The Aeroplane Speaks. Fifth Edition

On the other hand, it might be argued that if the aeroplane gets into a "spin," anything tending to depress the nose of the machine is of value, since it is often claimed that the best way to get out of a spin is to put the machine into a nose-dive--the great velocity of the dive rendering the controls more efficient and better enabling the pilot to regain control. It is, however, a very contentious point, and few are able to express opinions based on practice, since pilots indulging in nose-dive spins are either not heard of again or have usually but a hazy recollection of exactly what happened to them. GLIDING DESCENT WITHOUT PROPELLER THRUST.--All aeroplanes are, or should be, designed to assume their correct gliding angle when the power and thrust is cut off. This relieves the pilot of work, worry, and danger should he find himself in a fog or cloud. The pilot, although he may not realize it, maintains the correct attitude of the aeroplane by observing its position relative to the horizon. Flying into a fog or cloud the horizon is lost to view, and he must then rely upon his instruments--(1) the compass for direction; (2) an inclinometer (arched spirit-level) mounted transversely to the longitudinal axis, for lateral stability; and (3) an inclinometer mounted parallel to the longitudinal axis, or the airspeed indicator, which will indicate a nose-down position by increase in air speed, and a tail-down position by decrease in air speed. The pilot is then under the necessity of watching three instruments and manipulating his three controls to keep the instruments indicating longitudinal, lateral, and directional stability. That is a feat beyond the capacity of the ordinary man. If, however, by the simple movement of throttling down the power and thrust, he can be relieved of looking after the longitudinal stability, he then has only two instruments to watch. That is no small job in itself, but it is, at any rate, fairly practicable.