PPRuNe Forums - View Single Post - AF 447 Thread No. 6
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Old 27th Aug 2011, 21:58
  #540 (permalink)  
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Join Date: Jun 2009
Location: florida
Age: 81
Posts: 1,610
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Boldface, OODA and training

I am disturbed by some here that believe you can handle an emergency situation or an "upset" ( love that term, and cracks me up and guess it really means "WTF?, over") by following rote, memorized procedures for more than a few seconds.

I am a "professional pilot" or would not have joined the fray here. Granted, folks like me and RF4, Wolf, 'bird, Smilin', et al flew way beyond the envelope I would expect for a pilot hauling SLF and trying to get the zillion $$$ jet safely to the destination. Nevertheless, we had our "boldface" procedures to rely upon for the first few seconds. Then we tried to figure out exactly what was going on and what we could do about it. The ol' OODA loop.

Make no mistake, great cockpit displays and unambiguous caution/warning indications are extremely important. I don't believe the AF447 crew had such.

The stall warning implementation deeply disturbs me. No "stick shaker" gizmo, no clear display of AoA, etc. AF447 was above that 60 knot speed that disregards the AoA, and even if the pitot system was FUBAR and output was zero, the AoA should have been provided in a clear manner to help the crew. Some jets have very benign stall entry characteristics, preceded by mild buffet sans wing rock, little yaw moments, etc. hence the 'stick shaker/rudder shaker" and other gizmos. They told you, GET THE NOSE DOWN!!!

A few here have noted that at high speed the AoA only needs to be changed slightly to get really large changes in gee and pitch changes. True, but the 'bus FBW major pitch law is mainly gee, so big deal. OTOH, once getting slower and approaching or actually in a stall, the AoA is the best gauge, and friend, you have!! It's also super when flying an approach and something is awry with your weight versus approach speed calculations. in other words, it tells you something is wrong. And remember that the plane flies on AoA and not airspeed ( which can go Tango Uniform, as has happened numerous times in the 'bus"). i might add that the Viper AoA versus gee command function reduced available gee command from 9 to 1 as our AoA increased. So at max AoA we could only command one steenkeeng gee!

So I shall still not let Airbus off the hook. Neither shall I let the crew off the hook.

I would pray that current and future crews have a requirement to fly the jet in the alternate laws under strict supervision. Not depend upon simulators. Actually "feel" the plane and maybe even the buffet associated with an approach to stall.

Sorry if I have ranted.
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