Interrupter gear

Interrupter Gear: An obsolete gear designed to make possible the firing of a machine-gun or guns through the disc of a revolving propeller.

With the widespread adoption of interrupter gear, most benefits of the pusher configuration were lost and the tractor configuration was favoured. Pushers did not become extinct after the war but were a minority of new aircraft designs.

See also: Propeller, Aviation, Aircraft, Navigation, Front