Hewland AE75

The engine was designed specifically for the ARV Super2, a lightweight two-seater shoulder wing aircraft.

[5] The engine has a 2.7:1[6] Propeller Speed Reduction Unit (PSRU) with helical gears in an oil bath.

Final drive to the wooden 63 in (160 cm) diameter 2-blade Hoffman propeller[7] was via a rubber “doughnut” coupling.

This feature allowed a more pointed nose on the ARV, at the cost of slightly reduced propeller clearance.

The Hewland AE75 should not be confused with the Austro Engine AE75R,[9] a Wankel aero-engine developed from the MidWest AE50, a single-rotor version of the AE100.