PPRuNe Forums - View Single Post - AF447 final crew conversation - Thread No. 1
Old 9th Feb 2012, 02:59
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Lord Bracken
 
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The RAT doesn't deploy unless you lose both engine generators in all aircraft I have flown and the APU would not have been on for that short flight because they could bleed air off the engines. I didn't bother to respond because I knew most people knew.
You obviously "don't know" because the NTSB report very clearly states that the APU was started soon after the bird strike. Section 2.3, [Analysis of] Flight Crew Performance, 2.3.1 Decision to Use Engine Dual Failure Checklist:

Although the flight crew was only able to complete about one-third of the Engine Dual Failure checklist, immediately after the bird strike, the captain did accomplish one critical item that the flight crew did not reach in the checklist: starting the APU. Starting the APU early in the accident sequence proved to be critical because it improved the outcome of the ditching by ensuring that electrical power was available to the airplane. Further, if the captain had not started the APU, the airplane would not have remained in normal law mode. This critical step would not have been completed if the flight crew had simply followed the order of the items in the checklist.
The NTSB concludes that, despite being unable to complete the Engine Dual Failure checklist, the captain started the APU, which improved the outcome of the ditching by ensuring that a primary source of electrical power was available to the airplane and that the airplane remained in normal law and maintained the flight envelope protections, one of which protects against a stall.
My point is that "the automation that day was worthless because it couldn't handle it" is not a correct statement - the autopilot was never engaged, obviously, but the 'automation' in the sense of the flight control laws, remained active and assisted a superior pilot in handling the aircraft in a superior way (as is how an Airbus should be operated: by excellent pilots who know their aircraft...not without pilots, or by pilots without excellence.)
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