McDonnell XHJH Whirlaway

The McDonnell XHJH Whirlaway, aka McDonnell Model 65, was a 1940s American experimental twin-rotor helicopter designed and built by McDonnell Aircraft for the United States Navy and was the largest helicopter at the time, as well as the first successful twin-engined twin-rotor helicopter in the world.[1][2][3][4]

XHJH Whirlaway
Role Experimental twin-rotor helicopter
National origin United States
Manufacturer McDonnell Aircraft
First flight 27 April 1946
Number built 1

Design and development

In 1944, the United States Navy issued a requirement for a large rescue helicopter with capacity for ten occupants. The design was originally designated XHJD-1; shortly after flying it was re-designated the XHJH-1. It was derived from the single-engined, twin rotor Platt-LePage XR-1. James McDonnell had invested in that company in 1942 and some of his engineers had been working there, gaining experience of helicopter design and production techniques. McDonnell took control of the company in June 1944.[4] The XHJH-1 first flew two months later. It had twin side-by-side 46 ft (14 m) rotors at the end of pylon wings which turned in opposite directions. Each rotor was powered by a 450 hp (336 kW) Pratt & Whitney R-985-AN-14B Wasp Junior engine.[2]

Variants
XHJD-1
Original United States Navy designation.[1]
XHJH-1
Designation changed before first flight.[1]

Aircraft on display

The sole XHJH-1 is held by the National Air and Space Museum.[5]

Specifications

Data from Aerofiles :McDonnell,[2] Jane's All the World's Aircraft 1949-50,[6] McDonnell Douglas aircraft since 1920 Vol.2[4]

General characteristics

  • Crew: 1
  • Capacity: 1-9 pax
  • Length: 32 ft 2 in (9.80 m)
  • Wingspan: 41 ft (12 m) between rotor centres
  • Width: 87 ft (27 m) overall with rotors turning
  • Gross weight: 11,000 lb (4,990 kg)
  • Powerplant: 2 × Pratt & Whitney R-985-AN-14B Wasp Junior 9-cylinder air-cooled radial piston engines, 450 hp (340 kW) each
  • Main rotor diameter: 2× 46–50 ft (14–15 m)
  • Main rotor area: 3,324 sq ft (308.8 m2) rotors of varying diameter fitted for testing

Performance

  • Maximum speed: 120 mph (190 km/h, 100 kn) at 5,000 ft (1,524 m)
  • Cruise speed: 90 mph (140 km/h, 78 kn)
  • Range: 300 mi (480 km, 260 nmi)
  • Service ceiling: 12,900 ft (3,900 m) absolute
  • Rate of climb: 1,300 ft/min (6.6 m/s)
  • Disk loading: 2.8–3.3 lb/sq ft (14–16 kg/m2) dependent on rotors fitted
  • Power/mass: 0.082 hp/lb (0.135 kW/kg)

See also

Related lists

References
  1. Andrade, John (1979). U.S.Military Aircraft Designations and Serials since 1909. Midland Counties Publications. p. 194. ISBN 0-904597-22-9.
  2. "American airplanes - McDonnell". www.aerofiles.com. 25 March 2008. Retrieved 2010-02-16.
  3. "The War Years: 1939-1945". Boeing. Archived from the original on 2007-07-07. Retrieved 2007-07-07.
  4. Francillon, René J. (1990). McDonnell Douglas aircraft since 1920 Vol.2 (2nd ed.). London: Putnam. pp. 69–72. ISBN 978-0851778280.
  5. "McDonnell XHJD-1 Whirlaway". National Air and Space Museum. Smithsonian Institution. Retrieved 12 August 2019.
  6. Bridgman, Leonard, ed. (1949). Jane's All the World's Aircraft 1949-50. London: Sampson Low, Marston & Co. p. 248c.
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