Buffalo Q400 crash
"///" wrote:
On May 14, 8:12 am, James Robinson wrote:
There was a theory on one of the other pilot forums that the captain
might have done all of his stall training when the aircraft was under
manual control, untrimmed, with the throttles cut until the speed
dropped below stall speed. He might have gotten used to having some
backpressure on the control column to avoid altitude loss under those
conditions.
He might never have experienced stall training where the AP had
ratcheted the pitch trim toward its maximum, and was caught by
surprise with the sudden pitch up when the AP kicked off.
The FDR shows his immediate reaction to the stick shaker was to apply
20 lbs backpressure, which he immediately let go of as the aircraft
pitched up. He never pushed on the control column, however the wild
left/right/left/right rolls pretty well made controlling pitch a moot
point.
Those rolls were made harder to get out of by the fact that the
captain let the aircraft get all the way down to 80 kts at one point,
and at such low airspeeds, the ailerons have much less effect, which
he would have known if he had simply paid attention to his flight
instructor.
They immediately dropped to 80 kts when the aircraft pitched up. Think
of a Russian Sukhoi fighter doing the cobra manoeuver. The low speed and
wild rolls meant the chances of recovery at that point were pretty slim.
The initial pull up, combined with the overcorrection to the rolls pretty
well made the accident inevitable.
Pushing the control column forward when they were rolled 100 degrees from
level wouldn't have done much to help.
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