Ultra-Efficient Products Penetrater

The Ultra-Efficient Products Penetrater is an American ultralight aircraft designed by Nick Leighty and Rick Berstling and produced by Ultra-Efficient Products. It was first shown at the 1985 Sun 'n Fun air show.

The aircraft's most notable feature was that the pilot flew in the prone position. The pilot lay on top of the fuselage, and used elbow rests and foot stirrups. The aircraft had a cantilever low-wing, a fuselage consisting of a single aluminum alloy tube, a V-tail, a tricycle landing gear, and a single engine in pusher configuration.