PPRuNe Forums - View Single Post - AF 447 Thread No. 11
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Old 1st Nov 2013, 01:50
  #570 (permalink)  
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Join Date: Jun 2009
Location: florida
Age: 81
Posts: 1,610
Received 55 Likes on 16 Posts
C'mon, 'bird.

As you and I and Retired have said, the AoA vanes/cones should be taken as gospel unless they are all in disagreement or some other criteria is applied, and CAS isn't one of them.

The simple fact is that the 'bus control law reversion logic is complicated and has a plethora of modes and sub-modes and......... Sheesh.

AoA should be the primary "protection" according to the jet's aero capabilities. I have no problem with the 'bus "gee" implementation due to its mission. The fact is that planes fly using lift by wings that can produce whatever at whatever AoA. So the 'bus might use a law resembling ours that limited commanded gee versus AoA. Take our law and divide by 8 gees and you have it.

Make no mistake, I do not like a "direct" control law for the heavies due to many technical and aero reasons. If you have a FBW system, then you use whatever still works to fly the plane as the old ones used to fly. You don't have force feedback, but you can sense rates and gees. The planes since the mid-50's had hydraulics and a few direct mechanical connects to the control surfaces. They have not been like an Aeronica or Chipmunk since then, so enough of this macho direct control stuff. My ilk flew most of the time in pure "manual" with hydraulic valves at the base of the stick. No mechanical connections of any kind to flaps or spoilers or anything. We done just fine. And then came along fly-by-wire, and I was one of the initial cadre.

Glad to have a "final" few posts to get some things off our chests.
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