SAN DIEGO, 1 June 2009. The avionics and air traffic control communities are girding for big changes as U.S. and European aviation authorities start the long process of transforming commercial aircraft navigation between destinations.
How avionics designers, aircraft manufacturers, and aviation authorities deal with these changes was the subject of several sessions today at the Avionics USA conference and trade show in San Diego, which is sponsored by the PennWell Aerospace and Defense Media Group.
Perhaps the most fundamental change in the offing is the notion of enabling commercial aircraft to navigate between airports using satellite navigation systems like the Global Positioning System and Galileo.
In the United States today, aircraft use radio beacons on the ground to stay safely on course. These beacons, called VHF Omnirange (VOR) devices, force aircraft to fly primarily on well established air routes between beacons, which requires them to fly jagged courses rather than straight lines.
Switching from radio beacons to a satellite navigation approach of air traffic management (ATM) is referred to in the United States as the Next Generation Air Transport System (NextGen), and in Europe as the Single European Sky ATM Research Program (SESAR).
Making the changes will not be easy. "We are dealing with issues of system capacity and system saturation," said Mark Ballin, technical advisor of the airspace systems program at the U.S. National Aeronautics and Space Administration (NASA).
One of the key enabling technologies of next-generation ATM systems will be interactive digital avionics data links that enable aircraft to exchange information about their status, ability to hit route way points at appointed times, and deal with unexpected changes, Ballin told attendees.
All new [ATM] concepts must deal with trajectory prediction and uncertainty associated with wind and temperature; position uncertainty; sped and path control, and other aspects of uncertainty, Ballin said, adding, "We have a long way to go."
The primary benefits of switching to the new ATM systems are fuel savings, faster flight times between airports, and increased air traffic control capacity. "The most important point is the fuel savings," said Pierre Magro, head of avionics upgrades product line at Airbus in Toulouse, France, to Avionics USA attendees.
Today commercial aircraft flights are planned as routes from VOR to VOR, like stepping stones across a stream. The biggest change for aircraft and air traffic control systems of moving to next-generation ATM systems involves characterizing flights as four-dimensional trajectories involving compass headings, altitudes, and speeds.
Every flight within the future ATM systems will require aircraft and air traffic control to plan the flight's trajectory before the aircraft takes off from its airport of origin.
The air traffic management system and the aircraft must find ways of collaborating to compensate for uncertain conditions like changes in wind speed and temperatures, weather changes, aircraft malfunctions, and other factors that can change an pre-planned aircraft trajectory.