Why satellites failed to find missing plane

There is no constant tracking of planes when they go oceanic, although a sytem is being developed.
Cars have global position systems to pinpoint where drivers are when they get lost, so why can’t GPS be used to locate the exact position of planes when the worst happens?

It took search and rescue teams over 30 hours to locate the wreckage of the Air France plane that crashed in the Atlantic on Monday, the onboard GPS system proving no aid to rescuers in the mission. Although details of flight AF447’s fate remain uncertain, in some air accidents, this critical time could mean the difference of life and death for any survivors. According to industry experts, the satellite technology that would allow constant monitoring of the exact aircraft position is available, and although plans are afoot to introduce it, currently cost may be deterring some airlines. Michel Roelandt, aviation expert for Eurocontrol, a European air navigation safety organization told CNN that some planes are fitted with GPS systems, but these are essentially dumb units — like those in cars — which receive location information from satellites, but do not send any data back. So while a flight crew will know its exact position over an ocean, the information is not automatically relayed to air traffic control. That is left to someone in the cockpit to relay via satellite communication when out of radar range. Each sat-com signal would probably cost an airline money, says Roelandt. “Airlines often have a contract with a private operator to provide their satellite communications. Some companies pay for it, some have free contracts,” he said. “It can happen that during an hour you don’t have any contact. That is not uncommon.” Even though a plane is not constantly tracked beyond radar range, sat-com systems mean that planes need never out of contact. Roelandt stressed that the idea of GPS tracking has not been part of any safety review within the aviation industry. The general consensus has been that a trained flight crew is on hand that always has the capability to be in contact with someone on the ground should an emergency arise. In the case of Air France flight 447 between Rio de Janeiro and Paris, it appears that the crew had no time to relay a mayday message. Shortly before it disappeared, the plane’s automatic system initiated a four-minute exchange of messages to Air France’s maintenance computers, indicating that “several pieces of aircraft equipment were at fault or had broken down,” Air France CEO Pierre-Henri Gourgeon said on Monday. These were the planes automatic data link messages that send out information on the condition of the plane. “Usually these data reports send information on normal systems things like what the in-flight entertainment is doing, or that the cabin temperature has dropped by a few degrees,” Kieran Daly of online aviation news service Air Transport Intelligence told CNN. CNN’s Richard Quest adds: “It’s like your car telling you something is wrong, but in this case the A330-200 sent out a signal to Paris, basically warning that when it arrives in X number of hours this is what’s wrong with the plane. It was the automatic system on the plane telling Air France headquarters we’ve got a problem.” Search and rescue teams could work out from the route the plane was on and the timings of the data reports the rough area to look for the plane. However in an age when small yachts and even mobile phones have GPS, using a satellite to track a multi-million dollar jet carrying priceless human cargo doesn’t seem like such an unreasonable proposition. Upgrading from radar to satellite system There are moves being made in the industry to change from a radar-based tracking system to a satellite one, where air traffic control would know where a plane was at all times, even over oceans. The benefits of satellite tracking would be more direct and faster journeys, less fuel use and subsequently less pollution. “A system will be implemented in Europe 2015,” said Roelandt. “It means planes will automatically transmit the GPS position to the ground and surrounding aircraft within about 150 miles. In the far future the idea is to be in a free flight condition.”

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A330-200 profile

In a trial last year using an Automatic Dependent Surveillance — Broadcast system (ADS-B), two Airbus planes were able to change altitude while cruising over oceanic airspace. At present airliners flying over oceans are usually unable to change altitude to improve their flying efficiency because oceanic airspace beyond a certain distance from land cannot be controlled by radar. Controllers and pilots stay on vectors, highways in the sky, to maintain safe distances between aircraft cruising at the same altitudes. The ADS-B system is being developed internationally and the key part of a next generation of aviation plan that has been championed by the FAA, called NextGen. It has also been trialed at various locations in U.S. airspace. The expense of fitting out planes with satellite tracking equipment, estimated at $200,000 according to AP researched figures from 2008, is dwarfed by the cost to upgrade from radar to satellite tracking of planes. According to a 2006 Federal Aviation Authority report it would cost $4.6 billion over five years to change to a satellite-based system, with the following 10 years investment almost double that amount. There are also criticisms of the system, including the expense of updating air traffic control stations and planes.

“It’s a bit of a chicken and egg situation. If you don’t put an implementing rule on this equipment, airlines won’t install it as it’s a costly operation for them. It is ongoing and will be installed on European commercial airliners, but it takes time as always.” Ultimately it is hard to tell whether getting to the area sooner would have improved the chances of finding survivors in the case of flight 447, with wreckage being reported strewn over three mile area. However in a move to improve the aviation industry being able to pin-point planes at all time will be a part of the near future.