Sikorsky XH-39

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XH-39 (S-59)
Sikorsky XH-39.jpg
Sikorsky XH-39
Role Helicopter
Manufacturer Sikorsky Aircraft
Introduction not produced
Primary user United States Army
Number built 1[1]
Developed from Sikorsky S-52

The Sikorsky XH-39 (manufacturer designation S-59), developed by Sikorsky Aircraft in 1954, was the U.S. Army's first turbine-powered helicopter. It was fast and innovative, but ultimately rejected by the United States Army in favor of the Bell UH-1 Iroquois.

Design and development[edit]

The four-seat XH-39 was powered by one Continental CAE XT51-T-3 400 shp (298 kW) turboshaft engine, a license-built development of the Turbomeca Artouste. It was developed from a previous Sikorsky model, the H-18 (company model S-52), and had the same layout. It differed in using retractable landing gear, modified tail rotor, and four-blade main rotor.[1] In the end, the U.S. Army selected the Bell XH-40, prototype of the UH-1 Huey. Two YH-18As were modified into XH-39s; one for flight testing and the other for static test.

On 26 August 1954, the XH-39 set a world helicopter speed record of 156.005 mph (251 km/h) over a three kilometer closed course at Bradley Field (now Bradley International Airport) in Windsor Locks, Connecticut.[2] The same year, on October 17, 1954, it set an unofficial world helicopter altitude record of 24,500 ft (7,474 m) at Bridgeport, Connecticut.[3]

In addition to the two XH-39's, one S-59, serial number 52004, registration number N74150, was produced for use for company demonstration flights.[2] It has been restored and is now on display at the New England Air Museum, Windsor Locks, Connecticut.[4]


Former YH-18A modified for static testing, not flown and later modified back to YH-18A standard.
Former YH-18A modified for flight testing.

Specifications (XH-39)[edit]

S-59 during runup
Sikorsky S-59 on display at the New England Air Museum

Data from U.S. Army Aircraft Since 1947[5]

General characteristics


See also[edit]

Related development

Aircraft of comparable role, configuration and era

Related lists



  1. ^ a b Polmar and Kennedy 1981, p. 288.
  2. ^ a b
  3. ^ Hearst Magazines (February 1955). "Sets Helicopter Record". Popular Mechanics. Hearst Magazines. p. 113.
  4. ^
  5. ^ Harding 1990, p. 233.


  • Harding, Stephen. U.S. Army Aircraft Since 1947. Shrewsbury, England: Airlife, 1990. ISBN 1-85310-102-8.
  • Polmar, Norman and Floyd D. Kennedy, Jr. Military Helicopters of the World: Military Rotary-wing Aircraft Since 1917.. Annapolis, Maryland: Naval Institute Press, 1981. ISBN 0-87021-383-0.

External links[edit]