Lockheed XH-51 is a project of the American experimental helicopter, developed in 1962 by the aircraft manufacturing corporation Lockheed Corporation.
The design of the helicopter model Lockheed XH-51 began by American aircraft manufacturers in the late 50s of the last century. The development of the aircraft was associated with the need to provide American troops with high-speed multipurpose aircraft, capable of being used both as independent combat units, and as transport aircraft, and also as auxiliary equipment (patrolling the area, monitoring objects, providing electronic warfare, etc.).
The first flight of the Lockheed XH-51 model helicopter into the air took place on November 2, 1962, while the creation of the project fully met the expectations of aircraft manufacturers, since the aircraft successfully passed all the necessary tests. However, due to its high price, this model was not launched into serial production – interest in the helicopter was not shown either by the US Air Force or the US Navy, in connection with which the model of the aircraft began to be used exclusively as a test option for the creation of other aircraft.
For two years, from 1962 to 1964, 3 aircraft were built by American aircraft manufacturers, some of which have survived to the present, however, only a part of the museum exposition.
Among other things, the American aircraft manufacturers from Lockheed Corporation also tried to reprocess the military aircraft for civilian purposes, however, here, too, there was no interest in the aircraft.
The power plant of the Lockheed XH-51 model aircraft consists of one Pratt & Whitney Canada PT6B-9 gas turbine engine, which, thanks to its relatively low thrust, can accelerate the aircraft to a speed of 280 km \ h. (Maximum performance using the specified power plant ), however, this helicopter also used more powerful gas turbine aircraft engines, which allowed the helicopter to develop a thrust of 2900 hp. The maximum flight range of a helicopter model Lockheed XH-51 is 420 kilometers.
Depending on the modification and version of the aircraft, up to 5 people can be accommodated onboard the helicopter, including one or two pilots, while the helicopter could also carry cargo on its board with a total weight of up to 520 kilograms, which made it very popular, however, the high cost seriously hindered the popularization of the aircraft.
Helicopters of the Lockheed XH-51 model existed in the following variants:
- Lockheed XH-51A – four-seater version of the aircraft;
- Lockheed XH-51A Compound – A modified version of the aircraft, equipped with a gas turbine engine brand Pratt & Whitney J60-2, with a capacity of 2900 hp.;
- Lockheed XH-51N – 5-seater version, converted from the Lockheed XH-51A version;
- Lockheed Model 286 is a multi-purpose cargo-passenger version of the helicopter equipped with a low-power gas turbine power plant.
- Crew: 1-2 people (depending on version);
- Capacity: 3-4 people (depending on version);
- Length: 12.4 m.;
- Height: 2.5 m.;
- The diameter of the rotor: 10.68 m. (Depending on version);
- Empty helicopter mass: 1265 kg. (Depending on version);
- Maximum take-off weight: 1865 kg. (Depending on version);
- Cruising speed: 260 km \ h. (Depending on version);
- Maximum flight speed: 280 km \ h. (Depending on version);
- Maximum flight range: 420 km .;
- Maximum flight height: 4876 m.;
- Powerplant: Pratt & Whitney Canada PT6B-9 (Depending on version);
- Power: 550 hp (Depending on version).