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Old 16th May 2010, 13:41   #2 (permalink)
john_tullamarine
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Join Date: Apr 2001
Location: various places .....
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The advice is fairly standard certification stall stuff - concerned with maintaining/recovering control rather than minimising height loss. Other than in situations near to terrain it makes real good sense. Many civil OEMs, and probably all military, will investigate other stall manoeuvres and recovery techniques to address other than simple certification situations.

Suggest you search some of John Farley's posts on stall recovery.

Two concerns with an immediate slam throttle input -

(a) the underslung engines will provide a significant nose up pitching moment as the RPM/thrust ramps up

(b) due to the high alpha, the change in airflow direction at the engine intake will provide a significant vertical force at the engine intake lip as the RPM/thrust ramps up, adding to the nose up pitching moment. This effect is seen to be critical most commonly in piston to turboprop conversions where the heavier piston engine is replaced by a lighter turboprop located further out to the front of the aircraft .. providing an increased pitching moment due both to increased engine power (usually) and the increased pitching arm from the CG.

A third possible concern involves gyroscopic precession as the nose pitches up which may provide some yaw .. which is not what we want at the stall ...

Perhaps Sean R's voice finally has been heeded by the OEMs ?
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