The Hughes XH-17 "Flying Crane" was the first helicopter project for the helicopter division of Hughes Aircraft Company. The XH-17, which had a two-bladed main rotor system with a diameter of 134 feet (41 m), still holds the world record for flying with the largest rotor system. It was capable of flying at a gross weight of more than 50,000 pounds (23,000 kg), but proved too inefficient and cumbersome to be mass-produced beyond the prototype unit.
The XH-17 was a heavy-lift rotorcraft that was designed to lift loads in excess of 15 metric tons. To speed construction, parts of the XH-17 were scavenged from other aircraft. The front wheels came from a North American B-25 Mitchell and the rear wheels from a Douglas C-54 Skymaster. The fuel tank was a bomb bay-mounted unit from a Boeing B-29 Superfortress. The cockpit was from a Waco CG-15 military glider and the tail rotor from a Sikorsky H-19 Chickasaw was used for yaw control.
In the late 1940s, Hughes developed an interest in helicopters. In August 1947, helicopter manufacturer Kellett sold his design for the giant XH-17 Sky Crane to Hughes, who commissioned the development of the XH-17 Flying Crane research vehicle. In 1948, the XH-17 began to take shape. The giant helicopter was tested in Culver City, California over a three-year period beginning in 1952. The XH-17 flew in 1953 at a gross weight in excess of 50,000 pounds (23,000 kg). It still holds the record for flying with the world's largest rotor system. Only one unit was built, since the aircraft was too cumbersome and inefficient to warrant further development.
The propulsion system was unusual. Two General Electric J35turbojet engines were used, sending bleed air up through the rotor hub. The blades were hollow, and the hot compressed air traveled through the blades to tip jets where fuel was injected. In flight, the main rotor spun at a sedate 88 revolutions per minute, less than half the speed of typical helicopter rotors. Since the rotor was driven at the tips rather than the hub, little torque compensation was required, mostly due to friction in the main rotor bearing. Thus, the XH-17 had a very small tail rotor compared to its main rotor. This drive system was inefficient, limiting the test aircraft to a range of only 40 miles (64 km).
The XH-28 was a derivative, with a maximum weight of 104,000 pounds (47,000 kg). Though a wooden mockup of the design was made, the program was canceled and none were built.
Specificationsedit
Two cars parked beneath the XH-17 give a sense of scale.3-view line drawing of the Hughes XH-17
Data from McDonnell Douglas aircraft since 1920 Vol.2[1]
General characteristics
Crew: 3 (pilot, mechanic and in-flight test engineer)
Capacity: demonstrated loads up to 10,284 lb (4,665 kg) were carried
Length: 53 ft 3.6 in (16.246 m)
Height: 30 ft 1.2 in (9.174 m)
Empty weight: 28,562 lb (12,956 kg)
Gross weight: 31,270 lb (14,184 kg)
Max takeoff weight: 43,500 lb (19,731 kg)
Fuel capacity: 635 US gal (529 imp gal; 2,404 L) (Boeing B-29 bomb-bay tank)
Powerplant: 2 × General Electric 7E-TG-180-XR-17A gas generators, 3,480 hp (2,600 kW) each combined predicted gas power output, with rotor turning at 88 rpm
Main rotor diameter: 130 ft (40 m)
Main rotor area: 13,274.95 sq ft (1,233.283 m2)
Performance
Maximum speed: 90 mph (140 km/h, 78 kn) at 8,000 ft (2,438 m)
Cruise speed: 85 mph (137 km/h, 74 kn)
Range: 30 mi (48 km, 26 nmi) with 10,284 lb (4,665 kg) payload
^Francillon, René J. (20 September 1990). McDonnell Douglas aircraft since 1920 Vol.2 (2nd ed.). London: Putnam Aeronautical. pp. 131–135. ISBN978-0851778280.
Further readingedit
Winchester, Jim (2009). World's worst aircraft. New York, NY: Rosen. ISBN978-1404218376.
"Giant Jet Helicopter Ready For First Flight". Popular Mechanics: 116. August 1952.
"HOW FARES THE HELICOPTER? . ". Flight. 70 (2493): 710–716. 2 November 1956.
"A Spread of Giants". Flight. 69 (2450): 15. 6 January 1956.
External linksedit
Wikimedia Commons has media related to Hughes XH-17.
"Hughes XH-17". www.1000aircraftphotos.com. Retrieved 14 August 2020.
