Piasecki

Frank N. Piasecki was the first owner of an American helicopter pilot’s licence. In 1943, he founded the P. V. Engineering Forum dedicated to the development of rotary aircraft.

Piasecki PV-2, PV-3, and PV-17

History of Development
The first model of the Piasecki company to be successful was the experimental Piasecki PV-2. It was single-seated with a 90-shp (67-kW) Franklin flat-four engine driving the three-bladed main rotor. Piasecki was the pilot on the first flight that was conducted on 11 April, 1943.

The next project was the PV-3, a test model for the HRP Rescuer rescue and transport helicopter of the US Navy. The US Navy ordered the PV-3 on 1 February, 1944. It was equipped with a Wright R-975 piston engine and had tandem rotors. Its first flight was in March 1945 in Morton, Pennsylvania. Two XHRP-1 airframes followed, one of which was used for static tests, while the other was involved in the flight development programme. It was at this time that the company changed its name into Piasecki Helicopter Corporation. In June 1946, a first order of ten HRP-1 serial aircraft was received. The first aircraft took off on 15 August, 1947. It had a 600-shp (447-kW) Pratt & Whitney R-1340-AN-1 engine. 20 machines were eventually built, all having a tail unit with a metal skin and a fabric covering for the main cabin part, which, however, was often not applied. The operational tests were conducted by the US Navy Squadron VX-3 and by the US Marine Squadron HMX-1. The US Coast Guard received three machines with the designation HRP-1G. In June 1948, five improved helicopters with an all-metal skin fuselage were ordered as HRP-2, which also served with the American Coast Guard.

Specifications Piasecki HRP-2

Type: Transport/rescue helicopter with tandem rotors.
Powerplant: One 600-shp (447-kW) Pratt & Whitney R-1340-AN-1 radial engine.
Performance: Max. speed 169 km/h at sea level; cruise speed 148 km/h; max. range 483 km.
Weight: Empty weight 2,404 kg; max. take-off weight 3,277 kg.
Dimensions: Rotor diameter 12.50 m each; length 16.46 m; height 4.52 m; total rotor disc area 245.30 m².

Piasecki HUP Retriever

History of Development
The "flying banana" shape of the HRP-1 was not adopted for the Piasecki Model PV-14. Two prototypes with the designation XHJP-1 were ordered for carrier-supported rescue operations. This model was basis for the PV-18 (US Navy designation HUP-1) with rectangular endplate fins at the horizontal stabilisers mounted to the rear rotor pylon. Between February 1949 and 1952, 32 units of the HUP-1 with 525-shp (391-kW) Continental R-975-34 engines were built for the US Navy. The first squadron, HU-2, received the first model in February 1951. After successful testing with a Sperry auto pilot in an XHJP-1 the HUP-2 was developed. It had an improved directional stability, which made the end-plate fins unnecessary, and it was equipped with a more powerful 550-shp (410-kW) R-975-46 engine. 339 units were built, 193 of which were delivered to the US Navy. Some of them were fitted with a diving sonar system and got the designation HUP-2S. 15 HUP-2 were delivered to the French Navy. In 1953, the US Army ordered a number of improved H-25A Army Mule with R-975-46A engines, hydraulically boosted controls, reinforced cabin floor and larger hatches. 50 similar machines were delivered as HUP-3 to the US Navy. Three units served with the VU-21 Squadron of the Royal Canadian Navy. When the new designation system was introduced in September 1962, HUP-2 and HUP-3 became UH-25B and UH-25C, respectively.

Specifications Piasecki HUP-3

Type: Multi-purpose helicopter.
Powerplant: One 550-shp (410-kW) Continental R-975-46A radial engine.
Performance: Max. Speed 169 km; service ceiling 3,050 m; max. range 547 km.
Weight: Empty weight 1,782 kg; max. take-off weight 2,767 kg.
Dimensions: Rotor diameter 10.67 m each; length 17.35 m with rotors turning; height 3.81 m; total rotor disc area 178.76 m².