AF 447 Thread No. 8

[Lyman]

he

jcjeant

Howdy there. AF447 died of a frequently terminal (fatal) condition called STALL. She did not crash due to STALL WARNING.

On an a/c that shuns manual control and seat of the pants flying, there is no ALERT/STALL. ONLY a WARNING. It is clear the crew rejected STALL, (both its warning, and its physical eveidence) at least to me. Therefore, they are left with textbook aero behaviour of the STALL condition to diagnose it: Nose Drop and BUFFET, to get that the airframe is STALLED. The NOSE did not drop, at least characteristically, in fact, the PF may have lifted the NOSE each time he started to recover! Leaving the Mush state, and transiting through the beginning of LIFT, the Nose would have dropped, and the STALL WARN activated, at least once.

The "Buffet" that is touted by BEA as "possible", to me seems questionable, and anyway, it did not serve to alert the crew sufficiently to STALL.

So here. The evidence strongly points to crew ignorance of the STALL condition, and the physical clews were missing also. Without some emphatic a/c warning of ACTUAL STALL, the outcome is assured, as we see. There is no recovery from STALL, absent strict and prescribed maneuvers, as discussed here at length. Without a starting point (diagnosos of STALL), the crew will drop into the sea, again, as we see they did.

It is not a fault of the aircraft sufficient to even raise one's eyebrows. (IMHO).

The problem is straightforward. The Autopilot will not operate without Airspeed reporting that meets its criteria. The crew will not be able to fly without accurate a/s either, failing certain requirements that were obviously missing. At the very least, the Pilot Flying did not immediately acclimate to manual control, and never did understand his instruments, (assuming they were working, and accurate).

The a/c crashed due to the events we see reported by BEA, the picture is clear.
Unprepared, in turbulent air, and without accurate airspeeds, the plot was lost from the git by PF, and the PNF either did not understand either, or lacked the training to seize immediate control, instead (we assume) calling for the Captain, to help. What exactly caused the chain to fracture so quickly and terminally is open to discussion. By the time the a/c departed aero flight, there was no chance to recover, given the conditions to hand.

For me, the table appeared to be set for disaster directly by the lack of response in changing out defective (in theory) probes, and indirectly due lack of even a basic recognition of the dangers in flying an aircraft with such rapid changes occurring in a very narrow window of parameters. I do not understand how some here (with a straight face) are so dismissive of the piloting, and so reassured by the a/c. The a/c was no more in a state of readiness than the people. IMHO.

bon nuit

BTW, what happened to that leak re: Captain's initial reaction upon re-entering the cockpit? He is upposed to have said, "What are you doing? That is a STALL, Go with the nose down!!? " The quote in the report is "Er...what are you doing?"

Any question, regardless of content missing, means he knows something is wrong. On page 31 BEA IR #3, the last thing reported from CVR is "Er...what are you doing...." The conversation is then shut down, no more CVR, indexed with the plane's attitude. Why not? Those three pages, if continued further in sequence would tell us the rest of the story.