PPRuNe Forums - View Single Post - AF447 final crew conversation - Thread No. 1
Old 2nd Nov 2011, 17:38
  #624 (permalink)  
DozyWannabe
 
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@SLFinAZ

I don't think so - I think what he is saying is that in a lot of cases airline management decree use of the autoflight system to the extent that manual handling tends to fall by the wayside.

However, when he says...

As long as the FBW is in normal law, the SS is nothing more than a autopilot input device. Adding a bank request through the SS is the same as turning the heading select knob on the flight control panel. Both actions result in the autopilot turning the aircraft.
...he is actually incorrect, and conflating the FMS/autoflight system with the FCU system.

You are correct in stating that they Boeing FBW setup is exactly the same in terms of high-level function. The FCU (which mediates the flight control inputs and commands the flight surfaces) can be considered roughly equivalent to the old "Q-feel" system on hydraulically-controlled conventional airliners in that it translates the pilot's inputs to flight-surface deflection.

I suspect that TTex600 considers the FCU to be a quasi-autopilot because of the bank angle and pitch limitations in the Normal Law protection suite, whereas the Normal Law limitations in fact give a pilot more than twice as much leeway (in terms of bank angle limitation) as the old-fashioned autopilot bank and pitch limits.
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