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At least 919 records · Page 51

Initial piloted simulation study of geared flap control for tilt-wing V/STOL aircraft

A simulation study of a representative tilt wing transport aircraft was conducted in 1990 on the Ames Vertical Motion Simulator. This simulation is in response to renewed interest in the tilt wing concept for use in future military and civil applications. For past tilt wing concepts, pitch control in hover and low-speed flight has required a tail rotor or reaction jets at the tail. Use of mono cyclic propellers or a geared flap have also been proposed as alternate methods for providing pitch control at low speed. The geared flap is a subject of this current study. This report describes the geared flap concept, the tilt wing aircraft, the simulation model, the simulation facility and experiment setup, the pilots' evaluation tasks and procedures, and the results obtained from the simulation experiment. The pilot evaluations and comments are also documented in the report appendix.

Guerrero, Lourdes M.↗

Piloted simulation of an air-ground profile negotiation process in a time-based Air Traffic Control environment

Historically, development of airborne flight management systems (FMS) and ground-based air traffic control (ATC) systems has tended to focus on different objectives with little consideration for operational integration. A joint program, between NASA's Ames Research Center (Ames) and Langley Research Center (Langley), is underway to investigate the issues of, and develop systems for, the integration of ATC and airborne automation systems. A simulation study was conducted to evaluate a profile negotiation process (PNP) between the Center/TRACON Automation System (CTAS) and an aircraft equipped with a four-dimensional flight management system (4D FMS). Prototype procedures were developed to support the functional implementation of this process. The PNP was designed to provide an arrival trajectory solution which satisfies the separation requirements of ATC while remaining as close as possible to the aircraft's preferred trajectory. Results from the experiment indicate the potential for successful incorporation of aircraft-preferred arrival trajectories in the CTAS automation environment. Fuel savings on the order of 2 percent to 8 percent, compared to fuel required for the baseline CTAS arrival speed strategy, were achieved in the test scenarios. The data link procedures and clearances developed for this experiment, while providing the necessary functionality, were found to be operationally unacceptable to the pilots. In particular, additional pilot control and understanding of the proposed aircraft-preferred trajectory, and a simplified clearance procedure were cited as necessary for operational implementation of the concept.

Williams, David H.↗

High-altitude balloon-launched aircraft - A piloted simulation study

A real-time piloted simulation at the NASA Dryden Flight Research Facility was used to study the feasibility of launching a research aircraft from a high-altitude balloon. In the study, the simulated aircraft was launched in a nosedown attitude at zero airspeed from 110,000 ft. After launch, the pilot flew the aircraft through a near-maximum-lift pullout and then through a zoom climb to a trimmed, l-g flight condition at the test altitude. The study included parametric variations to measure the effects of launch altitude, gross weight, Mach number limit, and parachute size on the test altitude attained. The aerodynamic model of the simulated aircraft was based on flight test results, low Reynolds number windtunnel tests, and computational models; the model included significant Mach number and Reynolds number effects at high altitude. A small parachute was included in the simulation to limit Mach number during the pullout to avoid adverse transonic effects and their resultant energy losses. A small rocket motor was included in the simulation and was investigated for boosting the aircraft to a higher test altitude. In the study, a test altitude of approximately 95,000 ft was attained without rocket boost, and a test altitude in excess of 100,000 ft was attained using small rocket boost.

Murray, James E.↗

Piloted simulator investigations of a civil tilt-rotor aircraft on steep instrument approaches

NASA-Ames has used its Vertical Motion Simulator to investigate steep-glideslope instrument approaches for a civil transport tilt-rotor aircraft in two different cases: (1) where pilots used raw glideslope and localized error data for 6-25 deg slopes, terminating in slow roll-on landings, and (2) where a flight director commanded manual conversion from fixed-wing to helicopter modes and a deceleration on the glideslope led to a vertical landing on a small urban helipad. In the former, there occurred control problems directly ascribable to the slow approach speed; in the latter, the four-cue flight director's cockpit augmentation furnished adequate pilot ratings up to 15-deg glideslope.

