Yesterday morning, an old friend sent me a text: “Did you hear the news?”
I always get a pit in my stomach when I hear that. “No,” I emailed back. “What happened?”
What happened, of course, was Germanwings 9525. At the time all that was known was that an Airbus 321 carrying 150 people had crashed into the Alps. Soon enough details began to emerge, but how strange they were: a 24-year-old aircraft, en route from Barcelona to Dusseldorf, had climbed to its crusing altitude of 38,000 feet and then, within a matter of minutes, begun to descend at 3000 to 4000 feet per minute, apparently fairly steadily and while remaining on course, until it crashed eight minutes later into the French Alps. The flight crew issued no distress call.
I’d never heard of anything like it, but as the conversation developed online, some parallels emerged. Foremost was the case of LH1829, which took off from Bilbao last November and began an uncommanded descent of some 4000 feet per minute after the flight management system became confused by frozen angle-of-attack sensors.
In that case the pilots communicated with technicians on the ground and figured out how to solve the problem before a great deal of altitude was lost, but perhaps yesterday’s pilots had tried to tackle the issue by themselves and gotten too absorbed by the challenge to realize how much altitude they were losing, a la Eastern Air Line Flight 401?
Some speculated that a sudden decompression might have caused the tragedy. There have certainly been incidents in which aging, inadequately repaired aircraft have suffered catastrophic failure of their pressure hulls, leading to destruction of the plane, but those don’t generally look like this–the plane either breaks up at altitude or the pilots are able to don oxygen masks and keep flying the plane and communicating, if only for a while.
Another possibility–one hesitates to raise it in today’s climate of fear–is that a hijacker attempted to take control of the cockpit. I don’t think we can rule this out, either.
At this point, frankly, none of these scenarios make a great deal of sense, and I think the overall sentiment among people who spend a lot of time looking at this sort of thing is bafflement. “I’m at a loss,” one veteran 777 pilot emailed me yesterday. I think that about sums it up. Hopefully, the recovered cockpit voice recorder will provide some clarity.
UPDATE 3/26/2015: At a press conference in Marseille today prosecutor Brice Robin revealed that, according to audio recordings recovered from the Cockpit Voice Recorder, co-pilot Andreas Lubitz locked the captain out of the cockpit and initiated the descent that led to the plane’s crash into the Alps. “He took this action, for reasons we still don’t know why,” Robin said. “We can only deduce he destroyed the plane. He voluntarily allowed the plane to lose altitude. I think the victims only realised at the last moment because on the recording you only hear the screams on the last moments.”