of a mathematical model of the Agusta A109 helicopter, and subsequent use of the model as the baseline for a handling qualities study of cockpit centerstick requirements, are described. The technical approach included flight test, non-realtime analysis, and realtime piloted simulation. Results of the validation illustrate a time- and frequency-domain approach to the model and simulator issues. The final A109 model correlates well with the actual aircraft with the Stability Augmentation System (SAS) engaged, but is unacceptable without the SAS because of instability and response coupling at low speeds. Results of the centerstick study support the current U.S. Army handling qualities requirements for centerstick characteristics.

  19. Simulation evaluation of the effects of time delay and motion on rotorcraft handling qualities

    NASA Technical Reports Server (NTRS)

    Mitchell, David G.; Hoh, Roger H.; Atencio, Adolph, Jr.; Key, David L.

    1991-01-01

    A study aimed at determining the effects of simulator characteristics on perceived handling qualities is discussed. Evaluations were conducted with a baseline set of rotorcraft dynamics, using a simple transfer-function model of an uncoupled helicopter, under different conditions of visual and overall time delays. As the visual and motion parameters were changed, differences in pilot opinion were found reflecting a change in the pilots' perceptions of handling qualities, rather than changes in the aircraft model itself. It is concluded that it is necessary to tailor the motion washout dynamics to suit the task, with reduced washouts for precision maneuvering as compared to aggressive maneuvering. Visual-delay data suggest that it may be better to allow some time delay in the visual path to minimize the mismatch between visual and motion, rather than eliminate the visual delay entirely through lead compensation.

  20. Pre-slaughter handling and pork quality.

    PubMed

    Vermeulen, L; Van de Perre, V; Permentier, L; De Bie, S; Verbeke, G; Geers, R

    2015-02-01

    Environmental variables, as sound levels, were collected during the pre-slaughter process in 18 different Belgian commercial slaughterhouses. Four pre-slaughter phases were determined: firstly after arrival of the truck at the slaughterhouse and just before unloading, secondly during unloading, thirdly at lairage and finally while moving to the stunner. A total of 8508 pigs was examined during the pre-slaughter process, of which the pH(LT) (M. longissimus thoracis), at 30 min post-mortem was measured. For each pre-slaughter phase, variables which might influence pork quality were determined. Moreover, this study made it possible to infer a checklist to represent and predict PSE traits of pork for all kind of pre-slaughter situations. The checklist shows also that the impact on pork quality is more decisive for the variables measured close to the stunning phase. Hence, this information is useful for the industry to optimize handling of pigs, reducing the risk for PSE traits.

  1. Flight testing and frequency domain analysis for rotorcraft handling qualities characteristics

    NASA Technical Reports Server (NTRS)

    Ham, Johnnie A.; Gardner, Charles K.; Tischler, Mark B.

    1993-01-01

    A demonstration of frequency domain flight testing techniques and analyses was performed on a U.S. Army OH-58D helicopter in support of the OH-58D Airworthiness and Flight Characteristics Evaluation and the Army's development and ongoing review of Aeronautical Design Standard 33C, Handling Qualities Requirements for Military Rotorcraft. Hover and forward flight (60 knots) tests were conducted in 1 flight hour by Army experimental test pilots. Further processing of the hover data generated a complete database of velocity, angular rate, and acceleration frequency responses to control inputs. A joint effort was then undertaken by the Airworthiness Qualification Test Directorate (AQTD) and the U.S. Army Aeroflightdynamics Directorate (AFDD) to derive handling qualities information from the frequency response database. A significant amount of information could be extracted from the frequency domain database using a variety of approaches. This report documents numerous results that have been obtained from the simple frequency domain tests; in many areas, these results provide more insight into the aircraft dynamics that affect handling qualities than to traditional flight tests. The handling qualities results include ADS-33C bandwidth and phase delay calculations, vibration spectral determinations, transfer function models to examine single axis results, and a six degree of freedom fully coupled state space model. The ability of this model to accurately predict aircraft responses was verified using data from pulse inputs. This report also documents the frequency-sweep flight test technique and data analysis used to support the tests.

  2. Cooper-Harper Experience Report for Spacecraft Handling Qualities Applications

    NASA Technical Reports Server (NTRS)

    Bailey, Randall E.; Jackson, E. Bruce; Bilimoria, Karl D.; Mueller, Eric R.; Frost, Chad R.; Alderete, Thomas S.

    2009-01-01

    A synopsis of experience from the fixed-wing and rotary-wing aircraft communities in handling qualities development and the use of the Cooper-Harper pilot rating scale is presented as background for spacecraft handling qualities research, development, test, and evaluation (RDT&E). In addition, handling qualities experiences and lessons-learned from previous United States (US) spacecraft developments are reviewed. This report is intended to provide a central location for references, best practices, and lessons-learned to guide current and future spacecraft handling qualities RDT&E.

  3. Orion Capsule Handling Qualities for Atmospheric Entry

    NASA Technical Reports Server (NTRS)

    Tigges, Michael A.; Bihari, Brian D.; Stephens, John-Paul; Vos, Gordon A.; Bilimoria, Karl D.; Mueller, Eric R.; Law, Howard G.; Johnson, Wyatt; Bailey, Randall E.; Jackson, Bruce

    2011-01-01

    Two piloted simulations were conducted at NASA's Johnson Space Center using the Cooper-Harper scale to study the handling qualities of the Orion Command Module capsule during atmospheric entry flight. The simulations were conducted using high fidelity 6-DOF simulators for Lunar Return Skip Entry and International Space Station Return Direct Entry flight using bank angle steering commands generated by either the Primary (PredGuid) or Backup (PLM) guidance algorithms. For both evaluations, manual control of bank angle began after descending through Entry Interface into the atmosphere until drogue chutes deployment. Pilots were able to use defined bank management and reversal criteria to accurately track the bank angle commands, and stay within flight performance metrics of landing accuracy, g-loads, and propellant consumption, suggesting that the pilotability of Orion under manual control is both achievable and provides adequate trajectory performance with acceptable levels of pilot effort. Another significant result of these analyses is the applicability of flying a complex entry task under high speed entry flight conditions relevant to the next generation Multi Purpose Crew Vehicle return from Mars and Near Earth Objects.

  4. Incorporating Handling Qualities Analysis into Rotorcraft Conceptual Design

    NASA Technical Reports Server (NTRS)

    Lawrence, Ben

    2014-01-01

    This paper describes the initial development of a framework to incorporate handling qualities analyses into a rotorcraft conceptual design process. In particular, the paper describes how rotorcraft conceptual design level data can be used to generate flight dynamics models for handling qualities analyses. Also, methods are described that couple a basic stability augmentation system to the rotorcraft flight dynamics model to extend analysis to beyond that of the bare airframe. A methodology for calculating the handling qualities characteristics of the flight dynamics models and for comparing the results to ADS-33E criteria is described. Preliminary results from the application of the handling qualities analysis for variations in key rotorcraft design parameters of main rotor radius, blade chord, hub stiffness and flap moment of inertia are shown. Varying relationships, with counteracting trends for different handling qualities criteria and different flight speeds are exhibited, with the action of the control system playing a complex part in the outcomes. Overall, the paper demonstrates how a broad array of technical issues across flight dynamics stability and control, simulation and modeling, control law design and handling qualities testing and evaluation had to be confronted to implement even a moderately comprehensive handling qualities analysis of relatively low fidelity models. A key outstanding issue is to how to 'close the loop' with an overall design process, and options for the exploration of how to feedback handling qualities results to a conceptual design process are proposed for future work.

  5. The impact of flying qualities on helicopter operational agility

    NASA Technical Reports Server (NTRS)

    Padfield, Gareth D.; Lappos, Nick; Hodgkinson, John

    1993-01-01

    Flying qualities standards are formally set to ensure safe flight and therefore reflect minimum, rather than optimum, requirements. Agility is a flying quality but relates to operations at high, if not maximum, performance. While the quality metrics and test procedures for flying, as covered for example in ADS33C, may provide an adequate structure to encompass agility, they do not currently address flight at high performance. This is also true in the fixed-wing world and a current concern in both communities is the absence of substantiated agility criteria and possible conflicts between flying qualities and high performance. AGARD is sponsoring a working group (WG19) title 'Operational Agility' that deals with these and a range of related issues. This paper is condensed from contributions by the three authors to WG19, relating to flying qualities. Novel perspectives on the subject are presented including the agility factor, that quantifies performance margins in flying qualities terms; a new parameter, based on maneuver acceleration is introduced as a potential candidate for defining upper limits to flying qualities. Finally, a probabilistic analysis of pilot handling qualities ratings is presented that suggests a powerful relationship between inherent airframe flying qualities and operational agility.

  6. Handling qualities comparison of panoramic night vision goggles and 46-deg. night vision goggles

    NASA Astrophysics Data System (ADS)

    Craig, Gregory; Jennings, Sion; Thorndycraft, David

    2003-09-01

    Night Vision Goggles allow the user to see in extremely low illumination levels but the visual information provided by Night Vision Goggles has a limited field-of-view that diminishes handling-qualities in the night flying environment. Panoramic Night Vision Goggles were designed to correct this problem by providing a 100° horizontal field-of-view which is larger than currently used Night Vision Goggles. However, in the first generation Panoramic Night Vision Goggle, the improved field of view came at the cost of diminished resolution, contrast and central overlap area when compared to conventional Night Vision Goggles. This paper describes an evaluation that was conducted in the variable stability NRC Bell-205 helicopter to examine the influence on system handling qualities of the Panoramic Night Vision Goggles and a 46° field-of-view UK Night Vision Goggle. Five pilots flew the ADS-33D hover, sidestep and pirouette manoeuvres in simulated night conditions with the UK Night Vision Goggle and the Panoramic Night Vision Goggle. Both subjective and objective measures of task performance were obtained. Handling-qualities ratings showed the pirouette was performed better with the Panoramic Night Vision Goggles. This was the only manoeuvre where there was a clear-cut handling qualities improvement when using the Panoramic Night Vision Goggles. Other manoeuvres such as the sidestep and hover did not show definitive handling qualities rating differences between the two Night Vision Goggle types. The flight test results were interpreted in terms of the design trade-offs of the two night vision systems, with regard to the different acuity, binocular overlaps and fields-of-view.

  7. Analysis of Handling Qualities Design Criteria for Active Inceptor Force-Feel Characteristics

    NASA Technical Reports Server (NTRS)

    Malpica, Carlos A.; Lusardi, Jeff A.

    2013-01-01

    The force-feel system characteristics of the cyclic inceptors of most helicopters are set based on the characteristics of the mechanical components in the control system (mass, springs, friction dampers, etc.). For these helicopters, the force-feel characteristics typically remain constant over the entire flight envelope, with perhaps a trim release to minimize control forces while maneuvering. With the advent of fly-by-wire control systems and active inceptors in helicopters, the force-feel characteristics are now determined by the closed-loop response of the active inceptor itself as defined by the inertia, force/displacement gradient, damping, breakout force and detent shape configuration parameters in the inceptor control laws. These systems give the flexibility to dynamically prescribe different feel characteristics for different control modes or flight conditions, and the ability to provide tactile cueing to the pilot through the actively controlled side-stick or center-stick cyclic inceptor. For rotorcraft, a few studies have been conducted to assess the effects of cyclic force-feel characteristics on handling qualities in flight. An early study provided valuable insight into the static force-deflection characteristics (force gradient) and the number of axes controlled by the side-stick controller for the U.S. Army's Advanced Digital/Optical Control System (ADOCS) demonstrator aircraft [1]. The first of a series of studies providing insight on the inceptor dynamic force-feel characteristics was conducted on the NASA/Army CH-47B variable-stability helicopter [2]. This work led to a proposed requirement that set boundaries based on the cyclic natural frequency and inertia, with the stipulation of a lower damping ratio limit of 0.3 [3]. A second study was conducted by the Canadian Institute for Aerospace Research using their variable-stability Bell 205A helicopter [4]. This research suggested boundaries for stick dynamics based on natural frequency and damping

  8. Civil helicopter flight research. [for CH-53 helicopter

    NASA Technical Reports Server (NTRS)

    Snyder, W. J.; Schoultz, M. B.

    1976-01-01

    The paper presents a description of the NASA CH-53 Civil Helicopter Research Aircraft and discusses preliminary results of the aircraft flight research performed to evaluate factors and requirements for future helicopter transport operations. The CH-53 equipped with a 16-seat airline-type cabin and instrumented for flight research studies in noise, vibration, handling qualities, passenger acceptance, fuel utilization, terminal area maneuvers, and gust response. Predicted fuel usage for typical short-haul missions is compared with actual fuel use. Pilot ratings for an IFR handling quality task for three levels of stability augmentation are presented, and the effects of internal noise, vibration, and motion on passenger acceptance are discussed. Future planned CH-53 flight research within the Civil Helicopter Technology Program is discussed.

  9. Effects of simulator motion and visual characteristics on rotorcraft handling qualities evaluations

    NASA Technical Reports Server (NTRS)

    Mitchell, David G.; Hart, Daniel C.

    1993-01-01

    The pilot's perceptions of aircraft handling qualities are influenced by a combination of the aircraft dynamics, the task, and the environment under which the evaluation is performed. When the evaluation is performed in a groundbased simulator, the characteristics of the simulation facility also come into play. Two studies were conducted on NASA Ames Research Center's Vertical Motion Simulator to determine the effects of simulator characteristics on perceived handling qualities. Most evaluations were conducted with a baseline set of rotorcraft dynamics, using a simple transfer-function model of an uncoupled helicopter, under different conditions of visual time delays and motion command washout filters. Differences in pilot opinion were found as the visual and motion parameters were changed, reflecting a change in the pilots' perceptions of handling qualities, rather than changes in the aircraft model itself. The results indicate a need for tailoring the motion washout dynamics to suit the task. Visual-delay data are inconclusive but suggest that it may be better to allow some time delay in the visual path to minimize the mismatch between visual and motion, rather than eliminate the visual delay entirely through lead compensation.

  10. Review of US Navy VSTOL handling qualities requirements

    NASA Technical Reports Server (NTRS)

    Hutchings, D. E.

    1977-01-01

    Handling qualities requirements for V/STOL operations from small ships are considered in terms of the ship operating environment. Turbulence, wind over the deck, ship motion, visibility, and severe weather and sea conditions are among the factors discussed.

  11. Orion Handling Qualities During ISS Proximity Operations and Docking

    NASA Technical Reports Server (NTRS)

    Stephens, John-Paul; Vos, Gordon A.; Bilimoria, Karl D.; Mueller, Eric R.; Brazzel, Jack; Spehar, Pete

    2011-01-01

    NASA's Orion spacecraft is designed to autonomously rendezvous and dock with many vehicles including the International Space Station. However, the crew is able to assume manual control of the vehicle s attitude and flight path. In these instances, Orion must meet handling qualities requirements established by NASA. Two handling qualities assessments were conducted at the Johnson Space Center to evaluate preliminary designs of the vehicle using a six degree of freedom, high-fidelity guidance, navigation, and control simulation. The first assessed Orion s handling qualities during the last 20 ft before docking, and included both steady and oscillatory motions of the docking target. The second focused on manual acquisition of the docking axis during the proximity operations phase and subsequent station-keeping. Cooper-Harper handling qualities ratings, workload ratings and comments were provided by 10 evaluation pilots for the docking study and 5 evaluation pilots for the proximity operations study. For the docking task, both cases received 90% Level 1 (satisfactory) handling qualities ratings, exceeding NASA s requirement. All ratings for the ProxOps task were Level 1. These evaluations indicate that Orion is on course to meet NASA's handling quality requirements for ProxOps and docking.

  12. Getting a Handle on Academic Quality

    ERIC Educational Resources Information Center

    Massy, William F.; Graham, Steven W.; Short, Paula Myrick

    2007-01-01

    The quality of teaching, more than ever, is seen as the all-important results area for colleges and universities. Few board members would dispute the importance of teaching or their responsibility for exercising oversight over its quality and continuous improvement. Yet there is little consensus about how to accomplish such oversight. Few board…

  13. Impact of flying qualities on mission effectiveness for helicopter air combat, volume 1

    NASA Technical Reports Server (NTRS)

    Harris, T. M.; Beerman, D. A.

    1983-01-01

    A computer simulation to investigate the impact of flying qualities on mission effectiveness is described. The objective of the study was to relate the effects of flying qualities, such as precision of flight path control and pilot workload, to the ability of a single Scout helicopter, or helicopter team, to accomplish a specified anti-armor mission successfully. The model of the actual engagement is a Monte Carlo simulation that has the capability to assess the effects of helicopter characteristics, numbers, tactics and weaponization on the force's ability to accomplish a specific mission against a specified threat as a function of realistic tactical factors. A key feature of this program is a simulation of micro-terrain features and their effects on detection, exposure, and masking for nap-of-the-earth (NOE) flight.

  14. Evaluation of ride quality prediction methods for helicopter interior noise and vibration environments

    NASA Technical Reports Server (NTRS)

    Leatherwood, J. D.; Clevenson, S. A.; Hollenbaugh, D. D.

    1984-01-01

    The results of a simulator study conducted to compare and validate various ride quality prediction methods for use in assessing passenger/crew ride comfort within helicopters are presented. Included are results quantifying 35 helicopter pilots discomfort responses to helicopter interior noise and vibration typical of routine flights, assessment of various ride quality metrics including the NASA ride comfort model, and examination of possible criteria approaches. Results of the study indicated that crew discomfort results from a complex interaction between vibration and interior noise. Overall measures such as weighted or unweighted root-mean-square acceleration level and A-weighted noise level were not good predictors of discomfort. Accurate prediction required a metric incorporating the interactive effects of both noise and vibration. The best metric for predicting crew comfort to the combined noise and vibration environment was the NASA discomfort index.

  15. Operational military helicopter interior noise and vibration measurements with comparisons to ride quality criteria

    NASA Technical Reports Server (NTRS)

    Clevenson, S. A.; Leatherwood, J. D.; Hollenbaugh, D. D.

    1983-01-01

    Balka (1981) has identified the attainment of a 'jet-smooth' ride as a primary goal of the helicopter industry for commercial and certain military helicopters. It was noted that criteria accounting for both multiple axis vibration and interior noise are needed. The present investigation has the objective to present a vibration and interior noise data base in a format suitable for direct evaluation of aircraft ride quality. The investigation is also concerned with an assessment of the measured environment against available criteria as an indication of the state-of-the-art for current machines. Interior noise and vibration measurements were obtained on eight military helicopters during routine operational flights. The data are presented in the form of a number of parameters.

  16. 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.

  17. Theoretical and experimental methods to select aircraft handling qualities

    NASA Astrophysics Data System (ADS)

    Zaichik, L. E.; Yashin, Y. P.; Perebatov, V. S.; Desyatnik, P. A.

    2013-12-01

    A theoretical-experimental method is developed to analyze and adequately select aircraft handling qualities (HQ). A review is presented of the criteria developed by the authors to estimate the role of motion cues in controlling of an aircraft, and criteria to estimate the on-ground simulation fidelity. The method is presented to translate on-ground simulation results into real flight conditions.

  18. Ride quality sensitivity to SAS control law and to handling quality variations

    NASA Technical Reports Server (NTRS)

    Roberts, P. A.; Schmidt, D. K.; Swaim, R. L.

    1976-01-01

    The RQ trends which large flexible aircraft exhibit under various parameterizations of control laws and handling qualities are discussed. A summary of the assumptions and solution technique, a control law parameterization review, a discussion of ride sensitivity to handling qualities, and the RQ effects generated by implementing relaxed static stability configurations are included.

  19. Handling "Helicopter Parents"

    ERIC Educational Resources Information Center

    Lum, Lydia

    2006-01-01

    Once upon a time, parents would help their children move into dorm rooms and apartments, then wave good-bye for the semester. Not anymore. Baby boomers have arguably been more involved in their children's educations--and their lives in general--than any preceding generation of parents, university observers say. And boomers see no reason why that…

  20. Handling Qualities of Large Rotorcraft in Hover and Low Speed

    NASA Technical Reports Server (NTRS)

    Malpica, Carlos; Theodore, Colin R.; Lawrence , Ben; Blanken, Chris L.

    2015-01-01

    According to a number of system studies, large capacity advanced rotorcraft with a capability of high cruise speeds (approx.350 mph) as well as vertical and/or short take-off and landing (V/STOL) flight could alleviate anticipated air transportation capacity issues by making use of non-primary runways, taxiways, and aprons. These advanced aircraft pose a number of design challenges, as well as unknown issues in the flight control and handling qualities domains. A series of piloted simulation experiments have been conducted on the NASA Ames Research Center Vertical Motion Simulator (VMS) in recent years to systematically investigate the fundamental flight control and handling qualities issues associated with the characteristics of large rotorcraft, including tiltrotors, in hover and low-speed maneuvering.

  1. A Look at Handling Qualities of Canard Configurations

    NASA Technical Reports Server (NTRS)

    Anderson, Seth B.

    1986-01-01

    The first human-powered flight was achieved by a canard-configured aircraft (Wright Brothers). Although other canard concepts were flown with varying degrees of success over the years, the tail-aft configuration has dominated the aircraft market for both military and civil use. Reviewed are the development of several canard aircraft with emphasis on stability and control, handling qualities, and operating problems. The results show that early canard concepts suffered adversely in flight behavior because of a lack of understanding of the sensitivities of these concepts to basic stability and control principles. Modern canard designs have been made competitive with tail-aft configurations by using appropriate handling qualities design criteria.

  2. Subsonic Wing Optimization for Handling Qualities Using ACSYNT

    NASA Technical Reports Server (NTRS)

    Soban, Danielle Suzanne

    1996-01-01

    The capability to accurately and rapidly predict aircraft stability derivatives using one comprehensive analysis tool has been created. The PREDAVOR tool has the following capabilities: rapid estimation of stability derivatives using a vortex lattice method, calculation of a longitudinal handling qualities metric, and inherent methodology to optimize a given aircraft configuration for longitudinal handling qualities, including an intuitive graphical interface. The PREDAVOR tool may be applied to both subsonic and supersonic designs, as well as conventional and unconventional, symmetric and asymmetric configurations. The workstation-based tool uses as its model a three-dimensional model of the configuration generated using a computer aided design (CAD) package. The PREDAVOR tool was applied to a Lear Jet Model 23 and the North American XB-70 Valkyrie.

  3. 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.

  4. Effects of cockpit lateral stick characteristics on handling qualities and pilot dynamics

    NASA Technical Reports Server (NTRS)

    Mitchell, David G.; Aponso, Bimal L.; Klyde, David H.

    1992-01-01

    This report presents the results of analysis of cockpit lateral control feel-system studies. Variations in feel-system natural frequency, damping, and command sensing reference (force and position) were investigated, in combination with variations in the aircraft response characteristics. The primary data for the report were obtained from a flight investigation conducted with a variable-stability airplane, with additional information taken from other flight experiments and ground-based simulations for both airplanes and helicopters . The study consisted of analysis of handling qualities ratings and extraction of open-loop, pilot-vehicle describing functions from sum-of-sines tracking data, including, for a limited subset of these data, the development of pilot models. The study confirms the findings of other investigators that the effects on pilot opinion of cockpit feel-system dynamics are not equivalent to a comparable level of added time delay, and until a more comprehensive set of criteria are developed, it is recommended that feel-system dynamics be considered a delay-inducing element in the aircraft response. The best correlation with time-delay requirements was found when the feel-system dynamics were included in the delay measurements, regardless of the command reference. This is a radical departure from past approaches.

  5. Handling Qualities of a Capsule Spacecraft During Atmospheric Entry

    NASA Technical Reports Server (NTRS)

    Bilimoria, Karl D.; Mueller, Eric R.

    2010-01-01

    A piloted simulation was conducted to study handling qualities for capsule spacecraft entering the Earth s atmosphere. Eight evaluation pilots, including six pilot astronauts, provided Cooper-Harper ratings, workload ratings, and qualitative comments. The simulation began after descending through the atmospheric entry interface point and continued until the drogue parachutes deployed. There were two categories of piloting tasks, both of which required bank angle control. In one task category, the pilot followed a closed-loop bank angle command computed by the backup guidance system to manage g-loads during entry. In the other task category, the pilot used intuitive rules to determine the desired bank angle independently, based on an open-loop schedule of vertical speed, Mach, and total energy specified at several range-to-target gates along the entry trajectory. Pilots were able to accurately track the bank angle guidance commands and steered the capsule toward the recovery site with essentially the same range error as the benchmark autopilot trajectory albeit with substantially higher propellant usage, and the handling qualities for this task were satisfactory. Another key result was that the complex piloting task of atmospheric entry could be performed satisfactorily, even in the presence of large dispersions, by controlling bank angle to follow a simple open-loop schedule.

  6. Orion Handling Qualities During ISS Rendezvous and Docking

    NASA Technical Reports Server (NTRS)

    Hart, Jeremy J.; Stephens, J. P.; Spehar, P.; Bilimoria, K.; Foster, C.; Gonzalex, R.; Sullivan, K.; Jackson, B.; Brazzel, J.; Hart, J.

    2011-01-01

    The Orion spacecraft was designed to rendezvous with multiple vehicles in low earth orbit (LEO) and beyond. To perform the required rendezvous and docking task, Orion must provide enough control authority to perform coarse translational maneuvers while maintaining precision to perform the delicate docking corrections. While Orion has autonomous docking capabilities, it is expected that final approach and docking operations with the International Space Station (ISS) will initially be performed in a manual mode. A series of evaluations was conducted by NASA and Lockheed Martin at the Johnson Space Center to determine the handling qualities (HQ) of the Orion spacecraft during different docking and rendezvous conditions using the Cooper-Harper scale. This paper will address the specifics of the handling qualities methodology, vehicle configuration, scenarios flown, data collection tools, and subject ratings and comments. The initial Orion HQ assessment examined Orion docking to the ISS. This scenario demonstrates the Translational Hand Controller (THC) handling qualities of Orion. During this initial assessment, two different scenarios were evaluated. The first was a nominal docking approach to a stable ISS, with Orion initializing with relative position dispersions and a closing rate of approximately 0.1 ft/sec. The second docking scenario was identical to the first, except the attitude motion of the ISS was modeled to simulate a stress case ( 1 degree deadband per axis and 0.01 deg/sec rate deadband per axis). For both scenarios, subjects started each run on final approach at a docking port-to-port range of 20 ft. Subjects used the THC in pulse mode with cues from the docking camera image, window views, and range and range rate data displayed on the Orion display units. As in the actual design, the attitude of the Orion vehicle was held by the automated flight control system at 0.5 degree deadband per axis. Several error sources were modeled including Reaction

  7. Minimum-complexity helicopter simulation math model

    NASA Technical Reports Server (NTRS)

    Heffley, Robert K.; Mnich, Marc A.

    1988-01-01

    An example of a minimal complexity simulation helicopter math model is presented. Motivating factors are the computational delays, cost, and inflexibility of the very sophisticated math models now in common use. A helicopter model form is given which addresses each of these factors and provides better engineering understanding of the specific handling qualities features which are apparent to the simulator pilot. The technical approach begins with specification of features which are to be modeled, followed by a build up of individual vehicle components and definition of equations. Model matching and estimation procedures are given which enable the modeling of specific helicopters from basic data sources such as flight manuals. Checkout procedures are given which provide for total model validation. A number of possible model extensions and refinement are discussed. Math model computer programs are defined and listed.

  8. Helicopter roll control effectiveness criteria program summary

    NASA Technical Reports Server (NTRS)

    Heffley, Robert K.; Bourne, Simon M.; Mnich, Marc A.

    1988-01-01

    A study of helicopter roll control effectiveness is summarized for the purpose of defining military helicopter handling qualities requirements. The study is based on an analysis of pilot-in-the-loop task performance of several basic maneuvers. This is extended by a series of piloted simulations using the NASA Ames Vertical Motion Simulator and selected flight data. The main results cover roll control power and short-term response characteristics. In general the handling qualities requirements recommended are set in conjunction with desired levels of flight task and maneuver response which can be directly observed in actual flight. An important aspect of this, however, is that vehicle handling qualities need to be set with regard to some quantitative aspect of mission performance. Specific examples of how this can be accomplished include a lateral unmask/remask maneuver in the presence of a threat and an air tracking maneuver which recognizes the kill probability enhancement connected with decreasing the range to the target. Conclusions and recommendations address not only the handling qualities recommendations, but also the general use of flight simulators and the dependence of mission performance on handling qualities.

  9. A ground-simulator investigation of helicopter longitudinal flying qualities for instrument approach

    NASA Technical Reports Server (NTRS)

    Lebacqz, J. V.; Forrest, R. D.; Gerdes, R. M.

    1982-01-01

    A ground-simulation experiment was conducted to investigate the direct and interactive influences of several longitudinal static and dynamic stability parameters on helicopter flying qualities during terminal-area operations in instrument conditions. Variations that were examined included five levels of static control-position gradients ranging from stable to unstable; two levels of dynamic stability for the long-period oscillation; two levels of the steady-state pitch speed gradient; two levels of angle-of-attack stability and pitch-rate damping; and two levels of stability and control augmentation. These variations were examined initially in calm air and thin in simulated light-to-moderate turbulence and wind shear. Five pilots performed a total of 223 evaluations of these parameters for a representative microwave landing system precision approach task conducted in a dual-pilot crew-loading situation.

  10. The effects of aircraft design and atmospheric turbulence on handling and ride qualities

    NASA Technical Reports Server (NTRS)

    Jones, C. R.; Jacobson, I. D.

    1976-01-01

    The effects of aircraft dynamic characteristics on passenger ride quality were investigated to determine ride-quality isocontours similar to aircraft handling-qualities contours. Measurements were made on a motion-base simulator while varying the aircraft short-period and Dutch Roll frequencies and dampings. Both pilot ratings and subjective ride-quality ratings were obtained during simulator flight. Ride and handling qualities were found to be complimentary for the Dutch Roll mode, but not for the short-period mode. Regions of optimal ride and handling qualities were defined for the short-period mode, and the effects of changes in turbulence level studied using mathematical models.

  11. Flight investigation of effects of a fan-in-fin yaw control concept on helicopter flying-quality characteristics

    NASA Technical Reports Server (NTRS)

    Kelley, H. L.; West, T. C.

    1974-01-01

    Flight-test results which describe flying-quality factors related to the fan-in-fin yaw control concept as utilized on a pre-production version of a European helicopter are presented. Design compromises to be considered with this concept are also presented. The large, fixed vertical fin associated with the fan-in-fin system was helpful in maneuvering flight, but introduced several flying-quality problems when combined with the fan.

  12. Handling Quality Requirements for Advanced Aircraft Design: Longitudinal Mode

    DTIC Science & Technology

    1979-08-01

    regarded by implication or otherwise as in any manner licensing the holder or any other person or corporation, or conveying any rights or permission...analog hardware specifications and seleccion on the DFCS performance. * Consideration of the potential degradation of DFCS performance and handling...systems research or even for the engineering design of an aircraft or FCS, matters of style and personal taste can dictate how one chooses to

  13. Development of longitudinal handling qualities criteria for large advanced supersonic aircraft

    NASA Technical Reports Server (NTRS)

    Sudderth, R. W.; Bohn, J. G.; Caniff, M. A.; Bennett, G. R.

    1975-01-01

    Longitudinal handling qualities criteria in terms of airplane response characteristics were developed. The criteria cover high speed cruise maneuvering, landing approach, and stall recovery. Data substantiating the study results are reported.

  14. Aircraft model prototypes which have specified handling-quality time histories

    NASA Technical Reports Server (NTRS)

    Johnson, S. H.

    1976-01-01

    Several techniques for obtaining linear constant-coefficient airplane models from specified handling-quality time histories are discussed. One technique, the pseudodata method, solves the basic problem, yields specified eigenvalues, and accommodates state-variable transfer-function zero suppression. The method is fully illustrated for a fourth-order stability-axis small-motion model with three lateral handling-quality time histories specified. The FORTRAN program which obtains and verifies the model is included and fully documented.

  15. A design procedure for the handling qualities optimization of the X-29A aircraft

    NASA Technical Reports Server (NTRS)

    Bosworth, John T.; Cox, Timothy H.

    1989-01-01

    A design technique for handling qualities improvement was developed for the X-29A aircraft. As with any new aircraft, the X-29A control law designers were presented with a relatively high degree of uncertainty in their mathematical models. The presence of uncertainties, and the high level of static instability of the X-29A caused the control law designers to stress stability and robustness over handling qualities. During flight test, the mathematical models of the vehicle were validated or corrected to match the vehicle dynamic behavior. The updated models were then used to fine tune the control system to provide fighter-like handling characteristics. A design methodology was developed which works within the existing control system architecture to provide improved handling qualities and acceptable stability with a minimum of cost in both implementation as well as software verification and validation.

  16. Handling Qualities Evaluation of Pilot Tools for Spacecraft Docking in Earth Orbit

    NASA Technical Reports Server (NTRS)

    Bilimoria, Karl D.; Mueller, Eric; Frost, Chad

    2009-01-01

    A new generation of spacecraft is now under development by NASA to replace the Space Shuttle and return astronauts to the Moon. These spacecraft will have a manual control capability for several mission tasks, and the ease and precision with which pilots can execute these tasks will have an important effect on mission risk and training costs. This paper focuses on the handling qualities of a spacecraft based on dynamics similar to that of the Crew Exploration Vehicle, during the last segment of the docking task with a space station in low Earth orbit. A previous study established that handling qualities for this task degrade significantly as the level of translation-into-rotation coupling increases. The goal of this study is to evaluate the efficacy of various pilot aids designed to mitigate the handling qualities degradation caused by this coupling. Four pilot tools were ev adluaetead:d-band box/indicator, flight-path marker, translation guidance cues, and feed-forward control. Each of these pilot tools improved handling qualities, generally with greater improvements resulting from using these tools in combination. A key result of this study is that feedforward control effectively counteracts coupling effects, providing solid Level 1 handling qualities for the spacecraft configuration evaluated.

  17. ADS-33C related handling qualities research performed using the NRC Bell 205 airborne simulator

    NASA Technical Reports Server (NTRS)

    Morgan, J. Murray; Baillie, Stewart W.

    1993-01-01

    Over 10 years ago a project was initiated by the U.S. Army AVSCOM to update the military helicopter flying qualities specification MIL-8501-A. While not yet complete, the project reached a major milestone in 1989 with the publication of an Airworthiness Design Standard, ADS-33C. The 8501 update project initially set out to identify critical gaps in the requisite data base and then proceeded to fill them using a variety of directed research studies. The magnitude of the task required that it become an international effort: appropriate research studies were conducted in Germany, the UK and Canada as well as in the USA. Canadian participation was supported by the Department of National Defence (DND) through the Chief of Research and Development. Both ground based and in-flight simulation were used to study the defined areas and the Canadian Bell 205-A1 variable stability helicopter was used extensively as one of the primary research tools available for this effort. This paper reviews the involvement of the Flight Research Laboratory of the National Research Council of Canada in the update project, it describes the various experiments conducted on the Airborne Simulator, it notes significant results obtained and describes ongoing research associated with the project.

  18. Handling Qualities of Model Reference Adaptive Controllers with Varying Complexity for Pitch-Roll Coupled Failures

    NASA Technical Reports Server (NTRS)

    Schaefer, Jacob; Hanson, Curt; Johnson, Marcus A.; Nguyen, Nhan

    2011-01-01

    Three model reference adaptive controllers (MRAC) with varying levels of complexity were evaluated on a high performance jet aircraft and compared along with a baseline nonlinear dynamic inversion controller. The handling qualities and performance of the controllers were examined during failure conditions that induce coupling between the pitch and roll axes. Results from flight tests showed with a roll to pitch input coupling failure, the handling qualities went from Level 2 with the baseline controller to Level 1 with the most complex MRAC tested. A failure scenario with the left stabilator frozen also showed improvement with the MRAC. Improvement in performance and handling qualities was generally seen as complexity was incrementally added; however, added complexity usually corresponds to increased verification and validation effort required for certification. The tradeoff between complexity and performance is thus important to a controls system designer when implementing an adaptive controller on an aircraft. This paper investigates this relation through flight testing of several controllers of vary complexity.

  19. Efficient halal bleeding, animal handling, and welfare: A holistic approach for meat quality.

    PubMed

    Aghwan, Z A; Bello, A U; Abubakar, A A; Imlan, J C; Sazili, A Q

    2016-11-01

    Traditional halal slaughter and other forms of religious slaughter are still an issue of debate. Opposing arguments related to pre-slaughter handling, stress and pain associated with restraint, whether the incision is painful or not, and the onset of unconsciousness have been put forward, but no consensus has been achieved. There is a need to strike a balance between halal bleeding in the light of science and animal welfare. There is a paucity of scientific data with respect to animal welfare, particularly the use of restraining devices, animal handling, and efficient halal bleeding. However, this review found that competent handling of animals, proper use of restraining devices, and the efficient bleeding process that follows halal slaughter maintains meat eating quality. In conclusion, halal bleeding, when carried out in accordance with recommended animal welfare procedures, will not only maintain the quality and wholesomeness of meat but could also potentially reduce suffering and pain. Maintained meat quality increases consumer satisfaction and food safety.

  20. An Investigation of Large Tilt-Rotor Hover and Low Speed Handling Qualities

    NASA Technical Reports Server (NTRS)

    Malpica, Carlos A.; Decker, William A.; Theodore, Colin R.; Lindsey, James E.; Lawrence, Ben; Blanken, Chris L.

    2011-01-01

    A piloted simulation experiment conducted on the NASA-Ames Vertical Motion Simulator evaluated the hover and low speed handling qualities of a large tilt-rotor concept, with particular emphasis on longitudinal and lateral position control. Ten experimental test pilots evaluated different combinations of Attitude Command-Attitude Hold (ACAH) and Translational Rate Command (TRC) response types, nacelle conversion actuator authority limits and inceptor choices. Pilots performed evaluations in revised versions of the ADS-33 Hover, Lateral Reposition and Depart/Abort MTEs and moderate turbulence conditions. Level 2 handling qualities ratings were primarily recorded using ACAH response type in all three of the evaluation maneuvers. The baseline TRC conferred Level 1 handling qualities in the Hover MTE, but there was a tendency to enter into a PIO associated with nacelle actuator rate limiting when employing large, aggressive control inputs. Interestingly, increasing rate limits also led to a reduction in the handling qualities ratings. This led to the identification of a nacelle rate to rotor longitudinal flapping coupling effect that induced undesired, pitching motions proportional to the allowable amount of nacelle rate. A modification that counteracted this effect significantly improved the handling qualities. Evaluation of the different response type variants showed that inclusion of TRC response could provide Level 1 handling qualities in the Lateral Reposition maneuver by reducing coupled pitch and heave off axis responses that otherwise manifest with ACAH. Finally, evaluations in the Depart/Abort maneuver showed that uncertainty about commanded nacelle position and ensuing aircraft response, when manually controlling the nacelle, demanded high levels of attention from the pilot. Additional requirements to maintain pitch attitude within 5 deg compounded the necessary workload.

  1. Aircraft model prototypes which have specified handling-quality time histories

    NASA Technical Reports Server (NTRS)

    Johnson, S. H.

    1978-01-01

    Several techniques for obtaining linear constant-coefficient airplane models from specified handling-quality time histories are discussed. The pseudodata method solves the basic problem, yields specified eigenvalues, and accommodates state-variable transfer-function zero suppression. The algebraic equations to be solved are bilinear, at worst. The disadvantages are reduced generality and no assurance that the resulting model will be airplane like in detail. The method is fully illustrated for a fourth-order stability-axis small motion model with three lateral handling quality time histories specified. The FORTRAN program which obtains and verifies the model is included and fully documented.

  2. Dynamic stability and handling qualities tests on a highly augmented, statically unstable airplane

    NASA Technical Reports Server (NTRS)

    Gera, Joseph; Bosworth, John T.

    1987-01-01

    Novel flight test and analysis techniques in the flight dynamics and handling qualities area are described. These techniques were utilized at NASA Ames-Dryden during the initial flight envelope clearance of the X-29A aircraft. It is shown that the open-loop frequency response of an aircraft with highly relaxed static stability can be successfully computed on the ground from telemetry data. Postflight closed-loop frequency response data were obtained from pilot-generated frequency sweeps and it is found that the current handling quality requirements for high-maneuverability aircraft are generally applicable to the X-29A.

  3. Handling qualities criteria for the space shuttle orbiter during the terminal phase of flight

    NASA Technical Reports Server (NTRS)

    Stapleford, R. L.; Klein, R. H.; Hob, R. H.

    1972-01-01

    It was found that large portions of the military handling qualities specification are directly applicable. However a number of additional and substitute criteria are recommended for areas not covered or inadequately covered in the military specification. Supporting pilot/vehicle analyses and simulation experiments were conducted and are described. Results are also presented of analytical and simulator evaluations of three specific interim Orbiter designs which provided a test of the proposed handling qualities criteria. The correlations between the analytical and experimental evaluations were generally excellent.

  4. Interior noise and vibration measurements on operational military helicopters and comparisons with various ride quality criteria

    NASA Astrophysics Data System (ADS)

    Clevenson, S. A.; Leatherwood, J. D.; Hollenbaugh, D. D.

    1983-08-01

    The results of physical measurements of the interior noise and vibration obtained within eight operational military helicopters are presented. The data were extensively analyzed and are presented in the following forms: noise and vibration spectra, overall root-mean-square acceleration levels in three linear axes, peak accelerations at dominant blade passage frequencies, acceleration exceedance data, and overall and ""A'' weighted sound pressure levels. Peak acceleration levels were compared to the ISO 1-hr reduced comfort and fatigue decreased proficiency boundaries and the NASA discomfort criteria. The ""A'' weighted noise levels were compared to the NASA annoyance criteria, and the overall noise spectra were compared to MIL-STD-1294 (""Acoustical Noise Limits in Helicopters''). Specific vibration components at blade passage frequencies for several aircraft exceeded both the ISO reduced comfort boundary and the NASA passenger discomfort criteria. The ""A'' weighted noise levels, corrected for SPH-4 helmet attenuation characteristics, exceeded the NASA annoyance threshold for several aircraft.

  5. Interior noise and vibration measurements on operational military helicopters and comparisons with various ride quality criteria

    NASA Technical Reports Server (NTRS)

    Clevenson, S. A.; Leatherwood, J. D.; Hollenbaugh, D. D.

