SAS Performs First Managed 4D Trajectory Flight in Revenue Service

A SAS B-737 has performed, what SAS Sweden describes as, the first managed four-dimensional-trajectory (4DT) flight, as well as the first advanced continuous descent approach (A-CDA), ever made in revenue service.

The January 19^th flight (SK007) was from Luleå to Stockholm's Arlanda.  During the flight, the approach controller and the tactical supervisor at Arlanda interacted with the aircraft via datalink in order to set up the approach procedure and enable the aircraft to calculate its optimum trajectory.  The ground system also assigned a RTA (required time of arrival) for the runway threshold.

After the pilots entered the data into the aircraft's FMS (flight management system), the aircraft's 4D trajectory - including precise altitudes and times at all waypoints ahead to touchdown -  was downlinked to the ground system. The aircraft then executed an optimized approach procedure and accomplished the previously given RTA constraint within 2 seconds.

"The initial results look very promising" said Captain Peter Larsson, who leads the project for SAS Sweden.

According to SAS Sweden, additional 4DT operations will start in low traffic with its B-737 aircraft and dedicated personnel on the ground.  During the spring, as confidence and experience increase, the flights will become more common and will be performed on a more regular basis.

Stockholm Arlanda's 4DT operations is a part of the NUP2+ (second phase of the NEAN or North European ADS-B Network update) project. Partly funded by the European Union, NUP2+ is working to validate new ATM (air traffic management) applications that will increase the efficiency and safety, and also reduce aircraft fuel burn, emissions and noise.  The new A-CDA procedures are also called "green approaches" because of their promise to reduce emission and noise pollutants.

Earlier simulation demonstrations of these concepts took place in Aronsborg, Sweden, in the summer of 2004.

A large-scale demonstration of these procedures will take place in Stockholm this coming April, SAS Sweden says.  Also, system elements on the air and the groundside will be demonstrated during at ATC Maastricht 2006, February 14-16.  01-21-2006.

Click here to become a registered Flt Tech Online subscriber and receive headlines delivered to your e-mail each week

Click here to go back to the headlines