The K-190 and K-225 were an improved versions of the K-125, which first flew in April and July 1949 respectively. The U.S. Navy bought two and the Coast Guard one for $25,000 each. Later, they received the H-22 designation.
A modified K-225 equipped with a Boeing 502 (YT50) turboshaft engine became the world's first gas turbine powered helicopter in December 1951. This aircraft is now at the Smithsonian Institution in Washington, D.C.