Cockpit Display Of Traffic Information Research Articles

Analysis of in-trail following dynamics of CDTI-equipped aircraft

In connection with the necessity to provide greater terminal area capacity, attention is given to approaches in which the required increase in capacity will be obtained by making use of more automation and by involving the pilot to a larger degree in the air traffic control (ATC) process. It was recommended that NASA should make extensive use of its research aircraft and cockpit simulators to assist the FAA in examining the capabilities and limitations of cockpit displays of traffic information (CDTI). A program was organized which utilizes FAA ATC (ground-based) simulators and NASA aircraft and associated cockpit simulators in a research project which explores applications of the CDTI system. The present investigation is concerned with several questions related to the CDTI-based terminal area traffic tactical control concepts. Attention is given to longitudinal separation criteria, a longitudinal following model, longitudinal capture, combined longitudinal/vertical control, and lateral control.

Facility Requirements for Cockpit Traffic Display Research

There is a great deal of research being conducted on the efficacy of a cockpit display of traffic information (CDTI). The facilities used in this research vary from elaborate combinations of simulators to one piloted simulator with additional aircraft controlled by a person at a keyboard. This study examined the facility requirements to adequately research the implementation of CDTI's in terms of simulator fidelity and the number of CDTI-equipped simulators. The facility was used in two configurations. There were three air carrier simulator cabs and four general aviation (GA) pilots with continuous analog autopilot control. In the lower-fidelity configuration, there were two single-piloted simulator cabs and five GA aircraft controlled by one keyboard operator. The number of CDTI-equipped simulators was zero, two, or seven. All aircraft flew an instrument approach in terminal airspace under full control of an air traffic controller. Comparisons across conditions of simulator fidelity and the number of CDTI-equipped aircraft were made. Differences were found due to the presence of a CDTI. With a CDTI in their aircraft, there were more pilot/controller communications, the variance of intercrossing times at the middle marker was greater, and GA pilots made more speed and altitude changes. The horizontal flight path was longer without CDTI. The number of communications went up as the number of CDTI-equipped aircraft increased. However, this was the only measure showing a difference due to the number of aircraft with CDTI. Measures showing a difference due to simulator type were: altitude and localizer error at the outer marker, intercrossing time at the outer and middle marker, horizontal path length, number of communications, aircraft separation violations, and GA pilots' speed, heading and altitude changes. Differences due to the facility simulation configuration were the number of GA pilot speed, heading and altitude changes and the aircraft intercrossing times at the outer and middle marker. The latter suggests a difference in the air traffic control of the simulators and may have an inplication in CDTI research.

Contingency in Visual Scanning of Cockpit Traffic Displays

A statistical method to identify reliable, repetitive scanning patterns in the positions of visual fixations has been developed and applied to data from 8 airline pilots who monitored cockpit displays of traffic information (CDTI). Their fixational transition patterns between points of interest on the display showed deterministic, statistical dependencies generally associated with symbols predicting future aircraft position. These dependencies constitute deviations from stratified random sampling of the visual information on the display, confirm the importance of future aircraft position information for the use of CDTI, and provide objective support for the existence of “scanpaths” in visual fixation patterns.

Effect of Perceived Threat on Avoidance Maneuvers Selected While Viewing Cockpit Traffic Displays

Ten airline pilots rated the collision danger of air traffic presented on cockpit displays of traffic information (CDTI) while they monitored simulated departures from Denver. They selected avoidance maneuvers when necessary for separation. Most evasive maneuvers were turns rather than vertical maneuvers. Evasive maneuvers chosen for encounters with low or moderate perceived collision danger were generally toward the intruding aircraft. This tendency lessened as the perceived threat level increased. In the highest threat situations pilots turned toward the intruder only at chance levels. Some of the implications of the pilots' turning-towards tendencies are discussed with respect to automatic collision avoidance systems and coordination of avoidance maneuvers of conflicting aircraft.

Perception of Horizontal Aircraft Separation on a Cockpit Display of Traffic Information

Perception of aircraft separation on a cockpit display of traffic information (CDTI) may be influenced by many different display elements such as: information content of aircraft predictors and history, number and type of display background elements, map orientation, map scale, and update rate. The experimental task required subjects to judge whether an intruder aircraft would ultimately pass in front of or in back of their own aircraft. The results of nine experiments are described. Displayed history did not improve performance, although it was desired by pilots when there was no other explicit display of aircraft turn rate. Pilots made fewer errors when they had predictive information, especially with the predictor curved proportional to turn rate. Varying the rate of updating information on the display from 0.1 to 4 s did not affect performance. There was no difference in performance when display viewing time was varied from 1 to 16 s.

Evaluation of the Potential Format and Content of a Cockpit Display of Traffic Information

Computer-generated displays of traffic information may be available in airplane cockpits within a decade. Many questions exist, however, about the impact of such displays on the air traffic control system. The purpose of the following studies was to design suitable display(s) to be used in simulation research aimed at answering these questions. The initial approach was to solicit opinions from general aviation and airline pilots about display format, information content, and symbology after they had viewed more than 100 candidate displays and display options. The pilots' responses provided a preliminary indication of what information the potential user-population felt should be included in a traffic display. A series of later experiments was conducted to determine whether the features preferred in the pilot opinion survey would contribute to accurate and efficient pilot assessment of the spatial relationship between their own and another aircraft. A series of encounters between two aircraft were simulated in which the speed, heading, altitude, and geometrical relationship between the two aircraft were varied to allow a comparison between several graphic and symbolic formats for presenting information about the two aircraft.