Looks as if we’re about to learn the probable cause on the loss of Air France 447, the Airbus 330 that disappeared over the South Atlantic in convective weather about two years ago. The amazing discovery and recovery of the flight data recorders is a tribute to the skills and perseverance of the search teams. It is miraculous. The preliminary data from the FDRs shows that the aircraft was probably flyable but automated systems may have been dropping off line in steady succession as the computers were fed conflicting data due to icing . Please note there is more to be learned here and it’s not the final word.
The aircraft was up high and flying in a narrow portion of the flight envelope between over speed and stall. At some point the automation may have handed the aircraft back to the pilots and here’s where we’ll find out what the crew did or didn’t do. Was it out of trim? What were the thrust settings? What was the pitch attitude and bank?
Without being overly speculative, it may be that the “impossible” happened with compound system failures and a combination so improbable that there wasn’t a procedure or even a simulator scenario to cover it. The crew was overwhelmed and unprepared. Picture this – you’ve been airborne for 4 hours and everything is proceeding smoothly. You’ve flown thousands of hours and crossed the inter-tropical convergence zone dozens, maybe hundreds of times. Thunderstorms are a way of life here and one just works around them – there’s always been a way through – before.
Jet upset – something that used to be talked about much more in the dawn of the jet age – has never completely gone away. With better aerodynamics, more powerful engines and sophisticated autopilots it has become a rarity but stuff still happens. Did that happen? If the aircraft stalled it could be a long ride down and unlike light aircraft, big jets don’t recover easily.
Consider another area where we’ve seen the impossible. Dual engine failure is considered extremely unlikely and yet due to bird indigestion, extremely heavy rain or fuel interruption jet airplanes have become gliders. Happens often enough that crews should train for it. The Sioux City DC-10 accident decades ago where an improbable uncontained engine failure wiped out all three hydraulic systems was considered impossible. Stuff happens.
Retain just a bit of skepticism when someone says that something is “impossible.” Basic pilot skills never go out of style and perhaps even with the most sophisticated aircraft, it’s good to sometimes just fly the aircraft. Are your skills up to par? When was the last time you flew without a moving map? What about flying an approach on backup instrumentation? It’s easy to criticize other pilots who are no longer with us – a bit harder to know how we would measure up in a similar complex and confusing situation.
That the French are looking at criminal charges is not helpful and topic for another blog.
The more things change, the more they stay the same!