May 30, 2011

Absent Data Deepens the Mystery

Captain Dave, Flight Level 390:

"But why did the two young bucks (quoting one of my retired Captain buds) start increasing pitch angle? Why didn't they ignore the bogus data and fall back on pitch and power? Why, why, why... ?"

I was glad to read those words about the demise of Air France trip 447 from a working air transport pilot. I thought I had maybe missed something in the preliminary report, released a few days ago, despite reading it three times through. It indicated that the two co-pilots stalled the aircraft in rough weather. The airframe fell for three-and-a-half minutes to the ocean.

But the preliminary report doesn't give a hint as to why that happened. Why did those pilots believe raising the aircraft's nose was the right thing to do, despite an artificial horizon instrument that would have clearly indicated level flight, and engine exhaust indicators showing full thrust? Something prompted those pilots to believe they were taking the right action. It remains a mystery as to what that was.

At least I'm in good company.