An Airbus-led team and avionics provider ACSS last month demonstrated in-trail surveillance and efficiency boosting capabilities on transatlantic crossings using the airframer's A340-600 development aircraft and a Scandinavian Airlines A330 in revenue service.

ACSS, through Airbus, is providing air traffic situational awareness (ATSAW) applications for the programme using automatic dependent surveillance - broadcast (ADS-B) technology.

Airbus says that using ACSS's Traffic Computer the A340 performed several altitude changes relative to the SAS A330.

ACSS marketing manager Mark Salazar tells Flight International that pilots were able to see in-trail traffic at distances of up to 370km (200nm), allowing pilots the opportunity to optimise altitudes and routes for either fuel savings or ride comfort. Airbus says that the pilot-controller exchanges for clearance were sent via a datalink.

The test was part of the broader Airbus-led project dubbed "CRISTAL ITP" (in-trail procedure). Other team members include Eurocontrol, Isavia (the air traffic control provider in Iceland), the UK's National Air Traffic Services and SAS. The effort aims to demonstrate the operational benefits of bringing ADS-B information into the cockpit, particularly in the non-radar environment.

With ADS-B, an aircraft automatically broadcasts its GPS position information and identification data, providing a higher-fidelity alternative surveillance means to radar. The technology also offers efficiency-boosting opportunities when the same data is brought into the cockpit.

Such ADS-B "In" applications are the cornerstone of the ACSS's SafeRoute offering, which US cargo carrier UPS pilots are now using for continuous descent arrivals, cockpit display-assisted visual traffic separation and for precise situational awareness cues on the ground at the carrier's hub in Louisville, Kentucky.

ACSS is now developing similar capabilities for Airbus as part of the T3CAS integrated surveillance and safety system which the airframer will certificate for its entire A320, A330 and A340 aircraft models in late 2009. The ADS-B information on each pilot’s navigation display.

T3CSS includes traffic alert collision avoidance, terrain awareness and a Mode S transponder with ADS-B capabilities. ACSS plans to deliver T3CAS with ADS-B "In" software applications that include in-trail procedures, vertical separation on approach a surface position and traffic awareness programme. Each software application will be activated through Airbus service bulletins, says Salazar.