Aeronautical Products Inc A-1

Two undergraduate engineers of the University of Michigan, Corwin Denny and Karl Schakel, with the Aeronautical Products Corporation of Detroit, Michigan, have designed and built a helicopter. Both of the designers left the corporation, but work progressed on the helicopter they initiated. First flown April 1944, during preparations for a trial flight, was damaged, and was rebuilt.

The Denny and Schakel helicopter is a single, main-rotor machine with an auxiliary tail rotor for torque correction. The main rotor is 9m in diameter and is powered by a ninety-horsepower engine. The gross weight is reported to be approximately 540kg. It has a fixed tricycle landing gear.

Built of welded-steel tubular construction, this helicopter is a single-seater with enclosed cabin. The pilot sits behind the engine, which is mounted in the nose. A long shaft extends under the pilot's seat and is geared to the vertical shaft of the rotor.

It was not put into production.