Original author: Spark1645

Piasecki HUP Retriever

The Piasecki HUP Retriever/H-25 Army Mule is a compact single radial engine, twin overlapping tandem rotor utility helicopter developed by the Piasecki Helicopter Corporation of Morton, Pennsylvania. Designed to a United States Navy specification, the helicopter was produced from 1949 to 1954, and was also used by the United States Army and foreign navies. The HUP/H-25 was the first helicopter to be produced with an autopilot and also the first to perform a loop.

HUP-2

HUP-2
Improved version, 550 hp (410 kW) Continental R-975-42 piston engine, horizontal stabilizer endplate fins eliminated. 165 built for the US Navy, 15 for French Aeronavale.[citation needed] Redesignated UH-25B in 1962.