AF 447 Thread No. 5

[vbp.net]

AoA et al.

@ Diagnostic & Sensor_Validation

Quote : Reading the comments from other contributors here, it seems unlikely that whatever was wrong with AoA sensor #1 had a material impact on the events on this flight, although yet another fault added being into the mix is obviously a worry. Or do you believe the issue with this AoA sensor #1 was significant in the events that occurred?

Very hard to tell, but I would say probably not since we know the STALL warning went OFF as soon as the speed was deemed to be less than the prescribed 60 kts. What we are really seeing when looking at the AoA traces of the data is another story, IMHO. Keep in mind, though, that the "speed" (of the falling aircraft-object?) was certainly well above that : only the derived horizontal vector of it was calculated to be less than the trigger. Calculated from the pitot, at an angle out of the normal range... What I mean to say is the following: the AoA sensor was probably giving meaningful output since the flow of air around its actuator was certainly capable of moving it adequately. So, it remains very strange that the STALL warning would be muted in these circumstances when the "system" knows pretty well: 1. the aircraft's altitude and 2. there is no weight on wheels. I have little doubt that, recommendations from BEA or not, Airbus will implement some changes there in the future.

I wouldn't like to seem cynical, but can you imagine the benefits to be derived from the data retrieved from the bottom of the sea? A fully stalled 200+ tons aircraft data during the whole descent. No wonder Airbus did finance some of the recovery costs. To them, this is a goldmine. And they pretty well know how to interpret the data! Future aircraft generations (and even the current ones) will benefit from this disaster, whatever the BEA conclusions and recommendations will be. I'm confident.

This leaves the industry with the problem so adequately pointed to by the excellent video brought to our attention by CaptainGef (post #1867). Captain Sullivan also tried to wake up an almost empty audience in the Congress about the same problem. Trouble is: nobody seems much interested...