Experiments will determine whether new equipment can be used to manage flightpath changes without ATC approval
NASA is about to test a system designed to enable pilots and air traffic controllers to share the traffic separation task. The agency will run live simulations involving pilots and controllers to study ways to expand national airspace system capacity.
The concurrent simulations, involving pilots and controllers at NASA's Langley and Ames research centres, will continue for several months. The simulations will test whether aircraft equipped with advanced equipment can safely manage flightpath changes to maintain traffic separation without obtaining controller approval. The technology, known as distributed air/ground traffic management, allows pilots to file a flight plan that will enable them to fly autonomously during the en route section of the flight without the aid of ground-based controllers. It is designed to improve airspace efficiency and capacity near the USA's busiest airports.
Aircraft equipped with this "autonomous flight management" capability will use automatic dependent surveillance-broadcast (ADS-B) technology, a datalink that permits the continuous automatic exchange of relative position information between aircraft within 19-32km (10-30nm) of each other. Meanwhile, surveillance data relating to non-ADS-B equipped aircraft will be provided by a ground-based traffic information service-broadcast (TIS-B) uplink. Both ADS-B and TIS-B work simultaneously and will provide surveillance information for all traffic in the area within a 19km radius of any given aircraft.
Glass cockpit displays in most modern aircraft will be able to use the system, a NASA researcher says. "There is quite a bit...of urgency to try to improve capacity," says NASA's Mark Ballin, an aircraft systems and operations subproject manager. "The programme increases capacity by decreasing workload bottlenecks."
However, the seven-year, $55 million federally funded project faces its critics. The National Air Traffic Controllers Association (NATCA) says controllers can see the "big picture", and the association worries that pilots "who should be concerned with flying the aircraft" will unwittingly reduce safety margins by taking on the work of air traffic controllers. "This has never been a workload issue [for controllers], but rather a safety issue", says NATCA.
But NASA officials say autonomous flight management is only an option, and that individual operators would have a choice whether to participate, or whether to equip their fleets with the system. "By distributing the capability among individual users, the system is so redundant; there are few points of failure with it. With this system, there is very little voice communication between the crew [flying with this system] and controllers on the ground," Ballin says. He adds that pilot reaction and research results have been positive.
Plans to restructure terminal airspace around metropolitan New York and Philadelphia to improve traffic flow efficiency have been put back to late 2006 or early 2007. The Federal Aviation Administration says this is due to late filing by civil and military airspace users of information allowing it to draw up its environmental impact statement.
ERIK HUEY / WASHINGTON DC
Source: Flight International