One example was modified to become the world's first gas turbine-powered helicopter.

The United States Air Force evaluated one K-225 with the designation YH-22.

A modified K-225 equipped with a Boeing 502 (YT50) turboshaft engine became the first gas turbine-powered helicopter in December 1951.

[2] This aircraft is now at the Smithsonian Institution in Washington, D.C. A standard K-225 is preserved in the New England Air Museum at Windsor Locks Connecticut.

Related development Aircraft of comparable role, configuration, and era