Williams International

Williams International is an American manufacturer of small gas turbine engines based in Pontiac, Michigan, United States. It produces jet engines for cruise missiles and small jet aircraft.

Williams International
FormerlyWilliams Research Corporation
Founded1954 (1954)
FounderSam B. Williams
United States


Dr. Sam B. Williams worked at Chrysler on their automotive turbine systems, but always imagined a wider set of applications for the small gas turbine engine. He left Chrysler to form Williams Research Corporation in Birmingham, Michigan in 1954.[1][2] In 1981, the company became Williams International. It has been building small turbofan engines since the 1950s for use in cruise missiles as well as target and reconnaissance drones.

Using the missile engines, Williams developed a series of personal VTOL flying craft, including a jet-powered belt in 1969, the Williams Aerial Systems Platform (WASP), also known as the "flying pulpit" in the 1970s, and the X-Jet, which was evaluated by the United States Army in the 1980s.[3][4] The WASP platform was the only competitor to the Garrett STAMP in the United States Marine Corps STAMP (Small Tactical Aerial Mobility Platform) program of the early 1970s.

Also in the 1980s, Williams identified a need in the general aviation market for a small, light jet engine to power cost-effective personal and corporate jet aircraft. The company introduced the FJ44 engine, which in turn made possible the introduction of a number of small jet aircraft.

In 1992, NASA initiated its Advanced General Aviation Transport Experiments (AGATE) program to partner with manufacturers and help develop technologies that would revitalize the sagging general aviation industry. In 1996, Williams joined AGATE's General Aviation Propulsion program to develop a fuel-efficient turbofan engine that would be even smaller than the FJ44. The result was the FJX-2 engine. Williams then contracted with Burt Rutan's Scaled Composites to design and build the Williams V-Jet II, a Very Light Jet to use as a testbed and technology demonstrator to showcase the new engine. The aircraft and engine were debuted at the 1997 Oshkosh Airshow. The production version of the engine, the EJ22 flew on the prototype Eclipse 500 VLJ (which had evolved from the V-Jet II), but was subsequently replaced by a Pratt & Whitney engine.



Model name First flight Number built Type
Williams X-Jet 1980 3 Flying platform
Williams V-Jet II 1997 1 Twin jet engine monoplane business jet


Model name Variant US Military Designation (MIL-HDBK-1812) Configuration Power First Flight Used In
Williams WR1 WR1 regenerative free turbine turboshaft 75 shaft horsepower 1954
Williams Jet No. 1 single-shaft, centrifugal/centrifugal-axial flow turbojet 60 lbf 1957
Williams J400 WR2 single-shaft, centrifugal/centrifugal-axial flow turbojet 125 lbf 1960 Canadair CL-89,
Williams J400 WR24 J400-WR single-shaft, centrifugal/centrifugal-axial flow turbojet 240 lbf Northrop MQM/BQM-74 Chukar
Williams F107 WR19 F107-WR Turbofan 430 lbf AGM-86, BGM-109
Williams F122 WR19 F122-WR twin-shaft, axial-centrifugal-flow turbofan 900 lbf AGM-137
Williams F112 F112-WR twin-spool counter rotating turbofan 732 lbf 1985(?) X-36, X-50, AGM-129
Williams EJ22 3-spool medium-bypass ratio turbofan 770 lbf 2000(?) Eclipse 500 VLJ
Williams FJ33 Turbofan 1,846 lbf 1998(?) Cirrus Vision SF50
Williams FJ44 WR44 F129-WR Turbofan 1,900 lbf July 12, 1988
Williams WR34 WR34 turboshaft
Williams F121 WR36 F121-WR 1 stage axial fan, 6-stage axial compressor, single spool turbofan 70 lbf July 30, 1984 AGM-136 Tacit Rainbow
Williams WST117

See alsoEdit



  1. ^ "Sam Williams to Receive NBAA Meritorious Service Award; Skip Reed to Receive Doswell Award". Archived from the original on 2007-01-03. Retrieved 2006-12-13.
  2. ^ Richard A. Leyes and William A. Fleming, The History of North American Small Gas Turbine Aircraft Engines, p. 385
  3. ^ Williams WASP II
  4. ^ Kocivar, Ben. "Turbofan-powered flying carpet" Popular Science, September 1982. Accessed: September 2014.


  • Noland, David (November 2005). "The Little Engine That Couldn't". Air & Space. Retrieved 14 September 2021.
  • Wahl, Paul (April 1974). "Jet Flight With No Wings". Popular Science. pp. 88–89 and 152.

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