Originally Posted by
vilas
When you pull or push the stick it is to change the attitude which you have to see on the PFD. 447 guy just pulled never looked at the pitch. They didn't see anything nor hear the stall warning. AT FL350 pulling 16° pitch is irrational. The pilots didn't know unreliable speed procedure and stall recovery procedure either. That may have triggered the fear factor causing loss of cognitive awareness. That's why all their actions appear irrational. Connected stick may have some virtue but if pilot doesn't know if pull is correct or push then it's not going to help.
Anyway ultimately the automation has come to rescue again. Now there's fourth source that is called Digital Back Up Speed it's calculated speed from load factor, CG etc. without any anemometric data that compares normal ADR speeds. Whatever is outside threshold is rejected through ECAM actions. If all are wrong then digital speed is displayed which you fly. In A350 it's automatically done. So no more 447.
Where did you see 16° pitch ?
I read 11°, which is still way too much of course.
In this accident, I think contrarily that too much automation is the cause.
Since RVSM, it is not possible anymore to hand fly at high altitudes. And how much sim time is there to train hand flying at altitude ? Maybe less than 10 minutes in the entire type rating and then less than 5 minutes every three years...
If hand flying at altitude was allowed, it would not have disoriented them that much.
Let's simplify the matter. Have you heard of a single GA crash where the pilot lost control, stalled or crashed, with no medical condition, in clear skies, while attempting to fly straight and level ?
Well I don't think so because flying straight and level is basic flying, which GA pilots are trained for and do all the time (most light GA don't even have an AP let alone FDs). Or if it happened, said pilot should never have gotten his license in the first place. But it's perfectly possible to have three full ATPL pilots with less than 3 hours (total) manual flying at altitude and 0 minute real manual flying at altitude in the aircraft.
Light aircraft do crash (even a lot) but for other reasons.
Originally Posted by
Bidule
You should read the Accident Report for this Perpignan flight, which by the way was not a commercial flight. You will then see that it is much more complex than what you summarised to try supporting your views.
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Can you tell me in which ways ?
I read the report, I know it wasn't the designed, nominal functioning of the airbus because the AOA froze, but the THS able to go fully up is nominal.
Here is a google translate from the report :
At 15 h 45 min 19, the stall warning stopped. The captain's longitudinal input is still full forward. The elevators reach their maximum nose-down position at approximately 11.6 degrees.
The bank was 40 degrees to the left and the Captain gradually canceled his lateral order. One second later, the aircraft is in a 7 degree pitch attitude. Its wings were close to horizontal and its speed was 138 kt. The Captain canceled his longitudinal order. At 15 h 45 min 23, the pitch attitude and altitude then began to increase. The altitude reached approximately 2,250 ft. The Captain immediately gave a longitudinal stop forward order.
With 7° pitch attitude, wings level, 138kt, TOGA. With a THS at neutral the aircraft is saved. With a THS fully up, 2-3 seconds without a fully down order on the sidestick killed them, with a 50° increase in pitch in less than 20 seconds.
On any normal aircraft, this pilot would have completed his test with no problem at all.
The pilot should have been made aware that his trim was doing a runaway.
My view is that the responsibility of the pilot does not exonerate the manufacturer from having to provide the pilots with an intuitive, safe aircraft, that won't do anything dangerous unexpectedly and with no information. In short, that is the contrary of MCAS style design. Am I wrong to think so ?