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FLIGHT INSTRUCTOR'S MANUAL 195

speed. However, the speed should be reduced from cruising with most airplanes. With some airplanes failure to reduce this speed will result in two or more complete turns before the roll can be stopped. In others, a large sloppy gyration will result that in no way resembles a roll. These results of excess speed depend largely on the design and characteristics of the airplane.

Insufficient speed will result in a normal power spin from which recovery can be made in the usual manner.

When the correct speed has been assumed, the stick is pulled straight back abruptly with simultaneous abrupt application of full rudder in the direction in which it is desired to roll and full throttle. The controls are held in this position for approximately three-quarters of the revolution, when recovery should be started in order to stop the roll exactly in level flight.

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FIGURE 31. The snap roll.

In some airplanes, the throttle may be eased off - not completely closed - during the middle half of the maneuver, and then opened wide just before level flight is regained to stop the roll more precisely.

To recover and stop the roll, apply full rudder in the opposite direction simultaneously with forward stick, and then use the throttle, if it is to be used. Ailerons may be used to assist in stopping, but not in starting. Their use in either case is not recommended.

This maneuver requires perfect orientation, very rapid thinking, and rapid, accurate control use. The usual errors will be too much or too little speed at the start, over-shooting or under-shooting, and spinning as a result of poor timing and coordination.

The control use must be very positive and firm but not violent. Violent use, particularly with too much initial speed, will result in serious loads being placed on the aircraft structure.