The prolonged search for the Boeing 777-200 operated as Malaysia Airlines Flight MH370 brought attention to onboard data transmission systems that report an aircraft’s position and other information in real time. Such a system could help track an aircraft that disappears from radar coverage.
Tony Tyler, International Air Transport Association (IATA) director general and CEO, said his association “will play its part in helping to define an industry position” on real-time flight-following systems. Tyler remarked on the issue during an industry outlook teleconference on March 12, in response to a reporter’s question. He noted that many airlines already transmit engine monitoring and other data to their operations centers via the aircraft communications addressing and reporting system (Acars), which uses both VHF ground radio and satellite networks.
“But sending data continuously for the entire flight for all aircraft operating would create a huge amount of data for each flight. When you aggregate it up, it would be a massive amount of data to manage,” Tyler said. “I think, though, there is an opportunity to think carefully about what would be a sensible, useful subset of data to have monitored in real time and what the criteria should be for applying that…We’ll no doubt be discussing the possibility of working with manufacturers and airlines to help define this subset of data.”
Among recommendations stemming from its investigation into the loss of Air France Flight 447 in June 2009, France’s BEA civil aviation accident investigation bureau called on the International Civil Aviation Organization (ICAO) and the European Aviation Safety Agency (EASA) to “study the possibility of making it mandatory for airplanes performing public-transport flights to regularly transmit basic flight parameters (for example position, altitude, speed, heading).” In March 2010, the BEA created a “Triggered Transmission of Flight Data” working group to “assess the operational suitability” of a real-time flight reporting system. That group concluded that it is “technically feasible to significantly reduce the search area for wreckage” by transmitting appropriate data by satellite communications before impact, or automatically activating an emergency locator transmitter or increasing the frequency of aircraft position reports.
Flyht Aerospace Solutions, of Calgary, manufactures a data-monitoring and flight-following avionics box it calls AFIRS, for automated flight information reporting system. AFIRS models contain Iridium modems to provide satellite-based voice and data services, with global coverage. On its website, the company said it has been busy fielding calls about the system since MH370 disappeared from radar on March 8. It addressed the most frequent questions in the online posting. Had the Malaysia Airlines jet been equipped with AFIRs “and if it was enabled for triggered data transmission, we would know where the aircraft was when it last had electrical power and we would know the behavior of the aircraft at all times leading up to that point,” the company said. The unit would continue transmitting as long as it had electrical power and its associated antenna was intact. Installing AFIRS would cost “less than $100,000” depending on the aircraft type.
Outside of radar coverage, properly equipped aircraft can also be tracked by automatic dependent surveillance-broadcast (ADS-B). Through ADS-B, an aircraft fitted with a 1090ES mode-S datalink transponder broadcasts its GPS-derived position once per second to ground stations and other nearby aircraft. ADS-B receivers on satellites will eventually augment ground-based receiver networks, providing coverage in oceanic and remote airspace. According to media reports, a commercial flight-tracking company—Flightradar24—said it last detected a signal from MH370 at a point between Malaysia and Vietnam, using its network of more than 3,000 ADS-B receivers possessed by aviation enthusiasts.
Malaysia’s Department of Civil Aviation plans to fill a gap in the country’s radar coverage by installing ADS-B radio stations at Pulau Langkawi and Genting Highland, making possible ATC surveillance of western parts of its Kuala Lumpur flight information region. The agency’s schedule calls for installing the ground stations by 2016, sharing data with neighboring countries by 2017 and requiring operators to equip their aircraft to fly on certain routes by 2018. The plan is described in a paper summarizing the ninth meeting of the ICAO Southeast Asia and Bay of Bengal sub-regional ADS-B implementation working group in October.