    1983-01-01

    The results of physical measurements of the interior noise and vibration obtained within eight operational military helicopters are presented. The data were extensively analyzed and are presented in the following forms: noise and vibration spectra, overall root-mean-square acceleration levels in three linear axes, peak accelerations at dominant blade passage frequencies, acceleration exceedance data, and overall and ""A'' weighted sound pressure levels. Peak acceleration levels were compared to the ISO 1-hr reduced comfort and fatigue decreased proficiency boundaries and the NASA discomfort criteria. The ""A'' weighted noise levels were compared to the NASA annoyance criteria, and the overall noise spectra were compared to MIL-STD-1294 (""Acoustical Noise Limits in Helicopters''). Specific vibration components at blade passage frequencies for several aircraft exceeded both the ISO reduced comfort boundary and the NASA passenger discomfort criteria. The ""A'' weighted noise levels, corrected for SPH-4 helmet attenuation characteristics, exceeded the NASA annoyance threshold for several aircraft.

  6. Flight Control Development for the ARH-70 Armed Reconnaissance Helicopter Program

    NASA Technical Reports Server (NTRS)

    Christensen, Kevin T.; Campbell, Kip G.; Griffith, Carl D.; Ivler, Christina M.; Tischler, Mark B.; Harding, Jeffrey W.

    2008-01-01

    In July 2005, Bell Helicopter won the U.S. Army's Armed Reconnaissance Helicopter competition to produce a replacement for the OH-58 Kiowa Warrior capable of performing the armed reconnaissance mission. To meet the U.S. Army requirement that the ARH-70A have Level 1 handling qualities for the scout rotorcraft mission task elements defined by ADS-33E-PRF, Bell equipped the aircraft with their generic automatic flight control system (AFCS). Under the constraints of the tight ARH-70A schedule, the development team used modem parameter identification and control law optimization techniques to optimize the AFCS gains to simultaneously meet multiple handling qualities design criteria. This paper will show how linear modeling, control law optimization, and simulation have been used to produce a Level 1 scout rotorcraft for the U.S. Army, while minimizing the amount of flight testing required for AFCS development and handling qualities evaluation of the ARH-70A.

  7. Advanced helicopter cockpit and control configurations for helicopter combat missions

    NASA Technical Reports Server (NTRS)

    Haworth, Loran A.; Atencio, Adolph, Jr.; Bivens, Courtland; Shively, Robert; Delgado, Daniel

    1987-01-01

    Two piloted simulations were conducted by the U.S. Army Aeroflightdynamics Directorate to evaluate workload and helicopter-handling qualities requirements for single pilot operation in a combat Nap-of-the-Earth environment. The single-pilot advanced cockpit engineering simulation (SPACES) investigations were performed on the NASA Ames Vertical Motion Simulator, using the Advanced Digital Optical Control System control laws and an advanced concepts glass cockpit. The first simulation (SPACES I) compared single pilot to dual crewmember operation for the same flight tasks to determine differences between dual and single ratings, and to discover which control laws enabled adequate single-pilot helicopter operation. The SPACES II simulation concentrated on single-pilot operations and use of control laws thought to be viable candidates for single pilot operations workload. Measures detected significant differences between single-pilot task segments. Control system configurations were task dependent, demonstrating a need for inflight reconfigurable control system to match the optimal control system with the required task.

  8. Flight evaluation of HL-10 lifting body handling qualities at Mach numbers from 0.30 to 1.86

    NASA Technical Reports Server (NTRS)

    Kempel, R. W.; Manke, J. A.

    1974-01-01

    The longitudinal and lateral-directional handling qualities of the HL-10 lifting body vehicle were evaluated in flight at Mach numbers up to 1.86 and altitudes up to approximately 27,450 meters (90,000 feet). In general, the vehicle's handling qualities were considered to be good. Approximately 91 percent of the pilot ratings were 3.5 or better, and 42.4 percent were 2.0. Handling qualities problems were encountered during the first flight due to problems with the control system and vehicle aerodynamics. Modifications of the flight vehicle corrected all deficiencies, and no other significant handling qualities problems were encountered.

  9. Analytical study of ride smoothing benefits of control system configurations optimized for pilot handling qualities

    NASA Technical Reports Server (NTRS)

    Powers, B. G.

    1978-01-01

    An analytical study was conducted to evaluate the relative improvements in aircraft ride qualities that resulted from utilizing several control law configurations that were optimized for pilot handling qualities only. The airplane configuration used was an executive jet transport in the approach configuration. The control law configurations included the basic system, a rate feedback system, three command augmentation systems (rate command, attitude command, and rate command/attitude hold), and a control wheel steering system. Both the longitudinal and lateral directional axes were evaluated. A representative example of each control law configuration was optimized for pilot handling qualities on a fixed base simulator. The root mean square airplane responses to turbulence were calculated, and predictions of ride quality ratings were computed by using three models available in the literature.

  10. In Flight Evaluation of Active Inceptor Force-Feel Characteristics and Handling Qualities

    NASA Technical Reports Server (NTRS)

    Lusardi, Jeff A.; Blanken, Chris L.; Ott, Carl Raymond; Malpica, Carlos A.; von Gruenhagen, Wolfgang

    2012-01-01

    The effect of inceptor feel-system characteristics on piloted handling qualities has been a research topic of interest for many years. Most of the research efforts have focused on advanced fly-by-wire fixed-wing aircraft with only a few studies investigating the effects on rotorcraft. Consequently, only limited guidance is available on how cyclic force-feel characteristics should be set to obtain optimal handling qualities for rotorcraft. To study this effect, the U.S. Army Aeroflightdynamics Directorate working with the DLR Institute of Flight Systems in Germany under Task X of the U.S. German Memorandum of Understanding have been conducting flight test evaluations. In the U.S., five experimental test pilots have completed evaluations of two Mission Task Elements (MTEs) from ADS-33E-PRF and two command/response types for a matrix of center-stick cyclic force-feel characteristics at Moffett Field. In Germany, three experimental test Pilots have conducted initial evaluations of the two MTEs with two command/response types for a parallel matrix of side-stick cyclic force-feel characteristics at WTD-61 in Manching. The resulting data set is used to correlate the effect of changes in natural frequency and damping ratio of the cyclic inceptor on the piloted handling qualities. Existing criteria in ADS-33E and a proposed Handling Qualities Sensitivity Function that includes the effects of the cyclic force-feel characteristics are also evaluated against the data set and discussed.

  11. Initial Investigation of Reaction Control System Design on Spacecraft Handling Qualities for Earth Orbit Docking

    NASA Technical Reports Server (NTRS)

    Bailey, Randall E.; Jackson, E. Bruce; Goodrich, Kenneth H.; Ragsdale, W. Al; Neuhaus, Jason; Barnes, Jim

    2008-01-01

    A program of research, development, test, and evaluation is planned for the development of Spacecraft Handling Qualities guidelines. In this first experiment, the effects of Reaction Control System design characteristics and rotational control laws were evaluated during simulated proximity operations and docking. Also, the influence of piloting demands resulting from varying closure rates was assessed. The pilot-in-the-loop simulation results showed that significantly different spacecraft handling qualities result from the design of the Reaction Control System. In particular, cross-coupling between translational and rotational motions significantly affected handling qualities as reflected by Cooper-Harper pilot ratings and pilot workload, as reflected by Task-Load Index ratings. This influence is masked but only slightly by the rotational control system mode. While rotational control augmentation using Rate Command Attitude Hold can reduce the workload (principally, physical workload) created by cross-coupling, the handling qualities are not significantly improved. The attitude and rate deadbands of the RCAH introduced significant mental workload and control compensation to evaluate when deadband firings would occur, assess their impact on docking performance, and apply control inputs to mitigate that impact.

  12. A design procedure and handling quality criteria for lateral directional flight control systems

    NASA Technical Reports Server (NTRS)

    Stein, G.; Henke, A. H.

    1972-01-01

    A practical design procedure for aircraft augmentation systems is described based on quadratic optimal control technology and handling-quality-oriented cost functionals. The procedure is applied to the design of a lateral-directional control system for the F4C aircraft. The design criteria, design procedure, and final control system are validated with a program of formal pilot evaluation experiments.

  13. Analysis of Handling Qualities Design Criteria for Active Inceptor Force-Feel Characteristics

    DTIC Science & Technology

    2013-01-01

    a classical regulatory compensatory task. Sub-components for the structural pilot include neuromuscular dynamics ( ), proprioceptive and vestibular...feedback ( and ̇ respectively), and the visual error compensation ( ). Proprioceptive feedback fundamentally accounts for the ability of...inside of the proprioceptive feedback loop. This allows for the modeling approach to be of use in predicting the handling qualities impact of the

  14. Evaluating the Handling Qualities of Flight Control Systems Including Nonlinear Aircraft and System Dynamics

    NASA Astrophysics Data System (ADS)

    Lin, Raymond Chao

    The handling qualities evaluation of nonlinear aircraft systems is an area of concern in loss-of-control (LOC) prevention. The Get Transfer Function (GetTF) method was demonstrated for evaluating the handling qualities of flight control systems and aircraft containing nonlinearities. NASA's Generic Transport Model (GTM), a nonlinear model of a civilian jet transport aircraft, was evaluated. Using classical techniques, the stability, control, and augmentation (SCAS) systems were designed to control pitch rate, roll rate, and airspeed. Hess's structural pilot model was used to model pilot dynamics in pitch and roll-attitude tracking. The simulated task was simultaneous tracking of, both, pitch and roll attitudes. Eight cases were evaluated: 1) gain increase of pitch-attitude command signal, 2) gain increase of roll-attitude command signal, 3) gain reduction of elevator command signal, 4) backlash in elevator actuator, 5) combination 3 and 4 in elevator actuator, 6) gain reduction of aileron command signal, 7) backlash in aileron actuator, and 8) combination of 6 and 7 in aileron actuator. The GetTF method was used to estimate the transfer function approximating a linear relationship between the proprioceptive signal of the pilot model and the command input. The transfer function was then used to predict the handling qualities ratings (HQR) and pilot-induced oscillation ratings (PIOR). The HQR is based on the Cooper-Harper rating scale. In pitch-attitude tracking, the nominal aircraft is predicted to have Level 2* HQRpitch and 2 < PIORpitch < 4. The GetTF method generally predicted degraded handling qualities for cases with impaired actuators. The results demonstrate GetTF's utility in evaluating the handling qualities during the design phase of flight control and aircraft systems. A limited human-in-the-loop pitch tracking exercise was also conducted to validate the structural pilot model.

  15. Nonlinear programming in design of control systems with specified handling qualities.

    NASA Technical Reports Server (NTRS)

    Schy, A. A.

    1972-01-01

    A method is described for using nonlinear programing in the computer-aided design of aircraft control systems. It is assumed that the quality of such systems depends on many criteria. These criteria are included in the constraints vector, and the design proceeds through a sequence of nonlinear programing solutions in which the designer varies the specification of sets of requirements levels. The method is applied to design of a lateral stability augmentation system (SAS) for a fighter aircraft, in which the requirements vector is chosen from the official handling-qualities specifications. Results are shown for several simple SAS configurations designed to obtain desirable handling qualities over all design flight conditions with minimum feedback gains.

  16. Microphone Handling Noise: Measurements of Perceptual Threshold and Effects on Audio Quality.

    PubMed

    Kendrick, Paul; Jackson, Iain R; Fazenda, Bruno M; Cox, Trevor J; Li, Francis F

    2015-01-01

    A psychoacoustic experiment was carried out to test the effects of microphone handling noise on perceived audio quality. Handling noise is a problem affecting both amateurs using their smartphones and cameras, as well as professionals using separate microphones and digital recorders. The noises used for the tests were measured from a variety of devices, including smartphones, laptops and handheld microphones. The signal features that characterise these noises are analysed and presented. The sounds include various types of transient, impact noises created by tapping or knocking devices, as well as more sustained sounds caused by rubbing. During the perceptual tests, listeners auditioned speech podcasts and were asked to rate the degradation of any unwanted sounds they heard. A representative design test methodology was developed that tried to encourage everyday rather than analytical listening. Signal-to-noise ratio (SNR) of the handling noise events was shown to be the best predictor of quality degradation. Other factors such as noise type or background noise in the listening environment did not significantly affect quality ratings. Podcast, microphone type and reproduction equipment were found to be significant but only to a small extent. A model allowing the prediction of degradation from the SNR is presented. The SNR threshold at which 50% of subjects noticed handling noise was found to be 4.2 ± 0.6 dBA. The results from this work are important for the understanding of our perception of impact sound and resonant noises in recordings, and will inform the future development of an automated predictor of quality for handling noise.

  17. Microphone Handling Noise: Measurements of Perceptual Threshold and Effects on Audio Quality

    PubMed Central

    Kendrick, Paul; Jackson, Iain R.; Fazenda, Bruno M.; Cox, Trevor J.; Li, Francis F.

    2015-01-01

    A psychoacoustic experiment was carried out to test the effects of microphone handling noise on perceived audio quality. Handling noise is a problem affecting both amateurs using their smartphones and cameras, as well as professionals using separate microphones and digital recorders. The noises used for the tests were measured from a variety of devices, including smartphones, laptops and handheld microphones. The signal features that characterise these noises are analysed and presented. The sounds include various types of transient, impact noises created by tapping or knocking devices, as well as more sustained sounds caused by rubbing. During the perceptual tests, listeners auditioned speech podcasts and were asked to rate the degradation of any unwanted sounds they heard. A representative design test methodology was developed that tried to encourage everyday rather than analytical listening. Signal-to-noise ratio (SNR) of the handling noise events was shown to be the best predictor of quality degradation. Other factors such as noise type or background noise in the listening environment did not significantly affect quality ratings. Podcast, microphone type and reproduction equipment were found to be significant but only to a small extent. A model allowing the prediction of degradation from the SNR is presented. The SNR threshold at which 50% of subjects noticed handling noise was found to be 4.2 ± 0.6 dBA. The results from this work are important for the understanding of our perception of impact sound and resonant noises in recordings, and will inform the future development of an automated predictor of quality for handling noise. PMID:26473498

  18. 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.

  19. 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.

  20. Handling Qualities Results of an Initial Geared Flap Tilt Wing Piloted Simulation

    NASA Technical Reports Server (NTRS)

    Guerrero, Lourdes M.; Corliss, Lloyd D.

    1991-01-01

    An exploratory simulation study of a novel approach to pitch control for a tilt wing aircraft was conducted in 1990 on the NASA-Ames Vertical Motion Simulator. The purpose of the study was to evaluate and compare the handling qualities of both a conventional and a geared flap tilt wing control configuration. The geared flap is an innovative control concept which has the potential for reducing or eliminating the horizontal pitch control tail rotor or reaction jets required by prior tilt wing designs. The handling qualities results of the geared flap control configuration are presented in this paper and compared to the conventional (programmed flap) tilt wing control configuration. This paper also describes the geared flap concept, the tilt wing aircraft, the simulation model, the simulation facility and experiment setup, and the pilot evaluation tasks and procedures.

  1. Effects of dynamic aeroelasticity on handling qualities and pilot rating. [longitudinal control

    NASA Technical Reports Server (NTRS)

    Yen, W. Y.; Swaim, R. L.

    1977-01-01

    Pilot performance parameters, such as pilot ratings, tracking errors, and pilot comments were determined for a longitudinal pitch tracking task using a large, flexible bomber with parametric variations in the undamped natural frequencies of the two lowest frequency symmetric elastic modes. This pitch tracking task was programmed on a fixed base simulator with an electronic attitude-director display of pitch command, pitch angle, and pitch error. Low frequency structural flexibility significantly affects the handling qualities and pilot ratings in the task evaluated.

  2. Ground Based Simulation Evaluation of the Effects of Time Delays and Motion on Rotorcraft Handling Qualities

    DTIC Science & Technology

    1992-01-01

    Inc. C Lometa, CA ADOLPH ATENCIO, JR. DAVID L. KEY Aeroflightdynamics Directorate U.S. Army Aviation Systems Command Ames Research Center Moffett Field...CA JANUARY 1992 - . Final Report Prepared for Aeroflightdynamics Directorate US Army Aviation Systems Command Ames Research Center Moffett Field, CA...Ground-based simulation is an important tool in the assessment of handling qualities of rotorcraft for both research and development. The strengths and

  3. Dynamic stability and handling qualities tests on a highly augmented, statically unstable airplane

    NASA Technical Reports Server (NTRS)

    Gera, Joseph; Bosworth, John T.

    1987-01-01

    This paper describes some novel flight tests and analysis techniques in the flight dynamics and handling qualities area. These techniques were utilized during the initial flight envelope clearance of the X-29A aircraft and were largely responsible for the completion of the flight controls clearance program without any incidents or significant delays. The resulting open-loop and closed-loop frequency responses and the time history comparison using flight and linear simulation data are discussed.

  4. Evaluation of High-Speed Civil Transport Handling Qualities Criteria with Supersonic Flight Data

    NASA Technical Reports Server (NTRS)

    Cox, Timothy H.; Jackson, Dante W.

    1997-01-01

    Most flying qualities criteria have been developed from data in the subsonic flight regime. Unique characteristics of supersonic flight raise questions about whether these criteria successfully extend into the supersonic flight regime. Approximately 25 years ago NASA Dryden Flight Research Center addressed this issue with handling qualities evaluations of the XB-70 and YF-12. Good correlations between some of the classical handling qualities parameters, such as the control anticipation parameter as a function of damping, were discovered. More criteria have been developed since these studies. Some of these more recent criteria are being used in designing the High-Speed Civil Transport (HSCT). A second research study recently addressed this issue through flying qualities evaluations of the SR-71 at Mach 3. The research goal was to extend the high-speed flying qualities experience of large airplanes and to evaluate more recent MIL-STD-1797 criteria against pilot comments and ratings. Emphasis was placed on evaluating the criteria used for designing the HSCT. XB-70 and YF-12 data from the previous research supplemented the SR-71 data. The results indicate that the criteria used in the HSCT design are conservative and should provide good flying qualities for typical high-speed maneuvering. Additional results show correlation between the ratings and comments and criteria for gradual maneuvering with precision control. Correlation is shown between ratings and comments and an extension of the Neal/Smith criterion using normal acceleration instead of pitch rate.

  5. Handling Qualities of a Large Civil Tiltrotor in Hover using Translational Rate Command

    NASA Technical Reports Server (NTRS)

    Malpica, Carlos A.; Theodore, Colin R.; Lawrence, Ben; Lindsey, James; Blanken, Chris

    2012-01-01

    A Translational Rate Command (TRC) control law has been developed to enable low speed maneuvering of a large civil tiltrotor with minimal pitch changes by means of automatic nacelle angle deflections for longitudinal velocity control. The nacelle actuator bandwidth required to achieve Level 1 handling qualities in hover and the feasibility of additional longitudinal cyclic control to augment low bandwidth nacelle actuation were investigated. A frequency-domain handling qualities criterion characterizing TRC response in terms of bandwidth and phase delay was proposed and validated against a piloted simulation conducted on the NASA-Ames Vertical Motion Simulator. Seven experimental test pilots completed evaluations in the ADS-33E-PRF Hover Mission Task Element (MTE) for a matrix of nacelle actuator bandwidths, equivalent rise times and control response sensitivities, and longitudinal cyclic control allocations. Evaluated against this task, longitudinal phase delay shows the Level 1 boundary is around 0.4 0.5 s. Accordingly, Level 1 handling qualities were achieved either with a nacelle actuator bandwidth greater than 4 rad/s, or by employing longitudinal cyclic control to augment low bandwidth nacelle actuation.

  6. Ground-to-Flight Handling Qualities Comparisons for a High Performance Airplane

    NASA Technical Reports Server (NTRS)

    Brandon, Jay M.; Glaab, Louis J.; Brown, Philip W.; Phillips, Michael R.

    1995-01-01

    A flight test program was conducted in conjunction with a ground-based piloted simulation study to enable a comparison of handling qualities ratings for a variety of maneuvers between flight and simulation of a modern high performance airplane. Specific objectives included an evaluation of pilot-induced oscillation (PIO) tendencies and a determination of maneuver types which result in either good or poor ground-to-flight pilot handling qualities ratings. A General Dynamics F-16XL aircraft was used for the flight evaluations, and the NASA Langley Differential Maneuvering Simulator was employed for the ground based evaluations. Two NASA research pilots evaluated both the airplane and simulator characteristics using tasks developed in the simulator. Simulator and flight tests were all conducted within approximately a one month time frame. Maneuvers included numerous fine tracking evaluations at various angles of attack, load factors and speed ranges, gross acquisitions involving longitudinal and lateral maneuvering, roll angle captures, and an ILS task with a sidestep to landing. Overall results showed generally good correlation between ground and flight for PIO tendencies and general handling qualities comments. Differences in pilot technique used in simulator evaluations and effects of airplane accelerations and motions are illustrated.

  7. Handling Qualities Prediction of an F-16XL-Based Reduced Sonic Boom Aircraft

    NASA Technical Reports Server (NTRS)

    Cogan, Bruce; Yoo, Seung

    2010-01-01

    A major goal of the Supersonics Project under NASA s Fundamental Aeronautics program is sonic boom reduction of supersonic aircraft. An important part of this effort is development and validation of sonic boom prediction tools used in aircraft design. NASA Dryden s F- 16XL was selected as a potential testbed aircraft to provide flight validation. Part of this task was predicting the handling qualities of the modified aircraft. Due to the high cost of modifying the existing F-16XL control laws, it was desirable to find modifications that reduced the aircraft sonic boom but did not degrade baseline aircraft handling qualities allowing for the potential of flight test without changing the current control laws. This was not a requirement for the initial modification design work, but an important consideration for proceeding to the flight test option. The primary objective of this work was to determine an aerodynamic and mass properties envelope of the F-16XL aircraft. The designers could use this envelope to determine the effect of proposed modifications on aircraft handling qualities.

  8. A piloted simulator study on augmentation systems to improve helicopter flying qualities in terrain flight

    NASA Technical Reports Server (NTRS)

    Chen, R. T. N.; Talbot, P. D.; Gerdes, R. M.; Dugan, D. C.

    1979-01-01

    Four basic single-rotor helicopters, one teetering, on articulated, and two hingeless, which were found to have a variety of major deficiencies in a previous fixed-based simulator study, were selected as baseline configurations. The stability and control augmentation systems (SCAS) include simple control augmentation systems to decouple pitch and yaw responses due to collective input and to quicken the pitch and roll control responses; SCAS of rate-command type designed to optimize the sensitivity and damping and to decouple the pitch-roll due to aircraft angular tate; and attitude-command type SCAS. Pilot ratings and commentary are presented as well as performance data related to the task. SCAS control usages and their gain levels associated with specific rotor types are also discussed.

  9. Flight evaluation of the M2-F3 lifting body handling qualities at Mach numbers from 0.30 to 1.61

    NASA Technical Reports Server (NTRS)

    Kempel, R. W.; Dana, W. H.; Sim, A. G.

    1975-01-01

    Percentage distributions of 423 pilot ratings obtained from 27 flights are used to indicate the general level of handling qualities of the M2-F3 lifting body. Percentage distributions are compared on the basis of longitudinal and lateral-directional handling qualities, control system, control system status, and piloting task. Ratings of longitudinal handling qualities at low speed were slightly better than those for transonic and supersonic speed. The ratings of lateral-directional handling qualities were unaffected by speed and configuration. Specific handling qualities problems are discussed in detail, and comparisons are made with pertinent handling qualities criteria.

  10. Helicopter problems

    NASA Technical Reports Server (NTRS)

    Kussner, H G

    1937-01-01

    The present report deals with a number of the main problems requiring solution in the development of helicopters and concerning the lift, flying performance, stability, and drive. A complete solution is given for the stability of the helicopter with rigid blades and control surfaces. With a view to making a direct-lift propeller sufficient without the addition of auxiliary propellers, the "flapping drive" is assessed and its efficiency calculated.

  11. Microbiological quality and safe handling of enteral diets in a hospital in Minas Gerais, Brazil

    PubMed Central

    Pinto, Raquel Oliveira Medrado; Correia, Eliznara Fernades; Pereira, Keyla Carvalho; Costa, Paulo de Souza; da Silva, Daniele Ferreira

    2015-01-01

    Contamination of enteral diets represents a high risk of compromising the patient's medical condition. To assess the microbiological quality and aseptic conditions in the preparation and administration of handmade and industrialized enteral diets offered in a hospital in the Valley of Jequitinhonha, MG, Brazil, we performed a microbiological analysis of 50 samples of diets and 27 samples of surfaces, utensils, and water used in the preparation of the diets. In addition, we assessed the good handling practices of enteral diets according to the requirements specified by the Brazilian legislation. Both kinds of enteral diets showed contamination by coliforms and Pseudomonas spp. No sample was positive for Staphylococcus aureus and Salmonella spp. On the other hand, Listeria spp. was detected in only one sample of handmade diets. Contamination was significantly higher in the handmade preparations (p < 0.05). Nonconformities were detected with respect to good handling practices, which may compromise the diet safety. The results indicate that the sanitary quality of the enteral diets is unsatisfactory, especially handmade diets. Contamination by Pseudomonas spp. is significant because it is often involved in infection episodes. With regard to aseptic practices, it was observed the need of implementing new procedures for handling enteral diets. PMID:26273278

  12. The use of ground based simulation for handling qualities research: A new assessment

    NASA Technical Reports Server (NTRS)

    Mitchell, David G.; Hoh, Roger H.; Atencio, Adolph, Jr.; Key, David L.

    1992-01-01

    A study was conducted on the NASA Ames Research Center's Vertical Motion Simulator to determine the effects of simulator characteristics on perceived handling characteristics. Differences in pilot opinion were found as the visual and motion parameters were changed, reflecting a change in the pilots' perceptions of handling qualities, rather than changes in the aircraft model itself. The results indicate a need for tailoring the motion without dynamics to suit the task, with reduced washouts for precision maneuvering as compared to aggressive maneuvering. Visual delay data are inconclusive, but suggest that it may be better to allow some time delay in the visual path to minimize the mismatch between vision and motion, rather than eliminate the visual delay entirely through lead compensation. The simulation results are compared with ratings from a similar in-flight simulation experiment.

  13. Archive data base and handling system for the Orbiter flying qualities experiment program

    NASA Technical Reports Server (NTRS)

    Myers, T. T.; Dimarco, R.; Magdaleno, R. E.; Aponso, B. L.

    1986-01-01

    The OFQ archives data base and handling system assembled as part of the Orbiter Flying Qualities (OFQ) research of the Orbiter Experiments Program (EOX) are described. The purpose of the OFQ archives is to preserve and document shuttle flight data relevant to vehicle dynamics, flight control, and flying qualities in a form that permits maximum use for qualified users. In their complete form, the OFQ archives contain descriptive text (general information about the flight, signal descriptions and units) as well as numerical time history data. Since the shuttle program is so complex, the official data base contains thousands of signals and very complex entries are required to obtain data. The OFQ archives are intended to provide flight phase oriented data subsets with relevant signals which are easily identified for flying qualities research.

  14. Exploratory piloted simulator study of the effects of winglets on handling qualities of a representative agricultural airplane

    NASA Technical Reports Server (NTRS)

    Ogburn, M. E.; Brown, P. W.

    1980-01-01

    The effects on handling qualities of adding winglets to a representative agricultural aircraft configuration during swath-run maneuvering were evaluated. Aerodynamic data used in the simulation were based on low-speed wind tunnel tests of a full scale airplane and a subscale model. The Cooper-Harper handling qualities rating scale, supplementary pilot comments, and pilot vehicle performance data were used to describe the handling qualities of the airplane with the different wing-tip configurations. Results showed that the lateral-directional handling qualities of the airplane were greatly affected by the application of winglets and winglet cant angle. The airplane with winglets canted out 20 deg exhibited severely degraded lateral directional handling qualities in comparison to the basic airplane. When the winglets were canted inward 10 deg, the flying qualities of the configuration were markedly improved over those of the winglet-canted-out configuration or the basic configuration without winglets, indicating that proper tailoring of the winglet design may afford a potential benefit in the area of handling qualities.

  15. Improved Lunar Lander Handling Qualities Through Control Response Type and Display Enhancements

    NASA Technical Reports Server (NTRS)

    Mueller, Eric Richard; Bilimoria, Karl D.; Frost, Chad Ritchie

    2010-01-01

    A piloted simulation that studied the handling qualities for a precision lunar landing task from final approach to touchdown is presented. A vehicle model based on NASA's Altair Lunar Lander was used to explore the design space around the nominal vehicle configuration to determine which combination of factors provides satisfactory pilot-vehicle performance and workload; details of the control and propulsion systems not available for that vehicle were derived from Apollo Lunar Module data. The experiment was conducted on a large motion base simulator. Eight Space Shuttle and Apollo pilot astronauts and three NASA test pilots served as evaluation pilots, providing Cooper-Harper ratings, Task Load Index ratings and qualitative comments. Each pilot flew seven combinations of control response types and three sets of displays, including two varieties of guidance and a nonguided approach. The response types included Rate Command with Attitude Hold, which was used in the original Apollo Moon landings, a Velocity Increment Command response type designed for up-and-away flight, three response types designed specifically for the vertical descent portion of the trajectory, and combinations of these. It was found that Velocity Increment Command significantly improved handling qualities when compared with the baseline Apollo design, receiving predominantly Level 1 ratings. This response type could be flown with or without explicit guidance cues, something that was very difficult with the baseline design, and resulted in approximately equivalent touchdown accuracies and propellant burn as the baseline response type. The response types designed to be used exclusively in the vertical descent portion of the trajectory did not improve handling qualities.

  16. Development of longitudinal handling qualities criteria for large advanced supersonic aircraft

    NASA Technical Reports Server (NTRS)

    Sudderth, R. W.; Mcneill, W. E.

    1976-01-01

    A piloted simulation study was conducted with the aim of advancing the development of longitudinal handling qualities criteria for large supersonic cruise aircraft. The areas of study investigated included high-speed cruise maneuvering, and stall-recovery control power. Comparisons were made with existing criteria and, for the cruise condition, a time response criterion was developed which correlated well with pilot ratings and comments. For low-speed stall recovery a new criterion was developed in terms of nose-down angular acceleration capability.

  17. Flight Validation of a Handling Qualities Metric for a Damaged Aircraft

    NASA Technical Reports Server (NTRS)

    Cogan, Bruce R.

    2009-01-01

    Objectives: a) Develop an asymmetric handling qualities metric to predict cross coupling effects of a damaged aircraft: 1) Initial use of U.S Army Aeronautical Design Specification ADS-33; 2) Modification as required based on flight test results. b) Simulation and Flight Validation of proposed metric: 1) F-16 VISTA (March 2010); 2) F-18 Full Scale Test bed (Potential Early Experiment); and 3) Flight Simulators (GTM, ACFS, F-18 HILS). c) Provide flight validated metric and tool box to control law designers.

  18. In Flight Evaluation of Active Inceptor Force-Feel Characteristics and Handling Qualities

    DTIC Science & Technology

    2012-05-01

    Concepts Airborne Laboratory ( RASCAL ) JUH- 60A in-flight simulator with an active center stick, and in Germany DLR is utilizing their Active Control...susceptible to bio-feedback interference with the slalom task. It should be noted that when flying the slalom task in the AFDD JUH- 60A RASCAL the...handling qualities has been conducted with a center stick cyclic on the RASCAL JUH- 60A , and initiated with a side stick on the ACT/FHS EC-135. In

  19. A design procedure for the handling qualities optimization of the X-29A aircraft

    NASA Technical Reports Server (NTRS)

    Bosworth, John T.; Cox, Timothy H.

    1989-01-01

    The techniques used to improve the pitch-axis handling qualities of the X-29A wing-canard-planform fighter aircraft are reviewed. The aircraft and its FCS are briefly described, and the design method, which works within the existing FCS architecture, is characterized in detail. Consideration is given to the selection of design goals and design variables, the definition and calculation of the cost function, the validation of the mathematical model on the basis of flight-test data, and the validation of the improved design by means of nonlinear simulations. Flight tests of the improved design are shown to verify the simulation results.

  20. Modal control theory and application to aircraft lateral handling qualities design

    NASA Technical Reports Server (NTRS)

    Srinathkumar, S.

    1978-01-01

    A multivariable synthesis procedure based on eigenvalue/eigenvector assignment is reviewed and is employed to develop a systematic design procedure to meet the lateral handling qualities design objectives of a fighter aircraft over a wide range of flight conditions. The closed loop modal characterization developed provides significant insight into the design process and plays a pivotal role in the synthesis of robust feedback systems. The simplicity of the synthesis algorithm yields an efficient computer aided interactive design tool for flight control system synthesis.

  1. The Development of the CONDUIT Advanced Control System Design and Evaluation Interface with a Case Study Application to an Advanced Fly by Wire Helicopter Design

    NASA Technical Reports Server (NTRS)

    Colbourne, Jason

    1999-01-01

    This report details the development and use of CONDUIT (Control Designer's Unified Interface). CONDUIT is a design tool created at Ames Research Center for the purpose of evaluating and optimizing aircraft control systems against handling qualities. Three detailed design problems addressing the RASCAL UH-60A Black Hawk are included in this report to show the application of CONDUIT to helicopter control system design.

  2. Statistical survey of XB-70 airplane responses and control usage with an illustration of the application to handling qualities criteria

    NASA Technical Reports Server (NTRS)

    Powers, B. G.

    1972-01-01

    The magnitude and frequency of occurrence of aircraft responses and control inputs during 27 flights of the XB-70 airplane were measured. Exceedance curves are presented for the airplane responses and control usage. A technique is presented which makes use of these exceedance curves to establish or verify handling qualities criteria. This technique can provide a means of incorporating current operational experience in handling qualities requirements for future aircraft.

  3. Presentation of flight control design and handling quality commonality by separate surface stability augmentation for the family of commuter airplanes

    NASA Technical Reports Server (NTRS)

    Hensley, Douglas; Creighton, Thomas; Haddad, Raphael; Hendrich, Louis; Morgan, Louise; Russell, Mark; Swift, Gerald

    1987-01-01

    The methodology and results for a flight control design and implementation for common handling qualities by Separate Surface Stability Augmentation (SSSA) for the family of commuter airplanes are contained. The open and closed loop dynamics and the design results of augmenting for common handling qualities are presented. The physical and technology requirements are presented for implementing the SSSA system. The conclusion of this report and recommendations for changes or improvement are discussed.

  4. Initial Flight Evaluation of the Army/NASA RASCAL Variable Stability Helicopter

    NASA Technical Reports Server (NTRS)

    Moralez, Ernesto, III; Hindson, William S.; Arterburn, David R.

    2000-01-01

    NASA Ames Research Center and the U.S. Army Aeroflightdynamics Directorate (AFDD) [will] have performed initial flight evaluations of the Research Flight Control System (RFCS) that has been integrated into the Army/NASA Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) variable stability helicopter. The RASCAL, a highly modified JUH-60A Black Hawk helicopter, is a variable-stability, in-flight simulator that is designed to support flight research programs that leverage on the flight control and handling qualities design tools developed by the Army and NASA. These tools are used in the flight control design life cycle from initial concept definition, through simulation, and ultimately into flight on-board the RASCAL helicopter. The RASCAL will be used to validate methodologies for reducing design cycle costs for new or modified aircraft, and it will serve as a base for the investigation of new rotorcraft technology.

  5. Performance and Handling Qualities - AH-1G Helicopter Equipped with Three Hot Metal/Plume Infrared Suppressors

    DTIC Science & Technology

    1975-04-01

    relative to the aircraft longitudinal axis. The ejector action, created by the engine exhaust as it is accelerated through the replacement nozzle, draws...Lycoming duct is 55 degrees upward relative to the aircraft longitudinal axis. The airflow induced by the ejector is approximately 80 percent of engine...flow. It is estimted that the exhaust gas exits the elbow at approximately 30 degrees relative to the aircraft longitudinal axis. Net increase to the

  6. Effect of winglets on performance and handling qualities of general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Van Dam, C. P.; Holmes, B. J.; Pitts, C.

    1980-01-01

    Recent flight and wind tunnel evaluations of winglets mounted on general aviation airplanes have shown improvements in cruise fuel efficiency, and climbing and turning performance. Some of these analyses have also uncovered various effects of winglets on airplane handling qualities. Retrofitting an airplane with winglets can result in reduced cross wind take-off and landing capabilities. Also, winglets can have a detrimental effect on the lateral directional response characteristics of aircraft which have a moderate to high level of adverse yaw due to aileron. Introduction of an aileron-rudder-interconnect, and reduction of the effective dihedral by canting-in of the winglets, or addition of a lower winglet can eliminate these flying quality problems.

  7. Unified Theory for Aircraft Handling Qualities and Adverse Aircraft-Pilot Coupling

    NASA Technical Reports Server (NTRS)

    Hess, R. A.

    1997-01-01

    A unified theory for aircraft handling qualities and adverse aircraft-pilot coupling or pilot-induced oscillations is introduced. The theory is based on a structural model of the human pilot. A methodology is presented for the prediction of (1) handling qualities levels; (2) pilot-induced oscillation rating levels; and (3) a frequency range in which pilot-induced oscillations are likely to occur. Although the dynamics of the force-feel system of the cockpit inceptor is included, the methodology will not account for effects attributable to control sensitivity and is limited to single-axis tasks and, at present, to linear vehicle models. The theory is derived from the feedback topology of the structural model and an examination of flight test results for 32 aircraft configurations simulated by the U.S. Air Force/CALSPAN NT-33A and Total In-Flight Simulator variable stability aircraft. An extension to nonlinear vehicle dynamics such as that encountered with actuator saturation is discussed.

  8. UH-60 Black Hawk Disturbance Rejection Study for Hover/Low Speed Handling Qualities Criteria and Turbulence Modeling

    NASA Technical Reports Server (NTRS)

    Labows, Steven J.; Blanken, Chris L.; Tischler, Mark B.

    1999-01-01

    This paper will discuss the airborne flight test of the Sikorsky UH-60 Black Hawk helicopter in turbulent conditions to determine disturbance rejection criteria and develop a low speed wind/turbulence model for helicopter simulation.

  9. Spectral decontamination of a real-time helicopter simulation

    NASA Technical Reports Server (NTRS)

    Mcfarland, R. E.

    1983-01-01

    Nonlinear mathematical models of a rotor system, referred to as rotating blade-element models, produce steady-state, high-frequency harmonics of significant magnitude. In a discrete simulation model, certain of these harmonics may be incompatible with realistic real-time computational constraints because of their aliasing into the operational low-pass region. However, the energy is an aliased harmonic may be suppressed by increasing the computation rate of an isolated, causal nonlinearity and using an appropriate filter. This decontamination technique is applied to Sikorsky's real-time model of the Black Hawk helicopter, as supplied to NASA for handling-qualities investigations.

  10. New capabilities and recent research programs of the NASA/Army CH-47B variable-stability helicopter

    NASA Technical Reports Server (NTRS)

    Hindson, W. S.; Hilbert, K. B.; Tucker, G. E.; Chen, R. T. N.; Fry, E. B.

    1986-01-01

    The CH-47B is the third in a series of variable-stability helicopters developed and operated by NASA since 1952 to investigate helicopter and VTOL handling qualities. Recently, several new capabilities were added to this helicopter to enable it to better support new and evolving research requirements. The installation of a programmable force-feel system for the evaluation pilot's conventional cyclic stick, and a four-axis side-stick controller permit a range of in-flight investigations concerning manipulator characteristics and augmentation system features that had not been possible with earlier NASA research helicopters. A recently installed color electronic display system with a programmable symbol generator will permit the investigation of display formats for a variety of VTOL and helicopter missions. Finally, a powerful new general-purpose flight computer is now in operation. It is programmable in high-level languages and will provide more efficient support of research programs. In addition to these new hardware capabilities, flight-control software has been developed to improve the in-flight simulation capability of the aircraft. A brief description of the CH-47B's variable-stability research equipment is provided, recent research programs are summarized, and some remarks concerning the potential of the helicopter are presented.

  11. Application of frequency domain handling qualities criteria to the longitudinal landing task

    NASA Technical Reports Server (NTRS)

    Sarrafian, S. K.; Powers, B. G.

    1985-01-01

    Under NASA sponsorship, an in-flight simulation of the longitudinal handling qualities of several configurations for the approach and landing tasks was performed on the USAF/AFWAL Total In-Flight Simulator by the Calspan Corporation. The basic configuration was a generic transport airplane with static instability. The control laws included proportional plus integral gain loops to produce pitch-rate and angle-of-attack feedback loops. The evaluation task was a conventional visual approach to a flared touchdown at a designated spot on the runway with a lateral offset. The general conclusions were that the existing criteria are based on pitch-attitude response and that these characteristics do not adequately discriminate between the good and bad configurations of this study. This paper describes the work that has been done to further develop frequency-based criteria in an effort to provide better correlation with the observed data.

  12. Developing a workstation-based, real-time simulation for rapid handling qualities evaluations during design

    NASA Technical Reports Server (NTRS)

    Anderson, Frederick; Biezad, Daniel J.

    1994-01-01

    This paper describes the Rapid Aircraft DynamIcs AssessmeNt (RADIAN) project - an integration of the Aircraft SYNThesis (ACSTNT) design code with the USAD DATCOM code that estimates stability derivatives. Both of these codes are available to universities. These programs are then linked to flight simulation and flight controller synthesis tools and resulting design is evaluated on a graphics workstation. The entire process reduces the preliminary design time by an order of magnitude and provides an initial handling qualities evaluation of the design coupled to a control law. The integrated design process is applicable to both conventional aircraft taken from current textbooks and to unconventional designs emphasizing agility and propulsive control of attitude. The interactive and concurrent nature of the design process has been well received by industry and by design engineers at NASA. The process is being implemented into the design curriculum and is being used by students who view it as a significant advance over prior methods.

  13. Some lessons learned in three years with ADS-33C. [rotorcraft handling qualities specification

    NASA Technical Reports Server (NTRS)

    Key, David L.; Blanken, Chris L.; Hoh, Roger H.

    1993-01-01

    Three years of using the U.S. Army's rotorcraft handling qualities specification, Aeronautical Design Standard - 33, has shown it to be surprisingly robust. It appears to provide an excellent basis for design and for assessment, however, as the subtleties become more well understood, several areas needing refinement became apparent. Three responses to these needs have been documented in this paper: (1) The yaw-axis attitude quickness for hover target acquisition and tracking can be relaxed slightly. (2) Understanding and application of criteria for degraded visual environments needed elaboration. This and some guidelines for testing to obtain visual cue ratings have been documented. (3) The flight test maneuvers were an innovation that turned out to be very valuable. Their extensive use has made it necessary to tighten definitions and testing guidance. This was accomplished for a good visual environment and is underway for degraded visual environments.

  14. Dynamic stability and handling qualities tests on a highly augmented, statically unstable airplane

    NASA Technical Reports Server (NTRS)

    Gera, Joseph; Bosworth, John T.

