Lockheed XH-51

The Lockheed XH-51 (Model 186) was an American single-engine experimental helicopter designed by Lockheed Aircraft, utilizing a rigid rotor and retractable skid landing gear.

The XH-51 was selected as the test vehicle for a joint research program conducted by the United States Army and United States Navy to explore rigid rotor technology.

Variants

XH-51A

four place, three-bladed rotor

XH-51A Compound

modified with a four-bladed rotor and stub wings and an auxiliary 2,900 lbf (12.9 kN) Pratt & Whitney J60-2 engine.

XH-51N

five place, three-bladed rotor for NASA test purposes.

Model 286

Five place civilian or military light helicopter offered for sale, none were sold.

Specifications

Crew

2

Length

40 ft 9 in (12.42 m)

Height

8 ft 2.5 in (2.50 m)

Empty weight

2,790 lb (1,266 kg)

Max take-off weight

4,100 lb (1,860 kg)

Fuel capacity

80 US gal (67 imp gal; 300 L)

Powerplant

1 × Pratt & Whitney Canada PT6B-9 turboshaft, 500 shp (370 kW)

Main rotor diameter

35 ft 0 in (10.67 m)

Main rotor area

962 sq ft (89.4 m2)

Performance

Maximum speed

151 kn (174 mph, 280 km/h)

Cruise speed

140 kn (160 mph, 260 km/h)

Range

230 nmi (260 mi, 420 km)

Service ceiling

16,000 ft (4,900 m) (hover ceiling), in ground effect

Rate of climb

2,000 ft/min (10 m/s).