09/30/2009. Remarks by Ray Watkins: "In 1948 Piasecki won a fly-off against Sikorsky for a utility helicopter to perform search/rescue, plane guard and transport roles. Thirty-two (PV-14) HUP-1 Retriever's were produced between 1948 and 1952.

The PV-18 was an improved variant, with a more powerful engine and a large hatch in the floor for deployment of a winch cable to lift slung loads and facilitate rescue missions. Successful testing of a Sperry autopilot on the original XHJP-1 meant that the HUP-2 could be built without the need for rear control surfaces. A total of 234 HUP-2s (redesignated UH-25B in 1962) were produced for the USN and fifteen for the French Aeronavale.

The US Army procured seventy examples in 1953 of a version with a reinforced floor and hydraulically-boosted controls, designated the H-25A Army Mule, subsequently 50 were transferred to the USN, initially designated HUP-3, from 1962 as HU-25C.