    1987-01-01

    Initial envelope clearance and subsequent flight testing of a new, fully augmented airplane with an extremely high degree of static instability can place unusual demands on the flight test approach. Previous flight test experience with these kinds of airplanes is very limited or nonexistent. The safe and efficient flight testing may be further complicated by a multiplicity of control effectors that may be present on this class of airplanes. This paper describes some novel flight test and analysis techniques in the flight dynamics and handling qualities area. These techniques were utilized during the initial flight envelope clearance of the X-29A aircraft and were largely responsible for the completion of the flight controls clearance program without any incidents or significant delays.

  15. 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.

  16. 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.

  17. Handling Qualities Flight Testing of the Stratospheric Observatory for Infrared Astronomy (SOFIA)

    NASA Technical Reports Server (NTRS)

    Glaser, Scott T.; Strovers, Brian K.

    2011-01-01

    Airborne infrared astronomy has a long successful history, albeit relatively unknown outside of the astronomy community. A major problem with ground based infrared astronomy is the absorption and scatter of infrared energy by water in the atmosphere. Observing the universe from above 40,000 ft puts the observation platform above 99% of the water vapor in the atmosphere, thereby addressing this problem at a fraction of the cost of space based systems. The Stratospheric Observatory For Infrared Astronomy (SOFIA) aircraft is the most ambitious foray into the field of airborne infrared astronomy in history. Using a 747SP (The Boeing Company, Chicago, Illinois) aircraft modified with a 2.5m telescope located in the aft section of the fuselage, the SOFIA endeavors to provide views of the universe never before possible and at a fraction of the cost of space based systems. The modification to the airplane includes moveable doors and aperture that expose the telescope assembly. The telescope assembly is aimed and stabilized using a multitude of on board systems. This modification has the potential to cause aerodynamic anomalies that could induce undesired forces either at the cavity itself or indirectly due to interference with the empennage, both of which could cause handling qualities issues. As a result, an extensive analysis and flight test program was conducted from December 2009 through March 2011. Several methods, including a Lower Order Equivalent Systems analysis and pilot assessment, were used to ascertain the effects of the modification. The SOFIA modification was found to cause no adverse handling qualities effects and the aircraft was cleared for operational use. This paper discusses the history and modification to the aircraft, development of test procedures and analysis, results of testing and analysis, lessons learned for future projects and justification for operational certification.

  18. Data Quality in web-based HIV/AIDS research: Handling Invalid and Suspicious Data

    PubMed Central

    Bauermeister, Jose; Pingel, Emily; Zimmerman, Marc; Couper, Mick; Carballo-Diéguez, Alex; Strecher, Victor J.

    2011-01-01

    Invalid data may compromise data quality. We examined how decisions taken to handle these data may affect the relationship between Internet use and HIV risk behaviors in a sample of young men who have sex with men (YMSM). We recorded 548 entries during the three-month period, and created 6 analytic groups (i.e., full sample, entries initially tagged as valid, suspicious entries, valid cases mislabeled as suspicious, fraudulent data, and total valid cases) using data quality decisions. We compared these groups on the sample’s composition and their bivariate relationships. Forty-one cases were marked as invalid, affecting the statistical precision of our estimates but not the relationships between variables. Sixty-two additional cases were flagged as suspicious entries and found to contribute to the sample’s diversity and observed relationships. Using our final analytic sample (N = 447; M = 21.48 years old, SD = 1.98), we found that very conservative criteria regarding data exclusion may prevent researchers from observing true associations. We discuss the implications of data quality decisions and its implications for the design of future HIV/AIDS web-surveys. PMID:23180978

  19. An Investigation of Large Tilt-Rotor Short-Term Attitude Response Handling Qualities Requirements in Hover

    NASA Technical Reports Server (NTRS)

    Malcipa, Carlos; Decker, William A.; Theodore, Colin R.; Blanken, Christopher L.; Berger, Tom

    2010-01-01

    A piloted simulation investigation was conducted using the NASA Ames Vertical Motion Simulator to study the impact of pitch, roll and yaw attitude bandwidth and phase delay on handling qualities of large tilt-rotor aircraft. Multiple bandwidth and phase delay pairs were investigated for each axis. The simulation also investigated the effect that the pilot offset from the center of gravity has on handling qualities. While pilot offset does not change the dynamics of the vehicle, it does affect the proprioceptive and visual cues and it can have an impact on handling qualities. The experiment concentrated on two primary evaluation tasks: a precision hover task and a simple hover pedal turn. Six pilots flew over 1400 data runs with evaluation comments and objective performance data recorded. The paper will describe the experiment design and methodology, discuss the results of the experiment and summarize the findings.

  20. Flight evaluation of the effect of winglets on performance and handling qualities of a single-engine general aviation airplane

    NASA Technical Reports Server (NTRS)

    Holmes, B. J.; Vandam, C. P.; Brown, P. W.; Deal, P. L.

    1980-01-01

    A flight evaluation was conducted to determine the effects of winglets on the performance and handling qualities of a light, single-engine general aviation airplane. The performance measurements were made with a pace airplane to provide calibrated airspeeds; uncalibrated panel instruments in the test airplane were used to provide additional quantitative performance data. These tests were conducted with winglets on and off during the same day to measure relative performance effects. Handling qualities were evaluated by means of pilot comments. Winglets increased cruise speed 8 knots (5.6 percent) at 3962 m (13,000 ft) density altitude and 51 percent maximum continuous power setting. Maximum speed at 3962 m was virtually unchanged. Rate of climb increased approximately 6 percent, or 0.25 m/sec (50 ft/min), at 1524 m (5000 ft). Stall speed was virtually unchanged. Handling qualities were favorably affected.

  1. Helicopter Acoustics

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Exterior and interior noise problems are addressed both from the physics and engineering as well as the human factors point of view. The role of technology in closing the gap between what the customers and regulating agencies would like to have and what is available is explored. Noise regulation concepts, design, operations and testing for noise control, helicopter noise prediction, and research tools and measurements are among the topics covered.

  2. Estimation of Handling Qualities Parameters of the Tu-144 Supersonic Transport Aircraft from Flight Test Data

    NASA Technical Reports Server (NTRS)

    Curry, Timothy J.; Batterson, James G. (Technical Monitor)

    2000-01-01

    Low order equivalent system (LOES) models for the Tu-144 supersonic transport aircraft were identified from flight test data. The mathematical models were given in terms of transfer functions with a time delay by the military standard MIL-STD-1797A, "Flying Qualities of Piloted Aircraft," and the handling qualities were predicted from the estimated transfer function coefficients. The coefficients and the time delay in the transfer functions were estimated using a nonlinear equation error formulation in the frequency domain. Flight test data from pitch, roll, and yaw frequency sweeps at various flight conditions were used for parameter estimation. Flight test results are presented in terms of the estimated parameter values, their standard errors, and output fits in the time domain. Data from doublet maneuvers at the same flight conditions were used to assess the predictive capabilities of the identified models. The identified transfer function models fit the measured data well and demonstrated good prediction capabilities. The Tu-144 was predicted to be between level 2 and 3 for all longitudinal maneuvers and level I for all lateral maneuvers. High estimates of the equivalent time delay in the transfer function model caused the poor longitudinal rating.

  3. High-Alpha Handling Qualities Flight Research on the NASA F/A-18 High Alpha Research Vehicle

    NASA Technical Reports Server (NTRS)

    Wichman, Keith D.; Pahle, Joseph W.; Bahm, Catherine; Davidson, John B.; Bacon, Barton J.; Murphy, Patrick C.; Ostroff, Aaron J.; Hoffler, Keith D.

    1996-01-01

    A flight research study of high-angle-of-attack handling qualities has been conducted at the NASA Dryden Flight Research Center using the F/A-18 High Alpha Research Vehicle (HARV). The objectives were to create a high-angle-of-attack handling qualities flight database, develop appropriate research evaluation maneuvers, and evaluate high-angle-of-attack handling qualities guidelines and criteria. Using linear and nonlinear simulations and flight research data, the predictions from each criterion were compared with the pilot ratings and comments. Proposed high-angle-of-attack nonlinear design guidelines and proposed handling qualities criteria and guidelines developed using piloted simulation were considered. Recently formulated time-domain Neal-Smith guidelines were also considered for application to high-angle-of-attack maneuvering. Conventional envelope criteria were evaluated for possible extension to the high-angle-of-attack regime. Additionally, the maneuvers were studied as potential evaluation techniques, including a limited validation of the proposed standard evaluation maneuver set. This paper gives an overview of these research objectives through examples and summarizes result highlights. The maneuver development is described briefly, the criteria evaluation is emphasized with example results given, and a brief discussion of the database form and content is presented.

  4. 76 FR 7096 - Minimum Quality and Handling Standards for Domestic and Imported Peanuts Marketed in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-09

    ... Peanuts Marketed in the United States; Section 610 Review AGENCY: Agricultural Marketing Service, USDA...) review of the Minimum Quality and Handling Standards for Domestic and Imported Peanuts Marketed in the... Domestic and Imported Peanuts Marketed in the United States (Standards), as amended (7 CFR part 996),...

  5. Evaluation of High-Angle-of-Attack Handling Qualities for the X-31A Using Standard Evaluation Maneuvers

    NASA Technical Reports Server (NTRS)

    Stoliker, Patrick C.; Bosworth, John T.

    1996-01-01

    The X-31A aircraft gross-acquisition and fine-tracking handling qualities have been evaluated using standard evaluation maneuvers developed by Wright Laboratory, Wright-Patterson Air Force Base. The emphasis of the testing is in the angle-of-attack range between 30 deg and 70 deg. Longitudinal gross-acquisition handling qualities results show borderline Level 1/Level 2 performance. Lateral gross-acquisition testing results in Level 1/Level 2 ratings below 45 deg angle of attack, degrading into Level 3 as angle of attack increases. The fine-tracking performance in both longitudinal and lateral axes also receives Level 1 ratings near 30 deg angle of attack, with the ratings tending towards Level 3 at angles of attack greater than 50 deg. These ratings do not match the expectations from the extensive close-in combat testing where the X-31A aircraft demonstrated fair to good handling qualities maneuvering for high angles of attack. This paper presents the results of the high-angle-of-attack handling qualities flight testing of the X-31A aircraft. Discussion of the preparation for the maneuvers, the pilot ratings, and selected pilot comments are included. Evaluation of the results is made in conjunction with existing Neal-Smith, bandwidth, Smith-Geddes, and military specifications.

  6. 75 FR 22213 - Minimum Quality and Handling Standards for Domestic and Imported Peanuts Marketed in the United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 996 Minimum Quality and Handling Standards for Domestic and Imported Peanuts Marketed in the United States; Section 610 Review AGENCY: Agricultural Marketing Service,...

  7. A flight investigation of the stability, control, and handling qualities of an augmented jet flap STOL airplane

    NASA Technical Reports Server (NTRS)

    Vomaske, R. F.; Innis, R. C.; Swan, B. E.; Grossmith, S. W.

    1978-01-01

    The stability, control, and handling qualities of an augmented jet flap STOL airplane are presented. The airplane is an extensively modified de Havilland Buffalo military transport. The modified airplane has two fan-jet engines which provide vectorable thrust and compressed air for the augmentor jet flap and Boundary-Layer Control (BLC). The augmentor and BLC air is cross ducted to minimize asymmetric moments produced when one engine is inoperative. The modifications incorporated in the airplane include a Stability Augmentation System (SAS), a powered elevator, and a powered lateral control system. The test gross weight of the airplane was between 165,000 and 209,000 N (37,000 and 47,000 lb). Stability, control, and handling qualities are presented for the airspeed range of 40 to 180 knots. The lateral-directional handling qualities are considered satisfactory for the normal operating range of 65 to 160 knots airspeed when the SAS is functioning. With the SAS inoperative, poor turn coordination and spiral instability are primary deficiencies contributing to marginal handling qualities in the landing approach. The powered elevator control system enhanced the controllability in pitch, particularly in the landing flare and stall recovery.

  8. HOPE: An On-Line Piloted Handling Qualities Experiment Data Book

    NASA Technical Reports Server (NTRS)

    Jackson, E. B.; Proffitt, Melissa S.

    2010-01-01

    A novel on-line database for capturing most of the information obtained during piloted handling qualities experiments (either flight or simulated) is described. The Hyperlinked Overview of Piloted Evaluations (HOPE) web application is based on an open-source object-oriented Web-based front end (Ruby-on-Rails) that can be used with a variety of back-end relational database engines. The hyperlinked, on-line data book approach allows an easily-traversed way of looking at a variety of collected data, including pilot ratings, pilot information, vehicle and configuration characteristics, test maneuvers, and individual flight test cards and repeat runs. It allows for on-line retrieval of pilot comments, both audio and transcribed, as well as time history data retrieval and video playback. Pilot questionnaires are recorded as are pilot biographies. Simple statistics are calculated for each selected group of pilot ratings, allowing multiple ways to aggregate the data set (by pilot, by task, or by vehicle configuration, for example). Any number of per-run or per-task metrics can be captured in the database. The entire run metrics dataset can be downloaded in comma-separated text for further analysis off-line. It is expected that this tool will be made available upon request

  9. A Comparison of the NAVTOLAND (Navy Vertical Takeoff and Landing) SH-2F Helicopter Model with the Requirements of MIL-H-8501A and with Flight Data.

    DTIC Science & Technology

    2014-09-26

    NATIONAL BUREAU OF STANDARDS- 1963-A c" REPORT NO. NADC-84166-60 A COMPARISON OF THE NAVTOLAND SH-2F HELICOPTER MODEL WITH THE REQUIREMENTS OF MIL -H...Classification) A Comparison of the NAVTOLAND SH-2F Helicopter Model with the Requirements of MIL -H-8501A and with Flight Data - l12. PERSOr.NAUTHOR(S)R.- onald...Modelling, Handling Qualities, MIL -H-8501A 19. ABSTRACT (Continue on reverse if ncesury and identify by block number) This report uses an SH-2F

  10. The effects of lairage time and handling procedure prior to slaughter on stress and meat quality parameters in pigs.

    PubMed

    Dokmanović, M; Velarde, A; Tomović, V; Glamočlija, N; Marković, R; Janjić, J; Baltić, M Ž

    2014-10-01

    Lairage time (short - 8min to 2.7h, n=28 vs. long - 14 to 21.5h, n=72) and pig handling (gentle - no use of stick or electric prod, pig not slipping, falling, nor emitting high-pitched vocalizations vs. rough - where any of these occurred) effects on pig stress and meat quality were measured. Blood lactate and cortisol, plus post-mortem pH (pH60min; pH24h), temperature (T60min), drip loss, sensory and instrumental color and meat quality for the longissimus dorsi, pars lumbalis derived meat were determined. Carcass rigor mortis and skin damages were measured. Lairage time significantly affected blood lactate, carcass rigor mortis, skin damages, drip loss, color and meat quality. Handling procedure influenced blood lactate, pH60min and T60min. Long lairage was more stressful, and was detrimental to carcass quality, but caused better meat quality compared to short lairage. Rough handling was related to higher lactate and lower meat quality.

  11. A piloted simulation of helicopter air combat to investigate effects of variations in selected performance and control response characteristics

    NASA Technical Reports Server (NTRS)

    Lewis, Michael S.; Mansur, M. Hossein; Chen, Robert T. N.

    1987-01-01

    A piloted simulation study investigating handling qualities and flight characteristics required for helicopter air to air combat is presented. The Helicopter Air Combat system was used to investigate this role for Army rotorcraft. Experimental variables were the maneuver envelope size (load factor and sideslip), directional axis handling qualities, and pitch and roll control-response type. Over 450 simulated, low altitude, one-on-one engagements were conducted. Results from the experiment indicate that a well damped directional response, low sideforce caused by sideslip, and some effective dihedral are all desirable for weapon system performance, good handling qualities, and low pilot workload. An angular rate command system was favored over the attitude type pitch and roll response for most applications, and an enhanced maneuver envelope size over that of current generation aircraft was found to be advantageous. Pilot technique, background, and experience are additional factors which had a significant effect on performance in the air combat tasks investigated. The implication of these results on design requirements for future helicopters is presented.

  12. Analysis of Aircraft Control Performance using a Fuzzy Rule Base Representation of the Cooper-Harper Aircraft Handling Quality Rating

    NASA Technical Reports Server (NTRS)

    Tseng, Chris; Gupta, Pramod; Schumann, Johann

    2006-01-01

    The Cooper-Harper rating of Aircraft Handling Qualities has been adopted as a standard for measuring the performance of aircraft since it was introduced in 1966. Aircraft performance, ability to control the aircraft, and the degree of pilot compensation needed are three major key factors used in deciding the aircraft handling qualities in the Cooper- Harper rating. We formulate the Cooper-Harper rating scheme as a fuzzy rule-based system and use it to analyze the effectiveness of the aircraft controller. The automatic estimate of the system-level handling quality provides valuable up-to-date information for diagnostics and vehicle health management. Analyzing the performance of a controller requires a set of concise design requirements and performance criteria. Ir, the case of control systems fm a piloted aircraft, generally applicable quantitative design criteria are difficult to obtain. The reason for this is that the ultimate evaluation of a human-operated control system is necessarily subjective and, with aircraft, the pilot evaluates the aircraft in different ways depending on the type of the aircraft and the phase of flight. In most aerospace applications (e.g., for flight control systems), performance assessment is carried out in terms of handling qualities. Handling qualities may be defined as those dynamic and static properties of a vehicle that permit the pilot to fully exploit its performance in a variety of missions and roles. Traditionally, handling quality is measured using the Cooper-Harper rating and done subjectively by the human pilot. In this work, we have formulated the rules of the Cooper-Harper rating scheme as fuzzy rules with performance, control, and compensation as the antecedents, and pilot rating as the consequent. Appropriate direct measurements on the controller are related to the fuzzy Cooper-Harper rating system: a stability measurement like the rate of change of the cost function can be used as an indicator if the aircraft is under

  13. Real-time audiovisual feedback system in a physician-staffed helicopter emergency medical service in Finland: the quality results and barriers to implementation

    PubMed Central

    2013-01-01

    Objectives To evaluate the quality of cardiopulmonary resuscitation (CPR) in a physician staffed helicopter emergency medical service (HEMS) using a monitor-defibrillator with a quality analysis feature. As a post hoc analysis, the potential barriers to implementation were surveyed. Methods The quality of CPR performed by the HEMS from November 2008 to April 2010 was analysed. To evaluate the implementation rate of quality analysis, the HEMS database was screened for all cardiac arrest missions during the study period. As a consequence of the observed low implementation rate, a survey was sent to physicians working in the HEMS to evaluate the possible reasons for not utilizing the automated quality analysis feature. Results During the study period, the quality analysis was used for 52 out of 187 patients (28%). In these cases the mean compression depth was < 40 mm in 46% and < 50 mm in 96% of the 1-min analysis intervals, but otherwise CPR quality corresponded with the 2005 resuscitation guidelines. In particular, the no-flow fraction was remarkably low 0.10 (0.07, 0.16). The most common reasons for not using quality-controlled CPR were that the device itself was not taken to the scene, or not applied to the patient, because another EMS unit was already treating the patient with another defibrillator. Conclusions When quality-controlled CPR technology was used, the indicators of good quality CPR as described in the 2005 resuscitation guidelines were mostly achieved albeit with sufficient compression depth. The use of the well-described technology in improving patient care was low. Wider implementation of the automated quality control and feedback feature in defibrillators could further improve the quality of CPR on the field. Trial registration ClinicalTrials.gov (NCT00951704) PMID:23816325

  14. A study of the effects of Rotating Frame Turbulence (RFT) on helicopter flight mechanics

    NASA Technical Reports Server (NTRS)

    Schrage, D. P.; Prasad, J. V. B.; Gaonkar, G. H.

    1989-01-01

    The turbulence actually experienced by a helicopter blade-element significantly differs from the space-fixed free atmospheric turbulence. The turbulence in the rotor disk requires a rotationally sampled description in a rotating frame of reference. It is referred to as the rotating frame turbulence or RFT which exhibits a striking phenomenon. The RFT spectral density versus frequency shows high peak values at 1P,2P, or 3P, frequencies. The energy increase at these peaks is balanced by an energy decrease primarily at the lower-than-1P frequency range. Particularly for low altitude flight regimes of pure helicopters, such as the nap-of-the-earth maneuvers, the conventional space-fixed description of turbulence is not a good approximation, since the turbulence scale length can have values comparable to the rotor radius. Accordingly the flight mechanics characteristics with RFT description are compared with those based on the conventional space-fixed turbulence description. The results demonstrate that the RFT qualitatively and quantitatively affects the prediction of helicopter flight mechanics characteristics in turbulence. Such comparisons should play an important role in the new development of handling qualities specifications for helicopters.

  15. Investigation of Control System and Display Variations on Spacecraft Handling Qualities for Docking with Stationary and Rotating Targets

    NASA Technical Reports Server (NTRS)

    Jackson, E. Bruce; Goodrich, Kenneth H.; Bailey, Randall E.; Barnes, James R.; Ragsdale, William A.; Neuhaus, Jason R.

    2010-01-01

    This paper documents the investigation into the manual docking of a preliminary version of the Crew Exploration Vehicle with stationary and rotating targets in Low Earth Orbit. The investigation was conducted at NASA Langley Research Center in the summer of 2008 in a repurposed fixed-base transport aircraft cockpit and involved nine evaluation astronauts and research pilots. The investigation quantified the benefits of a feed-forward reaction control system thruster mixing scheme to reduce translation-into-rotation coupling, despite unmodeled variations in individual thruster force levels and off-axis center of mass locations up to 12 inches. A reduced rate dead-band in the phase-plane attitude controller also showed some promise. Candidate predictive symbology overlaid on a docking ring centerline camera image did not improve handling qualities, but an innovative attitude status indicator symbol was beneficial. The investigation also showed high workload and handling quality problems when manual dockings were performed with a rotating target. These concerns indicate achieving satisfactory handling quality ratings with a vehicle configuration similar to the nominal Crew Exploration Vehicle may require additional automation.

  16. A simulation investigation of scout/attack helicopter directional control requirements for hover and low-speed tasks

    NASA Technical Reports Server (NTRS)

    Bivens, Courtland C.; Guercio, Joseph G.

    1987-01-01

    A piloted simulator experiment was conducted to investigate directional axis handling qualities requirements for low speed and hover tasks performed by a Scout/Attack helicopter. Included were the directional characteristics of various candidate light helicopter family configurations. Also, the experiment focused on conventional single main/tail rotor configurations of the OH-58 series aircraft, where the first-order yaw-axis dynamic effects that contributed to the loss of tail rotor control were modeled. Five pilots flew 22 configurations under various wind conditions. Cooper-Harper handling quality ratings were used as the primary measure of merit of each configuration. The results of the experiment indicate that rotorcraft configurations with high directional gust sensitivity require greater minimum yaw damping to maintain satisfactory handling qualities during nap-of-the-Earth flying tasks. It was also determined that both yaw damping and control response are critical handling qualities parameters in performing the air-to-air target acquisition and tracking task. Finally, the lack of substantial yaw damping and larger values of gust sensitivity increased the possibility of loss of directional control at low airspeeds for the single main/tail rotor configurations.

  17. Rotor-state feedback in the design of flight control laws for a hovering helicopter

    NASA Technical Reports Server (NTRS)

    Takahashi, Marc D.

    1994-01-01

    The use of rigid-body and rotor-state feedback gains in the design of helicopter flight control laws was investigated analytically on a blade element, articulated rotor, helicopter model. The study was conducted while designing a control law to meet an existing military rotorcraft handling qualities design specification (ADS-33C) in low-speed flight. A systematic approach to meet this specification was developed along with an assessment of the function of these gains in the feedback loops. Using the results of this assessment, the pitch and roll crossover behavior was easily modified by adjusting the body attitude and rotor-flap feedback gains. Critical to understanding the feedback gains is that the roll and pitch rate dynamics each have second-order behavior, not the classic first-order behavior, which arises from a quasi-static rotor, six degree-of-freedom model.

  18. 77 FR 18970 - Airworthiness Directives; Bell Helicopter Textron Canada Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ... Directives; Bell Helicopter Textron Canada Helicopters AGENCY: Federal Aviation Administration (FAA), DOT... (AD) for the Bell Helicopter Textron Canada Limited (BHTC) Model 407 helicopters. This proposed AD is... Helicopter Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4, telephone (450)...

  19. Review of the transmissions of the Soviet helicopters

    NASA Technical Reports Server (NTRS)

    Chaiko, Lev I.

    1990-01-01

    A review of the following aspects of Soviet helicopter transmissions is presented: transmitted power, weight, reduction ratio, RPM, design configuration, comparison of different type of manufacturing methods, and a description of the materials and technologies applied to critical transmission components. Included are mechanical diagrams of the gearboxes of the Soviet helicopters and test stands for testing gearbox and main shaft. The quality of Soviet helicopter transmissions and their Western counterparts are assessed and compared.

  20. Flight Test Identification and Simulation of a UH-60A Helicopter and Slung Load

    NASA Technical Reports Server (NTRS)

    Cicolani, Luigi S.; Sahai, Ranjana; Tucker, George E.; McCoy, Allen H.; Tyson, Peter H.; Tischler, Mark B.; Rosen, Aviv

    2001-01-01

    Helicopter slung-load operations are common in both military and civil contexts. Helicopters and loads are often qualified for these operations by means of flight tests, which can be expensive and time consuming. There is significant potential to reduce such costs both through revisions in flight-test methods and by using validated simulation models. To these ends, flight tests were conducted at Moffett Field to demonstrate the identification of key dynamic parameters during flight tests (aircraft stability margins and handling-qualities parameters, and load pendulum stability), and to accumulate a data base for simulation development and validation. The test aircraft was a UH-60A Black Hawk, and the primary test load was an instrumented 8- by 6- by 6-ft cargo container. Tests were focused on the lateral and longitudinal axes, which are the axes most affected by the load pendulum modes in the frequency range of interest for handling qualities; tests were conducted at airspeeds from hover to 80 knots. Using telemetered data, the dynamic parameters were evaluated in near real time after each test airspeed and before clearing the aircraft to the next test point. These computations were completed in under 1 min. A simulation model was implemented by integrating an advanced model of the UH-60A aerodynamics, dynamic equations for the two-body slung-load system, and load static aerodynamics obtained from wind-tunnel measurements. Comparisons with flight data for the helicopter alone and with a slung load showed good overall agreement for all parameters and test points; however, unmodeled secondary dynamic losses around 2 Hz were found in the helicopter model and they resulted in conservative stability margin estimates.

  1. Effect of pre-slaughter handling, exercise and the presence of a dog on lamb welfare and meat quality.

    PubMed

    Sutherland, M A; Worth, G M; Stuart, A D; Dobbie, P M; Clerens, S

    2016-08-01

    Before slaughter, lambs may experience several stressors such as feed and water deprivation, handling and transport that have the potential to negatively impact welfare and meat quality. The objective of this study was to evaluate the effect of pre-slaughter handling, exercise and the presence of a dog on the behaviour and physiology of lambs and meat quality at slaughter. At 6 months of age, 60 lambs (n=20 lambs/replicate; three replicates) were allocated to one of the two treatment groups (n=30 lambs/treatment): low (LOW) intensive handling or high (HIGH) intensive handling. LOW lambs were moved short distances, quietly and without the use of a dog before transport. HIGH lambs were moved quickly, long distances and with a dog present before transport. Lamb behaviour (standing, lying, rumination and panting) was recorded for 1 h before (post-treatment) and after transport (post-transport), and for 30 min before slaughter (pre-slaughter). Blood samples were collected before (baseline), after transport (post-transport) and at exsanguination (at slaughter) to assess cortisol, lactate and non-esterified fatty acid (NEFA) concentrations. At slaughter, lamb carcases (M. longissimus lumborum) were evaluated for pH levels, drip and cook loss, and tenderness. HIGH lambs spent more time standing (P<0.001) and panting (P<0.001) and less time lying (P<0.001) and ruminating (P<0.001) post-treatment than LOW lambs, but more (P<0.001) time ruminating post-transport. All lambs spent more time standing (P<0.001) and less time lying (P<0.001) and panting (P<0.001) post-transport and pre-slaughter than post-treatment. Cortisol concentrations were greater (P<0.001) in lambs post-transport and at slaughter compared with baseline values. Lactate concentrations were lower (P=0.002) in HIGH than LOW lambs. In addition, NEFA concentrations were higher (P<0.001) post-transport and at slaughter in HIGH compared with LOW lambs. Ultimate pH was higher (P<0.001) in HIGH than LOW lambs and p

  2. V/STOLAND avionics system flight-test data on a UH-1H helicopter

    NASA Technical Reports Server (NTRS)

    Baker, F. A.; Jaynes, D. N.; Corliss, L. D.; Liden, S.; Merrick, R. B.; Dugan, D. C.

    1980-01-01

    The flight-acceptance test results obtained during the acceptance tests of the V/STOLAND (versatile simplex digital avionics system) digital avionics system on a Bell UH-1H helicopter in 1977 at Ames Research Center are presented. The system provides navigation, guidance, control, and display functions for NASA terminal area VTOL research programs and for the Army handling qualities research programs at Ames Research Center. The acceptance test verified system performance and contractual acceptability. The V/STOLAND hardware navigation, guidance, and control laws resident in the digital computers are described. Typical flight-test data are shown and discussed as documentation of the system performance at acceptance from the contractor.

  3. Design of fault tolerant control system for individual blade control helicopters

    NASA Astrophysics Data System (ADS)

    Tamayo, Sergio

    This dissertation presents the development of a fault tolerant control scheme for helicopters fitted with individually controlled blades. This novel approach attempts to improve fault tolerant capabilities of helicopter control system by increasing control redundancy using additional actuators for individual blade input and software re-mixing to obtain nominal or close to nominal conditions under failure. An advanced interactive simulation environment has been developed including modeling of sensor failure, swashplate actuator failure, individual blade actuator failure, and blade delamination to support the design, testing, and evaluation of the control laws. This simulation environment is based on the blade element theory for the calculation of forces and moments generated by the main rotor. This discretized model allows for individual blade analysis, which in turn allows measuring the consequences of a stuck blade, or loss of the surface area of the blade itself, with respect to the dynamics of the whole helicopter. The control laws are based on non-linear dynamic inversion and artificial neural network augmentation, which is a mix of linear and nonlinear methods that compensates for model inaccuracies due to linearization or failure. A stability analysis based on the Lyapunov function approach has shown that bounded tracking error is guaranteed, and under specific circumstances, global stability is guaranteed as well. An analysis over the degrees of freedom of the mechanical system and its impact over the helicopter handling qualities is also performed to measure the degree of redundancy achieved with the addition of individual blade actuators as compared to a classic swashplate helicopter configuration. Mathematical analysis and numerical simulation, using reconfiguration of the individual blade control under failure have shown that this control architecture can potentially improve the survivability of the aircraft and reduce pilot workload under failure

  4. Rotorcraft flying qualities improvement using advanced control

    NASA Technical Reports Server (NTRS)

    Walker, D.; Postlethwaite, I.; Howitt, J.; Foster, N.

    1993-01-01

    We report on recent experience gained when a multivariable helicopter flight control law was tested on the Large Motion Simulator (LMS) at DRA Bedford. This was part of a study into the application of multivariable control theory to the design of full-authority flight control systems for high-performance helicopters. In this paper, we present some of the results that were obtained during the piloted simulation trial and from subsequent off-line simulation and analysis. The performance provided by the control law led to level 1 handling quality ratings for almost all of the mission task elements assessed, both during the real-time and off-line analysis.

  5. Flight Testing and Real-Time System Identification Analysis of a UH-60A Black Hawk Helicopter with an Instrumented External Sling Load

    NASA Technical Reports Server (NTRS)

    McCoy, Allen H.

    1998-01-01

    Helicopter external air transportation plays an important role in today's world. For both military and civilian helicopters, external sling load operations offer an efficient and expedient method of handling heavy, oversized cargo. With the ability to reach areas otherwise inaccessible by ground transportation, helicopter external load operations are conducted in industries such as logging, construction, and fire fighting, as well as in support of military tactical transport missions. Historically, helicopter and load combinations have been qualified through flight testing, requiring considerable time and cost. With advancements in simulation and flight test techniques there is potential to substantially reduce costs and increase the safety of helicopter sling load certification. Validated simulation tools make possible accurate prediction of operational flight characteristics before initial flight tests. Real time analysis of test data improves the safety and efficiency of the testing programs. To advance these concepts, the U.S. Army and NASA, in cooperation with the Israeli Air Force and Technion, under a Memorandum of Agreement, seek to develop and validate a numerical model of the UH-60 with sling load and demonstrate a method of near real time flight test analysis. This thesis presents results from flight tests of a U.S. Army Black Hawk helicopter with various external loads. Tests were conducted as the U.S. first phase of this MOA task. The primary load was a container express box (CONEX) which contained a compact instrumentation package. The flights covered the airspeed range from hover to 70 knots. Primary maneuvers were pitch and roll frequency sweeps, steps, and doublets. Results of the test determined the effect of the suspended load on both the aircraft's handling qualities and its control system's stability margins. Included were calculations of the stability characteristics of the load's pendular motion. Utilizing CIFER(R) software, a method for near

  6. Handling Qualities Evaluations of Low Complexity Model Reference Adaptive Controllers for Reduced Pitch and Roll Damping Scenarios

    NASA Technical Reports Server (NTRS)

    Hanson, Curt; Schaefer, Jacob; Burken, John J.; Johnson, Marcus; Nguyen, Nhan

    2011-01-01

    National Aeronautics and Space Administration (NASA) researchers have conducted a series of flight experiments designed to study the effects of varying levels of adaptive controller complexity on the performance and handling qualities of an aircraft under various simulated failure or damage conditions. A baseline, nonlinear dynamic inversion controller was augmented with three variations of a model reference adaptive control design. The simplest design consisted of a single adaptive parameter in each of the pitch and roll axes computed using a basic gradient-based update law. A second design was built upon the first by increasing the complexity of the update law. The third and most complex design added an additional adaptive parameter to each axis. Flight tests were conducted using NASA s Full-scale Advanced Systems Testbed, a highly modified F-18 aircraft that contains a research flight control system capable of housing advanced flight controls experiments. Each controller was evaluated against a suite of simulated failures and damage ranging from destabilization of the pitch and roll axes to significant coupling between the axes. Two pilots evaluated the three adaptive controllers as well as the non-adaptive baseline controller in a variety of dynamic maneuvers and precision flying tasks designed to uncover potential deficiencies in the handling qualities of the aircraft, and adverse interactions between the pilot and the adaptive controllers. The work was completed as part of the Integrated Resilient Aircraft Control Project under NASA s Aviation Safety Program.

  7. Small Business Innovations (Helicopters)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The amount of engine power required for a helicopter to hover is an important, but difficult, consideration in helicopter design. The EHPIC program model produces converged, freely distorted wake geometries that generate accurate analysis of wake-induced downwash, allowing good predictions of rotor thrust and power requirements. Continuum Dynamics, Inc., the Small Business Innovation Research (SBIR) company that developed EHPIC, also produces RotorCRAFT, a program for analysis of aerodynamic loading of helicopter blades in forward flight. Both helicopter codes have been licensed to commercial manufacturers.

  8. Real-time simulation of helicopter IFR approaches into major terminal areas using RNAV, MLS, and CDTI

    NASA Technical Reports Server (NTRS)

    Tobias, L.; Lee, H. Q.; Peach, L. L.; Willett, F. M., Jr.; Obrien, P. J.

    1982-01-01

    Helicopter IFR routes at hub airports have been investigated in an air-traffic-control system simulation involving a piloted helicopter simulator, computer-generated air traffic, and air traffic controllers. Problems studied included: (1) pilot acceptance of the approach procedure and tracking accuracy; (2) ATC procedures for handling a mix of helicopter and fixed-wing traffic; and (3) utility of the Cockpit Display of Traffic Information (CDTI) for the helicopter. Results indicate that the helicopter routes were pilot acceptable and were noninterfering with fixed-wing traffic. Merging and spacing maneuvers using CDTI were successfully carried out by the pilots, but controllers had some reservations concerning CDTI.

  9. Tensor-based methods for handling missing data in quality-of-life questionnaires.

    PubMed

    Garg, Lalit; Dauwels, Justin; Earnest, Arul; Leong, Khai Pang

    2014-09-01

    A common problem with self-report quality-of-life questionnaires is missing data. Despite enormous care and effort to prevent it, some level of missing data is common and unavoidable. Missing data can have a detrimental impact on the data analysis. In this paper, a novel approach to imputing missing data in quality-of-life questionnaires is proposed, based on matrix and tensor decompositions. In order to illustrate and assess those methods, two datasets are considered: The first dataset contains the responses of 100 patients to a systemic lupus erythematosus-specific quality-of-life questionnaire; the other contains the responses of 43 patients to a rhino-conjunctivitis quality-of-life questionnaire. The two datasets contain almost no missing data, and for testing purposes, data entries are removed at random to have missing completely at random data. Several proportions of missing values are considered, and for each, the imputation error is assessed through k-fold cross validation. We also evaluate different imputation methods for missing at random and missing not at randomdata. The numerical results demonstrate that the proposed tensor factorization-based methods outperform standard methods in terms of root mean square error with at least 4% improvement, while the bias and variance are similar.

  10. Helicopter simulator qualification

    NASA Technical Reports Server (NTRS)

    Hampson, Brian

    1992-01-01

    CAE has extensive experience in building helicopter simulators and has participated in group working sessions for fixed-wing advisory circulars. Against this background, issues that should be addressed in establishing helicopter approval criteria were highlighted. Some of these issues are not immediately obvious and may, indeed, be more important than the criteria a themselves.

  11. The RMAX Helicopter UAV

    DTIC Science & Technology

    2007-11-02

    7 SYSTEM CONFIGURATION..................................8 OBSERVATION FLIGHT AT ERUPTING VOLCANO , MT. USU...autonomous flight control system. Because our autonomous, unmanned helicopter has succeeded in observation roles at erupting volcanoes , the Japanese...saving devices. In April 2000, we had our GPS-based autonomous helicopter play an observation role at an erupting volcano . This is the first time in

  12. Interpreting the handling qualities of aircraft with stability and control augmentation

    NASA Technical Reports Server (NTRS)

    Hodgkinson, J.; Potsdam, E. H.; Smith, R. E.

    1990-01-01

    The general process of designing an aircraft for good flying qualities is first discussed. Lessons learned are pointed out, with piloted evaluation emerging as a crucial element. Two sources of rating variability in performing these evaluations are then discussed. First, the finite endpoints of the Cooper-Harper scale do not bias parametric statistical analyses unduly. Second, the wording of the scale does introduce some scatter. Phase lags generated by augmentation systems, as represented by equivalent time delays, often cause poor flying qualities. An analysis is introduced which allows a designer to relate any level of time delay to a probability of loss of aircraft control. This view of time delays should, it is hoped, allow better visibility of the time delays in the design process.

  13. Longitudinal Handling Qualities of the Tu-144LL Airplane and Comparisons With Other Large, Supersonic Aircraft

    NASA Technical Reports Server (NTRS)

    Cox, Timothy H.; Marshall, Alisa

    2000-01-01

    Four flights have been conducted using the Tu-144LL supersonic transport aircraft with the dedicated objective of collecting quantitative data and qualitative pilot comments. These data are compared with the following longitudinal flying qualities criteria: Neal-Smith, short-period damping, time delay, control anticipation parameter, phase delay (omega(sp)*T(theta(2))), pitch bandwidth as a function of time delay, and flight path as a function of pitch bandwidth. Determining the applicability of these criteria and gaining insight into the flying qualities of a large, supersonic aircraft are attempted. Where appropriate, YF-12, XB-70, and SR-71 pilot ratings are compared with the Tu-144LL results to aid in the interpretation of the Tu-144LL data and to gain insight into the application of criteria. The data show that approach and landing requirements appear to be applicable to the precision flightpath control required for up-and-away flight of large, supersonic aircraft. The Neal-Smith, control anticipation parameter, and pitch-bandwidth criteria tend to correlate with the pilot comments better than the phase delay criterion, omega(sp)*T(theta(2)). The data indicate that the detrimental flying qualities implication of decoupled pitch-attitude and flightpath responses occurring for high-speed flight may be mitigated by requiring the pilot to close the loop on flightpath or vertical speed.

  14. Helicopter human factors

    NASA Technical Reports Server (NTRS)

    Hart, Sandra G.

    1988-01-01

    The state-of-the-art helicopter and its pilot are examined using the tools of human-factors analysis. The significant role of human error in helicopter accidents is discussed; the history of human-factors research on helicopters is briefly traced; the typical flight tasks are described; and the noise, vibration, and temperature conditions typical of modern military helicopters are characterized. Also considered are helicopter controls, cockpit instruments and displays, and the impact of cockpit design on pilot workload. Particular attention is given to possible advanced-technology improvements, such as control stabilization and augmentation, FBW and fly-by-light systems, multifunction displays, night-vision goggles, pilot night-vision systems, night-vision displays with superimposed symbols, target acquisition and designation systems, and aural displays. Diagrams, drawings, and photographs are provided.

  15. Flight-Time Identification of a UH-60A Helicopter and Slung Load

    NASA Technical Reports Server (NTRS)

    Cicolani, Luigi S.; McCoy, Allen H.; Tischler, Mark B.; Tucker, George E.; Gatenio, Pinhas; Marmar, Dani

    1998-01-01

    This paper describes a flight test demonstration of a system for identification of the stability and handling qualities parameters of a helicopter-slung load configuration simultaneously with flight testing, and the results obtained.Tests were conducted with a UH-60A Black Hawk at speeds from hover to 80 kts. The principal test load was an instrumented 8 x 6 x 6 ft cargo container. The identification used frequency domain analysis in the frequency range to 2 Hz, and focussed on the longitudinal and lateral control axes since these are the axes most affected by the load pendulum modes in the frequency range of interest for handling qualities. Results were computed for stability margins, handling qualities parameters and load pendulum stability. The computations took an average of 4 minutes before clearing the aircraft to the next test point. Important reductions in handling qualities were computed in some cases, depending, on control axis and load-slung combination. A database, including load dynamics measurements, was accumulated for subsequent simulation development and validation.

  16. Evaluation of hygiene practices and microbiological quality of cooked meat products during slicing and handling at retail.