Decker, William A.↗

Limitations of the Pilot in Applying Forces to Airplane Controls

Measurements were made to determine the relative maximum forces a pilot can exert on the controls of an airplane with the view of obtaining systematic data upon which to base the location of controls within the cockpit and the design of the control surfaces. A cockpit model of generous proportions, capable of being rotated to any attitude, was built with the location of the control stick and rudder pedals adjustable over a wide range of positions with respect to the seat. Besides measurements of maximum forces obtainable with various control locations and with the pilot in several attitudes, estimates of forces within the range normally encountered in flight were made to gain an indication of the accuracy of estimating control forces. The maximum aileron forces measured were of the order of 90 pounds, maximum elevator 200 pounds, and maximum rudder 450 pounds. The average forces applied with the controls in the neutral position for the various cockpit attitudes were of the order of 35, 95, and 400 pounds, respectively, for the ailerons, elevators, and rudder.

Gough, M N↗

Piloting technique for recovery from spins

Systematic flight investigation of the spinning characteristics of various airplanes over a period of several years have given the pilots engaged in the testing a varied and extensive experience. From this experience certain general rules of procedure have been formulated, particularly for the sequence of operation of the controls in recovery from spins, and are recommended to the attention of all pilots.

Mcavoy, W H↗

Maximum Forces Applied by Pilots to Wheel-type Controls

Measurements were made of the maximum push, pull, and tangential forces that could be applied to airplane wheel-type controls for a wide range of fore-and-aft positions of the wheel. The measurements were conducted with several sizes of wheels and several heights of the center of the wheel above the seat. Various one and two-hand grips with pilots both secure and free were studied for each of the two pilots used in the investigation.

Mcavoy, William H↗

Longitudinal stability in relation to the use of an automatic pilot

The effect of restraint in pitching introduced by an automatic pilot upon the longitudinal stability of an airplane has been studied. Customary simplifying assumptions have been made in setting down the equations of motion, and the results of computations based on the simplified equations are presented to show the effect of an automatic pilot installed in an airplane of known dimensions and characteristics. The equations developed have been applied by making calculations for a Clark biplane and a Fairchild 22 monoplane.

Klemin, Alexander↗

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

This document contains papers from a specialists' meeting entitled "Piloting Vertical Flight Aircraft. A Conference on Flying Qualities and Human Factors." The conference was co-sponsored by the American Helicopter Society--San Francisco Bay Chapter, and the NASA Ames Research Center. It was held January 20-22, 1993 at the Sheraton Hotel Fisherman's Wharf, San Francisco, California. 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. Recognizing that human capabilities and limitations form an integral aspect of the operations for these classes of vehicles, a secondary goal of the conference was to provide an initial venue for enhanced interaction between human factors and handling qualities specialists.

Helicopter↗

Design and pilot evaluation of the RAH-66 Comanche Core AFCS

This paper addresses the design and pilot evaluation of the Core Automatic Flight Control System (AFCS) for the Reconnaissance/Attack Helicopter (RAH-66) Comanche. During the period from November 1991 through February 1992, the RAH-66 Comanche control laws were evaluated through a structured pilot acceptance test using a motion base simulator. Design requirements, descriptions of the control law design, and handling qualities data collected from ADS-33 maneuvers are presented.

Fogler, Donald L., Jr.↗

Biotelemetry implant volume and weight in rats: A pilot study report

This paper reports the results of a pilot study in which a 240-gram rat was implanted for 41 days with biotelemetry devices weighing a total of 36 gm (18 cc). The implanted animal showed no differences in weight gain, food and water consumption, and postnecropsy organ weights when compared to both an unoperated control animal and an animal that underwent surgery but did not receive an implant. The implanted animal also had temperature and activity rhythms similar to those reported using much smaller implants. Thus, this pilot study showed that a 240-gm rat could be implanted with biotelemetry devices weighing nearly 15 percent of body weight without significant changes in health or behavior. A larger study involving more animals and similar implant sizes is recommended.

Somps, Chris J.↗

Managing systems faults on the commercial flight deck: Analysis of pilots' organization and prioritization of fault management information

In rare instances, flight crews of commercial aircraft must manage complex systems faults in addition to all their normal flight tasks. Pilot errors in fault management have been attributed, at least in part, to an incomplete or inaccurate awareness of the fault situation. The current study is part of a program aimed at assuring that the types of information potentially available from an intelligent fault management aiding concept developed at NASA Langley called 'Faultfinde' (see Abbott, Schutte, Palmer, and Ricks, 1987) are an asset rather than a liability: additional information should improve pilot performance and aircraft safety, but it should not confuse, distract, overload, mislead, or generally exacerbate already difficult circumstances.

