The Piasecki HUP series of helicopters was designed for the U.S. Navy as light utility helicopters.  Design work began in 1945 and the first one flew in 1948.  The helicopter uses a single engine to turn both rotors.  The early versions were primarily used for anti-submarine operations while the later HUP-3 was used for search and rescue and as a transport.  Many of the HUP-3 version began their lives as U.S. Army H-25A Army Mules.  After serving with the Army for several years fifty helicopters were transferred to the U.S. Navy and redesignated as HUP-3 Retrievers.  In 1962 the designation was again changed to UH-25C.  The last of them were retired in 1964.

Manufacturer
Piasecki

Markings
Utility Helicopter Squadron 1 (HU-1), Atsugi Naval Air Facility, Japan, 1961

Designation
HUP-3

Serial Number
147595 (51-16608)