    PubMed

    Pérez-Rodríguez, F; Castro, R; Posada-Izquierdo, G D; Valero, A; Carrasco, E; García-Gimeno, R M; Zurera, G

    2010-10-01

    Cooked meat ready-to-eat products are recognized to be contaminated during slicing which, in the last years, has been associated with several outbreaks. This work aimed to find out possible relation between the hygiene practice taking place at retail point during slicing of cooked meat products in small and medium-sized establishments (SMEs) and large-sized establishments (LEs) and the microbiological quality of sliced cooked meat products. For that, a checklist was drawn up and filled in based on scoring handling practice during slicing in different establishments in Cordoba (Southern Spain). In addition, sliced cooked meats were analyzed for different microbiological indicators and investigated for the presence of Listeria spp. and Listeria monocytogenes. Results indicated that SMEs showed a more deficient handling practices compared to LEs. In spite of these differences, microbiological counts indicated similar microbiological quality in cooked meat samples for both types of establishments. On the other hand, Listeria monocytogenes and Listeria inocua were isolated from 7.35% (5/68) and 8.82% (6/68) of analyzed samples, respectively. Positive samples for Listeria spp. were found in establishments which showed acceptable hygiene levels, though contamination could be associated to the lack of exclusiveness of slicers at retail points. Moreover, Listeria spp presence could not be statistically linked to any microbiological parameters; however, it was observed that seasonality influenced significantly (P<0.05) L. monocytogenes presence, being all samples found during warm season (5/5). As a conclusion, results suggested that more effort should be made to adequately educate handlers in food hygiene practices, focused specially on SMEs.

  17. Effect of epididymis handling conditions on the quality of ram spermatozoa recovered post-mortem.

    PubMed

    Kaabi, M; Paz, P; Alvarez, M; Anel, E; Boixo, J C; Rouissi, H; Herraez, P; Anel, L

    2003-10-15

    Post-mortem spermatozoa recovery is an important technique for obtaining germplasm reserves from genetically valuable animals or endangered species. However, there are many factors that influence the outcome of this technique. We have studied the effect of the interval between animal's death and sperm recovery (0, 24 or 48 h) on the quality and freezability of ram spermatozoa from cauda epididymidis. Storage temperature of epididymis (room temperature or 5 degrees C) was also analysed. Spermatozoa were diluted with Tes-Tris-Fructose solution supplemented with egg yolk (10%) and glycerol (4%), and frozen using a programmable biofreezer (-20 degrees C/min). Pre-freeze and post-thaw sperm samples showed viable spermatozoa up to 48 h after the animal's death, although their quality declined significantly as post-mortem storage time increased. Epididymis sperm stored at 5 degrees C showed better motility and a lower percentage of abnormal forms than epididymis stored at room temperature after 24 and 48 h. The fertilizing ability of cauda epididymis ram spermatozoa obtained at 0 and 24h after the animal's death is similar to that of ejaculated spermatozoa. Therefore, a good protocol for post-mortem semen collection in rams when epididymal spermatozoa cannot be collected immediately, is to preserve the epididymis at 5 degrees C and process the samples in the first 24h after the animal's death.

  18. ATC simulation of helicopter IFR approaches into major terminal areas using RNAV, MLS, and CDTI

    NASA Technical Reports Server (NTRS)

    Tobias, L.; Lee, H. Q.; Peach, L. L.; Willett, F. M., Jr.; Obrien, P. J.

    1981-01-01

    The introduction of independent helicopter IFR routes at hub airports was investigated in a real time air traffic control system simulation involving a piloted helicopter simulator, computer generated air traffic, and air traffic controllers. The helicopter simulator was equipped to fly area navigation (RNAV) routes and microwave landing system approaches. Problems studied included: (1) pilot acceptance of the approach procedure and tracking accuracy; (2) ATC procedures for handling a mix of helicopter and fixed wing traffic; and (3) utility of the cockpit display of traffic information (CDTI) for the helicopter in the hub airport environment. Results indicate that the helicopter routes were acceptable to the subject pilots and were noninterfering with fixed wing traffic. Merging and spacing maneuvers using CDTI were successfully carried out by the pilots, but controllers had some reservations concerning the acceptability of the CDTI procedures.

  19. Control equivalent turbulence input model for the UH-60 helicopter

    NASA Astrophysics Data System (ADS)

    Lusardi, Jeff

    the control system of the helicopter. This makes the CETI model suitable for use with any helicopter math model to study the effects of turbulence on handling qualities and for use in designing control systems to reject atmospheric turbulence.

  20. Establishing quality assurance criteria for serial dilution operations on liquid-handling equipment.

    PubMed

    Popa-Burke, Ioana; Lupotsky, Brian; Boyer, Joseph; Gannon, William; Hughes, Rob; Kadwill, Paul; Lyerly, Donald; Nichols, Jason; Nixon, Elizabeth; Rimmer, Darren; Saiz-Nicolas, Isabel; Sanfiz-Pinto, Beatriz; Holland, Sue

    2009-09-01

    Since the advent of high-throughput screening (HTS) in the early 1990s, parallel multichannel liquid handlers have become a mainstay in every drug discovery setting. Although several peer-reviewed publications have discussed methods and criteria for stamping multiwell copies, there is very little information about establishing a standard operating procedure (SOP) for standard (microliter-level) serial dilutions of compounds used in dose-response experiments. The authors discuss the 4 main criteria any serial dilution process must pass (accuracy, precision, fold dilution, and outliers) and the process for establishing thresholds for all of these values in a compound management or biological screening laboratory. The thresholds need to be both low enough to be acceptable from a biological potency variability perspective and high enough to allow the instruments to pass the quality assurance (QA) analysis on a regular basis. In this article, the authors suggest suitable thresholds arrived at by a variety of methods, including trend analysis of QA data, survey questionnaire from the main stakeholders (screening scientists, chemists), and published criteria for single-shot stamping. A mathematical analysis of the effect of threshold values on estimated XC(50)s was performed to ensure that the variability introduced by the serial dilution step is within acceptable overall variability limits.

  1. Effects of higher order control systems on aircraft approach and landing longitudinal handling qualities

    NASA Technical Reports Server (NTRS)

    Pasha, M. A.; Dazzo, J. J.; Silverthorn, J. T.

    1982-01-01

    An investigation of approach and landing longitudinal flying qualities, based on data generated using a variable stability NT-33 aircraft combined with significant control system dynamics is described. An optimum pilot lead time for pitch tracking, flight path angle tracking, and combined pitch and flight path angle tracking tasks is determined from a closed loop simulation using integral squared error (ISE) as a performance measure. Pilot gain and lead time were varied in the closed loop simulation of the pilot and aircraft to obtain the best performance for different control system configurations. The results lead to the selection of an optimum lead time using ISE as a performance criterion. Using this value of optimum lead time, a correlation is then found between pilot rating and performance with changes in the control system and in the aircraft dynamics. It is also shown that pilot rating is closely related to pilot workload which, in turn, is related to the amount of lead which the pilot must generate to obtain satisfactory response. The results also indicate that the pilot may use pitch angle tracking for the approach task and then add flight path angle tracking for the flare and touchdown.

  2. Design and numerical evaluation of full-authority flight control systems for conventional and thruster-augmented helicopters employed in NOE operations

    NASA Technical Reports Server (NTRS)

    Perri, Todd A.; Mckillip, R. M., Jr.; Curtiss, H. C., Jr.

    1987-01-01

    The development and methodology is presented for development of full-authority implicit model-following and explicit model-following optimal controllers for use on helicopters operating in the Nap-of-the Earth (NOE) environment. Pole placement, input-output frequency response, and step input response were used to evaluate handling qualities performance. The pilot was equipped with velocity-command inputs. A mathematical/computational trajectory optimization method was employed to evaluate the ability of each controller to fly NOE maneuvers. The method determines the optimal swashplate and thruster input histories from the helicopter's dynamics and the prescribed geometry and desired flying qualities of the maneuver. Three maneuvers were investigated for both the implicit and explicit controllers with and without auxiliary propulsion installed: pop-up/dash/descent, bob-up at 40 knots, and glideslope. The explicit controller proved to be superior to the implicit controller in performance and ease of design.

  3. CATEGORY II ARCTIC EVALUATION OF THE YCH-47A HELICOPTER.

    DTIC Science & Technology

    Stability Augmentation System ) operation, delamination of rotor blade fiberglass skins, and extreme difficulty in ground handling on hard packed snow, ice, or similar slippery surfaces. In order for the helicopter to be suitable for low temperature operation, new or modified rotor blades with assured structural integrity must be incorporated along with other improvements recommended in this report.

  4. A Piloted Simulation Investigating Handling Qualities and Performance Requirements of a Single-Pilot Helicopter in Air Combat Employing a Helmet-Driven Turreted Gun.

    DTIC Science & Technology

    1987-09-01

    57 10. Environmental IFactors ................................. 57 B. EXPERIMENTAL VARIABLES ............................ 60 I. Yaw Axis...chrceitiso oftre hanbl quities roure elpe Maior dfcmbait. Thsirbe iost rcoentiot eAir Comba 11 l PilotC im)pconduceJnuay196 inetgte control...equivalent to the IHADSS gunsight pipper used for the turreted gun. 10. Environmental Factors Adjustable environmental factors included visibility, wind

  5. Multimission helicopter cockpit displays

    NASA Astrophysics Data System (ADS)

    Terry, William S.; Terry, Jody K.; Lovelace, Nancy D.

    1996-05-01

    A new operator display subsystem is being incorporated as part of the next generation United States Navy (USN) helicopter avionics system to be integrated into the multi-mission helicopter (MMH) that replaces both the SH-60B and the SH-60F in 2001. This subsystem exploits state-of-the-art technology for the display hardware, the display driver hardware, information presentation methodologies, and software architecture. Both of the existing SH-60 helicopter display systems are based on monochrome CRT technology; a key feature of the MMH cockpit is the integration of color AMLCD multifunction displays. The MMH program is one of the first military programs to use modified commercial AMLCD elements in a tactical aircraft. This paper presents the general configuration of the MMH cockpit and multifunction display subsystem and discusses the approach taken for presenting helicopter flight information to the pilots as well as presentation of mission sensor data for use by the copilot.

  6. [Importance of helicopter rescue].

    PubMed

    Hofer, G; Voelckel, W G

    2014-03-01

    Helicopter emergency medical service (HEMS) have become a main part of prehospital emergency medical services over the last 40 years. Recently, an ongoing discussion about financial shortage and personal shortcomings question the role of cost-intensive air rescue. Thus, the value of HEMS must be examined and discussed appropriately. Since the number of physician-staffed ground ambulances may decrease due to the limited availability of qualified physicians, HEMS may fill the gap. In addition patient transfer to specialized hospitals will require an increasing number of air transports in order to minimize prehospital time. The higher risk ratio for HEMS missions when compared with ground rescue requires a rigorous quality management system. When it comes to missions in remote and exposed areas, the scope of medical treatment must be adjusted to the individual situation. Medical competence is key in order to balance guideline compliant or maximal care versus optimal care characterized as a mission-specific, individualized emergency care concept. Although, medical decision making and treatment is typically based on the best scientific evidence, personal skills, competence, and the mission scenario will determine the scope of interventions suitable to improve outcome. Thus, the profile of requirements for the HEMS medical crew is high.

  7. Pre-slaughter sound levels and pre-slaughter handling from loading at the farm till slaughter influence pork quality.

    PubMed

    Vermeulen, L; Van de Perre, V; Permentier, L; De Bie, S; Verbeke, G; Geers, R

    2016-06-01

    This study investigates the relationship between sound levels, pre-slaughter handling during loading and pork quality. Pre-slaughter variables were investigated from loading till slaughter. A total of 3213 pigs were measured 30 min post-mortem for pH(30LT) (M. Longissimus thoracis). First, a sound level model for the risk to develop PSE meat was established. The difference in maximum and mean sound level during loading, mean sound level during lairage and mean sound level prior to stunning remained significant within the model. This indicated that sound levels during loading had a significant added value to former sound models. Moreover, this study completed the global classification checklist (Vermeulen et al., 2015a) by developing a linear mixed model for pH(30LT) and PSE prevalence, with the difference in maximum and mean sound level measured during loading, the feed withdrawal period and the difference in temperature during loading and lairage. Hence, this study provided new insights over previous research where loading procedures were not included.

  8. Aircraft Handling Qualities Data

    DTIC Science & Technology

    1972-12-01

    34 sent an early estimate in the design process and perhaps the "nominal config- uration" is one which never left the drawing board. The data have been...09 * P 0,0 04@0 in WP5 5 4.55 *55 a0p @4 4.em #50 a,45 05555 eO-aO* ൈ 04 40 C’ L tip- left -ൌ It U4 - - -amw --- - - 2 - -- 4 -4 A-a A22 * ~127... seEen -ts and a movable stabilizer. The lateral con- trol empl(ys five srciler ;anels, an inboard aileron between the inboard and outboard flars, and an

  9. Helicopter emergency medical services (doctor-helicopter) in Fukushima Prefecture: present state and problems.

    PubMed

    Tase, Choichiro; Ohno, Yuko; Hasegawa, Arifumi; Tsukada, Yasuhiro; Shimada, Jiro; Ikegami, Yukihiro

    2010-06-01

    The purpose of this study is to identify the problems in operating an emergency medical service helicopter with an emergency medicine doctor on board (doctor-helicopter) in Fukushima Prefecture, Japan, which covers wide regions and many rural areas. The study looked at the numbers of flights and patients during the 523 days since the start of the doctor-helicopter service at the Fukushima Medical University Hospital. The items investigated were: number of flights, number of helicopter dispatches per month, number of patients, the hospitals where patients were taken to, the fire department dispatch centers that requested the doctor-helicopter, and the number of times each doctor flew on the helicopter. There were 450 flights. When the service was started, there were a few flights, but they gradually increased. The majority of the flights were to emergency scenes (295), while 75 flights were interfacility transports of critically ill patients, 79 flights were cancelled after take-off, and one flight was for a disaster relief operation. The nature of requests differed greatly depending on the fire department dispatch center requesting the service. The majority of patients were trauma patients (62.2%). Stroke (8.5%) and acute coronary syndrome (5.2%) patients requiring emergency treatment were fewer than anticipated. The final destination hospitals were appropriate hospitals in the region. Because the number of flight doctors is small, the burden on individual doctors is large. A system for early on-site diagnosis and helicopter request by emergency rescue team is required to maintain a high quality of emergency care.

  10. Occupational Survey Report. Helicopter Maintenance

    DTIC Science & Technology

    1994-03-01

    helicopters I-D53 Oversee helicopter inspectim or maintance activities during cross-country missions on H- I B15 0014 H-1Maian (Continued) H383 Remove or...Plan maintmeance or inspections of helicopters E95 Comdinate estimated times in commission (ETICs) of maintance jobs with job control A19 Plan work

  11. A piloted simulation investigation of yaw dynamics requirements for turreted gun use in low-level helicopter air combat

    NASA Technical Reports Server (NTRS)

    Decker, William A.; Morris, Patrick M.; Williams, Jeffrey N.

    1988-01-01

    A piloted, fixed-base simulation study was conducted to investigate the handling qualities requirements for helicopter air-to-air combat using turreted guns in the near-terrain environment. The study used a version of the helicopter air combat system developed at NASA Ames Research Center for one-on-one air combat. The study focused on the potential trade-off between gun angular movement capability and required yaw axis response. Experimental variables included yaw axis response frequency and damping and the size of the gun-movement envelope. A helmet position and sighting system was used for pilot control of gun aim. Approximately 340 simulated air combat engagements were evaluated by pilots from the Army and industry. Results from the experiment indicate that a highly-damped, high frequency yaw response was desired for Level I handling qualities. Pilot preference for those characteristics became more pronounced as gun turret movement was restricted; however, a stable, slow-reacting platform could be used with a large turret envelope. Most pilots preferred to engage with the opponent near the own-ship centerline. Turret elevation restriction affected the engagement more than azimuth restrictions.

  12. Helicopter simulator standards

    NASA Technical Reports Server (NTRS)

    Boothe, Edward M.

    1992-01-01

    The initial advisory circular was produced in 1984 (AC 120-XX). It was not finalized, however, because the FAR's for pilot certification did not recognize helicopter simulators and, therefore, permitted no credit for their use. That is being rectified, and, when the new rules are published, standards must be available for qualifying simulators. Because of the lack of a data base to support specification of these standards, the FAA must rely on the knowledge of experts in the simulator/training industry. A major aim of this workshop is to form a working group of these experts to produce a set of standards for helicopter training simulators.

  13. The handling qualities and flight characteristics of the Grumman design 698 simulated twin-engine tilt Nacelle V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Eskey, M. A.; Wilson, S. B., III

    1986-01-01

    This paper describes three government-conducted, piloted flight simulations of the Grumman Design 698 vertical and short takeoff and landing (V/STOL) aircraft. Emphasis is placed on the aircraft's handling qualities as rated by various NASA, Navy, and Grumman Aerospace Corporating pilots with flight experience ranging from conventional takeoff and landing (CTOL) to V/STOL aircraft. Each successive simulation incorporated modifications to the aircraft in order to resolve the flight problems which were of most concern to the pilots in the previous simulation. The objective of the first simulation was to assess the basic handling qualities of the aircraft with the noncross-shafted propulsion system. The objective of the second simulation was to examine the effects of incorporating the cross-shafted propulsion system. The objective of the third simulation was to examine inoperative single-engine characteristics with and without cross-shafted engines.

  14. Analysis of the longitudinal handling qualities and pilot-induced-oscillation tendencies of the High-Angle-of-Attack Research Vehicle (HARV)

    NASA Technical Reports Server (NTRS)

    Hess, Ronald A.

    1994-01-01

    The NASA High-Angle-of Attack Research Vehicle (HARV), a modified F-18 aircraft, experienced handling qualities problems in recent flight tests at NASA Dryden Research Center. Foremost in these problems was the tendency of the pilot-aircraft system to exhibit a potentially dangerous phenomenon known as a pilot-induced oscillation (PIO). When they occur, PIO's can severely restrict performance, sharply dimish mission capabilities, and can even result in aircraft loss. A pilot/vehicle analysis was undertaken with the goal of reducing these PIO tendencies and improving the overall vehicle handling qualities with as few changes as possible to the existing feedback/feedforward flight control laws. Utilizing a pair of analytical pilot models developed by the author, a pilot/vehicle analysis of the existing longitudinal flight control system was undertaken. The analysis included prediction of overall handling qualities levels and PIO susceptability. The analysis indicated that improvement in the flight control system was warranted and led to the formulation of a simple control stick command shaping filter. Analysis of the pilot/vehicle system with the shaping filter indicated significant improvements in handling qualities and PIO tendencies could be achieved. A non-real time simulation of the modified control system was undertaken with a realistic, nonlinear model of the current HARV. Special emphasis was placed upon those details of the command filter implementation which could effect safety of flight. The modified system is currently awaiting evaluation in the real-time, pilot-in-the-loop, Dual-Maneuvering-Simulator (DMS) facility at Langley.

  15. Autonomous vertical autorotation for unmanned helicopters

    NASA Astrophysics Data System (ADS)

    Dalamagkidis, Konstantinos

    Small Unmanned Aircraft Systems (UAS) are considered the stepping stone for the integration of civil unmanned vehicles in the National Airspace System (NAS) because of their low cost and risk. Such systems are aimed at a variety of applications including search and rescue, surveillance, communications, traffic monitoring and inspection of buildings, power lines and bridges. Amidst these systems, small helicopters play an important role because of their capability to hold a position, to maneuver in tight spaces and to take off and land from virtually anywhere. Nevertheless civil adoption of such systems is minimal, mostly because of regulatory problems that in turn are due to safety concerns. This dissertation examines the risk to safety imposed by UAS in general and small helicopters in particular, focusing on accidents resulting in a ground impact. To improve the performance of small helicopters in this area, the use of autonomous autorotation is proposed. This research goes beyond previous work in the area of autonomous autorotation by developing an on-line, model-based, real-time controller that is capable of handling constraints and different cost functions. The approach selected is based on a non-linear model-predictive controller, that is augmented by a neural network to improve the speed of the non-linear optimization. The immediate benefit of this controller is that a class of failures that would otherwise result in an uncontrolled crash and possible injuries or fatalities can now be accommodated. Furthermore besides simply landing the helicopter, the controller is also capable of minimizing the risk of serious injury to people in the area. This is accomplished by minimizing the kinetic energy during the last phase of the descent. The presented research is designed to benefit the entire UAS community as well as the public, by allowing for safer UAS operations, which in turn also allow faster and less expensive integration of UAS in the NAS.

  16. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project-longitudinal handling qualities study of a relaxed-stability airplane

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The results of a piloted simulation of longitudinal handling qualities of an airplane with relaxed static stability are described. This task was performed under the Integrated Application of Active Controls (IAAC) Technology Project within the NASA Energy Efficient Transport Program. A representative medium range transport airplane, the Boeing Model 757, was simulated. Evaluations were made of the unaugmented airplane and of the airplane with an Essential Pitch Augmented Stability (PAS) System and with a Primary PAS System at various center of gravity (cg) conditions. Level 2 pilot ratings were attained with cg locations aft to about 57% mean aerodynamic chord (MAC) or 6% aft of the neutral point for unaugmented landing approach. For Mach = 0.80, unaugmented cruise Level 2 ratings were attained to 47% MAC or 5% forward of the maneuver point. The augmented airplane model provided handling qualities close to or within the Level 1 boundary at all cg locations for both Essential and Primary PAS. Analyses of the test conditions when compared with existing handling qualities criteria based on classical unaugmented airplane characteristics agreed well with the pilot ratings. The unaugmented results are comparable to those reported by both the Douglas Aircraft Company and Lockheed California Company from simulation investigations of transport configurations with roughly similar dimensional and mass characteristics.

  17. Combat Rescue Helicopter (CRH)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-479 Combat Rescue Helicopter (CRH) As of FY 2017 President’s Budget Defense Acquisition...Research, Development, Test, and Evaluation SAR - Selected Acquisition Report SCP - Service Cost Position TBD - To Be Determined TY - Then Year UCR

  18. The Focke Helicopter

    NASA Technical Reports Server (NTRS)

    Focke, H; Kruger, K B

    1938-01-01

    This report presents some of the problems concerning tests of helicopters, such as forced landings, controllability and stability, general safety, piloting maneuvers, performance, servicing, and the production of lift of a propeller. Test flights are described including a 67.67 mph flight by Hanna Reitsch.

  19. Quality and safety issues highlighted by patients in the handling of laboratory test results by general practices–a qualitative study

    PubMed Central

    2014-01-01

    Background In general practice internationally, many care teams handle large numbers of laboratory test results relating to patients in their care. Related research about safety issues is limited with most of the focus on this workload from secondary care and in North American settings. Little has been published in relation to primary health care in the UK and wider Europe. This study aimed to explore experiences and perceptions of patients with regards to the handling of test results by general practices. Methods A qualitative research approach was used with patients. The setting was west of Scotland general practices from one National Health Service territorial board area. Patients were purposively sampled from practice held lists of patients who received a number of laboratory tests because of chronic medical problems or surveillance of high risk medicines. Focus groups were held and were audio-recorded. Tapes were transcribed and subjected to qualitative analysis. Transcripts were coded and codes merged into themes by two of the researchers. Results 19 participants from four medical practices took part in four focus groups. The main themes identified were: 1. Patients lacked awareness of the results handling process in their practice. 2. Patients usually did not contact their practice for test results, unless they considered themselves to be ill. 3. Patients were concerned about the appropriateness of administrators being involved in results handling. 4. Patients were concerned about breaches of confidentiality when administrators were involved in results handling. 5. Patients valued the use of dedicated results handling staff. 6. Patients welcomed the use of technology to alert them to results being available, and valued the ability to choose how this happened. Conclusions The study confirms the quality and safety of care problems associated with results handling systems and adds to our knowledge of the issues that impact in these areas. Practices need to be

  20. Utility of Helicopter Rotor Reflections at HF

    DTIC Science & Technology

    1972-12-29

    Vesuvius AE 15 Ammunition Helicopter platform Mount Katmai AE 16 Ammunition Helicopter platform Great Sitkin AE 17 Ammunition Helicopter platform Diamond...carried Mount Whitney LCC 20 Amphibious command Utility helicopter carried Eldorado LCC 11 Amphibious command Utility helicopter carried Iwo Jima LPH...Barbara AE 28 Special minesweeper Mount Hood AE 29 Special minesweeper Suribachi AE 21 Ammunition Helicopter platform Mauna Kea AE 22 Ammunition

  1. Helicopter external noise requirements: FAA perspective

    NASA Technical Reports Server (NTRS)

    Foster, C. R.

    1978-01-01

    Enactment of helicopter noise certification standards for the control of noise impact contributing to community annoyance is considered in terms of the development of helicopters as an environmentally compatible air transportation mode. Increased use of helicopters for commercial applications and public awareness of aircraft noise are cited as factors making development of helicopter noise standards necessary both for the protection of the environmental interest of the community and to ensure the orderly growth of the helicopter industry itself. Noise sources, technology trends in helicopter design, and design concepts to control helicopter noise are discussed along with the regulatory background and specific helicopter regulatory concepts.

  2. Droplet Handling

    NASA Astrophysics Data System (ADS)

    Torii, Toru

    When quantitative analysis or quantitative chemical synthesis is performed using a micrototal analysis system (microTAS), the technologies for precise metering, transporting, and mixing of droplets are required. In this chapter, several technologies for the handling of droplets are described. For metering, dispensing and transporting of droplets, pneumatic and electrokinetic forces are used. Separation of cells and particles is also performed by electrical operation. Other handling technique, such as ultrasonic or centrifugal force applications, are also reviewed. Robotic synthesis devices or high throughput screening devices are promising applications for these technologies.

  3. Droplet handling.

    PubMed

    Torii, Toru

    2010-01-01

    When quantitative analysis or quantitative chemical synthesis is performed using a micrototal analysis system (microTAS), the technologies for precise metering, transporting, and mixing of droplets are required. In this chapter, several technologies for the handling of droplets are described. For metering, dispensing and transporting of droplets, pneumatic and electrokinetic forces are used. Separation of cells and particles is also performed by electrical operation. Other handling technique, such as ultrasonic or centrifugal force applications, are also reviewed. Robotic synthesis devices or high throughput screening devices are promising applications for these technologies.

  4. Demonstration of frequency-sweep testing technique using a Bell 214-ST helicopter

    NASA Technical Reports Server (NTRS)

    Tischler, Mark B.; Fletcher, Jay W.; Diekmann, Vernon L.; Williams, Robert A.; Cason, Randall W.

    1987-01-01

    A demonstration of frequency-sweep testing using a Bell-214ST single-rotor helicopter was completed in support of the Army's development of an updated MIL-H-8501A, and an LHX (ADS-33) handling-qualities specification. Hover and level-flight (V sub a = 0 knots and V sub a = 90 knots) tests were conducted in 3 flight hours by Army test pilots at the Army Aviation Engineering Flight Activity (AEFA) at Edwards AFB, Calif. Bandwidth and phase-delay parameters were determined from the flight-extracted frequency responses as required by the proposed specifications. Transfer function modeling and verification demonstrates the validity of the frequency-response concept for characterizing closed-loop flight dynamics of single-rotor helicopters -- even in hover. This report documents the frequency-sweep flight-testing technique and data-analysis procedures. Special emphasis is given to piloting and analysis considerations which are important for demonstrating frequency-domain specification compliance.

  5. Helicopter blade tips

    NASA Technical Reports Server (NTRS)

    Lyothier, R.

    1983-01-01

    Methods of improving helicopter performance and vibration level by proper shaping of helicopter blade tips are considered. The principle involved consists of reducing the extent of the supersonic zone above the advancing tip and of the turbulent interaction. For stationary and advancing flight, the influence of the rotor and the problems posed by blade tips are reviewed. The theoretical methods of dealing with the two types of flight are briefly stated, and the experimental apparatus is described, including model triple and quadruple rotors. Different blade tip shapes are shown and briefly discussed. The theoretical results include an advancing speed of 309 km/H and a blade tip rotational speed of 215 m/s. The experimental values are advancing speed of 302 km/h and blade tip Mach number 0.86 for both types of rotors.

  6. A mathematical model of the CH-53 helicopter

    NASA Technical Reports Server (NTRS)

    Sturgeon, W. R.; Phillips, J. D.

    1980-01-01

    A mathematical model suitable for real time simulation of the CH-53 helicopter is presented. This model, which is based on modified nonlinear classical rotor theory and nonlinear fuselage aerodynamics, will be used to support terminal-area guidance and navigation studies on a fixed-base simulator. Validation is achieved by comparing the model response with that of a similar aircraft and by a qualitative comparison of the handling characteristics made by experienced pilots.

  7. Helicopter Visual Aid System

    NASA Technical Reports Server (NTRS)

    Baisley, R. L.

    1973-01-01

    The results of an evaluation of police helicopter effectiveness revealed a need for improved visual capability. A JPL program developed a method that would enhance visual observation capability for both day and night usage and demonstrated the feasibility of the adopted approach. This approach made use of remote pointable optics, a display screen, a slaved covert searchlight, and a coupled camera. The approach was proved feasible through field testing and by judgement against evaluation criteria.

  8. Apollo 10 Helicopter Recovery

    NASA Technical Reports Server (NTRS)

    1969-01-01

    A Navy helicopter arrivies to recover the Apollo 10 astronauts, seen entering a life raft, as the Command Module 'Charlie Brown' floats in the South Pacific. U.S. Navy underwater demolition team swimmers assist in the recovery operations. Splashdown occurred at 11:53 a.m., May 26, 1969, about 400 miles east of American Samoa. Note that in this photo the divers have attached a flotation collar to the spacecraft.

  9. Operational Helicopter Aviation Medicine

    DTIC Science & Technology

    1978-12-01

    acoustic stimuli travelling through the system to the inner ear. HEARING PROTECTOR AND VOICE COMMUNICATIONS SYSTEMS EFFECTS The humar auditory system just...equipment, communication noise, aircrew hearing loss, and weapons impulse noise. Helicopter Safety and Crashworthiness covered crash injury analysis...protect visual and auditory performance while performing aircrew duties were also pre- sented. A summ. ry of the excellent work presented supported the

  10. 77 FR 36131 - Airworthiness Directives; Enstrom Helicopter Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ...-28, 480, and 480B helicopters to add another trim relay to the applicability and to revise the modification instructions. This AD is prompted by the discovery that another part- numbered trim relay...-28F, 280C, 280F, 280FX, TH-28, 480, and 480B helicopters with a trim relay, part-number (P/N)...

  11. 77 FR 52264 - Airworthiness Directives; Hughes Helicopters, Inc., and McDonnell Douglas Helicopter Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ... Directives; Hughes Helicopters, Inc., and McDonnell Douglas Helicopter Systems (Type Certificate Currently... proposed AD, contact MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop... Airworthiness Directive (AD): Hughes Helicopters Inc., and McDonnel Douglas Helicopter Systems (Type...

  12. Handling Qualities of Unstable Highly Augmented Aircraft (Les Caracteristiques de Manoeuvrabilite des Aeronefs Instables a Stabilite Augmentee)

    DTIC Science & Technology

    1991-05-01

    emonstrawr T. ornado 2.h F- 16 (Y’F- 16) 1 1 -7 F-18 (NF- 17) 12 8. Space Shuttle 131 2.) General Aspects of the X-31I Flight Control Sy~steni 14 2.] 10...with extended flight envelopes lead to use of new technologies like active control and control configured unstable vehicles The review of the handling...are presented Other areas of interest are also considered basic aerodynamic design, specific issues relating to the feel system and control

  13. Helicopter simulation: Making it work

    NASA Technical Reports Server (NTRS)

    Payne, Barry

    1992-01-01

    The opportunities for improved training and checking by using helicopter simulators are greater than they are for airplane pilot training. Simulators permit the safe creation of training environments that are conducive to the development of pilot decision-making, situational awareness, and cockpit management. This paper defines specific attributes required in a simulator to meet a typical helicopter operator's training and checking objectives.

  14. Recent European Developments in Helicopters

    NASA Technical Reports Server (NTRS)

    1921-01-01

    Descriptions are given of two captured helicopters, one driven by electric power, the other by a gasoline engine. An account is given of flight tests of the gasoline powered vehicle. After 15 successful flight tests, the gasoline powered vehicle crashed due to the insufficient thrust. Also discussed here are the applications of helicopters for military observations, for meteorological work, and for carrying radio antennas.

  15. Helicopter Acoustics, part 2. [conferences

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Exterior and interior helicopter noise problems are addressed from the physics and engineering as well as the human factors point of view. Noise regulation concepts, human factors and criteria, rotor noise generation and control, design, operations and testing for noise control, helicopter noise prediction, and research tools and measurements are covered.

  16. Helicopter discrimination apparatus for the murine radar

    DOEpatents

    Webb, Jr., John G.; Gray, Roger M.

    1977-01-01

    A helicopter discrimination apparatus for a radar utilizing doppler filtering to discriminate between a missile and ground clutter. The short duration of the doppler filter pulses which are emitted by helicopter rotor blades are processed to prevent false alarms, thus allowing the radar-protected helicopter to operate in formation with other helicopters while maintaining protection against infra-red-seeking missiles.

  17. High-integrity databases for helicopter operations

    NASA Astrophysics Data System (ADS)

    Pschierer, Christian; Schiefele, Jens; Lüthy, Juerg

    2009-05-01

    Helicopter Emergency Medical Service missions (HEMS) impose a high workload on pilots due to short preparation time, operations in low level flight, and landings in unknown areas. The research project PILAS, a cooperation between Eurocopter, Diehl Avionics, DLR, EADS, Euro Telematik, ESG, Jeppesen, the Universities of Darmstadt and Munich, and funded by the German government, approached this problem by researching a pilot assistance system which supports the pilots during all phases of flight. The databases required for the specified helicopter missions include different types of topological and cultural data for graphical display on the SVS system, AMDB data for operations at airports and helipads, and navigation data for IFR segments. The most critical databases for the PILAS system however are highly accurate terrain and obstacle data. While RTCA DO-276 specifies high accuracies and integrities only for the areas around airports, HEMS helicopters typically operate outside of these controlled areas and thus require highly reliable terrain and obstacle data for their designated response areas. This data has been generated by a LIDAR scan of the specified test region. Obstacles have been extracted into a vector format. This paper includes a short overview of the complete PILAS system and then focus on the generation of the required high quality databases.

  18. The effect of water supply, handling and usage on water quality in relation to health indices in a developing community in South Africa.

    PubMed

    Genthe, B; Strauss, N; Vundule, C; Maforah, F; Seager, J

    1995-09-01

    This study examined the relationship between the quality of water consumed by people in a developing community in South Africa, and health outcomes for diarrhea. Water sources included no formal water supply, communal taps used by over 100 people, outdoor taps on individual plots, and indoor taps. The aim of this 3-year study was to determine water quality at point of collection, to examine patterns of water usage, and to determine the health consequences. This was a case control study and epidemiological assessment. The sample included over 300 households. Cases included pre-school children with severe diarrhea who visited a health facility in the study area. Interviews were conducted to determine hygiene, sanitation, education, and socioeconomic information. Controls of similar age and type of water supply were obtained from neighborhoods in the study area. Findings indicate that water, based on microbiological assay, was of good quality and complied with the South African Bureau of Standards. Water was significantly more contaminated after handling and storage compared to point of source. Cases and controls had equally poor water quality after collection and storage. Control indoor cases had higher levels of E. coli. There was a strong association between diarrhea and the attendance at a day care center. Increased risk of diarrhea was associated with poor kitchen hygiene and low levels of knowledge about hygiene and diarrhea prevention. Communal tap facilities had lower water quality than private taps.

  19. Helicopter Human Factors

    NASA Technical Reports Server (NTRS)

    Hart, Sandra G.; Sridhar, Banavar (Technical Monitor)

    1995-01-01

    Even under optimal conditions, helicopter flight is a most demanding form of human-machine interaction, imposing continuous manual, visual, communications, and mental demands on pilots. It is made even more challenging by small margins for error created by the close proximity of terrain in NOE flight and missions flown at night and in low visibility. Although technology advances have satisfied some current and proposed requirements, hardware solutions alone are not sufficient to ensure acceptable system performance and pilot workload. However, human factors data needed to improve the design and use of helicopters lag behind advances in sensor, display, and control technology. Thus, it is difficult for designers to consider human capabilities and limitations when making design decisions. This results in costly accidents, design mistakes, unrealistic mission requirements, excessive training costs, and challenge human adaptability. NASA, in collaboration with DOD, industry, and academia, has initiated a program of research to develop scientific data bases and design principles to improve the pilot/vehicle interface, optimize training time and cost, and maintain pilot workload and system performance at an acceptable level. Work performed at Ames, and by other research laboratories, will be reviewed to summarize the most critical helicopter human factors problems and the results of research that has been performed to: (1) Quantify/model pilots use of visual cues for vehicle control; (2) Improve pilots' performance with helmet displays of thermal imagery and night vision goggles for situation awareness and vehicle control; (3) Model the processes by which pilots encode maps and compare them to the visual scene to develop perceptually and cognitively compatible electronic map formats; (4) Evaluate the use of spatially localized auditory displays for geographical orientation, target localization, radio frequency separation; (5) Develop and flight test control

  20. World helicopter market study

    NASA Technical Reports Server (NTRS)

    Cleary, B.; Pearson, R. W.; Greenwood, S. W.; Kaplan, L.

    1978-01-01

    The extent of the threat to the US helicopter industry posed by a determined effort by foreign manufacturers, European companies in particular, to supply their own domestic markets and also to penetrate export markets, including the USA is assessed. Available data on US and world markets for civil and military uses are collated and presented in both graphic and tabular form showing the past history of production and markets and, where forecasts are available, anticipated future trends. The data are discussed on an item-by-item basis and inferences are drawn in as much depth as appears justified.

  1. Helicopter high gain control

    NASA Technical Reports Server (NTRS)

    Cunningham, T. B.; Nunn, E. C.

    1979-01-01

    High gain control is explored through a design study of the CH-47B helicopter. The plans are designed to obtain the maximum bandwidth possible given the hardware constraints. Controls are designed with modal control theory to specific bandwidths and closed loop mode shapes. Comparisons are made to an earlier complementary filter approach. Bandwidth improvement by removal of limitations is explored in order to establish hardware and mechanization options. Improvements in the pitch axis control system and in the rate gyro sensor noise characteristics in all axes are discussed. The use of rotor state feedback is assessed.

  2. Materials for helicopter gears

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Some of the power train transmission gears in helicopter drive systems can become critical components as performance requirements are increased; accordingly, increasing attention must be paid to new alloys in order to obtain required performance reliability and survivability. Candidate advanced alloys, with improved high temperature properties, while increasing the resistance to scoring and scuffing, tend to have lower ductility and fracture toughness. An attempt is made to identify design materials, and process problems and requirements. In addition, it is recommended that the characterization of candidate steels be accelerated; preliminary investigation indicates that new alloys may provide improved capability against surface distress.

  3. Impact of helicopters on trauma care and clinical results.

    PubMed Central

    Moylan, J A

    1988-01-01

    This report reviews the history of the development of civilian helicopter ambulance program as a component of a total emergency medical services (EMS) system. Current literature demonstrates significant reduction in trauma mortality for those patients transported by air either from the scene of the accident or from an outlying hospital to a trauma center. The primary factor is not the speed of the transport but administration of life-saving care by the helicopter medical crew at the scene of the accident or at the outlying hospital. Regulations have been developed to assure proper patient selection, quality care, safety, and minimization of misuse of this expensive resource. Images Fig. 1. PMID:3058056

  4. Medical helicopters: carbon monoxide risk?

    PubMed

    Poulton, T J

    1987-02-01

    Carbon monoxide exposure of medical personnel working beneath the turning rotor of a medical helicopter appeared to cause mild clinical illness. We measured the carbon monoxide levels found in various locations beneath the rotor of a jet helicopter under two different conditions. Carbon monoxide levels ranged from 8-76 ppm depending on location of sampling and speed of operation of the engine. This level of carbon monoxide is potentially a problem, as is the inhalation of jet fuel vapor, when working beneath the rotors of an operating helicopter.

  5. Helicopter human factors research

    NASA Technical Reports Server (NTRS)

    Nagel, David C.; Hart, Sandra G.

    1988-01-01

    Helicopter flight is among the most demanding of all human-machine integrations. The inherent manual control complexities of rotorcraft are made even more challenging by the small margin for error created in certain operations, such as nap-of-the-Earth (NOE) flight, by the proximity of the terrain. Accident data recount numerous examples of unintended conflict between helicopters and terrain and attest to the perceptual and control difficulties associated with low altitude flight tasks. Ames Research Center, in cooperation with the U.S. Army Aeroflightdynamics Directorate, has initiated an ambitious research program aimed at increasing safety margins for both civilian and military rotorcraft operations. The program is broad, fundamental, and focused on the development of scientific understandings and technological countermeasures. Research being conducted in several areas is reviewed: workload assessment, prediction, and measure validation; development of advanced displays and effective pilot/automation interfaces; identification of visual cues necessary for low-level, low-visibility flight and modeling of visual flight-path control; and pilot training.

  6. Helicopter noise regulations: An industry perspective

    NASA Technical Reports Server (NTRS)

    Wagner, R. A.

    1978-01-01

    A review of helicopter noise measurement programs and noise reduction/economic studies of FAA is given along with a critique of a study which addresses the economic impact of noise reduction on helicopter noise. Modification of several helicopters to reduce noise and demonstrate the economic impact of the application of the current state-of-the-art technology is discussed. Specific helicopters described include Boeing Vertol 347 Helicopter, Hughes OH-6 Helicopter, and Hughes 269C Helicopter. Other topics covered include: (1) noise trends and possible noise limits; (2) accuracy of helicopter noise prediction techniques; (3) limited change possibilities of derivatives; and (4) rotor impulsive noise. The unique operational capabilities of helicopters and the implications relative to noise regulations and certification are discussed.

  7. Handling qualities of a wide-body transport airplane utilizing Pitch Active Control Systems (PACS) for relaxed static stability application

    NASA Technical Reports Server (NTRS)

    Grantham, William D.; Person, Lee H., Jr.; Brown, Philip W.; Becker, Lawrence E.; Hunt, George E.; Rising, J. J.; Davis, W. J.; Willey, C. S.; Weaver, W. A.; Cokeley, R.

    1985-01-01

    Piloted simulation studies have been conducted to evaluate the effectiveness of two pitch active control systems (PACS) on the flying qualities of a wide-body transport airplane when operating at negative static margins. These two pitch active control systems consisted of a simple 'near-term' PACS and a more complex 'advanced' PACS. Eight different flight conditions, representing the entire flight envelope, were evaluated with emphasis on the cruise flight conditions. These studies were made utilizing the Langley Visual/Motion Simulator (VMS) which has six degrees of freedom. The simulation tests indicated that (1) the flying qualities of the baseline aircraft (PACS off) for the cruise and other high-speed flight conditions were unacceptable at center-of-gravity positions aft of the neutral static stability point; (2) within the linear static stability flight envelope, the near-term PACS provided acceptable flying qualities for static stabilty margins to -3 percent; and (3) with the advanced PACS operative, the flying qualities were demonstrated to be good (satisfactory to very acceptable) for static stabilty margins to -20 percent.