Rogers, William H.↗

The influence of air traffic control message length and timing on pilot communication

The present paper outlines an approach to air traffic control (ATC) communication that is based on theories of dialogue organization and describes several steps or phases in routine controller-pilot communication. The introduction also describes several kinds of communication problems that often disrupt these steps, as well as how these problems may be caused by factors related to ATC messages, the communication medium (radio vs. data link) and task workload. Next, a part-task simulation study is described. This study focused on how problems in radio communication are related to message factors. More specifically, we examined if pilots are more likely to misunderstanding longer ATC messages. A more general goal of the study is to show that communication analysis can help trace where problem occur and why.

Morrow, Daniel↗

Piloted Parameter Identification Flight Test Maneuvers for Closed Loop Modeling of the F-18 High Alpha Research Vehicle (HARV)

Flight test maneuvers are specified for the F-18 High Alpha Research Vehicle (HARV). The maneuvers were designed for closed loop parameter identification purposes, specifically for longitudinal and lateral linear model parameter estimation at 5, 20, 30, 45, and 60 degrees angle of attack, using the NASA 1A control law. Each maneuver is to be realized by the pilot applying square wave inputs to specific pilot station controls. Maneuver descriptions and complete specifications of the time/amplitude points defining each input are included, along with plots of the input time histories.

Morelli, Eugene A.↗

Structural dynamic model obtained from flight use with piloted simulation and handling qualities analysis

The ability to use flight data to determine an aircraft model with structural dynamic effects suitable for piloted simulation. and handling qualities analysis has been developed. This technique was demonstrated using SR-71 flight test data. For the SR-71 aircraft, the most significant structural response is the longitudinal first-bending mode. This mode was modeled as a second-order system, and the other higher order modes were modeled as a time delay. The distribution of the modal response at various fuselage locations was developed using a uniform beam solution, which can be calibrated using flight data. This approach was compared to the mode shape obtained from the ground vibration test, and the general form of the uniform beam solution was found to be a good representation of the mode shape in the areas of interest. To calibrate the solution, pitch-rate and normal-acceleration instrumentation is required for at least two locations. With the resulting structural model incorporated into the simulation, a good representation of the flight characteristics was provided for handling qualities analysis and piloted simulation.

Powers, Bruce G.↗

General Aviation Pilot Advisory and Training System (GAPATS)

The goal of this project is to achieve a validated General Aviation Pilot Advisor and Training System (GAPATS) engineering prototype, implemented according to commercial software standards and Federal Aviation Administration (FAA) issues of certification. Phase 2 builds on progress during Phase 1, which exceeded proposed objectives. The basic technology has been transferred from previous NASA research (1989 to 1994). We anticipate a commercially licensable prototype, validated by pilots in a flight simulator and in a light twin-engine research aircraft for FAA certification, by January 1998.

Painter, John↗

An Investigation of General Aviation Problems and Issues: An Integration of Pilot-Cockpit Interface Research

The General Aviation (GA) industry has suffered a ten-year decline in the number of airplanes sold. This decline is due mainly to the increase cost associated with purchasing, insuring, maintaining, operating, and pilot training a GA airplane. In response to this decline the Federal Aviation Administration (FAA) and the National Aeronautics and Space Administration (NASA) developed a program (Advanced General Aviation Transport Experiments - AGATE) to address these issues. The purpose of AGATE focused within this report is to reduce the costs to acquire and maintain instrument-flight-proficiency. The AGATE program defined four elements necessary to accomplish these goals: (1) new and intuitive cockpit displays and controls, (2) situation technologies for weather, traffic, and navigation, (3) expert systems for system monitoring, and (4) reduced cost training methods. One recognized need for the GA pilot and airplane is to provide cockpit displays and systems already available to transport category airplane. These displays such as Electronic Flight and Instrument System (EFIS), graphic weather and traffic displays, and flight management systems. The goal of this grant was to develop the AGATE GA Display Evaluation Workstation as a tool to test these existing and emerging technologies in the GA environment.

Bortolussi, Michael R.↗

A Qualitative Piloted Evaluation of the Tupolev Tu-144 Supersonic Transport

Two U.S. research pilots evaluated the Tupolev Tu-144 supersonic transport aircraft on three dedicated flights: one subsonic and two supersonic profiles. The flight profiles and maneuvers were developed jointly by Tupolev and U.S. engineers. The vehicle was found to have unique operational and flight characteristics that serve as lessons for designers of future supersonic transport aircraft. Vehicle subsystems and observed characteristics are described as are flight test planning and ground monitoring facilities. Maneuver descriptions and extended pilot narratives for each flight are included as appendices.

Rivers, Robert A.↗