Wide scale CTA flight trials at Stockholm Arlanda Airport

As part of the Cassis (CTA/ATC System Integration Studies) project, 308 flight trials have been carried out at Stockholm Arlanda Airport in cooperation with Scandinavian Airlines System. The trials, which took place in low and peak traffic, highlighted the potential benefits that can be gained by assuming that aircraft can meet a controlled time of arrival (CTA) with high accuracy and by assigning that time up to 45 minutes prior to a metering point for the Stockholm Terminal Maneuvering Area. Boeing 737NG aircraft, equipped with the most advanced Flight Management Systems, could meet their assigned time with 30 second accuracy in 88% of the trials. Pilots of MD-80 aircraft, which do not have an FMS function to aid pilots in meeting CTAs, met their assigned time with 30 second accuracy in 73% of trials. An analysis of these flight trials and the potential impact of their results is carried out. A number of CTA based applications which take advantage of the aircraft's ability to meet an assigned time are proposed and evaluated. One of these applications is ldquodelay en-routerdquo, or having aircraft slow down to meet a CTA rather than performing orbital holding at a low altitude. Another application explored was ldquodelay on groundrdquo, where aircraft departing from a nearby airport were assigned a CTA prior to takeoff and could avoid eventual holdings by delaying takeoff. This paper will also present recommendations as to how CTA operations can be further developed and introduced into operations.