  8. Vertebral pain in helicopter pilots

    NASA Technical Reports Server (NTRS)

    Auffret, R.; Delahaye, R. P.; Metges, P. J.; VICENS

    1980-01-01

    Pathological forms of spinal pain engendered by piloting helicopters were clinically studied. Lumbalgia and pathology of the dorsal and cervical spine are discussed along with their clinical and radiological signs and origins.

  9. 77 FR 5425 - Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... Helicopter Textron Canada Limited Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... the Bell Helicopter Textron Canada Limited (BHTC) Model 427 helicopters. This proposed AD is prompted... Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4, telephone (450) 437-2862 or (800)...

  10. The evolution of helicopters

    NASA Astrophysics Data System (ADS)

    Chen, R.; Wen, C. Y.; Lorente, S.; Bejan, A.

    2016-07-01

    Here, we show that during their half-century history, helicopters have been evolving into geometrically similar architectures with surprisingly sharp correlations between dimensions, performance, and body size. For example, proportionalities emerge between body size, engine size, and the fuel load. Furthermore, the engine efficiency increases with the engine size, and the propeller radius is roughly the same as the length scale of the whole body. These trends are in accord with the constructal law, which accounts for the engine efficiency trend and the proportionality between "motor" size and body size in animals and vehicles. These body-size effects are qualitatively the same as those uncovered earlier for the evolution of aircraft. The present study adds to this theoretical body of research the evolutionary design of all technologies [A. Bejan, The Physics of Life: The Evolution of Everything (St. Martin's Press, New York, 2016)].

  11. Some thoughts on the implementation of pilot night vision devices for helicopters

    NASA Technical Reports Server (NTRS)

    Tucker, G. E.

    1984-01-01

    Night vision enhancement devices greatly expand the range and quality of services by extending night operational capabilities. Evolving military tactical concepts for helicopters survivability and battlefield effectiveness necessitate nap-of-the-earth (NOE) flying under both day and night conditions. From a pilot workload standpoint, flying a helicopter NOE in day VFR conditions with minimum clearance between rotors and obstacles is quite demanding. Doing the same job at night is several times more difficult. There are two general categories of night vision devices in operation in helicopter aviation: the Night Vision Goggles (NVG) and forward looking infrared (FLIR) system. The capabilities and limitations of those two devices are discussed.

  12. A new helicostat from SNIAS helicopter division

    NASA Technical Reports Server (NTRS)

    Morisset, J.

    1977-01-01

    The Helicostat was described as a helicopter in which the vehicle weight is nullified by two balloons arranged in a catamaran fashion. Development of such a vehicle is discussed, and various uses for these helicopters are summarized.

  13. 21 CFR 820.140 - Handling.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Handling. 820.140 Section 820.140 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES QUALITY SYSTEM REGULATION Handling, Storage, Distribution, and Installation § 820.140 Handling....

  14. 21 CFR 820.140 - Handling.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Handling. 820.140 Section 820.140 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES QUALITY SYSTEM REGULATION Handling, Storage, Distribution, and Installation § 820.140 Handling....

  15. 21 CFR 820.140 - Handling.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Handling. 820.140 Section 820.140 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES QUALITY SYSTEM REGULATION Handling, Storage, Distribution, and Installation § 820.140 Handling....

  16. Helicopter External Load Acquisition Technology Investigation.

    DTIC Science & Technology

    1980-12-01

    101st Airborne Division, Fort Campbell, Ky. Evergreen Helicopters, McMinnville , Oregon The Army Technical Representative for the program was Mr. Richard...commercial helicopter operator, Evergreen Helicopters, McMinnville , Oregon, to obtain additional data on commercial solutions to external load acquisition

  17. Helicopter Aircrew Training Using Fused Reality

    DTIC Science & Technology

    2006-06-01

    RTO-MP-HFM-136 27 - 1 Helicopter Aircrew Training Using Fused Reality Dr. Ed Bachelder Systems Technology Inc. 13766 Hawthorne Blvd...applied to training helicopter aircrew personnel using a prototype simulator, the Prototype Aircrew Virtual Environment Training (PAVET) System...cabin) pixels using blue screen imaging techniques. This bitmap is overlaid on a virtual environment, and sent Bachelder, E. (2006) Helicopter Aircrew

  18. 29 CFR 1926.551 - Helicopters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... activating device so designed and installed as to prevent inadvertent operation. In addition, these cargo... allowed to approach within 50 feet of the helicopter when the rotor blades are turning. (p) Approaching helicopter. Whenever approaching or leaving a helicopter with blades rotating, all employees shall remain...

  19. 29 CFR 1926.551 - Helicopters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... activating device so designed and installed as to prevent inadvertent operation. In addition, these cargo... allowed to approach within 50 feet of the helicopter when the rotor blades are turning. (p) Approaching helicopter. Whenever approaching or leaving a helicopter with blades rotating, all employees shall remain...

  20. 29 CFR 1926.551 - Helicopters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... activating device so designed and installed as to prevent inadvertent operation. In addition, these cargo... allowed to approach within 50 feet of the helicopter when the rotor blades are turning. (p) Approaching helicopter. Whenever approaching or leaving a helicopter with blades rotating, all employees shall remain...

  1. 29 CFR 1926.551 - Helicopters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... activating device so designed and installed as to prevent inadvertent operation. In addition, these cargo... allowed to approach within 50 feet of the helicopter when the rotor blades are turning. (p) Approaching helicopter. Whenever approaching or leaving a helicopter with blades rotating, all employees shall remain...

  2. 29 CFR 1926.551 - Helicopters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... activating device so designed and installed as to prevent inadvertent operation. In addition, these cargo... allowed to approach within 50 feet of the helicopter when the rotor blades are turning. (p) Approaching helicopter. Whenever approaching or leaving a helicopter with blades rotating, all employees shall remain...

  3. Investigating Flight with a Toy Helicopter

    ERIC Educational Resources Information Center

    Liebl, Michael

    2010-01-01

    Flight fascinates people of all ages. Recent advances in battery technology have extended the capabilities of model airplanes and toy helicopters. For those who have never outgrown a childhood enthusiasm for the wonders of flight, it is possible to buy inexpensive, remotely controlled planes and helicopters. A toy helicopter offers an opportunity…

  4. Method for Studying Helicopter Longitudinal Maneuver Stability

    NASA Technical Reports Server (NTRS)

    Amer, Kenneth B

    1954-01-01

    A theoretical analysis of helicopter maneuver stability is made and the results are compared with experimental results for both a single and a tandem rotor helicopter. Techniques are described for measuring in flight the significant stability derivatives for use with the theory to aid in design studies of means for achieving marginal maneuver stability for a prototype helicopter.

  5. Effects of helicopter transport on red blood cell components

    PubMed Central

    Otani, Taiichi; Oki, Ken-ichi; Akino, Mitsuaki; Tamura, Satoru; Naito, Yuki; Homma, Chihiro; Ikeda, Hisami; Sumita, Shinzou

    2012-01-01

    Background There are no reported studies on whether a helicopter flight affects the quality and shelf-life of red blood cells stored in mannitol-adenine-phosphate. Materials and methods Seven days after donation, five aliquots of red blood cells from five donors were packed into an SS-BOX-110 container which can maintain the temperature inside the container between 2 °C and 6 °C with two frozen coolants. The temperature of an included dummy blood bag was monitored. After the box had been transported in a helicopter for 4 hours, the red blood cells were stored again and their quality evaluated at day 7 (just after the flight), 14, 21 and 42 after donation. Red blood cell quality was evaluated by measuring adenosine triphosphate, 2,3-diphosphoglycerate, and supernatant potassium, as well as haematocrit, intracellular pH, glucose, supernatant haemoglobin, and haemolysis rate at the various time points. Results During the experiment the recorded temperature remained between 2 and 6 °C. All data from the red blood cells that had undergone helicopter transportation were the same as those from a control group of red blood cell samples 7 (just after the flight), 14, 21, and 42 days after the donation. Only supernatant Hb and haemolysis rate 42 days after the donation were slightly increased in the helicopter-transported group of red blood cell samples. All other parameters at 42 days after donation were the same in the two groups of red blood cells. Discussion These results suggest that red blood cells stored in mannitol-adenine-phosphate are not significantly affected by helicopter transportation. The differences in haemolysis by the end of storage were small and probably not of clinical significance. PMID:22153688

  6. Air handling units for hospitals.

    PubMed

    Amoroso, V; Gjestvang, R

    1989-10-01

    Air handling units should provide proper quality and conditioned air to various hospital areas. Unit capacity should be able to meet limited space functionality or load changes as well as any smoke control requirements. System components should be readily accessible and appropriate for spaces served. In summary, engineers should consider the following: Environmental design criteria for area being served Components desired Unit type required Economic issues affecting design. Using this approach, design engineers can design hospital air handling units methodically and logically.

  7. [Back ache in helicopter pilots].

    PubMed

    Colak, S; Jovelić, S; Manojlović, J

    1992-01-01

    Due to low back pain (LBP) and harmful effects of flying, questionnaires were sent to 71 helicopter pilots of the experimental group, 22 mechanics helicopter flyers and to the control group of 28 air-traffic controllers. The prevalence of LBP was the highest in helicopter pilots, then in helicomechanics and air-traffic controllers (53%, 50% and 36%). Effects of exposure to vibration, body posture and working load have not contributed significantly to the occurrence of LBP. LBP has not lead to an important difference in the strength of the back musculature, body mass index and spondylosis, that is, scoliosis. The necessity of further study of LBP and maintaining of specific preventive measures are indicated.

  8. A review of helicopter rotor blade tip shapes

    NASA Astrophysics Data System (ADS)

    Brocklehurst, A.; Barakos, G. N.

    2013-01-01

    A review of helicopter rotor blade tip design technology has been carried out with a view to undertaking subsequent computations to evaluate the performance of new tip designs. The review starts by briefly looking at (fixed) wing tip design concepts and the underlying fluid mechanics on which they are based in order to see if there is any carry-over of ideas on which improved tip design concepts might be based. Then, rotor blade tip shapes that have been used, or suggested for use, on past and present rotorcraft are examined to obtain a better understanding of the helicopter tip design problem. In parallel, the review traces the development of analysis tools to evaluate the performance of the rotor and blade tip design. It is clear that in the past, the designer relied heavily on classical aerodynamic knowledge, supplemented by experience and intuition, supported by wind tunnel and model rotor testing, and relatively low-order aerodynamic calculations. New rotor designs were, and still are the subject of intensive flight test verification. However, recent development of Computational Fluid Dynamics (CFD) now offers an opportunity to accurately predict the viscous, compressible flow-field in the tip region, and thus predict the performance of new rotor and tip designs, provided that the solver has adequate resolution, is able to handle all aspects of the helicopter problem, and sufficient computational resources are available to complete the design in a practical time-scale.

  9. Annoyance of helicopter impulsive noise

    NASA Technical Reports Server (NTRS)

    Dambra, F.; Damongeot, A.

    1978-01-01

    Psychoacoustic studies of helicopter impulsive noise were conducted in order to qualify additional annoyance due to this feature and to develop physical impulsiveness descriptors to develop impulsivity correction methods. The currently proposed descriptors and methods of impulsiveness correction are compared using a multilinear regression analysis technique. It is shown that the presently recommended descriptor and correction method provides the best correlation with the subjective evaluations of real helicopter impulsive noises. The equipment necessary for data processing in order to apply the correction method is discussed.

  10. The helicopter - some ergonomic factors.

    PubMed

    Lovesey, E J

    1975-09-01

    Helicopter pilots are some of the hardest working human operators, because of the machine's inherant instability and control problems. This article covers some aspects where ergonomists might help to improve the overall system. After considering basic differences between helicopters and fixed wing aircraft, the author examines controls, where there are prospects of using miniature hand levers; cockpit vision and displays with particular reference to night and instrument flying; seating and vibration where the effects of protective clothing and harnesses are considered; and cabin noise from the engine, transmission and intercom systems. Finally, he assesses pilot activity using cine film techniques for different types of flight.

  11. Development of the remote-handled transuranic waste radioassay data quality objectives. An evaluation of RH-TRU waste inventories, characteristics, radioassay methods and capabilities

    SciTech Connect

    Meeks, A.M.; Chapman, J.A.

    1997-09-01

    The Waste Isolation Pilot Plant will accept remote-handled transuranic waste as early as October of 2001. Several tasks must be accomplished to meet this schedule, one of which is the development of Data Quality Objectives (DQOs) and corresponding Quality Assurance Objectives (QAOs) for the assay of radioisotopes in RH-TRU waste. Oak Ridge National Laboratory (ORNL) was assigned the task of providing to the DOE QAO, information necessary to aide in the development of DQOs for the radioassay of RH-TRU waste. Consistent with the DQO process, information needed and presented in this report includes: identification of RH-TRU generator site radionuclide data that may have potential significance to the performance of the WIPP repository or transportation requirements; evaluation of existing methods to measure the identified isotopic and quantitative radionuclide data; evaluation of existing data as a function of site waste streams using documented site information on fuel burnup, radioisotope processing and reprocessing, special research and development activities, measurement collection efforts, and acceptable knowledge; and the current status of technologies and capabilities at site facilities for the identification and assay of radionuclides in RH-TRU waste streams. This report is intended to provide guidance in developing the RH-TRU waste radioassay DQOs, first by establishing a baseline from which to work, second, by identifying needs to fill in the gaps between what is known and achievable today and that which will be required before DQOs can be formulated, and third, by recommending measures that should be taken to assure that the DQOs in fact balance risk and cost with an achievable degree of certainty.

  12. 78 FR 27867 - Airworthiness Directives; MD Helicopters Inc. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-13

    ..., leading to vibration, loss of tail rotor pitch control, and subsequent loss of tail rotor and helicopter... from cracking and separating from the blade, leading to an unbalanced condition, vibration, loss of...) separating from the tail rotor blade, leading to an unbalanced condition, vibration, loss of tail rotor...

  13. 78 FR 65180 - Airworthiness Directives; MD Helicopters, Inc., Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... actions are intended to prevent a pitch horn from cracking, leading to vibration, loss of tail rotor pitch... condition, vibration, loss of tail rotor pitch control, and loss of directional control of the helicopter... (pitch horn) separating from the tail rotor blade, leading to an unbalanced condition, vibration, loss...

  14. 78 FR 65195 - Airworthiness Directives; MD Helicopters, Inc. (MDHI) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... rotor blade (MRB) retention bolts (bolts) installed. This AD requires a daily check of the position of... other helicopters of the same type designs and that air safety and the public interest require adopting... (ASB SB900-116). ASB SB900-116 specifies a repetitive check of the blade retention bolts, part...

  15. 77 FR 23638 - Airworthiness Directives; Bell Helicopter Textron, Incorporated Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-20

    ..., and the AD ] applicability needs to be expanded to include additional grips similar in design, as well... rotor blade, and subsequent loss of control of the helicopter. DATES: We must receive comments on this... damage to the blade, blade bolt bore, or buffer pad tang surface were found in the two cracked...

  16. 77 FR 5427 - Airworthiness Directives; Bell Helicopter Textron, Inc., Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... creating a component history card or equivalent record and begin counting and recording the number of... Internet at http://www.regulations.gov or in person at the Docket Operations Office between 9 a.m. and 5 p... for the specified Bell model helicopters. This proposal would require creating a component...

  17. 77 FR 68055 - Airworthiness Directives; Bell Helicopter Textron Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ..., and 412CF helicopters. This AD requires a repetitive inspection of the collective lever for a crack, and if there is a crack, before further flight, replacing the collective lever with an airworthy... to detect a crack in the collective lever, which could lead to failure of the collective lever...

  18. 78 FR 18224 - Airworthiness Directives; Robinson Helicopter Company Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2012-1088; Directorate Identifier 2012-SW...): 2013-05-15 Robinson Helicopter Company: Amendment 39-17387; Docket No. FAA-2012-1088;...

  19. 78 FR 1730 - Airworthiness Directives; Bell Helicopter Textron Inc. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... 205A, 205A-1, and 205B helicopters with certain starter/generator power cable assemblies (power cable assemblies). This AD requires replacing the power cable assemblies and their associated parts, and performing continuity readings. This AD was prompted by the determination that the power cable assembly...

  20. 77 FR 729 - Airworthiness Directives; Enstrom Helicopter Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... certain trim relays to require modifying and testing the lateral and longitudinal cyclic trim actuator..., and 480B helicopters with a trim relay, part-number (P/N) KUP14D55-472, M83536/10-015M, or M83536/10...) and flight tests to determine that the trim relay is working correctly. This AD was prompted...

  1. [An ambulance helicopter in Jamtland. A survival necessity in a county of tourism].

    PubMed

    Ek, B; Zetterström, H

    2000-03-22

    The county of Jämtland is a sparsely populated area in which an ambulance-helicopter has been in use since the middle of the 1970's. A prospective study was undertaken during a six month period with the aim of evaluating the benefits of the helicopter as compared with the use of road-ambulance transport alone. Total number of patients involved was n = 249. Both flight nurses and receiving doctors found that in most cases, patients transported by helicopter manned with a flight nurse were given higher quality care. A follow-up study by specialists from the receiving departments confirmed that for 3% (n = 8), transport by ambulance-helicopter resulted in "probably better prognosis", and that for 2% (n = 6) the result was "lifesaving".

  2. Maximizing commonality between military and general aviation fly-by-light helicopter system designs

    NASA Astrophysics Data System (ADS)

    Enns, Russell; Mossman, David C.

    1995-05-01

    In the face of shrinking defense budgets, survival of the United States rotorcraft industry is becoming increasingly dependent on increased sales in a highly competitive civil helicopter market. As a result, only the most competitive rotorcraft manufacturers are likely to survive. A key ingredient in improving our competitive position is the ability to produce more versatile, high performance, high quality, and low cost of ownership helicopters. Fiber optic technology offers a path of achieving these objectives. Also, adopting common components and architectures for different helicopter models (while maintaining each models' uniqueness) will further decrease design and production costs. Funds saved (or generated) by exploiting this commonality can be applied to R&D used to further improve the product. In this paper, we define a fiber optics based avionics architecture which provides the pilot a fly-by-light / digital flight control system which can be implemented in both civilian and military helicopters. We then discuss the advantages of such an architecture.

  3. Helicopter Toy and Lift Estimation

    ERIC Educational Resources Information Center

    Shakerin, Said

    2013-01-01

    A $1 plastic helicopter toy (called a Wacky Whirler) can be used to demonstrate lift. Students can make basic measurements of the toy, use reasonable assumptions and, with the lift formula, estimate the lift, and verify that it is sufficient to overcome the toy's weight. (Contains 1 figure.)

  4. 78 FR 47531 - Airworthiness Directives; Various Restricted Category Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-06

    ... State University); Firefly Aviation Helicopter Services (previously Erickson Air-Crane Co.); California... State University); Firefly Aviation Helicopter Services (previously Erickson Air-Crane Co.); California... Falcon Exporters, Inc. (previously Utah State University); Firefly Aviation Helicopter...

  5. 77 FR 44434 - Airworthiness Directives; Various Restricted Category Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... State University); Firefly Aviation Helicopter Services (previously Erickson Air-Crane Co.); California... apply to Arrow Falcon Exporters, Inc. (previously Utah State University); Firefly Aviation Helicopter... Arrow Falcon Exporters, Inc. (previously Utah State University); Firefly Aviation Helicopter...

  6. 78 FR 54792 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... (Eurocopter) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Model EC225 LP helicopters. This proposed AD would add a new operating limitation that would require increasing the minimum density altitude flight limitation for helicopters without certain...

  7. Optimal landing of a helicopter in autorotation

    NASA Technical Reports Server (NTRS)

    Lee, A. Y. N.

    1985-01-01

    Gliding descent in autorotation is a maneuver used by helicopter pilots in case of engine failure. The landing of a helicopter in autorotation is formulated as a nonlinear optimal control problem. The OH-58A helicopter was used. Helicopter vertical and horizontal velocities, vertical and horizontal displacement, and the rotor angle speed were modeled. An empirical approximation for the induced veloctiy in the vortex-ring state were provided. The cost function of the optimal control problem is a weighted sum of the squared horizontal and vertical components of the helicopter velocity at touchdown. Optimal trajectories are calculated for entry conditions well within the horizontal-vertical restriction curve, with the helicopter initially in hover or forwared flight. The resultant two-point boundary value problem with path equality constraints was successfully solved using the Sequential Gradient Restoration Technique.

  8. Model predictive formation control of helicopter systems

    NASA Astrophysics Data System (ADS)

    Saffarian, Mehdi

    In this thesis, a robust formation control framework for formation control of a group of helicopters is proposed and designed. The dynamic model of the helicopter has been developed and verified through simulations. The control framework is constructed using two main control schemes for navigation of a helicopter group in three-dimensional (3D) environments. Two schemes are designed to maintain the position of one helicopter with respect to one or two other neighboring members, respectively. The developed parameters can uniquely define the position of the helicopters with respect to each other and can be used for any other aerial and under water vehicles such as airplanes, spacecrafts and submarines. Also, since this approach is modular, it is possible to use it for desired number and form of the group helicopters. Using the defined control parameters, two decentralized controllers are designed based on Nonlinear Model Predictive Control (NMPC) algorithm technique. The framework performance has been tested through simulation of different formation scenarios.

  9. 76 FR 66609 - Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model 407 and 427 Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-27

    ... Textron Canada (Bell) Model 407 and 427 Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION... the service information identified in this AD from Bell Helicopter Textron Canada Limited, 12,800 Rue... the helicopter. Transport Canada, the airworthiness authority for Canada, notified the FAA that...

  10. 78 FR 23688 - Airworthiness Directives; Bell Helicopter Textron Canada Inc. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-22

    ... Textron Canada Inc. Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... Bell Helicopter Textron Canada Inc. (BHT) Model 206A, 206B, and 206L helicopters. This proposed AD... Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4; telephone (450) 437-2862 or (800)...

  11. Documenting helicopter operations from an energy standpoint

    NASA Technical Reports Server (NTRS)

    Davis, S. J.; Stepniewski, W. Z.

    1974-01-01

    Results are presented of a study of the relative and absolute energy consumption of helicopters, including limited comparisons with fixed-wing aircraft, and selected surface transportation vehicles. Additional comparisons were made to determine the level of reduction in energy consumption expected from the application of advanced technologies to the helicopter design and sizing process. It was found that improvements in helicopter consumption characteristics can be accomplished through the utilization of advanced technology to reduce drag, structures weight, and powerplant fuel consumption.

  12. Research On The CH-47B Helicopter

    NASA Technical Reports Server (NTRS)

    Hilbert, Kathryn B.; Tucker, George E.; Chen, Robert T. N.; Fry, Emmett B.; Hindson, William S.

    1988-01-01

    Report describes equipment added to, and research capabilities of CH-47B helicopter. Programmable symbol generator provides display formats for variety of missions - those of vertical-takeoff-and-landing aircraft and helicopters. Powerful general-purpose flight computer in operation. Computer programmable in high-level languages and supports research more efficiently. Flight-control software developed to improve capability of helicopter to perform simulations in flight.

  13. Portable-Beacon Landing System for Helicopters

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Clary, George R.; Chisholm, John P.; Macdonald, Stanley L.

    1987-01-01

    Prototype beacon landing system (BLS) allows helicopters to make precise landings in all weather. BLS easily added to existing helicopter avionic equipment and readily deployed at remote sites. Small and light, system employs X-band radar and digital processing. Variety of beams pulsed sequentially by ground station after initial interrogation by weather radar of approaching helicopter. Airborne microprocessor processes pulses to determine glide slope, course deviation, and range.

  14. Assessment of worm gearing for helicopter transmissions

    NASA Technical Reports Server (NTRS)

    Chaiko, Lev

    1990-01-01

    A high-efficiency hydrostatic worm gear drive for helicopter transmissions is assessed. The example given is for a large cargo helicopter with three 4000-kW engines and transmission reduction ratio of 110. Also contained are: an efficiency calculation, a description of the test stand for evaluating the feasibility of worm gear hydrostatic mesh, a weight calculation, and a comparison with conventional helicopter transmissions of the same power and transmission reduction ratio.

  15. MUOS: Application in Naval Helicopter Operations

    DTIC Science & Technology

    2015-03-01

    frequency HSC Helicopter Sea Combat Squadron HSL Helicopter Anti-Submarine Squadron Light HSM Helicopter Strike Maritime Squadron ISAR inverse ...using the AN/APS 147 Inverse Synthetic Aperture Radar (ISAR), which gives the aircraft the ability to identify tracks based solely on radar data. The...footprint of the satellite (see Figure 12). Each beam is like a cell tower that covers approximately 600 square miles of earth (Buck & Russ, 2007). Using a

  16. Measurement and Characterization of Helicopter Noise in Steady-State and Maneuvering Flight

    NASA Technical Reports Server (NTRS)

    Schmitz, Fredric H.; Greenwood, Eric; Sickenberger, Richard D.; Gopalan, Gaurav; Sim, Ben Well-C; Conner, David; Moralez, Ernesto; Decker, William A.

    2007-01-01

    A special acoustic flight test program was performed on the Bell 206B helicopter outfitted with an in-flight microphone boom/array attached to the helicopter while simultaneous acoustic measurements were made using a linear ground array of microphones arranged to be perpendicular to the flight path. Air and ground noise measurements were made in steady-state longitudinal and steady turning flight, and during selected dynamic maneuvers. Special instrumentation, including direct measurement of the helicopter s longitudinal tip-path-plane (TPP) angle, Differential Global Positioning System (DGPS) and Inertial Navigation Unit (INU) measurements, and a pursuit guidance display were used to measure important noise controlling parameters and to make the task of flying precise operating conditions and flight track easier for the pilot. Special care was also made to test only in very low winds. The resulting acoustic data is of relatively high quality and shows the value of carefully monitoring and controlling the helicopter s performance state. This paper has shown experimentally, that microphones close to the helicopter can be used to estimate the specific noise sources that radiate to the far field, if the microphones are positioned correctly relative to the noise source. Directivity patterns for steady, turning flight were also developed, for the first time, and connected to the turning performance of the helicopter. Some of the acoustic benefits of combining normally separated flight segments (i.e. an accelerated segment and a descending segment) were also demonstrated.

  17. Advanced Control System Increases Helicopter Safety

    NASA Technical Reports Server (NTRS)

    2008-01-01

    With support and funding from a Phase II NASA SBIR project from Ames Research Center, Hoh Aeronautics Inc. (HAI), of Lomita, California, produced HeliSAS, a low-cost, lightweight, attitude-command-attitude-hold stability augmentation system (SAS) for civil helicopters and unmanned aerial vehicles. HeliSAS proved itself in over 160 hours of flight testing and demonstrations in a Robinson R44 Raven helicopter, a commercial helicopter popular with news broadcasting and police operations. Chelton Flight Systems, of Boise, Idaho, negotiated with HAI to develop, market, and manufacture HeliSAS, now available as the Chelton HeliSAS Digital Helicopter Autopilot.

  18. Transportation and handling loads

    NASA Technical Reports Server (NTRS)

    Ostrem, F. E.

    1971-01-01

    Criteria and recommended practices are presented for the prediction and verification of transportation and handling loads for the space vehicle structure and for monitoring these loads during transportation and handling of the vehicle or major vehicle segments. Elements of the transportation and handling systems, and the forcing functions and associated loads are described. The forcing functions for common carriers and typical handling devices are assessed, and emphasis is given to the assessment of loads at the points where the space vehicle is supported during transportation and handling. Factors which must be considered when predicting the loads include the transportation and handling medium; type of handling fixture; transport vehicle speed; types of terrain; weather (changes in pressure of temperature, wind, etc.); and dynamics of the transportation modes or handling devices (acceleration, deceleration, and rotations of the transporter or handling device).

  19. Control of helicopter rotorblade aerodynamics

    NASA Technical Reports Server (NTRS)

    Fabunmi, James A.

    1991-01-01

    The results of a feasibility study of a method for controlling the aerodynamics of helicopter rotorblades using stacks of piezoelectric ceramic plates are presented. A resonant mechanism is proposed for the amplification of the displacements produced by the stack. This motion is then converted into linear displacement for the actuation of the servoflap of the blades. A design which emulates the actuation of the servoflap on the Kaman SH-2F is used to demonstrate the fact that such a system can be designed to produce the necessary forces and velocities needed to control the aerodynamics of the rotorblades of such a helicopter. Estimates of the electrical power requirements are also presented. A Small Business Innovation Research (SBIR) Phase 2 Program is suggested, whereby a bench-top prototype of the device can be built and tested. A collaborative effort between AEDAR Corporation and Kaman Aerospace Corporation is anticipated for future effort on this project.

  20. Lytic spondylolisthesis in helicopter pilots.

    PubMed

    Froom, P; Froom, J; Van Dyk, D; Caine, Y; Ribak, J; Margaliot, S; Floman, Y

    1984-06-01

    Trauma to the back from the force of chronic stress is thought to be an etiologic factor in isthmic spondylolisthesis (SLL). The relationship of first degree spondylolisthesis to low back pain (LBP) is controversial. We compare the prevalence of SLL in helicopter pilots who are subject to strong vibrational forces, with other airforce personnel. Helicopter pilots had more than a four times higher prevalence of SLL (4.5%) than did cadets (1.0%) and transport pilots (0.9%). Low back pain was more frequent in pilots with SLL than in those without this lesion but in no case was the pain disabling or the defect progressive. We conclude that SLL may be induced by vibrational forces and although SLL is associated with LBP, the pain was little clinical significance.

  1. Mechanical chest compression: an alternative in helicopter emergency medical services?

    PubMed

    Gässler, Holger; Kümmerle, Simone; Ventzke, Marc-Michael; Lampl, Lorenz; Helm, Matthias

    2015-09-01

    Mechanical chest compression devices are mentioned in the current guidelines of the European Resuscitation Council (ERC) as an alternative in long-lasting cardiopulmonary resuscitations (CPR) or during transport with ongoing CPR. We compared manual chest compression with mechanical devices in a rescue-helicopter-based scenario using a resuscitation manikin. Manual chest compression was compared with the mechanical devices LUCAS™ 2, AutoPulse™ and animax mono (10 series each) using the resuscitation manikin AmbuMan MegaCode Wireless, which was intubated endotracheally and controlled ventilated during the entire scenario. The scenario comprised the installation of each device, transport and loading phases, as well as a 10-min phase inside the helicopter (type BK 117). We investigated practicability as well as measured compression quality. All mechanical devices could be used readily in a BK 117 helicopter. The LUCAS 2 group was the only one that fulfilled all recommendations of the ERC (frequency 102 ± 0.1 min(-1), compression depth 54 ± 3 mm, hands-off time 2.5 ± 1.6 %). Performing adequate manual chest compression was barely possible (fraction of correct compressions 21 ± 15 %). In all four groups, the total hands-off time was <10 %. Performing manual chest compressions during rescue-helicopter transport is barely possible, and only of poor quality. If rescuers are experienced, mechanical chest compression devices could be good alternatives in this situation. We found that the LUCAS 2 system complied with all recommendations of ERC guidelines, and all three tested devices worked consistently during the entire scenario.

  2. Helicopter tail rotor noise analyses

    NASA Technical Reports Server (NTRS)

    George, A. R.; Chou, S. T.

    1986-01-01

    A study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infinite span cutting through a moving vortex. The vortex and the geometry information required by the analyses are obtained through a free wake geometry analysis of the main rotor. The acoustic pressure-time histories for the tail rotor blade-vortex interactions are then calculated. These acoustic results are compared to tail rotor loading and thickness noise, and are found to be significant to the overall tail rotor noise generation. Under most helicopter operating conditions, large acoustic pressure fluctuations can be generated due to a series of skewed main rotor tip vortices passing through the tail rotor disk. The noise generation depends strongly upon the helicopter operating conditions and the location of the tail rotor relative to the main rotor.

  3. Pneumatic boot for helicopter rotor deicing

    NASA Technical Reports Server (NTRS)

    Blaha, B. J.; Evanich, P. L.

    1981-01-01

    Pneumatic deicer boots for helicopter rotor blades were tested. The tests were conducted in the 6 by 9 ft icing research tunnel on a stationary section of a UH-IH helicopter main rotor blade. The boots were effective in removing ice and in reducing aerodynamic drag due to ice.

  4. Study of Helicopter Roll Control Effectiveness Criteria.

    DTIC Science & Technology

    1986-04-01

    variety of helicopter configurations and control system types , and a wide range of flight tasks and maneuvers. The basis of the experimental design...represent a wide range of basic helicopter rotor hub and airframe designs and flight control system types . It was intended to generally limit

  5. Neural Network Based Helicopter Low Airspeed Indicator

    DTIC Science & Technology

    1996-10-24

    This invention relates generally to virtual sensors and, more particularly, to a means and method utilizing a neural network for estimating...helicopter airspeed at speeds below about 50 knots using only fixed system parameters (i.e., parameters measured or determined in a reference frame fixed relative to the helicopter fuselage) as inputs to the neural network .

  6. 46 CFR 109.577 - Helicopter fueling.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.577 Helicopter fueling. (a) The master or person in charge shall designate persons...

  7. 46 CFR 109.577 - Helicopter fueling.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.577 Helicopter fueling. (a) The master or person in charge shall designate persons...

  8. 46 CFR 109.577 - Helicopter fueling.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.577 Helicopter fueling. (a) The master or person in charge shall designate persons...

  9. 46 CFR 109.577 - Helicopter fueling.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.577 Helicopter fueling. (a) The master or person in charge shall designate persons...

  10. 46 CFR 109.577 - Helicopter fueling.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.577 Helicopter fueling. (a) The master or person in charge shall designate persons...

  11. Note on Hovering Turns with Tandem Helicopters

    NASA Technical Reports Server (NTRS)

    Reeder, John P; Tapscott, Robert J

    1955-01-01

    The source of an appreciable pitching-moment difference between left and right hovering turns for a tandem helicopter is described. The difference in pitching moment results from the difference in rotational speed of the counter rotating rotors with respect to the air while the helicopter is turning.

  12. NASA helicopter transmission system technology program

    NASA Technical Reports Server (NTRS)

    Zaretsky, E. V.

    1983-01-01

    The purpose of the NASA Helicopter Transmission System Technology Program is to improve specific mechanical components and the technology for combining these into advanced drive systems to make helicopters more viable and cost competitive for commerical applications. The history, goals, and elements of the program are discussed.

  13. Helicopter Operations and Personnel Safety (Helirescue Manual). Fourth Edition.

    ERIC Educational Resources Information Center

    Dalle-Molle, John

    The illustrated manual includes information on various aspects of helicopter rescue missions, including mission management roles for key personnel, safety rules around helicopters, requests for helicopter support, sample military air support forms, selection of landing zones, helicopter evacuations, rescuer delivery, passenger unloading, crash…

  14. Simulation and control of a helicopter operating in a ship airwake

    NASA Astrophysics Data System (ADS)

    Lee, Dooyong

    designed to simulate the gusts when driven by white noise. It is proposed that the stochastic gust model can be used to optimize the automatic flight control system in order to improve disturbance rejection properties of the aircraft. A stability augmentation system (SAS) is optimized for a UH-60 helicopter operating in the turbulent ship airwake. For disturbance rejection, a new performance specification is designed based on the power spectral density of the transfer function from the gust inputs to aircraft rate responses. The baseline limited authority SAS is modified and optimized using CONDUIT (Control Designer's Unified Interface) in order to improve handling-qualities and stability, and to minimize a weighted objective of gust responses. In addition, a Hinfinity controller is designed to provide an alternative SAS configuration. The optimized SAS and H infinity SAS are then tested using the non-linear simulation model with time-varying airwake. Time domain and frequency domain analyses of the simulation show that the modified SAS results in significant reduction of pilot workload.

  15. The Helicopter Antenna Radiation Prediction Code (HARP)

    NASA Technical Reports Server (NTRS)

    Klevenow, F. T.; Lynch, B. G.; Newman, E. H.; Rojas, R. G.; Scheick, J. T.; Shamansky, H. T.; Sze, K. Y.

    1990-01-01

    The first nine months effort in the development of a user oriented computer code, referred to as the HARP code, for analyzing the radiation from helicopter antennas is described. The HARP code uses modern computer graphics to aid in the description and display of the helicopter geometry. At low frequencies the helicopter is modeled by polygonal plates, and the method of moments is used to compute the desired patterns. At high frequencies the helicopter is modeled by a composite ellipsoid and flat plates, and computations are made using the geometrical theory of diffraction. The HARP code will provide a user friendly interface, employing modern computer graphics, to aid the user to describe the helicopter geometry, select the method of computation, construct the desired high or low frequency model, and display the results.

  16. 7 CFR 996.4 - Handle.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE MINIMUM QUALITY AND HANDLING STANDARDS FOR... consumption channels of commerce: Provided, That this term does not include sales or deliveries of peanuts...

  17. 7 CFR 996.4 - Handle.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE MINIMUM QUALITY AND HANDLING STANDARDS FOR... consumption channels of commerce: Provided, That this term does not include sales or deliveries of peanuts...

  18. 7 CFR 996.4 - Handle.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE MINIMUM QUALITY AND HANDLING STANDARDS FOR... consumption channels of commerce: Provided, That this term does not include sales or deliveries of peanuts...

  19. 7 CFR 996.4 - Handle.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE MINIMUM QUALITY AND HANDLING STANDARDS FOR... consumption channels of commerce: Provided, That this term does not include sales or deliveries of peanuts...

  20. The impact of urban operations on helicopter noise requirements

    NASA Technical Reports Server (NTRS)

    Spector, S. R.

    1978-01-01

    The interrelationship of urban helicopter operations, helicopter noise, and the establishment of urban public-use heliports is discussed. Public resistance to urban helicopter operations due to concern for safety and noise is shown to negatively impact the establishment of public-use heliports in urban centers. It is indicated that increased government and industry effort to reduce helicopter noise is needed to ensure continued growth in the helicopter industry.

  1. Helicopter flight control compensator design

    NASA Astrophysics Data System (ADS)

    Yaici, Malika; Hariche, Kamel; Clarke, Tim

    2017-01-01

    In a precedent paper a design process is described to achieve eigenstructure assignment using block poles. Systems described in state space equations are transformed to systems in matrix fractions description (MFD) and its desired eigenstructure is transformed to a desired latent structure, which is used to construct desired block poles. In this paper, the proposed design method is applied for attitude stabilization of a Lynx helicopter in hover. An input-output feedback configuration has been chosen for more generality, and to validate the results the output responses are compared to state and output feedback control responses.

  2. Special opportunities in helicopter aerodynamics

    NASA Technical Reports Server (NTRS)

    Mccroskey, W. J.

    1983-01-01

    Aerodynamic research relating to modern helicopters includes the study of three dimensional, unsteady, nonlinear flow fields. A selective review is made of some of the phenomenon that hamper the development of satisfactory engineering prediction techniques, but which provides a rich source of research opportunities: flow separations, compressibility effects, complex vortical wakes, and aerodynamic interference between components. Several examples of work in progress are given, including dynamic stall alleviation, the development of computational methods for transonic flow, rotor-wake predictions, and blade-vortex interactions.

  3. Wind tunnel investigation of helicopter-rotor wake effects on three helicopter fuselage models

    NASA Technical Reports Server (NTRS)

    Wilson, J. C.; Mineck, R. E.

    1975-01-01

    The effects of rotor wake on helicopter fuselage aerodynamic characteristics were investigated in the Langley V/STOL tunnel. Force, moment, and pressure data were obtained on three fuselage models at various combinations of windspeed, sideslip angle, and pitch angle. The data show that the influence of rotor wake on the helicopter fuselage yawing moment imposes a significant additional thrust requirement on the tail rotor of a single-rotor helicopter at high sideslip angles.

  4. Initial Results of Instrument-Flying Trials Conducted In A Single-Rotor Helicopter

    NASA Technical Reports Server (NTRS)

    Crim, Almer D; Reeder, John P; Whitten, James B

    1953-01-01

    Instrument-flying trials have been conducted in a single-rotor helicopter, the maneuver stability of which could be changed from satisfactory to unsatisfactory. The results indicated that existing longitudinal flying-qualities requirements based on contact flight were adequate for instrument flight at speeds above that for minimum power. However, lateral-directional problems were encountered at low speeds and during precision maneuvers. The adequacy, for helicopter use, of standard airplane instruments was also investigated, and the conclusion was reached that special instruments would be desirable under all conditions, and necessary for sustained low-speed instrument flight.

  5. What's Cookin' With Helicopter Microwave Landing Systems?

    NASA Technical Reports Server (NTRS)

    Taylor, Richard L.

    1980-01-01

    This article describes a joint effort of the FAA, NASA and the Helicopter Industry to establish a data base for (Microwave Landing Systems) MLS approaches, and to aid the FAA in developing the MLS Terminal Instrument Procedures (TERPS) criteria for rotary-wing IFR operations. The latter is of particular importance for it appears to signal sincere official interest in filling in the blanks in Chapter 11 of TERPS -- that portion set aside for helicopter IFR operations and recognition of the unique capabilities of the helicopter in the instrument environment. One of the program objectives is to find out what a sample of pilots can do with the MLS in a minimum machine.

  6. An introduction to the physical aspects of helicopter stability

    NASA Technical Reports Server (NTRS)

    Gessow, Alfred; Amer, Kenneth B

    1950-01-01

    In order to provide engineers interested in rotating-wing aircraft, but with no specialized training in stability theory, some understanding of the factors that influence the flying qualities of the helicopter, an explanation is made of both the static stability and the stick-fixed oscillation in hovering and forward flight in terms of fundamental physical quantities. Three significant stability factors -- static stability with angle of attack, static stability with speed, and damping due to a pitching or rolling velocity -- are explained in detail.

  7. Dynamics Control Approaches to Improve Vibratory Environment of the Helicopter Aircrew

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, Viresh Kanchana

    Although helicopter has become a versatile mode of aerial transportation, high vibration levels leads to poor ride quality for its passengers and aircrew. Undesired vibration transmitted through the helicopter seats have been known to cause fatigue and discomfort to the aircrew in the short-term as well as neck strain and back pain injuries due to long-term exposure. This research study investigated the use of novel active as well as passive methodologies integrated in helicopter seats to mitigate the aircrew exposure to high vibration levels. Due to significantly less certification effort required to modify the helicopter seat structure, application of novel technologies to the seat is more practical compared to flight critical components such as the main rotor to reduce aircrew vibration. In particular, this research effort developed a novel adaptive seat mount approach based on active vibration control technology. This novel design that incorporated two stacked piezoelectric actuators as active struts increases the bending stiffness to avoid the low frequency resonance while generating forces to counteract higher harmonic vibration peaks. A real-time controller implemented using a feed-forward algorithm based on adaptive notches counteracted the forced vibration peaks while a robust feedback control algorithm suppressed the resonance modes. The effectiveness of the adaptive seat mount system was demonstrated through extensive closed-loop control tests on a full-scale helicopter seat using representative helicopter floor vibration profiles. Test results concluded that the proposed adaptive seat mount approach based on active control technology is a viable solution for the helicopter seat vibration control application. In addition, a unique flight test using a Bell-412 helicopter demonstrated that the aircrew is exposed to high levels of vibration during flight and that the whole body vibration spectrum varied substantially depending on operating conditions as

  8. Transonic Aeroelasticity Analysis For Helicopter Rotor Blade

    NASA Technical Reports Server (NTRS)

    Chang, I-Chung; Gea, Lie-Mine; Chow, Chuen-Yen

    1991-01-01

    Numerical-simulation method for aeroelasticity analysis of helicopter rotor blade combines established techniques for analysis of aerodynamics and vibrations of blade. Application of method clearly shows elasticity of blade modifies flow and, consequently, aerodynamic loads on blade.

