On Mon, 16 Feb 2009 01:52:14 -0800, Matt Herron Jr. wrote:

I must be missing something. The nose pitch down is due to a stall on
the horizontal stabilizer. The advice is to pull back on the stick
immediately. Because the horizontal stab is an upside down wing, this
would have the effect of increasing the angle of attack even higher and
aggravating the stall. Is it just a wind deflector at that point, and
not a flying surface at all that is helping?

Yes, I think you are.

What the film showed was that the flow separation caused by the ice build-
up is a low pressure area. Once it grows big enough to extend back onto
part of the elevators, the low pressure in the separation bubble will
snatch the elevators down, driving the stick forward and causing an
immediate pitch-down. The pilot needs to pull hard to counter this and
stop the nose from dropping further. At least, that's how I understood
what the nice lady engineer was showing with her diagram and bit of
tailplane.

One of the flying sequences showed this too: the pilot reported 80 lbs
forward pressure on the stick as the nose dropped and recovered by
pulling the stick hard back.


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martin@ | Martin Gregorie
gregorie. | Essex, UK
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