PPRuNe Forums - View Single Post - AF 447 Thread No. 12
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Old 15th Jun 2014, 22:29
  #94 (permalink)  
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Join Date: Jun 2009
Location: florida
Age: 81
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I can't find the use of "standby gains" in the pubs I have recieved from you guys. Only the "direct" mode resembles what we used to fly with pure mechanical connections ( no hydraulics).

Seems the "alt" laws still use rate commands, and I can see this if the rate sensors are still active, and no reason to think they would be influenced by pitot-static problems, ya think. We had a Viper fly for about 10 minutes or so after a large pelican smashed the radome and the AoA sensors - no airspeed and no AoA, only inertial inputs, absolute pressure and "standby gains". The damage apparently got to the flight control computers, which eventually failed. The pilot was flying on instruments the whole time, as the blood covered the forward part of the canopy.

So I go with Doze that the roll PIO was pretty much dealt with by the time the jet ran outta energy and defeated the AoA protections ( same as Viper deep stall entry).

I also go with 'bird that the "startle factor" should not have been the primary cause of later control inputs. There was even a call about "alternate" law early on, wasn't there?

Finally, seems to me that the jet's control surfaces would have been trimmed pretty well when the pitots froze and AP disconnected. In short, let the jet go where it is trimmed before doing anything rash and getting into the roll PIO we are theorizing. BTW, I can't seem to find when the pitot system came back on line. If it did, did the input to the FLCS have to be enabled by the crew?
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