Published on industrie-techno.com, March 2018
Written by Marina Angel
There will soon be no more shadows over oceanic airspace. Based on the recommendations of the member states of the International Civil Aviation Organization (ICAO), an international working group led by the BEA (French Bureau d'Enquêtes et d'Analyses) is working on a concept called "Global Aeronautical Distress and Safety System". GADSS) to track aircraft in service, wherever they are in the world. After several years of consultation, this working group, which brings together thirty or so experts from CNES, NASA, BEA, Airbus and Boeing, has just met again in Toulouse, on the Thales site. Alenia Space, for a decisive meeting.
The countdown is indeed engaged. "The technical specifications of the future system must be stopped before mid-2018," explains Philippe Plantin de Hugues, BEA investigator. They will finalize international standards for distress detection and localization for enhanced aeronautical safety. "The project was launched in the aftermath of the Air France Flight 447 accident in June 2009 between Rio and Paris and from 2021, all new aircraft leaving the assembly lines will have to be equipped with such a system ", summarizes Philippe Plantin of Hugues.
In the planned scenario, it is a question of detecting the aircraft in distress everywhere around the planet in real time, as far upstream as possible, before the accident.
"This new scenario will soon enter the implementation phase and become a part of international regulation," says Philippe Plantin of Hugues. In this new scheme, when a technical incident occurs on board a long-haul aircraft, the on-board computer will identify the root cause and activate the distress beacon in full flight.
The beacon will then send a signal intercepted by the payloads of some satellites (including Galileo), which will retransmit it to a ground station. The latter will calculate the position of the transmitting beacon from the characteristics of the received signal and send this information to the mission control center which will inform the emergency coordination centers. The entire rescue chain will be organized even while the aircraft is still flying. Previously, the distress beacon was only designed to be activated after the crash of the device.
The ambition is to evolve globally the international satellite system Cospas-Sarsat, designed since the 80s to provide alert and location information to assist search and rescue operations. Several demonstrations have already proven the viability of the system and the concept, including first flight test campaigns.
On the satellite side, the new constellations, including Galileo, but also the Russian Glosnass system, the future GPS3 and the future Chinese project Beidou, are gradually entering the operational phase. Thanks to these constellations, the transmitted signal can be detected with an accuracy of 100 meters (against 5 kilometers for the current system). On the ground segment side, around ten stations around the world are already operational to capture these signals, including one in Toulouse, in the Cnes, developed by Thales Alenia Space. Its solution Meolut Next offers much more compact stations, which also include a new type of active antennas, able to detect and locate moving objects. It remains to industrialize the new generation tags.
Several manufacturers are in the starting blocks, including the Toulouse company Elta, a subsidiary of ECA Group. With its new standalone beacons, no need to wait for the crash on the airgraft for the beacon to activate, as is the case now. In case of proven distress, based on 4 well-identified criteria (unusual speed, altitude or attitude of the aircraft, or loss of power on all engines), the signal of the beacon will be triggered automatically, with a postponement of position every minute, which will make it possible to trace, before the accident, the trajectory of the aircraft and to determine with a better precision the zone in which it is likely to crash. A manual trigger can also be operated by the pilot, but also remotely, from the control tower in case of abnormal behavior of the device.