  9. Small crack test program for helicopter materials

    NASA Technical Reports Server (NTRS)

    Annigeri, Bal; Schneider, George

    1994-01-01

    Crack propagation tests were conducted to determine crack growth behavior in five helicopter materials for surface cracks between 0.005 to 0.020 inches in depth. Constant amplitude tests were conducted at stress ratios R equals 0.1 and 0.5, and emphasis was placed on near threshold data (i.e., 10-8 to 10-6 inches/cycle). Spectrum tests were conducted using a helicopter spectrum. The test specimen was an unnotched tension specimen, and cracks were initiated from a small EDM notch. An optical/video system was used to monitor crack growth. The material for the test specimens was obtained from helicopter part forgings. Testing was conducted at stresses below yield to reflect actual stresses in helicopter parts.

  10. 14 CFR 93.103 - Helicopter operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Orient Point, shall utilize the North Shore Helicopter route and altitude, as published. (b) Pilots may deviate from the route and altitude requirements of paragraph (a) of this section when necessary...

  11. 14 CFR 93.103 - Helicopter operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Orient Point, shall utilize the North Shore Helicopter route and altitude, as published. (b) Pilots may deviate from the route and altitude requirements of paragraph (a) of this section when necessary...

  12. Data Handling and Citizenship

    ERIC Educational Resources Information Center

    Tresidder, Gwen

    2006-01-01

    When marking GCSE data handling coursework, the author was repeatedly reminded just how poor the level of statistical understanding is among students. In response to a feeling that the teaching of handling data topics was limited, the author and her colleague designed a project with Y8 students to try to teach statistics for a deeper…

  13. Civil helicopter design and operational requirement

    NASA Technical Reports Server (NTRS)

    Waters, K. T.

    1978-01-01

    Design and operational requirements and other factors that have a restraining influence on expansion of the helicopter market are discussed. The needs of operators, users, pilots and the community at large are examined. The impact of future technology developments and other trends such as use, energy shortages, and civil and military helicopter requirements and development is assessed. Areas where research and development are needed to provide opportunities for lowering life cycle costs and removing barriers to further expansion of the industry are analyzed.

  14. Helicopter training simulators: Key market factors

    NASA Technical Reports Server (NTRS)

    Mcintosh, John

    1992-01-01

    Simulators will gain an increasingly important role in training helicopter pilots only if the simulators are of sufficient fidelity to provide positive transfer of skills to the aircraft. This must be done within an economic model of return on investment. Although rotor pilot demand is still only a small percentage of overall pilot requirements, it will grow in significance. This presentation described the salient factors influencing the use of helicopter training simulators.

  15. The effective acoustic environment of helicopter crewmen

    NASA Technical Reports Server (NTRS)

    Camp, R. T., Jr.; Mozo, B. T.

    1978-01-01

    Methods of measuring the composite acoustic environment of helicopters in order to quantify the effective acoustic environment of the crewmen and to assess the real acoustic hazards of the personnel are examined. It is indicated that the attenuation characteristics of the helmets and hearing protectors and the variables of the physiology of the human ear be accounted for in determining the effective acoustic environment of Army helicopter crewmen as well as the acoustic hazards of voice communications systems noise.

  16. Tail Rotor Airfoils Stabilize Helicopters, Reduce Noise

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Founded by former Ames Research Center engineer Jim Van Horn, Van Horn Aviation of Tempe, Arizona, built upon a Langley Research Center airfoil design to create a high performance aftermarket tail rotor for the popular Bell 206 helicopter. The highly durable rotor has a lifetime twice that of the original equipment manufacturer blade, reduces noise by 40 percent, and displays enhanced performance at high altitudes. These improvements benefit helicopter performance for law enforcement, military training, wildfire and pipeline patrols, and emergency medical services.

  17. The Evolution of the Advanced Attack Helicopter

    DTIC Science & Technology

    1975-06-06

    engineering laboratory at McCook Field, Dayton, Ohio. The first helicopter which appears to have been evaluated was th. Peter Cooper Hewitt design...through five decades to an evaluation of the Peter Cooper Hewitt design in 1918. The first helicopter contracted for by the military was the 199 200 de...used counter-rotating rotors, control vanes below, 24-hp Antoinette engine, two 20 foot rotors. On 13 Nov lifted inventor and two passen- gers, a

  18. Helicopter Performance Evaluation (HELPE) Computer Model

    DTIC Science & Technology

    1994-07-01

    questions : * For a given helicopter at given flight conditions and specified mission weight, how fast can the helicopter cruise in level flight...possible level speed its maneuverability in a turn, and its hover and climb capabilities in the in-ground and out-of-ground effects modes. The code... levels , and mappings ..... 2 2. Available engine power output as a function of altitude "h".................... 8 3. Schematic drawing of the thrust

  19. 77 FR 23388 - Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... helicopters with certain main rotor blades installed to reduce the life limit of those blades. This AD is... rotor blade failed because of fatigue cracking. These actions are intended to prevent failure of the main rotor blade and subsequent loss of control of the helicopter. DATES: This AD becomes effective...

  20. 78 FR 56148 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-12

    ... Textron Canada Limited (Bell) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... service information identified in this AD, contact Bell Helicopter Textron Canada Limited, 12,800 Rue de l...-2009-32, dated July 24, 2009, issued by Transport Canada Civil Aviation (TCCA), which is the...

  1. 78 FR 54751 - Airworthiness Directives; Bell Helicopter Textron Canada Inc. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ...-17576; AD 2013-18-03] RIN 2120-AA64 Airworthiness Directives; Bell Helicopter Textron Canada Inc... new airworthiness directive (AD) for certain Bell Helicopter Textron Canada Inc. (BHT) Model 206A... Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4; telephone (450) 437-2862 or...

  2. Analysis of helicopter noise data using international helicopter noise certification procedures

    NASA Astrophysics Data System (ADS)

    Newman, J. S.; Rickley, E. J.; Levanduski, D. A.; Woolridge, S. B.

    1986-03-01

    The results of a Federal Aviation Administration (FAA) noise measurement flight test program involving seven helicopters are documented. Noise levels were established using the basic testing, reduction and analysis techniques specified by the International Civil Aviation Organization (ICAO) for helicopter noise certification, supplemented with some procedural refinements contained in ICAO Working Group II recommendations for incorporation into the standard.

  3. Instrument Approach Aids for Helicopters.

    DTIC Science & Technology

    1982-07-01

    Me 3.9 "HELICOPTER ONLY" CRITERIA 3-27 h3-30 3.9.1 Procedure Limitations 3-30 3.9.2 Point in Space Concept 3-30 3.9.3 Descent Gradients 3-30 3.9.4...601-800 ft 3/4 mile 801 ft and up 1 mile * Point in space procedures HAS Visibility Minimum 250-800 ft 3/4 mile 801 ft and up 1 mile 1.3 ESTABLISHED...procedures. In the analysis of visibility data most procedures were able to achieve 1/2 mile minimums. A few, primarily the RNAV Point in Space

  4. 77 FR 58973 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-25

    ... ] power supply disruptions while a helicopter is on the ground, causing the landing gear to retract and... power supply disruptions, which caused the landing gear to retract and the helicopter to drop,...

  5. Further Study Of Face Gears For Helicopter Transmissions

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Wang, J. C.; Bossler, R. B., Jr.; Chen, Y. J. D.; Heath, G.; Lewicki, D. G.

    1995-01-01

    Document describes theoretical, computational, and experimental studies of feasibility of proposed lightweight, split-torque helicopter transmissions based on face gears. Majority of work also described in prior document "Face Gears for Helicopter Transmissions" (LEW-15840).

  6. 77 FR 18969 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ... Directives; Sikorsky Aircraft Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT... (AD) for certain Sikorsky Aircraft Corporation (Sikorsky) Model S-76C helicopters. This proposed AD is... Aircraft Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900 Main...

  7. CHR -- Character Handling Routines

    NASA Astrophysics Data System (ADS)

    Charles, A. C.; Rees, P. C. T.; Chipperfield, A. J.; Jenness, T.

    This document describes the Character Handling Routine library, CHR, and its use. The CHR library augments the limited character handling facilities provided by the Fortran 77 standard. It offers a range of character handling facilities: from formatting Fortran data types into text strings and the reverse, to higher level functions such as wild card matching, string sorting, paragraph reformatting and justification. The library may be used simply for building text strings for interactive applications or as a basis for more complex text processing applications.

  8. Future of remote handling

    SciTech Connect

    Grisham, D.L.; Lambert, J.E.

    1986-01-01

    The field of remote handling started in the late 1940's and early 1950's with the invention of mechanical master-slave and electromechanical manipulators. That field now consists of three major divisions: (1) conventional remote handling in fixed facilities with shielding windows and mechanical manipulators; (2) large area remote handling using portable equipment, electric master-slave manipulators, and television for viewing; and (3) the field of robotics which is beginning to be applied to repetitive operations on toxic and dangerous materials. All three divisions will continue to develop and evolve over the next decade.

  9. Lubricant Effects on Efficiency of a Helicopter Transmission.

    DTIC Science & Technology

    1982-01-01

    Research Cen- ter’s 500 hp torque regenerative helicopter transmission test stand. The test transmission was the 01158 helicopter main transmission...cooling systema. This effect adds to increase the payload capacity of the helicopter. The total power loss in a helicopter transmision is a function...friction between Sear teeth . Martin (rof 3) concentrates on the problem of calcmlatiui the losses in the tooth contact. Anderson and Loeventhel (ref 4

  10. Handling Pyrophoric Reagents

    SciTech Connect

    Alnajjar, Mikhail S.; Haynie, Todd O.

    2009-08-14

    Pyrophoric reagents are extremely hazardous. Special handling techniques are required to prevent contact with air and the resulting fire. This document provides several methods for working with pyrophoric reagents outside of an inert atmosphere.

  11. 77 FR 57524 - Stage 3 Helicopter Noise Certification Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-18

    ... applications for a new helicopter type design and for a supplemental type certificate for those new type designs. A helicopter type certificated under this standard would be designated as a Stage 3 helicopter... standards of the International Civil Aviation Organization (ICAO). The proposal of these more...

  12. 14 CFR 135.207 - VFR: Helicopter surface reference requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false VFR: Helicopter surface reference... VFR/IFR Operating Limitations and Weather Requirements § 135.207 VFR: Helicopter surface reference requirements. No person may operate a helicopter under VFR unless that person has visual surface reference...

  13. 78 FR 17593 - Airworthiness Directives; Bell Helicopter Textron, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ... helicopters. This AD requires establishing a lower life limit on certain swashplate outer ring assemblies... lead to the loss of main rotor (M/R) blade pitch control and subsequent loss of helicopter control..., which could lead to the loss of M/R blade pitch control and subsequent loss of helicopter...

  14. A helicopter flight investigation of roll-control sensitivity, damping and cross coupling in a low altitude lateral maneuvering task

    NASA Technical Reports Server (NTRS)

    Corliss, L. D.; Carico, D.

    1983-01-01

    A helicopter in-flight simulation was conducted to determine the effects of variations in roll damping, roll sensitivity, and pitch and roll rate cross-coupling on helicopter flying qualities in a low altitude maneuver. The experiment utilized the UH-1H helicopter in-flight simulator, which is equipped with the V/STOLAND avionics system. The response envelope of this vehicle allowed simulation of configurations with low to moderate damping and sensitivity. A visual, low level slalom course was set up, consisting of constant speed and constant altitude S-turns around the 1000 ft makers of an 8000 ft runway. Results are shown in terms of Cooper-Harper pilot ratings, pilot commentary, and statistical and frequency analyses of the lateral characteristics. These results show good consistency with previous ground simulator results and are compared with existing flying qualities criteria.

  15. Degenerative Changes of Spine in Helicopter Pilots

    PubMed Central

    Byeon, Joo Hyeon; Kim, Jung Won; Jeong, Ho Joong; Sim, Young Joo; Kim, Dong Kyu; Choi, Jong Kyoung; Im, Hyoung June

    2013-01-01

    Objective To determine the relationship between whole body vibration (WBV) induced helicopter flights and degenerative changes of the cervical and lumbar spine. Methods We examined 186 helicopter pilots who were exposed to WBV and 94 military clerical workers at a military hospital. Questionnaires and interviews were completed for 164 of the 186 pilots (response rate, 88.2%) and 88 of the 94 clerical workers (response rate, 93.6%). Radiographic examinations of the cervical and the lumbar spines were performed after obtaining informed consent in both groups. Degenerative changes of the cervical and lumbar spines were determined using four radiographs per subject, and diagnosed by two independent, blinded radiologists. Results There was no significant difference in general and work-related characteristics except for flight hours and frequency between helicopter pilots and clerical workers. Degenerative changes in the cervical spine were significantly more prevalent in the helicopter pilots compared with control group. In the cervical spine multivariate model, accumulated flight hours (per 100 hours) was associated with degenerative changes. And in the lumbar spine multivariate model, accumulated flight hours (per 100 hours) and age were associated with degenerative changes. Conclusion Accumulated flight hours were associated with degenerative changes of the cervical and lumbar spines in helicopter pilots. PMID:24236259

  16. Evolution of civil aeromedical helicopter aviation.

    PubMed

    Meier, D R; Samper, E R

    1989-07-01

    The rapid increase in the use of helicopters for hospital transport during the 1980s is the culmination of several hundred years of military medical innovation. Mass battefield casualties spurred both technologic and medical changes necessary for today's sophisticated helicopter systems in use worldwide, particularly in the United States. The Napoleonic Era and the American Civil War provided the framework for the evolution of today's state-of-the-art emergency medical techniques. The use of airplanes to evacuate the wounded eventually led to using helicopters for rescue missions in World War II. The combat experiences of the United States in Korea, the British in Malaya, and the French in Indochina proved that rotary-wing aircraft were invaluable in reducing battlefield death rates. Any skepticism about the efficacy of helicopter medical evacuation was erased during the Vietnam conflict. As an integral part of the modern battlefield, these specialized aircraft became a necessity. The observations and experience of American servicemen and medical personnel in Vietnam established the foundation for the acceptance of helicopter transport in modern hospital systems.

  17. All-weather capability for rescue helicopters

    NASA Astrophysics Data System (ADS)

    Kreitmair-Steck, Wolfgang; Haisch, Stefan

    2001-08-01

    In Germany as well as in numerous other countries the air rescue system has been extended significantly since the first operation of the rescue helicopter Christoph 1. The primary target of the air rescue system was to guarantee fast and efficient emergency medical services for victims of accidents. During the years, the scope of the helicopter operations has been extended not only to other types of emergency medical services, but also to secondary medical services like the displacement of patients from hospitals to special service hospitals. While in general the displacement of patients is operated from well known and registered helipads, the primary rescue service currently has to rely on available onboard systems only. Those operations are risky and challenging for the pilots because of time pressure and the danger of obstacles in the environment of the helicopter. In addition, reduced visibility due to fog, rainfall or low light levels can further increase the risks or can make the services unavailable at all. Almost one decade ago, Eurocopter started the investigation of technologies and systems that could help the pilots to perform their tasks with reduced workload and risk, and to allow for a 24 h operation of helicopters irrespective of the weather conditions. After a number of preliminary studies, in 1995 the research program 'All-weather helicopter' has been started as a joint effort of Eurocopter and the supplier industry in Europe. The first phase of the program has been successfully completed in 1999 and the second phase is currently in progress.

  18. Helicopter stability during aggressive maneuvers

    NASA Astrophysics Data System (ADS)

    Mohan, Ranjith

    The dissertation investigates helicopter trim and stability during level bank-angle and diving bank-angle turns. The level turn is moderate in that sufficient power is available to maintain level maneuver, and the diving turn is severe where the power deficit is overcome by the kinetic energy of descent. The investigation basically represents design conditions where the peak loading goes well beyond the steady thrust limit and the rotor experiences appreciable stall. The major objectives are: (1) to assess the sensitivity of the trim and stability predictions to the approximations in modeling stall, (2) to correlate the trim predictions with the UH-60A flight test data, and (3) to demonstrate the feasibility of routinely using the exact fast-Floquet periodic eigenvector method for mode identification in the stability analysis. The UH-60A modeling and analysis are performed using the comprehensive code RCAS (Army's Rotorcraft Comprehensive Analysis System). The trim and damping predictions are based on quasisteady stall, ONERA-Edlin (Equations Differentielles Lineaires) and Leishman-Beddoes dynamic stall models. From the correlation with the test data, the strengths and weaknesses of the trim predictions are presented.

  19. Helicopter emergency medical service in mountainous areas.

    PubMed

    Tomazin, Iztok

    2009-01-01

    The outcome of patient care can be dramatically improved by bringing rapid rescue-medical treatment to the scene and by rapid transport to a medical facility. In mountainous areas this is usually possible only with the use of helicopters. ICAR MEDCOM suggests international standards for competent and safe response to medical problems in mountainous and wilderness areas. Rescue helicopters should work within the existing emergency medical system with appropriate mountain rescue and medically-trained personnel and with medical and rescue equipment on board. Safety is most important issue in mountain rescue. Activation and approach time should be as short as possible. All persons responsible for activation and realization of a helicopter rescue operation should be aware of all specific problems in the mountains and wilderness.

  20. Flight service evaluation of composite helicopter components

    NASA Technical Reports Server (NTRS)

    Mardoian, G. H.; Ezzo, M. B.

    1986-01-01

    This report presents an assessment of composite helicopter tail rotor spars and horizontal stabilizers, exposed to the effects of the environment, after up to five and a half years of commercial service. This evaluation is supported by test results of helicopter components and panels which have been exposed to outdoor environmental effects since September 1979. Full scale static and fatigue tests have been conducted on graphite/epoxy and Kevlar/epoxy composite components obtained from Sikorsky Model S-76 helicopters in commercial operations in the Gulf Coast region of Louisiana. Small scale static and fatigue tests are being conducted on coupons obtained from panels under exposure to outdoor conditions in Stratford, Connecticut and West Palm, Florida. The panel layups are representative of the S-76 components. Additionally, this report discusses the results of moisture absorption evaluations and strength tests on the S-76 components and composite panels with up to five years of outdoor exposure.

  1. Flight service evaluation of composite helicopter components

    NASA Technical Reports Server (NTRS)

    Rich, M. J.; Lowry, D. W.

    1985-01-01

    An assessment of composite helicopter structures, exposed to environmental effects, after four years of commercial service is presented. This assessment is supported by test results of helicopter components and test panels which have been exposed to environmental effects since late 1979. Full scale static and fatigue tests are being conducted on composite components obtained from S-76 helicopters in commercial operations in the Gulf Coast region of Louisiana. Small scale tests are being conducted on coupons obtained from panels being exposed to outdoor conditions in Stratford, Connecticut and West Palm Beach, Florida. The panel layups represent S-76 components. Moisture evaluations and strength tests are being conducted, on the S-76 components and panels, over a period of eight years. Results are discussed for components and panels with up to four years of exposure.

  2. Neuro-optimal control of helicopter UAVs

    NASA Astrophysics Data System (ADS)

    Nodland, David; Ghosh, Arpita; Zargarzadeh, H.; Jagannathan, S.

    2011-05-01

    Helicopter UAVs can be extensively used for military missions as well as in civil operations, ranging from multirole combat support and search and rescue, to border surveillance and forest fire monitoring. Helicopter UAVs are underactuated nonlinear mechanical systems with correspondingly challenging controller designs. This paper presents an optimal controller design for the regulation and vertical tracking of an underactuated helicopter using an adaptive critic neural network framework. The online approximator-based controller learns the infinite-horizon continuous-time Hamilton-Jacobi-Bellman (HJB) equation and then calculates the corresponding optimal control input that minimizes the HJB equation forward-in-time. In the proposed technique, optimal regulation and vertical tracking is accomplished by a single neural network (NN) with a second NN necessary for the virtual controller. Both of the NNs are tuned online using novel weight update laws. Simulation results are included to demonstrate the effectiveness of the proposed control design in hovering applications.

  3. Disorientation phenomena in naval helicopter pilots.

    PubMed

    Tormes, F R; Guedry, F E

    1975-04-01

    The incidence of pilot disorientation in fixed- and rotary-wing aircraft has been previously investigated, but special orientation problems of naval helicopter pilots engaged in operations at sea and landing on moving platforms have not been previously investigated. A questionnaire concerning disorientations was answered anonymously and individually by 104 active naval helicopter pilots. Fifty-six percent indicated one or more espisodes of severe disorientation, and 8.6% indicated having experienced severe disorientation five or more times while piloting helicopters. A number of factors conducive to disorientation were identified. Some precipitating factors appear to be specific to operations over water or over a moving deck, although some of these may well have their counterparts in special operations over land. Other factors are common to fixed-wing as well as rotary-wing aircraft. A number of potential countermeasures for various precipitating factors are discussed.

  4. Workload and operational fatigue in helicopter pilots.

    PubMed

    Rotondo, G

    1978-02-01

    In light of the modern aetiopathogenic views, a brief review was made concerning possible causes of operational fatigue to which flying personnel in general are exposed in the exercise of flying activity. The author then describes and analyzes the meaning and importance of the various stressing factors that constitute the physical and psychic workload to which the helicopter pilot is subjected in performing his professional activities. Also analyzed are the influences exercised, both separately and jointly, on the genesis of flight fatigue in helicopter pilots by stressing and fatiguing effects of vibrations, noise, and psycho-emotional and psycho-sensorial factors related to the variety and danger of utilization of this modern aircraft. Such an analytical investigation enables the author to conclude that one must admit that helicopter piloting involves a psycho-physical workload certainly no less than that required by more powerful and faster aircraft.

  5. Helicopter impulsive noise: Theoretical and experimental status

    NASA Technical Reports Server (NTRS)

    Schmitz, F. H.; Yu, Y. H.

    1983-01-01

    The theoretical and experimental status of helicopter impulsive noise is reviewed. The two major source mechanisms of helicopter impulsive noise are addressed: high-speed impulsive noise and blade-vortex interaction impulsive noise. A thorough physical explanation of both generating mechanism is presented together with model and full-scale measurements of the phenomena. Current theoretical prediction methods are compared with experimental findings of isolated rotor tests. The noise generating mechanism of high speed impulsive noise are fairly well understood - theory and experiment compare nicely over Mach number ranges typical of today's helicopters. For the case of blade-vortex interaction noise, understanding of noise generating mechanisms and theoretical comparison with experiment are less satisfactory. Several methods for improving theory-experiment are suggested.

  6. Validation of helicopter noise prediction techniques

    NASA Technical Reports Server (NTRS)

    Succi, G. P.

    1981-01-01

    The current techniques of helicopter rotor noise prediction attempt to describe the details of the noise field precisely and remove the empiricisms and restrictions inherent in previous methods. These techniques require detailed inputs of the rotor geometry, operating conditions, and blade surface pressure distribution. The purpose of this paper is to review those techniques in general and the Farassat/Nystrom analysis in particular. The predictions of the Farassat/Nystrom noise computer program, using both measured and calculated blade surface pressure data, are compared to measured noise level data. This study is based on a contract from NASA to Bolt Beranek and Newman Inc. with measured data from the AH-1G Helicopter Operational Loads Survey flight test program supplied by Bell Helicopter Textron.

  7. A comprehensive plan for helicopter drag reduction

    NASA Technical Reports Server (NTRS)

    Williams, R. M.; Montana, P. S.

    1975-01-01

    Current helicopters have parasite drag levels 6 to 10 times as great as fixed wing aircraft. The commensurate poor cruise efficiency results in a substantial degradation of potential mission capability. The paper traces the origins of helicopter drag and shows that the problem (primarily due to bluff body flow separation) can be solved by the adoption of a comprehensive research and development plan. This plan, known as the Fuselage Design Methodology, comprises both nonaerodynamic and aerodynamic aspects. The aerodynamics are discussed in detail and experimental and analytical programs are described which will lead to a solution of the bluff body problem. Some recent results of work conducted at the Naval Ship Research and Development Center (NSRDC) are presented to illustrate these programs. It is concluded that a 75-per cent reduction of helicopter drag is possible by the full implementation of the Fuselage Design Methodology.

  8. A critical care helicopter system in trauma.

    PubMed Central

    Jacobs, L. M.; Bennett, B.

    1989-01-01

    Civilian helicopters and emergency medical services in the United States have been in existence for approximately 15 years. The rapid growth of this type of health care delivery coupled with an increasing number of accidents has prompted professional and lay scrutiny of these programs. Although they have a demonstrated history of benefit to patients, the type and severity of injuries to patients who are eligible for helicopter transportation need further definition. The composition of the medical crews and the benefits that particular crew members bring to the patients require ongoing evaluation. Significant questions regarding the number of pilots in a helicopter and in a program remain to be answered. This article reviews the role of emergency medical air transport services in providing care to trauma patients, staff training and evaluation, and safety criteria and offers recommendations to minimize risks to patients and crews. PMID:2695653

  9. Validation of helicopter noise prediction techniques

    NASA Astrophysics Data System (ADS)

    Succi, G. P.

    1981-04-01

    The current techniques of helicopter rotor noise prediction attempt to describe the details of the noise field precisely and remove the empiricisms and restrictions inherent in previous methods. These techniques require detailed inputs of the rotor geometry, operating conditions, and blade surface pressure distribution. The purpose of this paper is to review those techniques in general and the Farassat/Nystrom analysis in particular. The predictions of the Farassat/Nystrom noise computer program, using both measured and calculated blade surface pressure data, are compared to measured noise level data. This study is based on a contract from NASA to Bolt Beranek and Newman Inc. with measured data from the AH-1G Helicopter Operational Loads Survey flight test program supplied by Bell Helicopter Textron.

  10. ALLFlight: multisensor data fusion for helicopter operations

    NASA Astrophysics Data System (ADS)

    Doehler, H.-U.; Lueken, T.

    2010-04-01

    The objective of the project ALLFlight (Assisted Low Level Flight and Landing on Unprepared Landing Sites) is to demonstrate and evaluate the characteristics of different sensors for helicopter operations within degraded visual environments, such as brownout or whiteout. The sensor suite, which is mounted onto DLR's research helicopter EC135 consists of standard color or black and white TV cameras, an un-cooled thermal infrared camera (EVS-1000, Max-Viz, USA), an optical radar scanner (HELLAS-W, EADS, Germany; a millimeter wave radar system (AI-130, ICx Radar Systems, Canada). Data processing is designed and realized by a sophisticated, high performance sensor co-computer (SCC) cluster architecture, which is installed into the helicopter's experimental electronic cargo bay. This paper describes applied methods and the software architecture in terms of real time data acquisition, recording, time stamping and sensor data fusion. First concepts for a pilot HMI are presented as well.

  11. Helicopter Mechanic Career Ladder (AFSC 431X0C/D).

    DTIC Science & Technology

    1986-05-01

    SYSTEMS ON H-i HELICOPTERS 88 G352 LAUNCH H-i HELICOPTERS 88 G415 REMOVE OR INSTALL BATTERIES ON H-i HELICOPTERS 88 G351 JACK H-i HELICOPTERS 88 F165...PREPARE AFTO FORMS 781H (AEROSPACE VEHICLE FLIGHT STATUS AND MAINTENANCE DOCUMENT) 72 G351 JACK H-i HELICOPTERS 72 E122 PREPARE AFTO FORMS 350...H-I HELICOPTERS 97 G308 ATTACH OR DETACH TOW BARS ON H-i HELICOPTERS 96 G351 JACK H-I HELICOPTERS 95 G507 TIE DOWN BLADES ON H-i HELICOPTERS 93 G336

  12. Performance of a real-time sensor and processing system on a helicopter

    NASA Astrophysics Data System (ADS)

    Kurz, F.; Rosenbaum, D.; Meynberg, O.; Mattyus, G.; Reinartz, P.

    2014-11-01

    A new optical real-time sensor system (4k system) on a helicopter is now ready to use for applications during disasters, mass events and traffic monitoring scenarios. The sensor was developed light-weighted, small with relatively cheap components in a pylon mounted sideward on a helicopter. The sensor architecture is finally a compromise between the required functionality, the development costs, the weight and the sensor size. Aboard processors are integrated in the 4k sensor system for orthophoto generation, for automatic traffic parameter extraction and for data downlinks. It is planned to add real-time processors for person detection and tracking, for DSM generation and for water detection. Equipped with the newest and most powerful off-the-shelf cameras available, a wide variety of viewing configurations with a frame rate of up to 12 Hz for the different applications is possible. Based on three cameras with 50 mm lenses which are looking in different directions, a maximal FOV of 104° is reachable; with 100 mm lenses a ground sampling distance of 3.5 cm is possible at a flight height of 500 m above ground. In this paper, we present the first data sets and describe the technical components of the sensor. The effect of vibrations of the helicopter on the GNSS/IMU accuracy and on the 4k video quality is analysed. It can be shown, that if the helicopter hoovers the rolling shutter effect affects the 4k video quality drastically. The GNSS/IMU error is higher than the specified limit, which is mainly caused by the vibrations on the helicopter and the insufficient vibrational absorbers on the sensor board.

  13. SPAR data handling utilities

    NASA Technical Reports Server (NTRS)

    Giles, G. L.; Haftka, R. T.

    1978-01-01

    The SPAR computer software system is a collection of processors that perform particular steps in the finite-element structural analysis procedure. The data generated by each processor are stored on a data base complex residing on an auxiliary storage device, and these data are then used by subsequent processors. The SPAR data handling utilities use routines to transfer data between the processors and the data base complex. A detailed description of the data base complex organization is presented. A discussion of how these SPAR data handling utilities are used in an application program to perform desired user functions is given with the steps necessary to convert an existing program to a SPAR processor by incorporating these utilities. Finally, a sample SPAR processor is included to illustrate the use of the data handling utilities.

  14. Integrated flight path planning system and flight control system for unmanned helicopters.

    PubMed

    Jan, Shau Shiun; Lin, Yu Hsiang

    2011-01-01

    This paper focuses on the design of an integrated navigation and guidance system for unmanned helicopters. The integrated navigation system comprises two systems: the Flight Path Planning System (FPPS) and the Flight Control System (FCS). The FPPS finds the shortest flight path by the A-Star (A*) algorithm in an adaptive manner for different flight conditions, and the FPPS can add a forbidden zone to stop the unmanned helicopter from crossing over into dangerous areas. In this paper, the FPPS computation time is reduced by the multi-resolution scheme, and the flight path quality is improved by the path smoothing methods. Meanwhile, the FCS includes the fuzzy inference systems (FISs) based on the fuzzy logic. By using expert knowledge and experience to train the FIS, the controller can operate the unmanned helicopter without dynamic models. The integrated system of the FPPS and the FCS is aimed at providing navigation and guidance to the mission destination and it is implemented by coupling the flight simulation software, X-Plane, and the computing software, MATLAB. Simulations are performed and shown in real time three-dimensional animations. Finally, the integrated system is demonstrated to work successfully in controlling the unmanned helicopter to operate in various terrains of a digital elevation model (DEM).

  15. Helicopter trajectory planning using optimal control theory

    NASA Technical Reports Server (NTRS)

    Menon, P. K. A.; Cheng, V. H. L.; Kim, E.

    1988-01-01

    A methodology for optimal trajectory planning, useful in the nap-of-the-earth guidance of helicopters, is presented. This approach uses an adjoint-control transformation along with a one-dimensional search scheme for generating the optimal trajectories. In addition to being useful for helicopter nap-of-the-earth guidance, the trajectory planning solution is of interest in several other contexts, such as robotic vehicle guidance and terrain-following guidance for cruise missiles and aircraft. A distinguishing feature of the present research is that the terrain constraint and the threat envelopes are incorporated in the equations of motion. Second-order necessary conditions are examined.

  16. CMU's autonomous helicopter explores new territory.

    NASA Astrophysics Data System (ADS)

    Charles, J.

    1998-10-01

    In the summer of 1998, several members of Carnegie Mellon University's (CMUs) Autonomous Helicopter Project team joined NASA on a multidisciplinary expedition to the Canadian Arctic's Haughton Crater. NASA was willing to travel to such a remote corner of the globe because of its similarity to an even more remote locale - Mars. Researchers are studying the 23-million-year-old meteorite impact crater in the hope of learning more about Mars's environment. While there, they also tested a number of technologies that will enable future exploration of Mars, including CMU's autonomous helicopter.

  17. Influence of maneuverability on helicopter combat effectiveness

    NASA Technical Reports Server (NTRS)

    Falco, M.; Smith, R.

    1982-01-01

    A computational procedure employing a stochastic learning method in conjunction with dynamic simulation of helicopter flight and weapon system operation was used to derive helicopter maneuvering strategies. The derived strategies maximize either survival or kill probability and are in the form of a feedback control based upon threat visual or warning system cues. Maneuverability parameters implicit in the strategy development include maximum longitudinal acceleration and deceleration, maximum sustained and transient load factor turn rate at forward speed, and maximum pedal turn rate and lateral acceleration at hover. Results are presented in terms of probability of skill for all combat initial conditions for two threat categories.

  18. Efficient fault diagnosis of helicopter gearboxes

    NASA Technical Reports Server (NTRS)

    Chin, H.; Danai, K.; Lewicki, D. G.

    1993-01-01

    Application of a diagnostic system to a helicopter gearbox is presented. The diagnostic system is a nonparametric pattern classifier that uses a multi-valued influence matrix (MVIM) as its diagnostic model and benefits from a fast learning algorithm that enables it to estimate its diagnostic model from a small number of measurement-fault data. To test this diagnostic system, vibration measurements were collected from a helicopter gearbox test stand during accelerated fatigue tests and at various fault instances. The diagnostic results indicate that the MVIM system can accurately detect and diagnose various gearbox faults so long as they are included in training.

  19. Contingency power concepts for helicopter turboshaft engine

    NASA Technical Reports Server (NTRS)

    Hirschkron, R.; Davis, R. H.; Goldstein, D. N.; Haynes, J. F.; Gauntner, J. W.

    1984-01-01

    Twin helicopter engines are often sized by power requirement of safe mission completion after the failure of one of the two engines. This study was undertaken for NASA Lewis by General Electric Co. to evaluate the merits of special design features to provide a 2-1/2 minute Contingency Power rating, permitting an engine size reduction. The merits of water injection, cooling flow modulation, throttle push and an auxiliary power plant were evaluated using military life cycle cost (LCC) and commercial helicopter direct operating cost (DOC) merit factors in a rubber engine/rubber aircraft scenario.

  20. Helicopter-based live-line work. Volume 1, Helicopter platform work between phases: Final report

    SciTech Connect

    Gela, G.

    1993-06-01

    This report presents experimental data on tests of a configuration consisting of a helicopter between two energized phases (for AC and switching surge) or poles (for DC). The configuration is that related to live-line work from a hovering helicopter. The McDonnell Douglas 500 Series helicopter was used for the tests. All tests were performed with phase-to-phase, or pole-to-pole energization. For AC tests, proper relationship between the phase-to-ground voltages and the phase-to-phase voltage was maintained by energizing the experimental setup from a balanced 3-{phi} AC source. For DC tests, one pole was energized with positive DC voltage to ground, while the other pole was energized with negative DC voltage to ground. For switching surge tests, a surge of positive polarity and a specific peak voltage magnitude was applied to one phase while a surge of negative polarity and the same peak voltage Magnitude was simultaneously applied to the other phase, resulting in {alpha} = 0.5 ({alpha} is the ratio between negative and total surge). In the research program, four conditions were investigated, namely helicopter operating versus not operating, and helicopter bonded to one phase or pole versus not bonded. Results from this research show effects of the rotating main rotor blade of the helicopter, effect of the position of the electrically floating helicopter in the phase-to-phase or pole-to-pole gap, effects of the mannequin, importance of the polarity of the DC poles and switching surges, and effects of inclement weather such as rain. The overall conclusion of this research is that the phase-to-phase or pole-to-pole spacings that cause sparkover with the helicopter between phases (poles) were always significantly smaller than the typical spacings on actual existing overhead transmission lines of the corresponding voltage rating.

  1. Grain Grading and Handling.

    ERIC Educational Resources Information Center

    Rendleman, Matt; Legacy, James

    This publication provides an introduction to grain grading and handling for adult students in vocational and technical education programs. Organized in five chapters, the booklet provides a brief overview of the jobs performed at a grain elevator and of the techniques used to grade grain. The first chapter introduces the grain industry and…

  2. Microforms in Information Handling.

    ERIC Educational Resources Information Center

    Williams, B. J. S.

    In an attempt to identify some of the factors which influence the utility of microforms as a medium for information handling, this report first traces some of the landmarks in the evolution of microforms since their invention in 1893. It next provides a factual account of current microform media and formats. The last section of the report contains…

  3. 7 CFR 996.40 - Handling standards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Handling standards. 996.40 Section 996.40 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE MINIMUM QUALITY AND...

  4. Helicopter Parents Can Be a Good Thing

    ERIC Educational Resources Information Center

    Hiltz, Julie

    2015-01-01

    Helicopter parents get a bad rap. Teachers and administrators should view them as a resource--not a nuisance. By encouraging open communication, teachers can begin to understand the motivations of these parents and find creative ways to connect them with opportunities to promote their students' academic success and the school's overall…

  5. 29 CFR 1910.183 - Helicopters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... cargo hooks shall have the electrical activating device so designed and installed as to prevent... employee shall be permitted to approach within 50 feet of the helicopter when the rotor blades are turning... blades rotating, all employees shall remain in full view of the pilot and keep in a crouched position....

  6. 29 CFR 1910.183 - Helicopters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... cargo hooks shall have the electrical activating device so designed and installed as to prevent... employee shall be permitted to approach within 50 feet of the helicopter when the rotor blades are turning... blades rotating, all employees shall remain in full view of the pilot and keep in a crouched position....

  7. 29 CFR 1910.183 - Helicopters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... cargo hooks shall have the electrical activating device so designed and installed as to prevent... employee shall be permitted to approach within 50 feet of the helicopter when the rotor blades are turning... blades rotating, all employees shall remain in full view of the pilot and keep in a crouched position....

  8. Flight service evaluation of composite helicopter components

    NASA Technical Reports Server (NTRS)

    Mardoian, George H.; Ezzo, Maureen B.

    1990-01-01

    An assessment is presented of ten composite tail rotor spars and four horizontal stabilizers exposed to the effects of in-flight commercial service for up to nine years to establish realistic environmental factors for use in future designs. This evaluation is supported by test results of helicopter components and panels which have been exposed to outdoor environmental effects since 1979. Full scale static and fatigue tests were conducted on graphite/epoxy and Kevlar/epoxy composite components removed from Sikorsky Model S-76 helicopters in commercial operations off the Gulf Coast of Louisiana. Small scale static and fatigue tests were conducted on coupons obtained from panels exposed to outdoor conditions in Stratford, CT and West Palm Beach, Florida. The panel materials and ply configurations were representative of the S-76 components. The results are discussed of moisture analyses and strength tests on both the S-76 components and composite panels after up to nine years of outdoor exposure. Full scale tests performed on the helicopter components did not disclose any significant reductions from the baseline strengths. The results increased confidence in the long term durability of advanced composite materials in helicopter structural applications.

  9. Finite element analysis of helicopter structures

    NASA Technical Reports Server (NTRS)

    Rich, M. J.

    1978-01-01

    Application of the finite element analysis is now being expanded to three dimensional analysis of mechanical components. Examples are presented for airframe, mechanical components, and composite structure calculations. Data are detailed on the increase of model size, computer usage, and the effect on reducing stress analysis costs. Future applications for use of finite element analysis for helicopter structures are projected.

  10. Helicopter support of North Sea oil exploration.

    PubMed

    Preston, F S

    1978-04-01

    Exploration for oil beneath the North Sea started in the early 1960's with the discovery of natural gas and oil in the southern part between the coasts of East Anglia and the Netherlands. Since then oil exploration has built up considerably, the main effort moving northwards between the Shetland Islands and the Norwegian coasts. The helicopter offered the most direct and rapid contact with off-shore oil rigs and since these early days and immense helicopter operation has been built up round the borders of the North Sea by all the nations involved. Flying conditions in this area, particularly in winter, are at times difficult if not to say hazardous. Nevertheless, a sophisticated helicopter support service has been built up using modern aircraft and equipment which is unique in aviation history. This paper attempts to trace the history of the service, the operational problems involved and the special needs such as survival equipment and clothing. In addition, a co-ordinated air/sea rescue service largely based on helicopters has been built up and provides not only rescue facilities for possible rig disasters but also for shipping emergencies in the area.

  11. HH-60D night hawk helicopter

    NASA Technical Reports Server (NTRS)

    Richardson, C. S.

    1984-01-01

    Fundamental development issues, system requirements and improvements are reported for the HH-60D night hawk helicopter. The HH-60D mission requirements are for combat search and rescue (aerospace rescue and recovery service user based at Scott AFB) and special operations (special operations forces based at Hurlburt AFB). Cockpit design, computer architecture and software are described in detail.

  12. Computer Programs for Helicopter Aerodynamic Stability Evaluation

    DTIC Science & Technology

    1976-08-01

    augmentation system . Two methods of calculating the required stability derivatives and solution of the equations of motion in terms of period and time to damp or time histories for various control motions are shown....The three equations of motion for helicopters are reviewed for both pitch and roll. These include provisions for a simplified second order stability

  13. 29 CFR 1910.183 - Helicopters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the system with the employees in advance of hoisting the load. This applies to both radio and hand... employee shall be permitted to approach within 50 feet of the helicopter when the rotor blades are turning... blades rotating, all employees shall remain in full view of the pilot and keep in a crouched position....

  14. Technical Workshop: Advanced Helicopter Cockpit Design

    NASA Technical Reports Server (NTRS)

    Hemingway, J. C. (Editor); Callas, G. P. (Editor)

    1984-01-01

    Information processing demands on both civilian and military aircrews have increased enormously as rotorcraft have come to be used for adverse weather, day/night, and remote area missions. Applied psychology, engineering, or operational research for future helicopter cockpit design criteria were identified. Three areas were addressed: (1) operational requirements, (2) advanced avionics, and (3) man-system integration.

