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d) STALL
TURN
Chose a line feature on the ground and fly along it in a shallow dive until a speed of 92 knots (170
km/hr.) is attained if flying solo or 97 knots (180 km/hr.) if flying dual. Ease the control column back to
bring the nose up into an almost vertical climb, keeping the wings level by use of ailerons. Check the
attitude by reference to the angle made by the wing tips with the horizon, and ease the control column
forward slightly to maintain this attitude. As the speed falls to 70—76 knots (130—140 km/hr.), apply
gradually full rudder in the required direction of turn so that the sailplane appears to rotate on the wing
tip. Full deflection of the rudder should be reached when the sailplane heads about 45° in the direction
of turn. The ailerons should be used against the direction of turn as necessary to prevent the sailplane
rolling to the inverted position.
As the nose approaches the reciprocal heading, centralize the rudder and, keeping the wings level
laterally by use of ailerons, ease out of the resulting dive, taking care not to apply excessive "g".
e) ROLL OFF THE TOP OF A LOOP
Begin this manoeuvre as in the first half of a loop but at the higher initial speed of between 97 and 103
knots (180-190 km/hr.) when flying solo, and between 103 and 108 knots (190-200 km/hr.) when flying
dual. Because of the higher speed, the control column must be eased back very gently at the beginning
of this manoeuvre.
As the inverted position is reached, check the loop by moving the control column gently forward and
then apply full aileron so as to roll the sailplane into the normal level flight attitude- When the vertically
banked position is reached, a considerable amount of top rudder may be necessary in order to prevent
the nose falling below the horizon and further forward pressure on the control column may be necessary
to maintain direction.
