Even when countries around the world this week removed the Boeing 737 Max from their airspace, the US Federal Aviation Administration held out. There were "no system performance issues" that the experts could identify while linking the crash of a 737 Max in Indonesia last year and another in Ethiopia on March 10, and the flight data recorders of the last accident still had to be analyzed.
Then the FAA suddenly decided to ground the much-used plane on March 13. Daniel Elwell, the acting FAA manager, said he made the decision after viewing "refined" flight data provided by the company Aireon, which uses a network of satellites to provide the first real-time monitoring of aircraft around the world .
"At the request of the Federal Aviation Administration (FAA), the US National Transportation Safety Board (NTSB), Transport Canada and various other aviation authorities, Aireon has provided the data provided by Flight 302 to support the accident investigation," said Aireon in a ruling. "This unfortunate tragedy further emphasizes the need for a global, real-time air traffic control system."
Aireon & # 39; s analysis showed that Lion Air flight 610 and Ethiopian Airlines flight 302 shared a similar flight profile before they crashed. This provides some confirmation that faulty pilot assistance software suspected of causing the first crash may also be the culprit in the most recent tragedy. Before the grounding, that software was still used in cockpits with thousands of passengers.
The 737 Max, released in 2017, is designed to improve the reach and efficiency of Boeing & # 39; s popular singe aisle jet without starting all over again. The new, larger engines and other design features have given the aircraft a tendency to stay in certain situations, a problem that Boeing has solved with software that would drift the nose off the aircraft.
But this software was not well explained to pilots, and crash investigators fear that a lack of experience with the program, in combination with defective sensors, could force the jetliners to dive that their pilots could not escape. Boeing and the FAA are working on a patch to repair the software.
The data that Aireon used for its analysis comes from a system called ADS-B, which air traffic controllers started to implement ten years ago. Aircraft are required to use global positioning satellites to monitor their position and to broadcast the details location, altitude, speed-per second. Air traffic controllers collect the broadcasts at ground stations, giving them a real-time picture of their airspace.
However, Aireon collects that data from a constellation of satellites that was completed earlier this year, although it still certifies its system for integrated operations with air traffic controllers. By collecting ADS-B signals from space, the company can track aircraft over the ocean where no ground stations are located and track air traffic in one database, not distributed across national territory.
The Lion Air crash occurred within the coverage area of the ADS-B collection system in Indonesia, but according to Captain Miguel Marin, head of the Operational Safety Section of the International Civil Aviation Organization, "the ground-based crash occurred in Ethiopia ADS-B offers ". only limited coverage, and therefore the space-based data from the pre-operational Aireon network had to be relied on. "
Aireon said the raw data, which takes time to analyze, to the FAA and the National Transportatin Security Council on March 11. The aviation regulator did not respond to questions about how it analyzed the data, but the two organizations are working together to test out the monitoring service across the Caribbean this year.
Read more about the coverage of Quartz from the Boeing 737 Max crisis.