Thread: AF447
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Old 28th Jun 2009, 20:43
  #2460 (permalink)  
Will Fraser
Join Date: Apr 2009
Location: Petaluma
Posts: 330

I may see some of what I would call 'personification' in your post. It is always tempting to put a human shade on what might be called 'stark data'. 'Sensors are not computers'. That's not wrong, nor is 'we trade human errors for computer errors'. If I may I'll use some of your logic to ask a question of another.


Histrionics aside, may I ask for clarification on one of your recent posts re: 447, flight computers, and hand flying? With possible corruption of sensors, 330 flight computers seem to produce a reasonably consistent chain of output that may 'confuse', or inhibit manual flying which results as a trip out of the a/p and consequent degradation to Alternate Law or Alternate Law 2. Reference Qantas and NWA, the computer displays 'Stall Stall'. Whether or not that cue is to be taken seriously seems to depend on decisions made by the PF. Do you consider that a hindrance in recovery? Or, could the PF, acting on cue, push the nose down, even add power, though the a/c is anything but stalled?

Also, re: Rudder Travel Limiter. If due to corrupt AS data the ship loses Rudder protection, and possibly all limit to Rudder travel, would you think that a Rudder input might put beyond-fail stress on the VS? To wit, as AS data is lost, could the Rudder Limit reach a status of Low Speed restrictions as determined by the computer? In other words, could the Rudder's travel be deflected enough to convince the sensors in the tail in concert with corrupt a/s that low speed had actually been obtained allowing this deflection to be the new parameter, though the a/c is still travelling at M.80?

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