Drift Due to Engine Torque: Some Experiments Confirming Theoretical View of the Importance of the Effect on Navigation Available to Purchase

THE air flow in the slipstream of an airscrew is helical in nature. It follows, therefore, that there is a torque reaction on the whole aircraft which must be overcome by an equal and opposite moment produced by an asymmetrical distribution of air forces on the aeroplane as a whole. These torque effects are very marked in small aircraft with high power; particularly when the airscrew is slow running, and when the speed is low at take‐off or in climb. They show up most noticeably in regard to the control movements which are necessary to neutralise them. In multi‐engined aircraft the engines are arranged to turn in opposite directions and so neutralise torque effects. It is clear, however, that in all cases where there is no deliberate attempt to neutralise there will be some “Residual Torque.”