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This paper summarizes insights into pilot compliance to Traffic alert and Collision Avoidance System (TCAS) Resolution Advisories (RA's), as gained in a series of experiments in an integrated air traffic-flight simulator with airline pilots. The simulator had a full implementation of TCAS, and the aircraft's path was controlled by an air traffic controller as part of a busy traffic stream arriving into Dallas-Fort Worth. The pilots were urged to apply their best judgment to resolve traffic events. The experiments varied Air Traffic Control (ATC) communications, including traffic call-outs and instructions that directly conflicted with TCAS advisories.-Additionally, the experiments varied traffic events by both relative trajectory (including events during approach intercept and with noncontrolled Visual Flight Regulation traffic passing 500 feet below) and a range of resolution advisory types (including preventive, corrective, and crossing-corrective RA's). The compliance of the pilots is detailed here, including examination of aspects of pilot responses to RAs that caused non-compliance. Further, the impact of several interventions - auto-execution, pilot training, and displays - will be compared for its impact on pilot compliance.

The Traffic alert and Collision Avoidance System (TCAS) is designed to reduce the number of mid-air collisions. TCAS monitors the nearby airspace for other aircraft which are shown to the pilot on a traffic situation display (TSD). In addition, TCAS alerts the pilot to the presence of nearby aircraft with a precautionary Traffic Advisory (TA). If separation continues to degrade, TCAS then provides a Resolution Advisory (RA) which will audibly and visually instruct the pilot to make a vertical avoidance maneuver. However, pilots do not always comply with the RA. Changing the TSD could help improve pilot compliance. During an RA, the pilot is asked to maneuver vertically, but the TSD provides a top-down horizontal view which does not project the flight-path of other traffic and does not show if the other traffic is also receiving an RA. This project performed a literature review, a work domain analysis, and pilot interviews to inform design changes. The design methods echoed a need to provide pilots with better altitude information during traffic events along with a better picture of traffic heading and velocity. From these results, a new display was designed and is described using an animation. Future work includes evaluation of the new display as part of an iterative design process.