BEagle
N H Birch and A E Bramson - FLIGHT BRIEFING FOR PILOTS 1
" THE FULLY DEVELOPED STALL
Due to manufacturing inaccuracies and particularly on aeroplanes with highly tapered wings it is usual for one wing to stall slightly before the other. The early stalling wing will drop first causing the relative airflow to approach from below, thus still further increasing its angle of attack and stalling that wing even more. Concurrent with these developments the up-going wing partially unstalls because its relative airflow comes from above. If allowed to develop the nose will swing towards the lower wing because of increased drag on the fully stalled wing and weathercock action. All the conditiond for a SPIN would then apply. An attempt to raise the wing with aileron would merely aggravate the situation since in the case illustrated the left aileron would be depressed. Such action would in effect still further increase the angle of attack. Likewise the up-going aileron on the raised wing would,in effect,reduce its angle of attack, aggravating the roll/yaw situation already mentioned. When a wing drops during a stall, yaw must be prevented by application of opposite rudder (in this case RIGHT), when the wings may be levelled after flying speed has been regained. The full recovery procedure is outlined under Flight Practice.
Flight Practice
The Standard Recovery
( Stall and Recovery with Power)
a) Proceed into the stall as before, noting height shortly before the stall.
b) As soon as the nose commences to drop, open the throttle fully and gently ease the stick forward. It should not be necessary for the nose to go far below the horizon. Note that very little height is lost.
Recovery when a Wing Drops.
If a wing should drop. opposite rudder must be used to prevent a yaw developing. Level the wings after flying speed has been regained "
Always found Birch & Bramson literature to be easy reading, and after all I think its the wording that matters here.
In my early PPL training my instructor, whose words I often recall even after 25 years, were
" PREVENT FURTHER YAW WITH OPPOSITE RUDDER "
regards,