The Problem of Autorotation: A Brief Summary of Some of the Factors Affecting Stability and Aeroplane Control at Low Speeds

THERE is little doubt at the present time as to the great advance in safety which the invention of the automatic slot has brought to the aeroplane. It has been the means of overcoming one of its chief failings, the loss of stability and control at the stall. Automatic slots at the wing tips are themselves capable of converting an aeroplane which is unstable in roll at incidences beyond the stall into one which is definitely stable; at the same time the aileron control is increased and improved in that its application is not accompanied by so great an adverse yawing moment as for ailerons working on an unslotted wing. Further, if some form of interconnection between ailerons and slots is adopted, or some device (e.g. the “interceptor”), by means of which the action of the slot can be spoiled, a further big addition to the control at the stall can be made as well as further improvement in the shape of a reversal of the usual yawing moment. Whether such addition is desirable for all types of machine remains to bo seen; it may be that in certain types the automatic slots alone, without interconnection, will provide all the increase in stability and control at the stall which is required.