Automatic Dependent Surveillance-Broadcast/Cockpit Display of Traffic Information: Innovations in Pilot-Managed Departures

摘要

Avionics devices that provide a cockpit display of traffic information (CDTI) enable pilots to acquire, verify, and maintain pre-defined spacing intervals from other aircraft. It is of interest to the Federal Aviation Administration to determine how the use of these displays influences pilot/controller operational communications. The operational evaluation of the CDTI in October 2000 provided an opportunity to examine some of these issues. Departure profiles (13 without CDTI, 32 with CDTI) were established to evaluate the ability of flight crews and air traffic controllers to manage long (6 nm) and short (4.5 nm) spacing intervals between departing aircraft during 3 day and 2 night operations. Subject-matter experts evaluated 15 hours of verbatim transcripts and audiotapes for benefits that may have resulted from pilot use of the ADS-B/CDTI. They also evaluated these communications for communication problems associated with misidentified aircraft, confusions, uncertainties, and operational concerns. Computed for each departure was the time the aircraft was under local control, runway ownership time, and the number and duration of messages. Approximately 4% of the departures conducted when CDTI was not used, and 9% when it was, involved communication problems. In particular, for pilot messages during CDTI departures, aircraft call signs were misstated or incorrect. However, when CDTI was not used, controller messages included the correct flight identifier but the wrong company name. In addition, more messages were exchanged during the short spacing interval. In contrast, when pilots executed CDTI departures, there was an overall increase in time on frequency, more time was spent under local control during the day, and departures were completed in less time when assigned the short spacing interval. Communication problems were associated with the call sign procedure that was designed to distinguish between aircraft being talked to versus talked about. Fortunately, controllers and pilots detected and corrected these problems in mid-stream, and statistically, communication efficiency was not affected. In light of the findings and comments from the controllers and pilots, alternative call sign procedures will be constructed and evaluated for the departure spacing application.