Realizing this, the Kellett Autogiro Corporation made a proposal to the USAAF on 11 November 1942 for the development of a twin-rotor helicopter that would eliminate the need for a tail rotor and its attendant loss of power.

Initially discounted on theoretical grounds, the proposal was re-examined in the light of tests done with models by the Army's Experimental Engineering Section, and was accepted on 7 January the following year.

This was followed on 11 September with a contract for nearly $1,000,000 to build two prototypes with the three-bladed rotors contained in Kellett's proposal, along with an alternative two-bladed system.

Similarly, it became apparent that the rigid rotor system was going to require extensive redesign of the aircraft, and this effort was dropped as well.

In 2022, it was transferred to the National Museum of the United States Air Force for restoration with a view to going on public display for the first time.