Pusher Configuration - Engine Installation Considerations

Engine Installation Considerations

Specifically, the force provided by the propeller is pushing towards the engine, rather than away. To convert a tractor engine and propeller combination to pusher operation it is not sufficient to simply turn the engine and propeller round, since the propeller would continue to "pull" driving the aircraft to the rear. Assuming the engine cannot be run in the reverse direction, the "handedness" of the propeller must be reversed. The loads on the thrust race (bearings that prevent fore and aft movement of the crankshaft) are also reversed, because the pusher propeller is pushing into the engine rather than pulling away from it as in a tractor. Some modern engines designed for light aircraft are fitted with a thrust race suitable for both "pushing" and "pulling", but others require a different part depending in which sense they are operating.