PIASECKI PV-3

Aunque fue construido en un modesto número, el Piasecki HRP-1 tomó su lugar en la historia, en virtud de ser el primer helicóptero en tandem en el mundo, y en el momento de su presentación, el helicóptero mas grande.

Frank N. Piasecki, fue la primer persona en obtener la licencia de piloto de helicópteros en USA, formando su compañía en 1943.

El PV-3 estaba potenciado por un motor Wright R-975, realizando su primer vuelo en Morton, Pennsylvania en marzo de 1945, lo que fue seguido de otros dos prototipos XHRP-1, uno para las pruebas de la U.S. Navy y otro para ensayos estáticos y dinámicos. Las pruebas fueron finalizadas en el verano de 1947, cuando ya la compañía había cambiado su nombre por el de Piasecki Helicopter Corporation. Construyo primero 10 modelos para la U.S. Navy, potenciados con el motor Pratt & Whitney R-1340-AN-1 de 600 HP.

El HRP-1 podía llevar dos pilotos y hasta 8 pasajeros en una cabina de 11,33 m3 y fue conocido con el apodo 'flying banana' (banana voladora).Tenia solo un motor ubicado en la parte trasera con una caja de transmisión en el medio la que llevaba la potencia a otras dos cajas reductoras debajo de cada uno de los rotores.

En junio de 1948 la U.S. Navy ordenó 5 ejemplares del mas desarrollado PV-17 con la designación HRP-2. Este era mas largo, con mas espacio de cabina y rotores diferentes.

Although it was built only in modest numbers and had an unspectacular (though useful) service career, the Piasecki HRP-1 has its place in the history of rotorcraft by virtue of being the world's first practical tandem-rotor helicopter and, at the time of its appearance, the world's largest helicopter of any kind. Frank N. Piasecki, holder of the first helicopter pilot's licence to be issued in the United States, became interested in rotorcraft development before America's entry into World War 2, and in 1943 he formed a company known as the P.V. Engineering Forum whose first design, the PV-2, was a single-seat, single main rotor helicopter with a 90hp Franklin engine. This machine, which flew for the first time on 11 April 1943, was Piasecki's first and only single-rotor helicopter, for on 1 February 1944 he received a contract to develop a tandem-rotor utility transport and rescue aircraft for the U.S. Navy.

Given the factory designation PV-3, this machine, powered by a Wright R-975 piston-engine, made a successful first flight at Morton, Pennsylvania, in March 1945 and was followed by two XHRP-1 prototypes, one for U.S. Navy flight trials and the other for static and dynamic tests. The test programme was completed in the spring of 1947, by which time the company title had changed to Piasecki Helicopter Corporation, and work had already begun on an initial batch of ten HRP-1 Rescuers ordered by the U.S. Navy in June 1946. The first of these flew on 15 August 1947, and a second batch of ten was built later, the final machine being delivered in 1949. These were powered by 600hp Pratt & Whitney R-1340-AN-1 engines. Twelve of the HRP-1's were eventually assigned to the U.S. Marine Corps for assault training, while three others, as HRP-1G's, were used as rescue craft by the U.S. Coast Guard. After withdrawal of the Rescuer from military service in the early 1950s, about six appeared on the U.S. civil register.

The tandem-rotor layout offered a wider choice of e.g. positions, together with a small frontal area and a large lifting area; thus the HRP-1 was able to register a significant step forward, from craft whose main purpose had been to prove the flight principles of the helicopter, to a vehicle capable of : doing a real job of work. Nicknamed - for obvious reasons - the 'flying banana', the HRP-1 carried a crew of 2 sitting in tandem, and its 11.33m3 cabin could accommodate 8 passengers, 907kg of cargo or 6 stretchers. The single engine was mounted in the rear part of the fuselage, with a clutch and gearbox amidships from which drive shafts ran to reduction gearboxes below each of the rotor hubs.

In June 1948 the U.S. Navy ordered five examples of the much-developed PV-17 with the designation HRP-2. This had a considerably longer, redesigned fuselage with an all-metal skin (the HRP-1's front half was fabric-covered), a more roomy crew cabin with side-by-side seats, and modified rotor heads. This version formed the basis of the later PD-22 model which became the highly successful military Vertol H-21 series.

Characteristics Características	Information Información	Characteristics Características	Information Información
First Flight Primer Vuelo	1945	Engine Motor	1 Pratt & Whitney R-1340-AN-1
Seating Capacity Plazas	2 / 8	Power Potencia	600 HP
Empty Weight Peso Vacío	2400 Kg	Hover Ceiling O.G.E. Estacionario O.G.E	NA
Maximum Weight Peso Máximo	3280 Kg	Hover Ceiling I.G.E. Estacionario I.G.E	Ft
Vel. Cruise Vel. crucero	80 Kts	Service Ceiling Techo de Servicio	Ft
V.N.E. V.N.E	90 Kts	Maximum Range (Std) Alcance (Std)	260 NM