April 12, 2024
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This article includes a list of references related reading or external links but its sources remain unclear because it lacks inline citations Please help improve this article by introducing more precise citations July 2014 Learn how and when to remove this template message The Hughes XH 17 Flying Crane was the first helicopter project for the helicopter division of Hughes Aircraft Company The XH 17 which had a two bladed main rotor system with a diameter of 134 feet 41 m still holds the world record for flying with the largest rotor system It was capable of flying at a gross weight of more than 50 000 pounds 23 000 kg but proved too inefficient and cumbersome to be mass produced beyond the prototype unit XH 17 Flying Crane Role HelicopterManufacturer Hughes HelicoptersFirst flight 23 October 1952Retired December 1955Status ScrappedNumber built 1 Contents 1 Design and development 2 Specifications 3 See also 4 References 5 Further reading 6 External linksDesign and development editThe XH 17 was a heavy lift rotorcraft that was designed to lift loads in excess of 15 metric tons To speed construction parts of the XH 17 were scavenged from other aircraft The front wheels came from a North American B 25 Mitchell and the rear wheels from a Douglas C 54 Skymaster The fuel tank was a bomb bay mounted unit from a Boeing B 29 Superfortress The cockpit was from a Waco CG 15 military glider and the tail rotor from a Sikorsky H 19 Chickasaw was used for yaw control In the late 1940s Hughes developed an interest in helicopters In August 1947 helicopter manufacturer Kellett sold his design for the giant XH 17 Sky Crane to Hughes who commissioned the development of the XH 17 Flying Crane research vehicle In 1948 the XH 17 began to take shape The giant helicopter was tested in Culver City California over a three year period beginning in 1952 The XH 17 flew in 1953 at a gross weight in excess of 50 000 pounds 23 000 kg It still holds the record for flying with the world s largest rotor system Only one unit was built since the aircraft was too cumbersome and inefficient to warrant further development The propulsion system was unusual Two General Electric J35 turbojet engines were used sending bleed air up through the rotor hub The blades were hollow and the hot compressed air traveled through the blades to tip jets where fuel was injected In flight the main rotor spun at a sedate 88 revolutions per minute less than half the speed of typical helicopter rotors Since the rotor was driven at the tips rather than the hub little torque compensation was required mostly due to friction in the main rotor bearing Thus the XH 17 had a very small tail rotor compared to its main rotor This drive system was inefficient limiting the test aircraft to a range of only 40 miles 64 km The XH 28 was a derivative with a maximum weight of 104 000 pounds 47 000 kg Though a wooden mockup of the design was made the program was canceled and none were built Specifications edit nbsp Two cars parked beneath the XH 17 give a sense of scale nbsp 3 view line drawing of the Hughes XH 17Data from McDonnell Douglas aircraft since 1920 Vol 2 1 General characteristicsCrew 3 pilot mechanic and in flight test engineer Capacity demonstrated loads up to 10 284 lb 4 665 kg were carried Length 53 ft 3 6 in 16 246 m Height 30 ft 1 2 in 9 174 m Empty weight 28 562 lb 12 956 kg Gross weight 31 270 lb 14 184 kg Max takeoff weight 43 500 lb 19 731 kg Fuel capacity 635 US gal 529 imp gal 2 404 L Boeing B 29 bomb bay tank Powerplant 2 General Electric 7E TG 180 XR 17A gas generators 3 480 hp 2 600 kW each combined predicted gas power output with rotor turning at 88 rpm Main rotor diameter 130 ft 40 m Main rotor area 13 274 95 sq ft 1 233 283 m2 Performance Maximum speed 90 mph 140 km h 78 kn at 8 000 ft 2 438 m Cruise speed 85 mph 137 km h 74 kn Range 30 mi 48 km 26 nmi with 10 284 lb 4 665 kg payload Service ceiling 13 100 ft 4 000 m Rate of climb 1 650 ft min 8 4 m s Disk loading 2 4 lb sq ft 12 kg m2 Power mass 0 111 hp lb 0 182 kW kg See also editAircraft of comparable role configuration and era Sikorsky S 60 Sikorsky CH 54 Tarhe Sikorsky S 64 SkycraneReferences edit Francillon Rene J 20 September 1990 McDonnell Douglas aircraft since 1920 Vol 2 2nd ed London Putnam Aeronautical pp 131 135 ISBN 978 0851778280 Further reading editWinchester Jim 2009 World s worst aircraft New York NY Rosen ISBN 978 1404218376 Giant Jet Helicopter Ready For First Flight Popular Mechanics 116 August 1952 HOW FARES THE HELICOPTER Flight 70 2493 710 716 2 November 1956 A Spread of Giants Flight 69 2450 15 6 January 1956 External links edit nbsp Wikimedia Commons has media related to Hughes XH 17 Hughes XH 17 www 1000aircraftphotos com Retrieved 14 August 2020 Retrieved from https en wikipedia org w index php title Hughes XH 17 amp oldid 1185822419, wikipedia, wiki, book, books, library,