  15. Computerized Analysis Of Helicopter-Rotor Aeroelasticity

    NASA Technical Reports Server (NTRS)

    Reddy, T. S. R.

    1988-01-01

    Analysis of aeroelastic stability of helicopter rotor automated. Symbolic-manipulation program, HESL, written in FORTRAN, used to aid in derivation of government equations of motion for elastic-bladed rotor. Operates both on expressions and matrices. By transferring some burden of algebraic manipulations from human analyst to computer, program reduces tedium analysis and conequent opportunity for errors.

  16. Considerations of Methods of Improving Helicopter Efficiency

    NASA Technical Reports Server (NTRS)

    Dingeldein, Richard C.

    1961-01-01

    Recent NASA helicopter research indicates that significant improvements in hovering efficiency, up to 7 percent, are available from the use of a special airfoil section formed by combining an NACA 632A015 thickness distribution with an NACA 230 mean line. This airfoil should be considered for flying-crane-type helicopters. Application of standard leading-edge roughness causes a large drop in efficiency; however, the cambered rotor is shown to retain its superiority over a rotor having a symmetrical airfoil when both rotors have leading-edge roughness. A simple analysis of available rotor static-thrust data indicates a greatly reduced effect of compressibility effects on the rotor profile-drag power than predicted from calculations. Preliminary results of an experimental study of helicopter parasite drag indicate the practicability of achieving an equivalent flat-plate parasite-drag area of less than 4 square feet for a rotor-head-pylon-fuselage configuration (landing gear retracted) in the 2,000-pound minimum-flying-weight class. The large drag penalty of a conventional skid-type landing (3.6 square feet) can be reduced by two-thirds by careful design. Clean, fair, and smooth fuselages that tend to have narrow, deep cross sections are shown to have advantages from the standpoint of drag and download. A ferry range of the order of 1,500 miles is indicated to be practicable for the small helicopter considered.

  17. Solid waste handling

    SciTech Connect

    Parazin, R.J.

    1995-05-31

    This study presents estimates of the solid radioactive waste quantities that will be generated in the Separations, Low-Level Waste Vitrification and High-Level Waste Vitrification facilities, collectively called the Tank Waste Remediation System Treatment Complex, over the life of these facilities. This study then considers previous estimates from other 200 Area generators and compares alternative methods of handling (segregation, packaging, assaying, shipping, etc.).

  18. Renal phosphate handling: Physiology

    PubMed Central

    Prasad, Narayan; Bhadauria, Dharmendra

    2013-01-01

    Phosphorus is a common anion. It plays an important role in energy generation. Renal phosphate handling is regulated by three organs parathyroid, kidney and bone through feedback loops. These counter regulatory loops also regulate intestinal absorption and thus maintain serum phosphorus concentration in physiologic range. The parathyroid hormone, vitamin D, Fibrogenic growth factor 23 (FGF23) and klotho coreceptor are the key regulators of phosphorus balance in body. PMID:23961477

  19. Uranium hexafluoride handling. Proceedings

    SciTech Connect

    Not Available

    1991-12-31

    The United States Department of Energy, Oak Ridge Field Office, and Martin Marietta Energy Systems, Inc., are co-sponsoring this Second International Conference on Uranium Hexafluoride Handling. The conference is offered as a forum for the exchange of information and concepts regarding the technical and regulatory issues and the safety aspects which relate to the handling of uranium hexafluoride. Through the papers presented here, we attempt not only to share technological advances and lessons learned, but also to demonstrate that we are concerned about the health and safety of our workers and the public, and are good stewards of the environment in which we all work and live. These proceedings are a compilation of the work of many experts in that phase of world-wide industry which comprises the nuclear fuel cycle. Their experience spans the entire range over which uranium hexafluoride is involved in the fuel cycle, from the production of UF{sub 6} from the naturally-occurring oxide to its re-conversion to oxide for reactor fuels. The papers furnish insights into the chemical, physical, and nuclear properties of uranium hexafluoride as they influence its transport, storage, and the design and operation of plant-scale facilities for production, processing, and conversion to oxide. The papers demonstrate, in an industry often cited for its excellent safety record, continuing efforts to further improve safety in all areas of handling uranium hexafluoride. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  20. Recommendations for cask features for robotic handling from the Advanced Handling Technology Project

    SciTech Connect

    Drotning, W.

    1991-02-01

    This report describes the current status and recent progress in the Advanced Handling Technology Project (AHTP) initiated to explore the use of advanced robotic systems and handling technologies to perform automated cask handling operations at radioactive waste handling facilities, and to provide guidance to cask designers on the impact of robotic handling on cask design. Current AHTP tasks have developed system mock-ups to investigate robotic manipulation of impact limiters and cask tiedowns. In addition, cask uprighting and transport, using computer control of a bridge crane and robot, were performed to demonstrate the high speed cask transport operation possible under computer control. All of the current AHTP tasks involving manipulation of impact limiters and tiedowns require robotic operations using a torque wrench. To perform these operations, a pneumatic torque wrench and control system were integrated into the tool suite and control architecture of the gantry robot. The use of captured fasteners is briefly discussed as an area where alternative cask design preferences have resulted from the influence of guidance for robotic handling vs traditional operations experience. Specific robotic handling experiences with these system mock-ups highlight a number of continually recurring design principles: (1) robotic handling feasibility is improved by mechanical designs which emphasize operation with limited dexterity in constrained workspaces; (2) clearances, tolerances, and chamfers must allow for operations under actual conditions with consideration for misalignment and imprecise fixturing; (3) successful robotic handling is enhanced by including design detail in representations for model-based control; (4) robotic handling and overall quality assurance are improved by designs which eliminate the use of loose, disassembled parts. 8 refs., 15 figs.

  1. Subjective field study of response to impulsive helicopter noise

    NASA Technical Reports Server (NTRS)

    Powell, C. A.

    1981-01-01

    Subjects, located outdoors and indoors, judged the noisiness and other subjective noise characteristics of flyovers of two helicopters and a propeller driven airplane as part of a study of the effects of impulsiveness on the subjective response to helicopter noise. In the first experiment, the impulsive characteristics of one helicopter was controlled by varying the main rotor speed while maintaining a constant airspeed in level flight. The second experiment which utilized only the helicopters, included descent and level flight operations. The more impulsive helicopter was consistently judged less noisy than the less impulsive helicopter at equal effective perceived noise levels (EPNL). The ability of EPNL to predict noisiness was not improved by the addition of either of two proposed impulse corrections. A subjective measure of impulsiveness, however, which was not significantly related to the proposed impulse corrections, was found to improve the predictive ability of EPNL.

  2. Helicopter Control Energy Reduction Using Moving Horizontal Tail

    PubMed Central

    Oktay, Tugrul; Sal, Firat

    2015-01-01

    Helicopter moving horizontal tail (i.e., MHT) strategy is applied in order to save helicopter flight control system (i.e., FCS) energy. For this intention complex, physics-based, control-oriented nonlinear helicopter models are used. Equations of MHT are integrated into these models and they are together linearized around straight level flight condition. A specific variance constrained control strategy, namely, output variance constrained Control (i.e., OVC) is utilized for helicopter FCS. Control energy savings due to this MHT idea with respect to a conventional helicopter are calculated. Parameters of helicopter FCS and dimensions of MHT are simultaneously optimized using a stochastic optimization method, namely, simultaneous perturbation stochastic approximation (i.e., SPSA). In order to observe improvement in behaviors of classical controls closed loop analyses are done. PMID:26180841

  3. Finite difference time domain grid generation from AMC helicopter models

    NASA Technical Reports Server (NTRS)

    Cravey, Robin L.

    1992-01-01

    A simple technique is presented which forms a cubic grid model of a helicopter from an Aircraft Modeling Code (AMC) input file. The AMC input file defines the helicopter fuselage as a series of polygonal cross sections. The cubic grid model is used as an input to a Finite Difference Time Domain (FDTD) code to obtain predictions of antenna performance on a generic helicopter model. The predictions compare reasonably well with measured data.

  4. Combat Maintenance Concepts and Repair Techniques for Helicopter Airframe Structures

    DTIC Science & Technology

    1981-01-01

    helicopter airframe and to de- velop concepts for the assessment and repair of airframe combat damage. A computer model was developed to generate...random simulated hallistic strikes on the Black Hawk helicopter airframe. Random shotlines were generated with the model , and cases involving damage...Distribution of Ballistic Hits on Helicopters from Southeast Asia Combat Experience 23 Shotline Simulation Model 24 Conventions for Azimuth and

  5. Economic Effects of Noise Abatement Regulations on the Helicopter Industry.

    DTIC Science & Technology

    1982-12-01

    are estimated. The effects an consumer utilization are also discussed. An appendix compares two independent research studies that used weight...helicopter by subsystem. This thesis proposes that if noise abatement regulations are iqposed on the helicopter industry without due consideration for future...abatement regu- lations on Sikorsky’s s-7S helicopter are estimated. The effects on consumer utilization are also discussed. kn appendix compares two

  6. The application of active side arm controllers in helicopters

    NASA Technical Reports Server (NTRS)

    Knorr, R.; Melz, C.; Faulkner, A.; Obermayer, M.

    1993-01-01

    Eurocopter Deutschland (ECD) started simulation trials to investigate the particular problems of Side Arm Controllers (SAC) applied to helicopters. Two simulation trials have been performed. In the first trial, the handling characteristics of a 'passive' SAC and the basic requirements for the application of an 'active' SAC were evaluated in pilot-in-the-loop simulations, performing the tasks in a realistic scenario representing typical phases of a transport mission. The second simulation trial investigated the general control characteristics of the 'active' in comparison to the 'passive' control principle. A description of the SACs developed by ECD and the principle of the 'passive' and 'active' control concept is given, as well as specific ratings for the investigated dynamic and ergonomic parameters effecting SAC characteristics. The experimental arrangements, as well as the trials procedures of both simulation phases, are described and the results achieved are discussed emphasizing the advantages of the 'active' as opposed to the 'passive' SAC concept. This also includes the presentation of some critical aspects still to be improved and proposals to solve them.

  7. Complying with US and European complaint handling requirements.

    PubMed

    Donawa, M E

    1997-09-01

    The importance of customer complaints for providing valuable information on the use of medical devices is clearly reflected in United States (US) and European quality system requirements for handling complaints. However, there are significant differences in US and European complaint handling requirements. This article will discuss those differences and methods for ensuring compliance.

  8. 10 CFR 71.127 - Handling, storage, and shipping control.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Handling, storage, and shipping control. 71.127 Section 71.127 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE MATERIAL Quality Assurance § 71.127 Handling, storage, and shipping control. The licensee,...

  9. 10 CFR 71.127 - Handling, storage, and shipping control.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Handling, storage, and shipping control. 71.127 Section 71.127 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE MATERIAL Quality Assurance § 71.127 Handling, storage, and shipping control. The licensee,...

  10. 10 CFR 71.127 - Handling, storage, and shipping control.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Handling, storage, and shipping control. 71.127 Section 71.127 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE MATERIAL Quality Assurance § 71.127 Handling, storage, and shipping control. The licensee,...

  11. 10 CFR 71.127 - Handling, storage, and shipping control.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Handling, storage, and shipping control. 71.127 Section 71.127 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE MATERIAL Quality Assurance § 71.127 Handling, storage, and shipping control. The licensee,...

  12. 10 CFR 71.127 - Handling, storage, and shipping control.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Handling, storage, and shipping control. 71.127 Section 71.127 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE MATERIAL Quality Assurance § 71.127 Handling, storage, and shipping control. The licensee,...

  13. Helicopter mission optimization study. [portable computer technology for flight optimization

    NASA Technical Reports Server (NTRS)

    Olson, J. R.

    1978-01-01

    The feasibility of using low-cost, portable computer technology to help a helicopter pilot optimize flight parameters to minimize fuel consumption and takeoff and landing noise was demonstrated. Eight separate computer programs were developed for use in the helicopter cockpit using a hand-held computer. The programs provide the helicopter pilot with the ability to calculate power required, minimum fuel consumption for both range and endurance, maximum speed and a minimum noise profile for both takeoff and landing. Each program is defined by a maximum of two magnetic cards. The helicopter pilot is required to key in the proper input parameter such as gross weight, outside air temperature or pressure altitude.

  14. Research requirements to improve safety of civil helicopters

    NASA Technical Reports Server (NTRS)

    Waters, K. T.

    1977-01-01

    Helicopter and fixed-wing accident data were reviewed and major accident causal factors were established. The impact of accidents on insurance rates was examined and the differences in fixed-wing and helicopter accident costs discussed. The state of the art in civil helicopter safety was compared to military helicopters. Goals were established based on incorporation of known technology and achievable improvements that require development, as well as administrative-type changes such as the impact of improved operational planning, training, and human factors effects. Specific R and D recommendations are provided with an estimation of the payoffs, timing, and development costs.

  15. NASA helicopter blades get new paint job for safety

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Workers put the finishing touches on new paint for the blades of a NASA UH-1H helicopter. They have changed the black to a pattern of white and yellow stripes. The pattern provides better visibility in smoke and fire conditions. When the rotors are turning, the stripes create a yellow and white circle that is more easily seen from above by a second helicopter. The helicopters, primarily used for security and medical evacuation for NASA, will be used to deliver water via buckets during brush fires. The change was made to comply with U.S. Fish and Wildlife and Department of Forestry regulations for helicopter-assisted fire control.

  16. NASA helicopter blades get new paint job for safety

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Workers paint the blades of a NASA UH-1H helicopter, changing the black to a pattern of white and yellow stripes. The pattern provides better visibility in smoke and fire conditions. When the rotors are turning, the stripes create a yellow and white circle that is more easily seen by a second helicopter from above. The helicopters, primarily used for security and medical evacuation for NASA, will be used to deliver water via buckets during brush fires. The change was made to comply with U.S. Fish and Wildlife and Department of Forestry regulations for helicopter-assisted fire control.

  17. Automatic guidance and control laws for helicopter obstacle avoidance

    NASA Technical Reports Server (NTRS)

    Cheng, Victor H. L.; Lam, T.

    1992-01-01

    The authors describe the implementation of a full-function guidance and control system for automatic obstacle avoidance in helicopter nap-of-the-earth (NOE) flight. The guidance function assumes that the helicopter is sufficiently responsive so that the flight path can be readily adjusted at NOE speeds. The controller, basically an autopilot for following the derived flight path, was implemented with parameter values to control a generic helicopter model used in the simulation. Evaluation of the guidance and control system with a 3-dimensional graphical helicopter simulation suggests that the guidance has the potential for providing good and meaningful flight trajectories.

  18. 78 FR 44045 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ... Corporation (Sikorsky) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... directive (AD): Sikorsky Aircraft Corporation (Sikorsky): Docket No. FAA-2013-0636; Directorate...

  19. Standardizing the Handling of Surgical Specimens.

    PubMed

    Shirey, Cheryl; Perrego, Kristen

    2015-11-01

    To standardize the handling of surgical specimens, the OR clinical educators in a community hospital setting devised a series of departmental changes as a quality improvement project. A newly created skill validation was reviewed in an hour-long educational meeting with all OR staff members. In addition to creating a new annual skill validation, discussions about specimens were included in the hand over, the time out, and a newly instituted debriefing tool to be used toward the end of a procedure. This interdisciplinary group devised interventions to improve the process of handling specimens such as standardizing the labeling process and changing the transparency of the specimen container. The goal was to assure standardization of specimen handling, specifically to assist novice staff members, and to harmonize inconsistencies between specialties within the practice of existing staff members. These combined methods helped to ensure accurate communication and procurement of specimens for all procedures.

  20. Solid handling valve

    DOEpatents

    Williams, William R.

    1979-01-01

    The present invention is directed to a solids handling valve for use in combination with lock hoppers utilized for conveying pulverized coal to a coal gasifier. The valve comprises a fluid-actuated flow control piston disposed within a housing and provided with a tapered primary seal having a recessed seat on the housing and a radially expandable fluid-actuated secondary seal. The valve seals are highly resistive to corrosion, erosion and abrasion by the solids, liquids, and gases associated with the gasification process so as to minimize valve failure.

  1. Students' Strategies for Exception Handling

    ERIC Educational Resources Information Center

    Rashkovits, Rami; Lavy, Ilana

    2011-01-01

    This study discusses and presents various strategies employed by novice programmers concerning exception handling. The main contributions of this paper are as follows: we provide an analysis tool to measure the level of assimilation of exception handling mechanism; we present and analyse strategies to handle exceptions; we present and analyse…

  2. Pilot evaluation of sailplane handling qualities

    NASA Technical Reports Server (NTRS)

    Bennett, A. G., Jr.

    1978-01-01

    The evaluation sailplanes were found generally deficient in the area of cockpit layout. The pilots indicated general dissatisfaction with high pitch sensitivity especially when coupled with inertially induced stick forces. While all sailplanes were judged satisfactory for centering thermals and in the ease of speed control in circling flight, pilot opinions diverged on the maneuvering response, pull-out characteristics from a dive, and on phugoid damping. Lateral-directional control problems were noted mainly during takeoff and landing for most sailplanes with the landing wheel ahead of center of gravity. Pilot opinion of in-flight lateral-directional stability and control was generally satisfactory. Five of the evaluation sailplanes exhibited a very narrow airspeed band in which perceptible stall warning buffet occurred. However, this characteristic was considered not objectionable when stall recovery was easy. The pilots objected to the characteristics of a wide airspeed band of stall warning followed by a stall with yawing and rolling tendency and substantial loss of altitude during the stall. Glide path control for the evaluation sailplanes was found to be generally objectionable.

  3. Handling Qualities Evaluations of Unmanned Aircraft Systems

    DTIC Science & Technology

    2015-05-04

    limit to how large the delta can be. For example, if the error limit is ±10° for pitch , an input of +20° pitch from a 0° pitch angle will result in the...indicates feedback pitch attitude. Using the pitch ladders, establish two zones UP and DOWN, which are between 0° and 5° pitch , positive and negative...the Pitch Axis Begin the maneuver in level flight then with low frequency inputs maneuver to either the UP or DOWN boundary, as called by the test

  4. Criteria for Handling Qualities of Military Aircraft.

    DTIC Science & Technology

    1982-06-01

    loop precognitive manner. The pilot is able to apply discrete, step-like inputs which more or less exactly produce the desired aircraft response. Some...While closed loop operation depends upon the frequency domain response characteristics, successful precognitive control requires the time domain...represents the other extreme of the pilot task from the precognitive time response situation. Mich work was done in attempting to predict pilot opinion from

  5. Report of the aviation safety review of Department of Energy helicopter operations

    SciTech Connect

    Not Available

    1992-02-01

    In a memorandum dated November 27, 1991, the Secretary of Energy directed the Office of Environment, Safety and Health (EH) to lead, with Program Secretarial Office participation, an aviation safety review of the safe operation of the Department`s helicopter program. The Aviation Safety Review Team comprised of aviation experts from the US Army, the Federal Aviation Administration, private consulting organizations, and Department of Energy (DOE) staff was assembled. The scope of the Aviation Safety Review Team`s appraisals included the following as applicable: policy; operations; maintenance; crew training; previous appraisals; contract requirements; aviation safety analysis reports; refueling facilities and management; night vision goggle (NVG) operations; helicopter limited standdown initiative; Secretary of Energy Notice (SEN) -6D-91 Compliance; and, DOE/contractor organizational structures and responsibilities. The appraisals at each site included a review of aviation policy, manuals, procedures, facilities, and documentation pertaining to management, safety, operations, maintenance, and quality control.

  6. Report of the aviation safety review of Department of Energy helicopter operations

    SciTech Connect

    Not Available

    1992-02-01

    In a memorandum dated November 27, 1991, the Secretary of Energy directed the Office of Environment, Safety and Health (EH) to lead, with Program Secretarial Office participation, an aviation safety review of the safe operation of the Department's helicopter program. The Aviation Safety Review Team comprised of aviation experts from the US Army, the Federal Aviation Administration, private consulting organizations, and Department of Energy (DOE) staff was assembled. The scope of the Aviation Safety Review Team's appraisals included the following as applicable: policy; operations; maintenance; crew training; previous appraisals; contract requirements; aviation safety analysis reports; refueling facilities and management; night vision goggle (NVG) operations; helicopter limited standdown initiative; Secretary of Energy Notice (SEN) -6D-91 Compliance; and, DOE/contractor organizational structures and responsibilities. The appraisals at each site included a review of aviation policy, manuals, procedures, facilities, and documentation pertaining to management, safety, operations, maintenance, and quality control.

  7. Factors impacting on the activation and approach times of helicopter emergency medical services in four Alpine countries

    PubMed Central

    2012-01-01

    Background The outcome of severely injured or ill patients can be time dependent. Short activation and approach times for emergency medical service (EMS) units are widely recognized to be important quality indicators. The use of a helicopter emergency medical service (HEMS) can significantly shorten rescue missions especially in mountainous areas. We aimed to analyze the HEMS characteristics that influence the activation and approach times. Methods In a multi-centre retrospective study, we analyzed 6121 rescue missions from nine HEMS bases situated in mountainous regions of four European countries. Results We found large differences in mean activation and approach times among HEMS bases. The shortest mean activation time was 2.9 minutes; the longest 17.0 minutes. The shortest mean approach time was 10.4 minutes; the longest 45.0 minutes. Short times are linked (p < 0.001) to the following conditions: helicopter operator is not state owned; HEMS is integrated in EMS; all crew members are at the same location; doctors come from state or private health institutions; organization performing HEMS is privately owned; helicopters are only for HEMS; operation area is around 10.000 km2; HEMS activation is by a dispatching centre of regional government who is in charge of making decisions; there is only one intermediator in the emergency call; helicopter is equipped with hoist or fixed line; HEMS has more than one base with helicopters, and one team per base; closest neighboring base is 90 km away; HEMS is about 20 years old and has more than 650 missions per year; and modern helicopters are used. Conclusions An improvement in HEMS activation and approach times is possible. We found 17 factors associated with shorter times. PMID:22905968

  8. Flight service evaluation of composite helicopter components

    NASA Technical Reports Server (NTRS)

    Rich, M. J.; Lowry, D. W.

    1982-01-01

    This first interim report presents the technical background for including environmental effects in the design of helicopter composite structures, and test results after approximately two year field exposure of components and panels. Composite structural components were removed from Sikorsky S-76 helicopters commercially operated in the Gulf Coast region of Louisiana. Fatigue tests were conducted for a graphite/epoxy tail rotor spar and static test for a graphite/epoxy and Kevlar/epoxy stabilizer. Graphite/epoxy and Kevlar/epoxy panels are being exposed to the outdoor environment in Stratford, Connecticut and West Palm Beach, Florida. For this reporting period the two year panels were returned, moisture measurements taken, and strength tests conducted. Results are compared with initial type certificate strengths for components and with initial laboratory coupon tests for the exposed panels. Comparisons are also presented with predicted and measured moisture contents.

  9. Effect of helicopter noise on passenger annoyance

    NASA Technical Reports Server (NTRS)

    Clevenson, S. A.; Leatherwood, J. D.

    1979-01-01

    The effects of helicopter interior noise on passenger annoyance for both reverie and listening situations was investigated. The relative effectiveness of several metrics for quantifying annoyance response for these situations was also studied. The noise stimuli were based upon recordings of the interior noise of civil helicopter research aircraft. These noises were presented at levels ranging from approximately 70 to 86 d with various tonal components selectively attenuated to give a range of spectra. The listening task required the subjects to listen to and record phonetically-balanced words presented within the various noise environments. Results indicate that annoyance during a listening condition is generally higher than annoyance under a reverie condition for corresponding interior noise environments. Attenuation of the tonal components results in increases in listening performance but has only a small effect upon annoyance for a given noise level.

  10. NASA/FAA helicopter simulator workshop

    NASA Technical Reports Server (NTRS)

    Larsen, William E. (Editor); Randle, Robert J., Jr. (Editor); Bray, Richard S. (Editor); Zuk, John (Editor)

    1992-01-01

    A workshop was convened by the FAA and NASA for the purpose of providing a forum at which leading designers, manufacturers, and users of helicopter simulators could initiate and participate in a development process that would facilitate the formulation of qualification standards by the regulatory agency. Formal papers were presented, special topics were discussed in breakout sessions, and a draft FAA advisory circular defining specifications for helicopter simulators was presented and discussed. A working group of volunteers was formed to work with the National Simulator Program Office to develop a final version of the circular. The workshop attracted 90 individuals from a constituency of simulator manufacturers, training organizations, the military, civil regulators, research scientists, and five foreign countries.

  11. Helmet mounted display systems for helicopter simulation

    NASA Technical Reports Server (NTRS)

    Haworth, Loran A.; Bucher, Nancy; Runnings, David

    1989-01-01

    Simulation scientists continually pursue improved flight simulation technology with the goal of closely replicating the 'real world' physical environment. The presentation/display of visual information for flight simulation is one such area enjoying recent technical improvements that are fundamental for conducting simulated operations close to the terrain. Detailed and appropriate visual information is especially critical for Nap-Of-the-Earth (NOE) helicopter flight simulation where the pilot maintains an 'eyes-out' orientation to avoid obstructions and terrain. This paper elaborates on the visually coupled Wide Field Of View Helmet Mounted Display (WFOVHMD) system technology as a viable visual display system for helicopter simulation. In addition the paper discusses research conducted on the NASA-Ames Vertical Motion Simulator that examined one critical research issue for helmet mounted displays.

  12. Noise reduction experience at Hughes Helicopter, Inc.

    NASA Technical Reports Server (NTRS)

    Janakiram, D. S.

    1982-01-01

    Noise reduction is mostly limited to light helicopters whose noise signature is dominated by their tail rotors. It is primarily hardware oriented. Well known noise reduction techniques such as reduction of rotor speeds with an accompanying increase in solidity to maintain performance, engine noise reduction with the use of exhaust mufflers, and acoustic blanketing of transmission and engine compartment are used. The concept of blade phasing as a means of reducing tail rotor noise is also used. Engine noise (exhaust noise), power train noise and airframe noise becomes important at low rotor tip speeds and means must be found to reduce these noise sources if further noise reductions are desired. The use of a special test rig aids in isolating the various noise sources and arriving at the penalties (performance or payload) involved in quieting them. Significant noise reduction are achieved for the light helicopter with minimum performance or weight penalties because of the dominance of a single noise source (the tail rotor).

  13. Helicopter low-speed yaw control

    NASA Technical Reports Server (NTRS)

    Wilson, John C. (Inventor); Kelley, Henry L. (Inventor); Crowell, Cynthia A. (Inventor)

    1993-01-01

    A system for improving yaw control at low speeds consists of one strake placed on the upper portion of the fuselage facing the retreating rotor blade and another strake placed on the lower portion of the fuselage facing the advancing rotor blade. These strakes spoil the airflow on the helicopter tail boom during hover, low speed flight, and right or left sidewards flight so that less side thrust is required from the tail rotor.

  14. Helicopter crew/passenger vibration sensitivity -

    NASA Technical Reports Server (NTRS)

    Gabel, R.; Reed, D. A.

    1972-01-01

    Helicopter crew and passenger vibration sensitivity are presented. Pilot subjective ratings are established for discrete frequencies and the impact of combinations of harmonic frequencies is examined. A passenger long term comfort level and a short term limit are defined for discrete frequencies and compared with pilot ratings. The results show reasonable agreement between pilot and passenger. Subjective comfort levels obtained for mixed frequency environments clearly demonstrate the need for a multi-frequency criterion.

  15. Feasibility of Helicopter Support Seek Frost.

    DTIC Science & Technology

    1980-05-01

    of helicopters in this function as a straight forward appiication. Our past and current work activity has required solutions to the type of problems ...climatic conditions permitted, the problems associated, the capabilities thus proven, and the plans for the future. In view of the growing need for more...more of a visibility problem . Again, this can be obviated by climbing to higher altitudes. Performance Effect Based on the initial trials, the British

  16. Detection And Avoidance Of Obstacles By Helicopters

    NASA Technical Reports Server (NTRS)

    Cheng, Victor H. L.; Sridhar, Banavar

    1992-01-01

    Report discusses problems relevant to control subsystems enabling helicopters on nap-of-the-Earth flight paths to detect and avoid obstacles automatically. Indicates similarities between this and obstacle-avoidance problem of industrial mobile robots. Two approaches extend two-dimensional obstacle-avoidance concept to three dimensions. First involves direct search of three-dimensional range-map data for indications of openings between obstacles. Second involves compression of data into two-dimensional map for path search.

  17. Fatigue life estimates for helicopter loading spectra

    NASA Technical Reports Server (NTRS)

    Khosrovaneh, A. K.; Dowling, N. E.; Berens, A. P.; Gallagher, J. P.

    1989-01-01

    Helicopter loading histories applied to notch metal samples are used as examples, and their fatigue lives are calculated by using a simplified version of the local strain approach. This simplified method has the advantage that it requires knowing the loading history in only the reduced form of ranges and means and number of cycles from the rain-flow cycle counting method. The calculated lives compare favorably with test data.

  18. Analysis of muscle fatigue in helicopter pilots.

    PubMed

    Balasubramanian, Venkatesh; Dutt, Ashwani; Rai, Shobhit

    2011-11-01

    Helicopter pilots espouse ergonomically unfavourable postures and endure vibration which result in low back pain. The objective of this study was to investigate the effects of a helicopter flight on pilots back and shoulder muscles using surface Electromyography (sEMG) analysis. This study also correlates low back pain symptoms from Rehabilitation Bioengineering Group Pain Scale (RBGPS) questionnaire with muscle fatigue rates obtained. RBGPS was administered on 20 Coast Guard helicopter pilots. sEMG was acquired before and after flight from erector spinae and trapezius muscles in 8 of these 20 pilots. Statistical analysis of time and frequency domain parameters indicated significant fatigue in right trapezius muscle due to flying. Muscle fatigue correlated with average duration of flight (r² = 0.913), total service as pilot (r² = 0.825), pain (r² = 0.463) and total flying hours (r² = 0.507). However, muscle fatigue weakly correlated with Body Mass Index (BMI) (r² = 0.000144) and age (r² = 0.033).

  19. Helicopter Airborne Laser Positioning System (HALPS)

    NASA Technical Reports Server (NTRS)

    Eppel, Joseph C.; Christiansen, Howard; Cross, Jeffrey; Totah, Joseph

    1990-01-01

    The theory of operation, configuration, laboratory, and ground test results obtained with a helicopter airborne laser positioning system developed by Princeton University is presented. Unfortunately, due to time constraints, flight data could not be completed for presentation at this time. The system measures the relative position between two aircraft in three dimensions using two orthogonal fan-shaped laser beams sweeping across an array of four detectors. Specifically, the system calculates the relative range, elevation, and azimuth between an observation aircraft and a test helicopter with a high degree of accuracy. The detector array provides a wide field of view in the presence of solar interference due to compound parabolic concentrators and spectral filtering of the detector pulses. The detected pulses and their associated time delays are processed by the electronics and are sent as position errors to the helicopter pilot who repositions the aircraft as part of the closed loop system. Accuracies obtained in the laboratory at a range of 80 ft in the absence of sunlight were + or - 1 deg in elevation; +0.5 to -1.5 deg in azimuth; +0.5 to -1.0 ft in range; while elevation varied from 0 to +28 deg and the azimuth varied from 0 to + or - 45 deg. Accuracies in sunlight were approximately 40 deg (+ or - 20 deg) in direct sunlight.

  20. Automated Power Assessment for Helicopter Turboshaft Engines

    NASA Technical Reports Server (NTRS)

    Simon, Donald L.; Litt, Jonathan S.

    2008-01-01

    An accurate indication of available power is required for helicopter mission planning purposes. Available power is currently estimated on U.S. Army Blackhawk helicopters by performing a Maximum Power Check (MPC), a manual procedure performed by maintenance pilots on a periodic basis. The MPC establishes Engine Torque Factor (ETF), an indication of available power. It is desirable to replace the current manual MPC procedure with an automated approach that will enable continuous real-time assessment of available power utilizing normal mission data. This report presents an automated power assessment approach which processes data currently collected within helicopter Health and Usage Monitoring System (HUMS) units. The overall approach consists of: 1) a steady-state data filter which identifies and extracts steady-state operating points within HUMS data sets; 2) engine performance curve trend monitoring and updating; and 3) automated ETF calculation. The algorithm is coded in MATLAB (The MathWorks, Inc.) and currently runs on a PC. Results from the application of this technique to HUMS mission data collected from UH-60L aircraft equipped with T700-GE-701C engines are presented and compared to manually calculated ETF values. Potential future enhancements are discussed.

  1. Helicopter immobilization of elk in southcentral Washington

    SciTech Connect

    McCorquodale, S.M.; Eberhardt, L.E. ); Petron, S.E. )

    1988-01-01

    Free-ranging elk are commonly immobilized for research or management by rifle-fired darts shot from a helicopter. Compounds used for this purpose have included succinylcholine chloride (succinylcholine), etorphine hydrochloride (etorphine), and xylazine hydrochloride (xylazine). To assess the efficacy of various immobilizing drugs used in helicopter applications, we darted 38 elk from a helicopter on the Arid Lands Ecology Reserve, Washington from 1983 to 1987. We used either succinylcholine, etorphine hydrochloride, or xylazine hydrochloride a primary immobilants. Unsuccessful immobilizations were most common in elk darted with succinylcholine. Yohimbine was used to reverse xylazine immobilizations. The use of xylazine and yohimbine provides an efficient, cost-effective alternative to etorphine, diprenorphine immobilization and reversal in elk while increasing handler safety. Etorphine appeared to be the best immobilant when extended pain-producing procedures (such as surgical telemetry implantation) are planned because it induced the longest and deepest anesthesia. When the potential to lose contact with darted animals exist, we believe succinylcholine may be the preferred immobilant because of rapid, spontaneous recovery.

  2. Aeromechanics Analysis of a Compound Helicopter

    NASA Technical Reports Server (NTRS)

    Yeo, Hyeonsoo; Johnson, Wayne

    2006-01-01

    A design and aeromechanics investigation was conducted for a 100,000-lb compound helicopter with a single main rotor, which is to cruise at 250 knots at 4000 ft/95 deg F condition. Performance, stability, and control analyses were conducted with the comprehensive rotorcraft analysis CAMRAD II. Wind tunnel test measurements of the performance of the H-34 and UH-1D rotors at high advance ratio were compared with calculations to assess the accuracy of the analysis for the design of a high speed helicopter. In general, good correlation was obtained with the increase of drag coefficients in the reverse flow region. An assessment of various design parameters (disk loading, blade loading, wing loading) on the performance of the compound helicopter was made. Performance optimization was conducted to find the optimum twist, collective, tip speed, and taper using the comprehensive analysis. Blade twist was an important parameter on the aircraft performance and most of the benefit of slowing the rotor occurred at the initial 20 to 30% reduction of rotor tip speed. No stability issues were observed with the current design and the control derivatives did not change much with speed, but did exhibit significant coupling.

  3. Optimum Design of a Compound Helicopter

    NASA Technical Reports Server (NTRS)

    Yeo, Hyeonsoo; Johnson, Wayne

    2006-01-01

    A design and aeromechanics investigation was conducted for a 100,000-lb compound helicopter with a single main rotor, which is to cruise at 250 knots at 4000 ft/95 deg F condition. Performance, stability, and control analyses were conducted with the comprehensive rotorcraft analysis CAMRAD II. Wind tunnel test measurements of the performance of the H-34 and UH-1D rotors at high advance ratio were compared with calculations to assess the accuracy of the analysis for the design of a high speed helicopter. In general, good correlation was obtained when an increase of drag coefficients in the reverse flow region was implemented. An assessment of various design parameters (disk loading, blade loading, wing loading) on the performance of the compound helicopter was conducted. Lower wing loading (larger wing area) and higher blade loading (smaller blade chord) increased aircraft lift-to-drag ratio. However, disk loading has a small influence on aircraft lift-to-drag ratio. A rotor parametric study showed that most of the benefit of slowing the rotor occurred at the initial 20 to 30% reduction of the advancing blade tip Mach number. No stability issues were observed with the current design. Control derivatives did not change significantly with speed, but the did exhibit significant coupling.

  4. Piloting Vertical Flight Aircraft: A Conference on Flying Qualities and Human Factors

    NASA Technical Reports Server (NTRS)

    Blanken, Christopher L. (Editor); Whalley, Matthew S. (Editor)

    1993-01-01

    This document contains papers from a specialists' meeting entitled 'Piloting Vertical Flight Aircraft: A Conference on Flying Qualities and Human Factors.' Vertical flight aircraft, including helicopters and a variety of Vertical Takeoff and Landing (VTOL) concepts, place unique requirements on human perception, control, and performance for the conduct of their design missions. The intent of this conference was to examine, for these vehicles, advances in: (1) design of flight control systems for ADS-33C standards; (2) assessment of human factors influences of cockpit displays and operational procedures; (3) development of VTOL design and operational criteria; and (4) development of theoretical methods or models for predicting pilot/vehicle performance and mission suitability. A secondary goal of the conference was to provide an initial venue for enhanced interaction between human factors and handling qualities specialists.

  5. Helicopter flights with night-vision goggles: Human factors aspects

    NASA Technical Reports Server (NTRS)

    Brickner, Michael S.

    1989-01-01

    Night-vision goggles (NVGs) and, in particular, the advanced, helmet-mounted Aviators Night-Vision-Imaging System (ANVIS) allows helicopter pilots to perform low-level flight at night. It consists of light intensifier tubes which amplify low-intensity ambient illumination (star and moon light) and an optical system which together produce a bright image of the scene. However, these NVGs do not turn night into day, and, while they may often provide significant advantages over unaided night flight, they may also result in visual fatigue, high workload, and safety hazards. These problems reflect both system limitations and human-factors issues. A brief description of the technical characteristics of NVGs and of human night-vision capabilities is followed by a description and analysis of specific perceptual problems which occur with the use of NVGs in flight. Some of the issues addressed include: limitations imposed by a restricted field of view; problems related to binocular rivalry; the consequences of inappropriate focusing of the eye; the effects of ambient illumination levels and of various types of terrain on image quality; difficulties in distance and slope estimation; effects of dazzling; and visual fatigue and superimposed symbology. These issues are described and analyzed in terms of their possible consequences on helicopter pilot performance. The additional influence of individual differences among pilots is emphasized. Thermal imaging systems (forward looking infrared (FLIR)) are described briefly and compared to light intensifier systems (NVGs). Many of the phenomena which are described are not readily understood. More research is required to better understand the human-factors problems created by the use of NVGs and other night-vision aids, to enhance system design, and to improve training methods and simulation techniques.

  6. Heavy Lift Helicopter - Cargo Handling ATC Program, Volume III. Results of Tests, Inspections, and Evaluations

    DTIC Science & Technology

    1976-10-01

    button was worn through the electroless nickle plating. Wear in the actuator button did not effect the switch operation and L 1 had little effect on the... electroless nickel- boron coating on high-strength carbon steel wire to resist corrosion and to determine the compatibility of the coating with the...for drawing to final size. The coating was applied by dipping in an electroless nickel-boron bath at 90*C. The coating 171 ra thickness used for the

  7. Bulk material handling system

    DOEpatents

    Kleysteuber, William K.; Mayercheck, William D.

    1979-01-01

    This disclosure relates to a bulk material handling system particularly adapted for underground mining and includes a monorail supported overhead and carrying a plurality of conveyors each having input and output end portions with the output end portion of a first of the conveyors positioned above an input end portion of a second of the conveyors, a device for imparting motion to the conveyors to move the material from the input end portions toward the output end portions thereof, a device for supporting at least one of the input and output end portions of the first and second conveyors from the monorail, and the supporting device including a plurality of trolleys rollingly supported by the monorail whereby the conveyors can be readily moved therealong.

  8. Tracking Helicopters with a Seismic Array

    NASA Astrophysics Data System (ADS)

    Eibl, Eva P. S.; Lokmer, Ivan; Bean, Christopher J.; Akerlie, Eggert

    2015-04-01

    We observed that the pressure or acoustic wave created by the rotor blades of a helicopter can couple to the ground even at 30 km distance where it creates a signal strong enough to be detected by a seismometer. The signal is harmonic tremor with a fundamental frequency downgliding with the inflection point at e.g. 14 Hz and two equally spaced overtones up to the Nyquist frequency of 50 Hz. No difference in the amplitudes between the fundamental frequency and higher harmonics was observed. Such a signature is a consequence of the regularly repeating pressure pulses generated by the helicopter's rotor blades. The signal was recorded by a seven station broadband array with an aperture of 1.6 km. Our spacing is close enough to record the signal at all stations and far enough to observe traveltime differences. The separation of the spectral lines corresponds to the time interval between the repeating sources. The highlighted harmonics contain information about the spectral content of the single source as our signal corresponds to the convolution of an infinite comb function and a single pulse. As we see all harmonics and they have the same amplitude up to the Nyquist frequency we can deduce that the frequency content of the single pulse is flat i.e. it is effectively a delta function up to the Nyquist frequency. We perform a detailed spectral and location analysis of the signal, and compare our results with the known information on the helicopter's speed, location, the frequency of the blades rotation and the amount of blades. This analysis is based on the characteristic shape of the curve i.e. speed of the gliding, minimum and maximum fundamental frequency, amplitudes at the inflection points at different stations and traveltimes deduced from the inflection points at different stations. This observation has an educative value, because the same principle could be used for the analysis of the volcanic harmonic tremor. Harmonic volcanic tremor usually has fundamental

  9. Platelets: handle with care.

    PubMed

    Thomas, S

    2016-10-01

    Platelets are delicate cells that require careful handling between collection, preparation and transfusion. This review addresses practical questions relating to platelet concentration, resting time after collection, total time and number of periods without agitation and temperature. The bags in which platelets are stored are made from gas-permeable plastic to allow sufficient oxygen for the platelets to maintain aerobic respiration. Manufacturers have assigned limits for platelet content and concentration, and these must not be exceeded. There is no strong evidence for or against the resting of platelets post-collection and pre-agitation, but platelets should not be over-wrapped during this period as this compromises gas exchange; a short rest period of up to 1 h may allow the separation of minor aggregates. It is necessary to transport platelet concentrates (e.g. from manufacturing site to hospital), but these periods without gas exchange must be limited to avoid excessive damage to the platelets. Current data support a total of 24 h of transportation per component but with no individual period lasting more than 8 h. Platelets need to be stored at 20-24 °C based on evidence that colder storage leads to irreversible changes on the platelet membrane, resulting in phagocytosis of the platelets following transfusion. Storage at warmer temperatures may lead to an increase in bacterial risk. On the basis of this review, the UK Guidelines for Blood Transfusion Services have been updated to ensure that platelets are handled in the most appropriate way to ensure that efficacious components are provided for patients.

