Developed in 1949, the K-225 is the same as the Kaman K-190 except for engine and performance. CAA certificated, 11 were produced with the primary use of crop dusting. In March 1950, three K-225s were delivered to the United States Navy and Coast Guard for evaluation. Of those delivered, the K-225 performed the first loop by a helicopter. The Navy took the K-225 into service, modifying it under the designation of HTK-1. This version used a reciprating engine.
Source: Hirschberg, Michael. "The American Helicopter" (2000). Page 58.
VTOL type: Helicopter
Lift devices: 2 in Synchropter configuration
Crew required: 1 in Single seater arrangement
Landing gear: Wheels (non-retractable)