Search NASA⌕ Search

Engineering topics

Person, L. H., Jr.

Publications and source records attributed to Person, L. H., Jr..

18 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

NASA B737 flight test results of the Total Energy Control System

The Total Energy Control System was developed and tested in September 1985 during five flights on the NASA Langley Transport System Research Vehicle, a modified Boeing B737. In the system, the total kinetic and potential energy of the aircraft is controlled by the throttles, and the energy distribution is controlled by the elevator. A common inner loop is used for each mode of the autopilot, and all the control functions of a conventional pitch autopilot and autothrottle are integrated into a single generalized control concept, providing decoupled flightpath and maneuver control, and a coordinated throttle response for all maneuvers. No instabilities or design problems requiring gain adjustment in flight were found, and comparison with simulation results showed excellent path tracking.

Bruce, K. R.↗
NASA NTRS1984

An advanced media interface for control of modern transport aircraft navigational systems

With the advent of digital avionics, the workload of the pilot in a moderen transport aircraft is increasing significantly. This situation makes it necessary to reduce pilot workload with the aid of new advanced technologies. As part of an effort to improve information management systems, NASA has, therefore, studied an advanced concept for managing the navigational tasks of a modern transport aircraft. This concept is mainly concerned with the simplification of the pilot interface. The advanced navigational system provides a simple method for a pilot to enter new waypoints to change his flight plan because of heavy traffic, adverse weather conditions, or other reasons. The navigational system was implemented and evaluated in a flight simulator representative of a modern transport aircraft. Attention is given to the simulator, flight simulation, multimode devices, and the navigational system.

Jones, D. R.↗
NASA NTRS1981

Influence of display and control compatibility on pilot-induced oscillations

The differences in techniques used by seven pilots to acquire information from an advanced display for instrument approaches to and landings on a runway were investigated. A fixed base simulator programmed with dynamics resembling the terminal configured vehicle (TCV) was studied. It is shown that the seven pilots can be divided into two groups which used the display with distinctly different strategies for controlling the airplane. A related pattern of performance differences resulted. It is found that pilots who primarily use raw flight path information experience longitudinal oscillations while pilots using attitude information did not.

Waller, M. C.↗
NASA NTRS1981

The integration of control and display concepts for improved pilot situational awareness

Consideration is given to a part of the Langley Terminal Configured Vehicle program in which the pilot is retained as an active segment of an integrated system. The pilot is active in the outer control loop and controls the orientation of the aircraft velocity. The pilot thus has a task, but a low workload. Attention is also given to first- and second-generation primary flight display for horizontal and vertical situation awareness.

Person, L. H., Jr.↗
NASA NTRS1981

Test results of flight guidance for fuel conservative descents in a time-based metered air traffic environment

The NASA developed, implemented, and flight tested a flight management algorithm designed to improve the accuracy of delivering an airplane in a fuel-conservative manner to a metering fix at a time designated by air traffic control. This algorithm provides a 3D path with time control (4D) for the TCV B-737 airplane to make an idle-thrust, clean configured (landing gear up, flaps zero, and speed brakes retracted) descent to arrive at the metering fix at a predetermined time, altitude, and airspeed. The descent path is calculated for a constant Mach/airspeed schedule from linear approximations of airplane performance with considerations given for gross weight, wind, and nonstandard pressure and temperature effects. The flight management descent algorithms are described and flight test results are presented.

Knox, C. E.↗
NASA NTRS1980

Flight investigation of cockpit-displayed traffic information utilizing coded symbology in an advanced operational environment

Traffic symbology was encoded to provide additional information concerning the traffic, which was displayed on the pilot's electronic horizontal situation indicators (EHSI). A research airplane representing an advanced operational environment was used to assess the benefit of coded traffic symbology in a realistic work-load environment. Traffic scenarios, involving both conflict-free and conflict situations, were employed. Subjective pilot commentary was obtained through the use of a questionnaire and extensive pilot debriefings. These results grouped conveniently under two categories: display factors and task performance. A major item under the display factor category was the problem of display clutter. The primary contributors to clutter were the use of large map-scale factors, the use of traffic data blocks, and the presentation of more than a few airplanes. In terms of task performance, the cockpit-displayed traffic information was found to provide excellent overall situation awareness. Additionally, mile separation prescribed during these tests.

Abbott, T. S.↗
NASA NTRS1980

Early flight test experience with Cockpit Displayed Traffic Information (CDTI)

Coded symbology, based on the results of early human factors studies, was displayed on the electronic horizontal situation indicator and flight tested on an advanced research aircraft in order to subject the coded traffic symbology to a realistic flight environment and to assess its value by means of a direct comparison with simple, uncoded traffic symbology. The tests consisted of 28 curved, decelerating approaches, flown by research-pilot flight crews. The traffic scenarios involved both conflict-free and blunder situations. Subjective pilot commentary was obtained through the use of a questionnaire and extensive pilot debriefing sessions. The results of these debriefing sessions group conveniently under either of two categories: display factors or task performance. A major item under the display factor category was the problem of display clutter. The primary contributors to clutter were the use of large map-scale factors, the use of traffic data blocks, and the presentation of more than a few aircraft. In terms of task performance, the cockpit displayed traffic information was found to provide excellent overall situation awareness.

