Aircraft, airspace, and the use of energy management based algorithms to conduct flight deck interval management (IM)

Abstract

A 19-day flight test of an Interval Management (IM) avionics prototype was conducted in Washington State using three aircraft to precisely achieve and maintain a spacing interval behind the preceding aircraft. Four different types of IM operations were investigated during the flight test, and these operations occurred in the en route, arrival, and final approach phases of flight. Many of the IM operations met or exceeded the design goals established prior to the test. For example, the average spacing accuracy for all IM operations where the end of the IM operation contained a maintain stage was within two seconds and the standard deviation was within three seconds. However, there were issues discovered throughout the flight test, including the number and magnitude of speed changes, the rate of IM commanded speed changes, the lack of aircraft energy management, and the difference between expected and actual aircraft deceleration rates.