Beyond that, partial panel, unusual attitude recovery are 'recoverable' because they are trained in a setting where the pilot will know if his inputs have corrected the upset. Here, if it happened due to Unreliable airspeed, AP chasing crap IAS and trimming as if it was part of a fairy tale, there is no reason to think the pilots could have recovered from an unknown and uncued 'status'; when would they know they had succeeded? Without cues to rely on (demonstrably absent if UAS is the culprit), where is straight and level? what is our position? where is up? Unreliable airspeed recoveries as reported in other instances have proven resistant to a checklist; it is perhaps possible to train UAS in conditions similar to what we imagine existed for 447, but why? Who will determine what 'Recovery' looks like on the panel? Repetitive loss of airspeed is demonstrated in this type involving thousands of feet lost in altitude, and visual extra cockpit cues for reference.
More important to me would be an a/p that annunciates its actions, with visual cues on the glass, so the pilot can 'get' the a/c by panel when the pitots go astray, knowing that what he has is flying, and what is required is constant duplication by manual handling after disconnect, which itself would be announced prior to, not after its occurrence, and that by surprise.
Oh, and an Artificial Horizon.
Let me ask a quick question. If the pilot had been hand flying the a/c in Normal Law, what's the probability of losing it to Alt Law2 after loss of pitot probes? This flight went to AltLaw2 because the a/p quit. If the a/p isn't in the mix, would the outcome have been substantially different?
Last edited by Will Fraser; 24th Sep 2009 at 00:08.