Pilot responses to traffic events during NextGen high traffic density terminal operations

Implementation of NextGen operations into a high traffic density terminal area must be robust against traffic events, particularly where aircraft are coupled to other aircraft via ADS-B In information. For example, in a traffic flow in which arriving aircraft are carefully maintaining a specified time interval one behind another, an aircraft crossing the traffic flow could cause not only one aircraft to be commanded to follow a Traffic Alert and Collision Avoidance System (TCAS) Resolution Advisory (RA), but also then disrupt the aircraft following the maneuvering aircraft. This work evaluates pilot responses to TCAS RAs during NextGen operations, such as Advanced Flightdeck Interval Management (AFIM), which couple an aircraft's autoflight system to the flight path of another aircraft via ADS-B In information. Pilot's compliance to RAs was as low in prior studies of compliance in current-day operations, and did not appear to vary with when the pilot chose to discontinue AFIM operations or with alerts about AFIM operation. Likewise, this paper examines the pilot's ability to both maintain an interval and re-establish it after a TCAS resolution advisory (RA) involving either the pilot's own aircraft or the lead aircraft. The error in spacing was found to grow through the traffic event, particularly in the case of corrective RAs requiring either the own aircraft or lead aircraft to maneuver, and pilots often were not able to re-engage the IM mode within 30 seconds after Clear of Conflict.