Engineering topics

Harris, R. L., Sr.

Publications and source records attributed to Harris, R. L., Sr..

29 records · Page 2

NASA NTRS1981

How a pilot looks at altitude

Commercial pilot eye scanning data previously collected were reanalyzed to evaluate how pilots used the drum pointer altimeter. The results of these tests showed that the pilots seldom used the drum window apparently because it was difficult to read as indicated by average drum window dwell times of 0.6 sec. It is suggested that pilot scanning data be collected for other types of altimeters in order to find those with good scanning characteristics.

Spady, A. A., Jr.↗

NASA NTRS1981

How a pilot looks at altitude

Commerical pilot eye scanning data previously collected were reanalyzed to evaluate how pilot used the drum pointer altimeter. The results of these tests showed that the pilots seldom used the drum window apparently because it was difficult to read as indicated by average drum window dwell times of .6 seconds. It is suggested that pilot scanning data be collected for other type of altimeters in order to find those with good scanning characteristics.

Spady, A. A., Jr.↗

NASA NTRS1981

Visual scanning behavior and pilot workload

An experimental paradigm and a set of results which demonstrate a relationship between the level of performance on a skilled man-machine control task, the skill of the operator, the level of mental difficulty induced by an additional task imposed on the basic control task, and visual scanning performance. During a constant, simulated piloting task, visual scanning of instruments was found to vary as a function of the level of difficulty of a verbal mental loading task. The average dwell time of each fixation on the pilot's primary instrument increased as a function of the estimated skill level of the pilots, with novices being affected by the loading task much more than the experts. The results suggest that visual scanning of instruments in a controlled task may be an indicator of both workload and skill.

Harris, R. L., Sr.↗

NASA NTRS1980

What do pilots see in displays

Based on pilots' scanning data and discussions with pilots, general aviation flight instruments have been classified into three categories. The classification is related to the type of information presented, the way the information is used, and the pilot's role as a monitor and controller. Suggestions are made for modifying the instruments of one category to improve the information displayed such that when monitoring, the pilot can more quickly extract the information needed.

Harris, R. L., Sr.↗

NASA NTRS1979

Preliminary investigation of pilot scanning techniques of dial pointing instruments

Two pilots' methods of looking at instruments with needle pointers in a fixed base helicopter simulation were observed. A total of 45 runs were analyzed for each pilot. The data indicated that two apparently different techniques were being used; one looking at the needle point, the other looking at a fixed spot on the instrument and reading the needle direction parafoveally. The latter technique is found to be somewhat faster with both pilots accomplishing the flying task.

Harris, R. L., Sr.↗

NASA NTRS1979

Advanced transport operation effects on pilot scan patterns

Long straight-in and close-in, curved, descending instrument approaches were made in NASA's fixed-base Terminal Configured Vehicle simulator. The pilot either manually controlled the simulator or monitored the automatic system control of the simulated aircraft during the approach. Tests were performed with or without the display of traffic. The results indicate that the pilots' use of the Electronic Horizontal Situation Indicator (EHSI) increased appreciably for the close-in, curved, descending approach compared to the conventional straight-in approach. When operating as a monitor of the autopilot system, the pilot scanned around more with less attention devoted to the Electronic Attitude Direction Indicator (EADI). The pilots preferred the manual mode because it kept them in the control loop. The addition of displayed traffic to the EHSI increased the pilots' use of the EHSI with a corresponding reduction in his use of the EADI. Also, the pilot's pupil diameter increased during the landing flare indicating a higher stress level even though the tests were conducted in a fixed-base simulator.

Harris, R. L., Sr.↗

NASA NTRS1979

An evaluation of some display parameters for an advanced landing display

This paper discusses the results of a series of tests conducted to better understand some of the design parameters related to presenting an aircraft landing display on a cathode ray tube (CRT). The study was conducted on an aircraft simulator and the results were evaluated in terms of touchdown performance, pilot control activity, and scanning behavior, that is, how the pilot used the display. The results of the study indicate that magnification, presentation of symbols representing aircraft state, and whether the display is presented in a conventional CRT head-down configuration or a collimated head-up configuration, all play a role in the pilot's performance.

Waller, M. C.↗

NASA NTRS1978

Simulation and flight evaluation of a head-up landing aid for general aviation

A head-up general aviation landing aid called a landing site indicator (LASI) was tested in a fixed-base, visual simulator and in an airplane to determine the effectiveness of the LASI. The display, which had a simplified format and method of implementation, presented to the pilot in his line of sight through the windshield a graphic representation of the airplane's velocity vector. In each testing model (simulation of flight), each of 4 pilots made 20 landing approaches with the LASI and 20 approaches without it. The standard deviations of approach and touchdown parameters were considered an indication of pilot consistency. Use of the LASI improved consistency and also reduced elevator, aileron, and rudder control activity. Pilots' comments indicated that the LASI reduced work load. An appendix is included with a discussion of the simulator effectiveness for visual flight tasks.

Harris, R. L., Sr.↗

NASA NTRS1978

Instructor and student pilots' subjective evaluation of a general aviation simulator with a terrain visual system

Ten student pilots were given a 1 hour training session in the NASA Langley Research Center's General Aviation Simulator by a certified flight instructor and a follow-up flight evaluation was performed by the student's own flight instructor, who has also flown the simulator. The students and instructors generally felt that the simulator session had a positive effect on the students. They recommended that a simulator with a visual scene and a motion base would be useful in performing such maneuvers as: landing approaches, level flight, climbs, dives, turns, instrument work, and radio navigation, recommending that the simulator would be an efficient means of introducing the student to new maneuvers before doing them in flight. The students and instructors estimated that about 8 hours of simulator time could be profitably devoted to the private pilot training.

Kiteley, G. W.↗

NASA NTRS1974

Simulation and flight evaluation of a heads-up display for general aviation

A landing-site indicator (LASI) has been devised as a relatively simple heads-up display to show the pilot the magnitude and direction of the aircraft's velocity vector superimposed on the pilot's view of the landing area. A total of 160 landings were performed in a fixed-base simulation program by four pilots with and without the LASI display. These tests showed the display to be of beneficial use in making the approaches more consistent. Some inferences were also made that the physical workload would also be less with its use. The pilots generally agreed that the LASI, as represented in the simulation was a useful landing aid. Additional pilot comments from preliminary flight tests of a breadboard LASI display unit tend to confirm the simulator results.

Harris, R. L., Sr.↗

NASA NTRS1973

An exploratory simulation study of a head-up display for general aviation lightplanes

The concept of a simplified head-up display referred to as a landing-site indicator (LASI) for use in lightplanes is discussed. Results of a fixed-base simulation study exploring the feasibility of the LASI concept are presented in terms of measurements of pilot performance, control-activity parameters, and subjective comments of four test subjects. These subjects, all of whom had various degrees of piloting experience in this type aircraft, performed a series of simulated landings both with and without the LASI starting from different initial conditions in the final approach leg of the landing maneuver.

Harris, R. L., Sr.↗