Abbott, T. S.↗
NASA NTRS1979

Flying NASA's terminal configured vehicle against the microwave landing system

Technology for advanced airborne systems and flight procedures to improve terminal-area operations in ATC environment is developed. The terminal configured vehicle (TCV) aircraft, its integrated digital electronic displays and flight controls, and how the pilot interfaces with the aircraft to fly precise curved descending approaches using Microwave Landing System (MLS) guidance are discussed.

Person, L. H., Jr.↗
NASA NTRS1979

Flying NASA's Terminal Configured Vehicle against the Microwave Landing System

A prototype Boeing 737 aircraft has been received for use in the Terminal Configured Vehicle (TCV) Program, the aim of which is to develop technology for advanced airborne systems and flight procedures to improve terminal area operations in the future ATC environment. The paper discusses the TCV aircraft, its integrated digital electronic displays and flight controls, and the means by which the pilot interfaces with the aircraft to fly precise curved descending approaches under MLS guidance.

Person, L. H., Jr.↗
NASA NTRS1978

Terminal-area flight experience with the NASA Terminal Configured Vehicle

Increases in the volume of air traffic around major terminals, as well as the advent of MLS and other sophisticated ATC techniques, have prompted the development of aircraft specifically optimized for flight in terminal areas. A modified Boeing 737, developed by NASA, is presented as an illustration of a Terminal Configured Vehicle (TCV). Among the TCV systems discussed are the electronic attitude direction indicator (EADI) and the electronic horizontal situation indicator (EHSI), both of which are advanced display systems capable of positioning the runway center line from a variety of glide slope paths, and with reference to time, i.e., the on-board computer can predict where the aircraft will be at a given number of seconds from the time of the analysis. Thus, 4-D navigation (time path) can be selected as a control mode, together with vertical and horizontal path modes.

Morello, S. A.↗
NASA NTRS1977

Flight investigation of a vertical-velocity command system for VTOL aircraft

A flight investigation was undertaken to assess the potential benefits afforded by a vertical-velocity command system (VVCS) for VTOL (vertical take-off and landing) aircraft. This augmentation system was conceived primarily as a means of lowering pilot workload during decelerating approaches to a hover and/or landing under category III instrument meteorological conditions. The scope of the investigation included a determination of acceptable system parameters, a visual flight evaluation, and an instrument flight evaluation which employed a 10 deg, decelerating, simulated instrument approach task. The results indicated that the VVCS, which decouples the pitch and vertical degrees of freedom, provides more accurate glide-path tracking and a lower pilot workload than does the unaugmented system.

Kelly, J. R.↗
NASA NTRS1977

The effect of variations in controls and displays on helicopter instrument approach capability

A flight investigation was conducted with a variable stability helicopter to determine the effects of variations in controls and displays on helicopter instrument approach capabilities. The baseline instrument approach task was a decelerating approach to a hover along a 6 deg glide slope. Pilot evaluations were obtained for both the constant speed part of the task and the deceleration and hover part of the task. The attitude stability augmentation system (SAS) was strongly preferred over the rate SAS because the aircraft had a divergent pitch response. From a display variation standpoint, it was not possible to decelerate to a hover in a consistent manner, regardless of the control system employed, with situation information only. In particular, the deceleration and hover part of the task was unacceptable without flight director command information.

Niessen, F. R.↗
NASA NTRS1976

A piloted-simulation evaluation of two electronic display formats for approach and landing

The results of a piloted-simulation evaluation of the benefits of adding runway symbology and track information to a baseline electronic-attitude-director-indicator (EADI) format for the approach-to-landing task were presented. The evaluation was conducted for the baseline format and for the baseline format with the added symbology during 3 deg straight-in approaches with calm, cross-wind, and turbulence conditions. Flight-path performance data and pilot subjective comments were examined with regard to the pilot's tracking performance and mental workload for both display formats. The results show that the addition of a perspective runway image and relative track information to a basic situation-information EADI format improve the tracking performance both laterally and vertically during an approach-to-landing task and that the mental workload required to assess the approach situation was thus reduced as a result of integration of information.

Steinmetz, G. G.↗
NASA NTRS1972

A flight evaluation of a vectored thrust jet V/STOL airplane during simulated instrument approaches using the Kestrel (XV-6A) airplane

An in-flight investigation was made to determine the terminal-area operating problems of a vectored-thrust-jet vertical and short take-off landing (V/STOL) airplane under simulated instrument conditions. Handling-qualities data pertinent to the terminal-area approach and landing task are presented in the text, and additional documentation is included in the appendixes. Problems dealing with the cruise letdown to localizer capture, conversion to powered-lift flight, precise control of the glide slope, approach velocity or deceleration schedule, hover, and landing are discussed.

Morello, S. A.↗