  10. Scoop attachment makes helicopter recoveries easier and safer

    NASA Technical Reports Server (NTRS)

    Koons, W. E.

    1965-01-01

    Helicopter with rigid boom and net attachment performs rescue or recovery operations easily and safely. The attachment in the front of the helicopter scoops objects from difficult and otherwise inaccessible areas and pivots to the side hatch of the aircraft so that no crew member need leave the craft.

  11. Environmental Assessment: Apalachicola National Forest Helicopter Landing Zones Florida

    DTIC Science & Technology

    2003-12-01

    Use, Sustained Yield Act, "the national forests are established and shall be administered for outdoor recreation , range, timber, watershed, and...ENVIRONMENTAL ASSESSEMENT APALACHICOLA NATIONAL FOREST HELICOPTER LANDING ZONES FLORIDA MOODY AIR FORCE BASE...Assessment: Apalachicola National Forest Helicopter Landing Zones Florida 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S

  12. Summary of drive-train component technology in helicopters

    NASA Technical Reports Server (NTRS)

    Weden, G. J.; Coy, J. J.

    1984-01-01

    A review of current helicopters was conducted to determine the technology in the drive-train systems. The design features are highlighted including reliability characteristics in transmission systems for the OH-58, UH-1, CH-47, and UH-60 helicopters. In addition, trade-offs involving cost, reliability and life are discussed.

  13. 78 FR 23692 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-22

    ... proposed AD are intended to prevent loss of a T/R blade tab, which could result in excessive vibration and..., and that the loss of the tab leads to a significant increase in the aircraft's vibration level. As a... in excessive vibration of the helicopter and loss of control of the helicopter. (c) Comments Due...

  14. USAF Combat Rescue Helicopter: Addressing Joint Force Capability Shortfalls

    DTIC Science & Technology

    2013-04-07

    Sikorsky Will Probably Win the Combat Rescue Helicopter Contract.” (blog) Wordpress , December 18, 2012 http://xbradtc.com/2012/12/18/sikorsky-will...Posture, 112th Cong., March 2012. XBRADTC (Pseudonym). “Sikorsky Will Probably Win the Combat Rescue Helicopter Contract.” (blog) Wordpress

  15. 77 FR 58794 - Airworthiness Directives; Bell Helicopter Textron, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-24

    ... rotor (M/R) blade pitch control and subsequent loss of helicopter control. DATES: We must receive... pitch control of the main rotor blades and loss of helicopter control. FAA's Determination We are... condition exists and is likely to exist or develop on other products of these same type designs....

  16. Neural Network Based Method for Estimating Helicopter Low Airspeed

    DTIC Science & Technology

    1996-10-24

    The present invention relates generally to virtual sensors and, more particularly, to a means and method utilizing a neural network for estimating...helicopter airspeed at speeds below about 50 knots using only fixed system parameters (i.e., parameters measured or determined in a reference frame fixed relative to the helicopter fuselage) as inputs to the neural network .

  17. Astronaut James Lovell hoisted from water by recovery helicopter

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut James A. Lovell Jr., pilot of the Gemini 7 space flight, is hoisted from the water by a recovery helicopter from the Aircraft Carrier U.S.S. Wasp. Astronaut Frank Borman, command pilot, waits in the raft to be hoisted aboard the helicopter.

  18. 78 FR 66668 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-06

    ... inspecting frame number (No.) 9 for a crack. This proposed AD is prompted by a report of a crack in frame No. 9 on an AS365 helicopter. The proposed actions are intended to detect a crack and prevent loss of... a crack was discovered during the ``T'' inspection of an AS365 helicopter. The crack started at...

  19. 78 FR 9634 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... AS350 and AS355 helicopters, to require inspecting for a crack in the control lever attachment yokes... casting of TGB casing assemblies, which may lead to cracking. A crack in the control lever attachment... AS 350 and AS 355 helicopters. EASA advises that cracks were found on some TGB casing assemblies...

  20. Basic Helicopter Handbook, Revised. AC 61-13A.

    ERIC Educational Resources Information Center

    Federal Aviation Administration (DOT), Washington, DC. Flight Standards Service.

    This technical manual was designed to assist applicants preparing for the private, commercial, and flight instructor pilot certificates with a helicopter rating. The chapters outline general aerodynamics, aerodynamics of flight, loads and load factors, function of controls, other helicopter components and their functions, introduction to the…

  1. 78 FR 17076 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... deterioration of the MRH bearing of the rotating star installed on a Model AS332L1 helicopter. The actions of this AD are intended to detect deterioration of the MRH bearing and to prevent overloading the scissor... helicopters to require a one-time inspection of the main rotor head (MRH) swash-plate upper bearing...

  2. The elaboration of a new family of helicopter blade profiles

    NASA Technical Reports Server (NTRS)

    Thibert, J. J.

    1981-01-01

    An airfoil family of helicopter rotor blades was designed. Three airfoils with thickness to chord ratios of 12, 9, and 7% were designed. Their improved performance in two dimensional rotor mockup wind tunnel tests led to testing of the tapered blades on four bladed rotors in a wind tunnel and flight tests on the Dauphin series of helicopters, confirming the expected gains.

  3. Unmanned Aerial Vehicles: Replacing the Army’s Comanche Helicopter?

    DTIC Science & Technology

    2007-11-02

    This strategic research project explores the possibility of unmanned aerial vehicles replacing the Comanche Helicopter in its doctrinal missions...capabilities of unmanned aerial vehicles , and analyzes unmanned aerial vehicles capabilities against those aviation critical tasks. This research will...Army’s current helicopters, this analysis reveals that unmanned aerial vehicles can only perform 67% of the reconnaissance critical tasks, 50% of the

  4. Model Tests on the Economy and Effectiveness of Helicopter Propellers

    NASA Technical Reports Server (NTRS)

    Munk, Max M

    1925-01-01

    The average velocity of helicopter blades relative to the air is greater than that of airplane wings. The helicopter may turn out to be more economical than the airplane wing for extreme velocities of horizontal flight, the airplane then requiring a very great speed range.

  5. The Helicopter Parent: Research toward a Typology (Part I)

    ERIC Educational Resources Information Center

    Somers, Patricia; Settle, Jim

    2010-01-01

    With 117,000 hits on a recent Google[TM] search, the phenomenon of helicopter parenting has been widely reported in the popular press. Yet the scholarly literature is anemic on the topic. This article, part one of a two-part series, presents the small body of research on helicopter parenting and describes a qualitative study of 190 participants…

  6. The Helicopter Parent (Part 2): International Arrivals and Departures

    ERIC Educational Resources Information Center

    Somers, Patricia; Settle, Jim

    2010-01-01

    The phenomenon of helicopter parenting has been widely reported, yet the research literature is anemic on the topic. Based on interviews and focus groups involving 190 academic and student services professionals, this article continues by discussing the social, psychological, economic, and cultural factors that influence helicoptering; exploring…

  7. Helicopter emergency medical service scene communications made easy.

    PubMed

    Koval, Michael

    2014-01-01

    Narrowbanding has caused numerous communication issues. The solution is to use a mutual aid frequency like 123.025. That frequency is 155.3400, and every helicopter emergency medical service operator and emergency medical service agency should name this frequency as "EMS [Emergency Medical Services] Mutual Aid" and preset this frequency for all helicopter emergency medical service scene operations.

  8. 78 FR 52407 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-23

    ... helicopters with a certain emergency flotation gear (float) installed. This AD requires inspecting the float... Eurocopter Model EC120B helicopters with a left-hand (LH) emergency flotation gear, part number (P/N) 215674...) emergency flotation gear, P/N 215675-0, 215675-1, or 215675-2 installed, fitted with a float, P/N...

  9. 78 FR 12648 - Airworthiness Directives; Robinson Helicopter Company

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-25

    ... Company AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to supersede an existing airworthiness directive (AD) for Robinson Helicopter Company... identified in this proposed AD, contact Robinson Helicopter Company, 2901 Airport Drive, Torrance, CA...

  10. 29 CFR 1926.958 - External load helicopters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false External load helicopters. 1926.958 Section 1926.958 Labor... External load helicopters. In all operations performed using a rotorcraft for moving or placing external loads, the provisions of § 1926.551 of subpart N of this part shall be complied with....

  11. 29 CFR 1926.958 - External load helicopters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false External load helicopters. 1926.958 Section 1926.958 Labor... External load helicopters. In all operations performed using a rotorcraft for moving or placing external loads, the provisions of § 1926.551 of subpart N of this part shall be complied with....

  12. 77 FR 18965 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ... Directives; Eurocopter France Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice... Eurocopter France Model SA341G helicopters. This proposed AD is prompted by an analysis and tests performed... Civile (DGAC), which is the aviation authority for France, has issued French AD No. F-2004-070, dated...

  13. 78 FR 70202 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ... coupling. This AD is prompted by a crack discovered in the area of the center cross-member at station X... helicopter fitted with the collective-to-yaw control coupling. The actions of this AD are intended to prevent... coupling. Since we issued AD No. 2010-21-01, we discovered that we included all helicopters in the...

  14. 78 FR 34288 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ... could lead to failure of the MGB supporting structure, detachment of the MGB, and loss of helicopter... MGB supporting structure, detachment of the MGB, and subsequent loss of control of the helicopter. (c... change, and include supporting data. To ensure the docket does not contain duplicate comments,...

  15. 77 FR 68058 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ... Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule; request for... Aircraft Corporation (Sikorsky) Model S-70, S-70A, S-70C, S-70C(M), and S-70C(M1) helicopters with a... service information identified in this AD, contact Sikorsky Aircraft Corporation, Attn:...

  16. On the Use of Active Higher Harmonic Blade Pitch Control for Helicopter Vibration Reduction,

    DTIC Science & Technology

    1980-06-01

    G., and Gabel, R.: Vibration Optimization of the CH-47C Helicopter Using NASTRAN . Symposium on Mathematical Modeling in Structural Engineering... helicopter . DESCRIPTION OF MODEL AND TESTS The basic wind tunnel model used in this investigation was the Structures Laboratory Aeroelastic Rotor...dynamically-scaled helicopter rotor model in which an active control system employing higher harmonic blade pitch was used for helicopter vibration

  17. The Use of Commercial Remote Sensing Systems in Predicting Helicopter Brownout Conditions

    DTIC Science & Technology

    2009-09-01

    REMOTE SENSING IN PREDICTING HELICOPTER BROWNOUT CONDITIONS by Christine Kay Rabaja September 2009 Thesis Advisor: Richard C. Olsen...Master’s Thesis 4. TITLE AND SUBTITLE The Use of Commercial Remote Sensing Systems in Predicting Helicopter Brownout Conditions 6. AUTHOR...soils susceptible to helicopter brownout . Helicopter brownout occurs when downwash disturbs the dust and sand beneath the aircraft during takeoff

  18. Signal Detection Theory Applied to Helicopter Transmission Diagnostic Thresholds

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Keller, Jonathan A.; Wade, Daniel R.

    2008-01-01

    Helicopter Health Usage Monitoring Systems (HUMS) have potential for providing data to support increasing the service life of a dynamic mechanical component in the transmission of a helicopter. Data collected can demonstrate the HUMS condition indicator responds to a specific component fault with appropriate alert limits and minimal false alarms. Defining thresholds for specific faults requires a tradeoff between the sensitivity of the condition indicator (CI) limit to indicate damage and the number of false alarms. A method using Receiver Operating Characteristic (ROC) curves to assess CI performance was demonstrated using CI data collected from accelerometers installed on several UH60 Black Hawk and AH64 Apache helicopters and an AH64 helicopter component test stand. Results of the analysis indicate ROC curves can be used to reliably assess the performance of commercial HUMS condition indicators to detect damaged gears and bearings in a helicopter transmission.

  19. A neural network for the identification of measured helicopter noise

    NASA Technical Reports Server (NTRS)

    Cabell, R. H.; Fuller, C. R.; O'Brien, W. F.

    1991-01-01

    The results of a preliminary study of the components of a novel acoustic helicopter identification system are described. The identification system uses the relationship between the amplitudes of the first eight harmonics in the main rotor noise spectrum to distinguish between helicopter types. Two classification algorithms are tested; a statistically optimal Bayes classifier, and a neural network adaptive classifier. The performance of these classifiers is tested using measured noise of three helicopters. The statistical classifier can correctly identify the helicopter an average of 67 percent of the time, while the neural network is correct an average of 65 percent of the time. These results indicate the need for additional study of the envelope of harmonic amplitudes as a component of a helicopter identification system. Issues concerning the implementation of the neural network classifier, such as training time and structure of the network, are discussed.

  20. Helicopter transmission testing at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Coy, John J.

    1987-01-01

    The helicopter has evolved into a highly valuable air mobile vehicle for both military and civilian needs. The helicopter transmission requires advanced studies to develop a technology base for future rotorcraft advances. A joint helicopter transmission research program between the NASA Lewis Research Center and the U.S. Army Aviation Systems Command has existed since 1970. Program goals are to reduce weight and noise and to increase life and reliability. The current experimental activities at Lewis consist of full-scale helicopter transmission testing, a base effort in gearing technology, and a future effort in noise reduction technology. The experimental facilities at Lewis for helicopter transmission testing are described. A description of each of the rigs is presented along with some significant results and near-term plans.

  1. NASA helicopter blades get new paint job for safety

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A newly repainted NASA helicopter is transported to S.R. 3 for return to Patrick AFB. Workers painted the blades of four NASA UH-1H helicopters, changing the black to a pattern of white and yellow stripes. The pattern provides better visibility in smoke and fire conditions. When the rotors are turning, the stripes create a yellow and white circle that is more easily seen by a second helicopter from above. The helicopters, primarily used for security and medical evacuation for NASA, will be used to deliver water via buckets during brush fires. The change was made to comply with U.S. Fish and Wildlife and Department of Forestry regulations for helicopter-assisted fire control.

  2. NASA helicopter blades get new paint job for safety

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Workers get ready to move a NASA UH-1H helicopter outside. They have been painting the blades of four NASA UH-1H helicopters, changing the black to a pattern of white and yellow stripes. The pattern provides better visibility in smoke and fire conditions. When the rotors are turning, the stripes create a yellow and white circle that is more easily seen by a second helicopter from above. The helicopters, primarily used for security and medical evacuation for NASA, will be used to deliver water via buckets during brush fires. The change was made to comply with U.S. Fish and Wildlife and Department of Forestry regulations for helicopter-assisted fire control.

  3. NASA helicopter blades get new paint job for safety

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A NASA UH-1H helicopter is prepared for transfer back to Patrick Air Force Base after being painted. The blades of four NASA UH-1H helicopters were repainted, changing the black to a pattern of white and yellow stripes. The pattern provides better visibility in smoke and fire conditions. When the rotors are turning, the stripes create a yellow and white circle that is more easily seen by a second helicopter from above. The helicopters, primarily used for security and medical evacuation for NASA, will be used to deliver water via buckets during brush fires. The change was made to comply with U.S. Fish and Wildlife and Department of Forestry regulations for helicopter-assisted fire control.

  4. Signal Detection Theory Applied to Helicopter Transmission Diagnostic Thresholds

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Keller, Jonathan A.; Wade, Daniel R.

    2009-01-01

    Helicopter Health Usage Monitoring Systems (HUMS) have potential for providing data to support increasing the service life of a dynamic mechanical component in the transmission of a helicopter. Data collected can demonstrate the HUMS condition indicator responds to a specific component fault with appropriate alert limits and minimal false alarms. Defining thresholds for specific faults requires a tradeoff between the sensitivity of the condition indicator (CI) limit to indicate damage and the number of false alarms. A method using Receiver Operating Characteristic (ROC) curves to assess CI performance was demonstrated using CI data collected from accelerometers installed on several UH60 Black Hawk and AH64 Apache helicopters and an AH64 helicopter component test stand. Results of the analysis indicate ROC curves can be used to reliably assess the performance of commercial HUMS condition indicators to detect damaged gears and bearings in a helicopter transmission.

  5. 78 FR 51126 - Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-20

    ... 204B helicopters. This proposed AD would require inspecting the tail rotor (T/R) cable assembly for an... intended to prevent disengagement of the cable from the barrel, failure of the T/R pitch control, and... the cable, could result in disengagement of the cable, T/R pitch control failure in a fixed...

  6. 77 FR 36389 - Airworthiness Directives; Bell Helicopter Textron Canada, Limited, Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-19

    .... (ASU), Night Vision Imaging System (NVIS) lighting modified by Supplemental Type Certificate SR01383SE... unfiltered turbine outlet temperature (TOT) internal over-temperature warning light, and based on those... prevent subsequent loss of control of the helicopter. DATES: This AD is effective July 24, 2012....

  7. 78 FR 4762 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-23

    ... Textron Canada Limited (Bell) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4; telephone (450) 437-2862 or (800) 363... based on those comments. Discussion Transport Canada Civil Aviation (TCCA) has issued AD No....

  8. 78 FR 23114 - Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-18

    ... indicated airspeed when the helicopter was tested to the cold temperature limits (-40 degrees centigrade... revealed when testing at low temperatures to minus 40 degrees Centigrade (-40 C). The TCCA advises that modification to the instrumentation is required to reflect the Vne airspeed values tested at temperatures...

  9. Analysis of Helicopter Noise Data Using International Helicopter Noise Certification Procedures,

    DTIC Science & Technology

    1986-03-01

    establishes noise levels using the basic testing, reduction and analysis procedures specified by the International Civil Aviation Organization ( ICAO ...for helicopter noise certification supplemented with some procedural refinements contained in ICAO Working Group II recommendations for incorporation...Noise levels are plotted versus the logarithm of maximum gross takeoff weight and are shown relative to the ICAO noise level limits. Data from the ICAO

  10. 78 FR 34958 - Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell), Model Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... directive (AD) for the Bell Model 412, 412CF, and 412EP helicopters. The AD currently requires reidentifying... the Instructions for Continued Airworthiness (ICAs) accordingly. Since we issued the AD, we have... requirements of the existing AD impossible. This proposed AD would retain the current requirements with...

  11. 78 FR 56592 - Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-13

    ..., for affected Model 205A-1 helicopters, replacing the chain and cable control system with a push- pull control system. This new AD requires, for Bell Model 204B, inspecting certain chains at specified..., replacing the chain and cable control system with an airworthy tail rotor push-pull control system kit....

  12. 78 FR 12646 - Airworthiness Directives; Agusta S.p.A. and Bell Helicopter Textron Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-25

    ... 412EP helicopters with certain DART Aerospace Ltd. (Dart) high gear aft crosstubes (crosstube) installed... five separate reports of crosstube failures. The actions in this proposed AD are intended to prevent... Aerospace LTD., 1270 Aberdeen St, Hawkesbury, ON, K6A 1K7, Canada; telephone: 1 613 632 5200; Fax: 1 613...

  13. 64 FR 3819 - Airworthiness Directives; Bell Helicopter Textron, Inc. Model 212 Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    1999-01-26

    ...-hours TIS, or that has passed an x-ray diffraction inspection in accordance with Bell Helicopter Textron... airworthy yoke assembly that has zero-hours TIS, or that has passed an x-ray diffraction inspection in... assembly (regardless of TIS) that has passed an x-ray diffraction inspection in accordance with...

  14. The Duke University Helicopter Observation Platform (HOP) for Environmental and Earth Science Studies

    NASA Astrophysics Data System (ADS)

    Avissar, R.; Holder, H. E.; Bolch, A.

    2006-12-01

    Duke University purchased a new Bell 206B3 ("JetRanger") helicopter to perform various atmospheric in situ and remotely-sensed environmental observations (referred to as the Helicopter Observation Platform HOP). As compared to other aircraft, the helicopter has the unequaled flexibility and maneuverability to fly slowly and close to the ground. Furthermore, it can land and refuel at station, which allows performing long-term observations during field campaigns. It can also operate from a ship at sea. This presents significant advantages especially for the observations of aerosols, fluxes of heat, water and other gases important for various environmental and Earth science studies. The Duke HOP is currently equipped with high-frequency sensors that can measure the 3D components of the wind, temperature, moisture and CO2. It is also equipped with an inlet to sample undisturbed air outside of the zone of influence of the main rotor wake and it is designed to support many other remote and in-situ sensors. A computational fluid dynamics (CFD) software was used to simulate the aerodynamical envelope of the HOP in flight at various airspeeds. Together with in- situ observations of turbulence in front of the helicopter nose where all the sensors are attached, the CFD results are used to demonstrate that the HOP can make high-quality observations of the above-mentioned environmental characteristics unaffected by the main-rotor wake at airspeeds as low as 15 m/s and as high as 60 m/s. This emphasizes the strong potential of this platform for environmental observations, especially of aerosols, which are sampled very inefficiently with other aircraft platforms. Flights conducted in the Neuse River Basin in North Carolina where atmospheric variables were collected simultaneously with a tethered sonde, a lidar, and on towers demonstrate the HOP capability and potential.

  15. Real-time classification of ground from lidar data for helicopter navigation

    NASA Astrophysics Data System (ADS)

    Eisenkeil, Ferdinand; Schafhitzel, Tobias; Kühne, Uwe; Deussen, Oliver

    2013-05-01

    Helicopter pilots often have to deal with bad weather conditions and degraded views. Such situations may decrease the pilots' situational awareness significantly. The worst-case scenario would be a complete loss of visual reference during an off-field landing due to brownout or white out. In order to increase the pilots' situational awareness, helicopters nowadays are equipped with different sensors that are used to gather information about the terrain ahead of the helicopter. Synthetic vision systems are used to capture and classify sensor data and to visualize them on multifunctional displays or pilot's head up displays. This requires the input data to be a reliably classified into obstacles and ground. In this paper, we present a regularization-based terrain classifier. Regularization is a popular segmentation method in computer vision and used in active contours. For a real-time application scenario with LIDAR data, we developed an optimization that uses different levels of detail depending on the accuracy of the sensor. After a preprocessing step where points are removed that cannot be ground, the method fits a shape underneath the recorded point cloud. Once this shape is calculated, the points below this shape can be distinguished from elevated objects and are classified as ground. Finally, we demonstrate the quality of our segmentation approach by its application on operational flight recordings. This method builds a part of an entire synthetic vision processing chain, where the classified points are used to support the generation of a real-time synthetic view of the terrain as an assistance tool for the helicopter pilot.

  16. REMOTE HANDLING ARRANGEMENTS

    DOEpatents

    Ginns, D.W.

    1958-04-01

    A means for handling remotely a sample pellet to be irradiated in a nuclear reactor is proposed. It is comprised essentially of an inlet tube extending through the outer shield of the reactor and being inclined so that its outer end is at a higher elevation than its inner end, an outlet tube extending through the outer shield being inclined so that its inner end is at a higher elevation than its outer end, the inner ends of these two tubes being interconnected, and a straight tube extending through the outer shield and into the reactor core between the inlet and outlet tubes and passing through the juncture of said inner ends. A rod-like member is rotatably and slidely operated within the central straight tube and has a receptacle on its inner end for receiving a sample pellet from the inlet tube. The rod member is operated to pick up a sample pellet from the inlet tube, carry the sample pellet into the irradiating position within the core, and return to the receiving position where it is rotated to dump the irradiated pellet into the outlet tube by which it is conveyed by gravity to the outside of the reactor. Stop members are provided in the inlet tube, and electrical operating devices are provided to control the sequence of the operation automatically.

  17. Quadrotor helicopter for surface hydrological measurements

    NASA Astrophysics Data System (ADS)

    Pagano, C.; Tauro, F.; Porfiri, M.; Grimaldi, S.

    2013-12-01

    Surface hydrological measurements are typically performed through user-assisted and intrusive field methodologies which can be inadequate to monitor remote and extended areas. In this poster, we present the design and development of a quadrotor helicopter equipped with digital acquisition system and image calibration units for surface flow measurements. This custom-built aerial vehicle is engineered to be lightweight, low-cost, highly customizable, and stable to guarantee optimal image quality. Quadricopter stability guarantees minimal vibrations during image acquisition and, therefore, improved accuracy in flow velocity estimation through large scale particle image velocimetry algorithms or particle tracking procedures. Stability during the vehicle pitching and rolling is achieved by adopting large arm span and high-wing configurations. Further, the vehicle framework is composed of lightweight aluminum and durable carbon fiber for optimal resilience. The open source Ardupilot microcontroller is used for remote control of the quadricopter. The microcontroller includes an inertial measurement unit (IMU) equipped with accelerometers and gyroscopes for stable flight through feedback control. The vehicle is powered by a 3 cell (11.1V) 3000 mAh Lithium-polymer battery. Electronic equipment and wiring are hosted into the hollow arms and on several carbon fiber platforms in the waterproof fuselage. Four 35A high-torque motors are supported at the far end of each arm with 10 × 4.7 inch propellers. Energy dissipation during landing is accomplished by four pivoting legs that, through the use of shock absorbers, prevent the impact energy from affecting the frame thus causing significant damage. The data capturing system consists of a GoPro Hero3 camera and in-house built camera gimbal and shock absorber damping device. The camera gimbal, hosted below the vehicle fuselage, is engineered to maintain the orthogonality of the camera axis with respect to the water surface by

  18. Handling the Heat.

    ERIC Educational Resources Information Center

    Caton, Jay

    1991-01-01

    School food-service programs, endangered by rising costs, would benefit by taking the following steps: (1) improve food quality and presentation; (2) renovate the appearance of cafeterias; (3) enlist cafeteria personnel in reforms and include profit sharing; (4) update management procedures; and (5) cut bureaucracy. (MLF)

  19. Design of helicopter rotors to noise constraints

    NASA Technical Reports Server (NTRS)

    Schaeffer, E. G.; Sternfeld, H., Jr.

    1978-01-01

    Results of the initial phase of a research project to study the design constraints on helicopter noise are presented. These include the calculation of nonimpulsive rotor harmonic and broadband hover noise spectra, over a wide range of rotor design variables and the sensitivity of perceived noise level (PNL) to changes in rotor design parameters. The prediction methodology used correlated well with measured whirl tower data. Application of the predictions to variations in rotor design showed tip speed and thrust as having the most effect on changing PNL.

  20. Prediction of helicopter rotor rotational noise

    NASA Astrophysics Data System (ADS)

    Xu, Guohua; Gao, Zheng

    1991-06-01

    Based on Farassat (1981) formulation 1A for subsonic time domain, a method is developed for predicting the rotor rotational noise, which is valid for arbitrary observer positions and all linear flight conditions. Without considering the elasticity of the blade, the retarded time equation and all of the integrands in the formulation 1A are derived and expressed as the proper form for numerical calculation. As examples, the noise calculation of the helicopter Z-8 rotor and 1/4 scale UH-1 rotor in hover are carried out. Discussions are presented on the influence of rotor parameters, such as the tip Mach number, the disk loading, and the blade airfoil.

  1. Climatic Laboratory Survey Hughes YAH-64 Helicopter

    DTIC Science & Technology

    1982-03-01

    considerations. Airflow velocity data were ob- tained with a hot wire anemometer placed 8 to 10 inches (23.3 to 25.4 cm) from the left and right...tenqeo side If noaweea7 and identify by block numboer) Environmental Testing YAH-64 Hel 4 copter Climatic Laboratory 125, 70, -25, and -50°F Nine...Deficiencies Twenty-two Shortcomings 2M AftRACTr (urama inflf Se Na ffllmny ad ideltly 57 block mmbw) Environmental testing of the YAH-64 helicopter was

  2. Analysis of potential helicopter vibration reduction concepts

    NASA Technical Reports Server (NTRS)

    Landgrebe, A. J.; Davis, M. W.

    1985-01-01

    Results of analytical investigations to develop, understand, and evaluate potential helicopter vibration reduction concepts are presented in the following areas: identification of the fundamental sources of vibratory loads, blade design for low vibration, application of design optimization techniques, active higher harmonic control, blade appended aeromechanical devices, and the prediction of vibratory airloads. Primary sources of vibration are identified for a selected four-bladed articulated rotor operating in high speed level flight. The application of analytical design procedures and optimization techniques are shown to have the potential for establishing reduced vibration blade designs through variations in blade mass and stiffness distributions, and chordwise center-of-gravity location.

  3. Development and validation of a piloted simulation of a helicopter and external sling load

    NASA Technical Reports Server (NTRS)

    Shaughnessy, J. D.; Deaux, T. N.; Yenni, K. R.

    1979-01-01

    A generalized, real time, piloted, visual simulation of a single rotor helicopter, suspension system, and external load is described and validated for the full flight envelope of the U.S. Army CH-54 helicopter and cargo container as an example. The mathematical model described uses modified nonlinear classical rotor theory for both the main rotor and tail rotor, nonlinear fuselage aerodynamics, an elastic suspension system, nonlinear load aerodynamics, and a loadground contact model. The implementation of the mathematical model on a large digital computing system is described, and validation of the simulation is discussed. The mathematical model is validated by comparing measured flight data with simulated data, by comparing linearized system matrices, eigenvalues, and eigenvectors with manufacturers' data, and by the subjective comparison of handling characteristics by experienced pilots. A visual landing display system for use in simulation which generates the pilot's forward looking real world display was examined and a special head up, down looking load/landing zone display is described.

  4. Flight crew fatigue III: North Sea helicopter air transport operations.

    PubMed

    Gander, P H; Barnes, R M; Gregory, K B; Graeber, R C; Connell, L J; Rosekind, M R

    1998-09-01

    We studied 32 helicopter pilots before, during, and after 4-5 d trips from Aberdeen, Scotland, to service North Sea oil rigs. On duty days, subjects awoke 1.5 h earlier than pretrip or posttrip, after having slept nearly an hour less. Subjective fatigue was greater posttrip than pretrip. By the end of trip days, fatigue was greater and mood more negative than by the end of pretrip days. During trips, daily caffeine consumption increased 42%, reports of headache doubled, reports of back pain increased 12-fold, and reports of burning eyes quadrupled. In the cockpits studied, thermal discomfort and high vibration levels were common. Subjective workload during preflight, taxi, climb, and cruise was related to the crewmembers' ratings of the quality of the aircraft systems. During descent and approach, workload was affected by weather at the landing site. During landing, it was influenced by the quality of the landing site and air traffic control. Beginning duty later, and greater attention to aircraft comfort and maintenance, should reduce fatigue in these operations.

  5. General equilibrium characteristics of a dual-lift helicopter system

    NASA Technical Reports Server (NTRS)

    Cicolani, L. S.; Kanning, G.

    1986-01-01

    The equilibrium characteristics of a dual-lift helicopter system are examined. The system consists of the cargo attached by cables to the endpoints of a spreader bar which is suspended by cables below two helicopters. Results are given for the orientation angles of the suspension system and its internal forces, and for the helicopter thrust vector requirements under general circumstances, including nonidentical helicopters, any accelerating or static equilibrium reference flight condition, any system heading relative to the flight direction, and any distribution of the load to the two helicopters. Optimum tether angles which minimize the sum of the required thrust magnitudes are also determined. The analysis does not consider the attitude degrees of freedom of the load and helicopters in detail, but assumes that these bodies are stable, and that their aerodynamic forces in equilibrium flight can be determined independently as functions of the reference trajectory. The ranges of these forces for sample helicopters and loads are examined and their effects on the equilibrium characteristics are given parametrically in the results.

  6. Fluid handling equipment: A compilation

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Devices and techniques used in fluid-handling and vacuum systems are described. Section 1 presents several articles on fluid lines and tubing. Section 2 describes a number of components such as valves, filters, and regulators. The last section contains descriptions of a number of innovative fluid-handling systems.

  7. Adoption of an unmanned helicopter for low-altitude remote sensing to estimate yield and total biomass of a rice crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A radio-controlled unmanned helicopter-based LARS (Low-Altitude Remote Sensing) platform was used to acquire quality images of high spatial and temporal resolution, in order to estimate yield and total biomass of a rice crop (Oriza Sativa, L.). Fifteen rice field plots with five N-treatments (0, 33,...

  8. System identification techniques for helicopter higher harmonic control

    NASA Technical Reports Server (NTRS)

    Jacklin, S. A.

    1986-01-01

    This paper presents and compares several system identification techniques proposed for use with higher harmonic control algorithms designed to alleviate helicopter vibration. All method for actively controlling helicopter vibration require the knowledge of how the vibration outputs are related to the control inputs. Off-line or batch identification methods for obtaining this knowledge are presented first. Then the more advanced, adaptive identification techniques proposed to track the helicopter model parameters in flight are discussed. Considerations regarding system identifiability, identification algorithm stability, and computer implementation are also discussed.

  9. Helicopter acoustic alerting system for high-security facilities

    NASA Astrophysics Data System (ADS)

    Steadman, Robert L.; Hansen, Scott; Park, Chris; Power, Dennis

    2009-05-01

    Helicopters present a serious threat to high security facilities such as prisons, nuclear sites, armories, and VIP compounds. They have the ability to instantly bypass conventional security measures focused on ground threats such as fences, check-points, and intrusion sensors. Leveraging the strong acoustic signature inherent in all helicopters, this system would automatically detect, classify, and accurately track helicopters using multi-node acoustic sensor fusion. An alert would be generated once the threat entered a predefined 3-dimension security zone in time for security personnel to repel the assault. In addition the system can precisely identify the landing point on the facility grounds.

  10. Optical Shaft-Angle Encoder For Helicopter Rotor

    NASA Technical Reports Server (NTRS)

    Golub, Robert A.; Fitzpatrick, Fred; Dennis, Dale V.; Taylor, Bryant D.

    1993-01-01

    Angular position of helicopter rotor blade determined precisely. Accomplished by use of optical shaft-angle encoder called "256 Ring" on rotor swashplate. Each 360 degree rotation of helicopter main rotor broken down into 256 reflective segments. As rotor rotates, beam of light reflected in turn from each segment into optoelectronic system. One of 256 segments reflects larger pulse than others do. Position of rotor determined by counting number of pulses after this reference pulse. While swashplate mounting requirements unique to each type of helicopter, concept applicable to all types of rotorcraft.

  11. Research requirements to reduce civil helicopter life cycle cost

    NASA Technical Reports Server (NTRS)

    Blewitt, S. J.

    1978-01-01

    The problem of the high cost of helicopter development, production, operation, and maintenance is defined and the cost drivers are identified. Helicopter life cycle costs would decrease by about 17 percent if currently available technology were applied. With advanced technology, a reduction of about 30 percent in helicopter life cycle costs is projected. Technological and managerial deficiencies which contribute to high costs are examined, basic research and development projects which can reduce costs include methods for reduced fuel consumption; improved turbine engines; airframe and engine production methods; safety; rotor systems; and advanced transmission systems.

  12. Thermal and Structural Analysis of Helicopter Transmission Housings Using NASTRAN

    NASA Technical Reports Server (NTRS)

    Howells, R. W.; Sciarra, J. J.; Ng, G. S.

    1976-01-01

    The application of NASTRAN to improve the design of helicopter transmission housings is described. A finite element model of the complete forward rotor transmission housing for the Boeing Vertol CH-47C helicopter was used to study thermal distortion and stress, stress and deflection due to static and dynamic loads, load paths, and design optimization by the control of structural energy distribution. The analytical results are correlated with test data and used to reduce weight and to improve strength, service life, failsafety, and reliability. The techniques presented, although applied herein to helicopter transmissions, are sufficiently general to be applicable to any power transmission system.

  13. [Anaesthesia under unfavorable conditions - rescue helicopter].

    PubMed

    Knacke, Peer G; Gehring, Hartmut; Saur, Petra

    2011-03-01

    Rescue helicopters are used for emergency care and transport of emergency patients. The dimension of the cabin is clearly limited. A transport is carried out under spatial narrowness and high noise levels. Acoustic alarms or noises caused by the patient are hardly to be perceived, so that the view at optical alarms is necessary. Environmental conditions affect the concentration on the patient. Rearrangement maneuvers represent the most critical phases. Always the whole apparative monitoring and respirator must be in the field of view of the emergency doctor, drugs to the care must be handy to be quickly administered, the quantity of oxygen has to be observed. Infusions and option of airway management are ready to set in advance. Standardized work with the aid of algorithms and knowledge of treatment recommendations and guidelines help to prevent errors. To optimize the care of emergency patients, special training courses for the crew of rescue helicopters are offered. A training simulator to practice different scenarios and the establishment of a CIRS system are recommended.

  14. Compound cycle engine for helicopter application

    NASA Technical Reports Server (NTRS)

    Castor, Jere; Martin, John; Bradley, Curtiss

    1987-01-01

    The compound cycle engine (CCE) is a highly turbocharged, power-compounded, ultra-high-power-density, lightweight diesel engine. The turbomachinery is similar to a moderate-pressure-ratio, free-power-turbine gas turbine engine and the diesel core is high speed and a low compression ratio. This engine is considered a potential candidate for future military helicopter applications. Cycle thermodynamic specific fuel consumption (SFC) and engine weight analyses performed to establish general engine operating parameters and configurations are presented. An extensive performance and weight analysis based on a typical 2-hour helicopter (+30 minute reserve) mission determined final conceptual engine design. With this mission, CCE performance was compared to that of a contemporary gas turbine engine. The CCE had a 31 percent lower-fuel consumption and resulted in a 16 percent reduction in engine plus fuel and fuel tank weight. Design SFC of the CCE is 0.33 lb/hp-hr and installed wet weight is 0.43 lb/hp. The major technology development areas required for the CCE are identified and briefly discussed.

  15. Helicopter pilot back pain: a preliminary study.

    PubMed

    Shanahan, D F; Reading, T E

    1984-02-01

    Because of the high prevalence of back pain experienced by U.S. Army helicopter pilots, a study was conducted to ascertain the feasibility of reproducing these symptoms in the laboratory. A mock-up of a UH-1H seat and control configuration was mounted to a multi-axis vibration simulator (MAVS). Eleven subjects were tested on the apparatus for two 120-min periods. During one period, the MAVS was programmed to reproduce vibrations recorded from a UH-1H in cruise flight. The subjects received no vibration during the other test period. All subjects reported back pain which they described as identical to the pain they experience during flight, during one or more of their test periods. There was no statistical difference between the vibration and nonvibration test conditions (p greater than 0.05) in terms of time of onset of pain or intensity of pain as measured by a visual analog scale. It appears the vibration at the frequencies and amplitudes tested plays little or no role in the etiology of the back symptoms reported by these pilots. It is proposed that the primary etiological factor for these symptoms is the poor posture pilots are obliged to assume for extended periods while operating helicopters.

  16. Flight service evaluation of composite helicopter components

    NASA Technical Reports Server (NTRS)

    Mardoian, George H.; Ezzo, Maureen B.

    1994-01-01

    This paper presents the results of a NASA funded contract and Sikorsky research and development programs to evaluate structural composite components in flight service on Sikorsky Model S-76 helicopters. Selected components were removed and tested at prescribed intervals over a nine year time frame. Four horizontal stabilizers and thirteen tail rotor spars were returned from commercial service in West Palm Beach, Florida and in the Gulf Coast region of Louisiana to determine the long term effects of operations in hot and humid climates on component performance. Concurrent with the flight component evaluation, panels of materials used in their fabrication were exposed to the environment in ground racks. Selected panels were tested annually to determine the effects of exposure on physical and mechanical properties. The results of 55,741 component flight hours and 911 months of field exposure are reported and compared with initial Federal Aviation Administration (FAA) certification data. The findings of this program have provided increased confidence in the long term durability of advanced composite materials used in helicopter structural applications.

  17. Compound cycle engine for helicopter application

    NASA Technical Reports Server (NTRS)

    Castor, Jere G.

    1986-01-01

    The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded, ultra-high power density, light-weight diesel engine. The turbomachinery is similar to a moderate pressure ratio, free power turbine engine and the diesel core is high speed and a low compression ratio. This engine is considered a potential candidate for future military light helicopter applications. This executive summary presents cycle thermodynamic (SFC) and engine weight analyses performed to establish general engine operating parameters and configuration. An extensive performance and weight analysis based on a typical two hour helicopter (+30 minute reserve) mission determined final conceptual engine design. With this mission, CCE performance was compared to that of a T-800 class gas turbine engine. The CCE had a 31% lower-fuel consumption and resulted in a 16% reduction in engine plus fuel and fuel tank weight. Design SFC of the CCE is 0.33 lb-HP-HR and installed wet weight is 0.43 lbs/HP. The major technology development areas required for the CCE are identified and briefly discussed.

  18. An unsteady helicopter rotor: Fuselage interaction analysis

    NASA Technical Reports Server (NTRS)

    Lorber, Peter F.; Egolf, T. Alan

    1988-01-01

    A computational method was developed to treat unsteady aerodynamic interactions between a helicopter rotor, wake, and fuselage and between the main and tail rotors. An existing lifting line prescribed wake rotor analysis and a source panel fuselage analysis were coupled and modified to predict unsteady fuselage surface pressures and airloads. A prescribed displacement technique is used to position the rotor wake about the fuselage. Either a rigid blade or an aeroelastic blade analysis may be used to establish rotor operating conditions. Sensitivity studies were performed to determine the influence of the wake fuselage geometry on the computation. Results are presented that describe the induced velocities, pressures, and airloads on the fuselage and on the rotor. The ability to treat arbitrary geometries is demonstrated using a simulated helicopter fuselage. The computational results are compared with fuselage surface pressure measurements at several locations. No experimental data was available to validate the primary product of the analysis: the vibratory airloads on the entire fuselage. A main rotor-tail rotor interaction analysis is also described, along with some hover and forward flight.

  19. A guide to forest seed handling

    SciTech Connect

    Willan, R.L.

    1986-01-01

    This guide to forest seed handling focuses on seed quality, i.e., the physiological viability and vigor of the seeds. Seed and fruit development, germination, and dormancy and the fundamentals of planning seed collections are covered. The guide includes discussions on seed collection of fallen fruits or seeds from the forest floor from the crowns of felled trees, and from standing trees with access from the ground and with other means of access. Also considered are precautions to be followed during fruit and seed handling between collection and processing. The different stages in seed processing are detailed, including extraction, depulping, drying, tumbling and threshing, dewinging, cleaning, grading, and mixing. Factors affecting seed longevity in storage and the choice of storage methods are reviewed. Different forms of seed pretreatment and seed testing methods are described.

  20. Information Handling is the Problem

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.

    2001-01-01

    This slide presentation reviews the concerns surrounding the automation of information handling. There are two types of decision support software that supports most Space Station Flight Controllers. one is very simple, and the other is very complex. A middle ground is sought. This is the reason for the Human Centered Autonomous and Assistant Systems Testbed (HCAAST) Project. The aim is to study flight controllers at work, and in the bigger picture, with particular attention to how they handle information and how coordination of multiple teams is performed. The focus of the project is on intelligent assistants to assist in handling information for the flight controllers.