Allison J71


F-3C J-71 VF-121 NAN6-63.jpg
J71 engine change in progress on a F3H-2 Demon, 1963.
Type Turbojet
Manufacturer Allison Engine Company
First run 1950
Major applications B-66 Destroyer
F3H Demon
Developed from Allison J35

The Allison J71 was a single spool turbojet engine, designed and built in the United States. It began development in 1948 as a much modified J35, originally designated J35-A-23.[1]

Operational history

The Allison J71 turbojet powered the Douglas B-66 Destroyer and the McDonnell F3H-2 Demon after the failed Westinghouse J40 proved unworkable. The prototype P6M SeaMasters were also fitted with the engine.


Data from: Aircraft engines of the World 1953[2]

Powered the McDonnell F3H Demon
9,700 lbf (43.15 kN) thrust (14,000 lbf (62.28 kN) thrust with afterburner), for the McDonnell F3H-2 Demon.
7,000 lbf (31.14 kN) thrust (9,500 lbf (42.26 kN) thrust with afterburner)
Afterburning turbojet engines for the Martin XP6M-1 Seamaster flying boat prototypes.
Afterburning turbojet engines for the Martin YP6M-1 Seamaster pre-production flying boats.
14,000 lbf (62.28 kN) thrust with afterburner
Powered the Douglas RB-66 Destroyer
10,200 lbf (45.37 kN) thrust

Specifications (Allison J71-A-2)

Data from Aircraft engines of the World 1957[3]

General characteristics

  • Type: afterburning turbojet
  • Length: 284.5 in (7,230 mm)
  • Diameter: 39.5 in (1,000 mm)
  • Frontal area: 8.5 sq ft (0.79 m2)
  • Dry weight: 4,890 lb (2,220 kg)


  • Compressor: 16-stage axial compressor
  • Combustors: cannular with 10 flame tubes
  • Turbine: 3-stage axial
  • Fuel type: JP-4 / aviation kerosene
  • Oil system: pressure spray with scavenge at 10–60 psi (69–414 kPa)


See also

Related development

Related lists


  1. ^ Gunston, Bill (1989). World Encyclopaedia of Aero Engines (2nd ed.). Cambridge, England: Patrick Stephens Limited. p. 11. ISBN 978-1-85260-163-8.
  2. ^ Wilkinson, Paul H. (1953). Aircraft engines of the World 1953 (11th ed.). London: Sir Isaac Pitman & Sons Ltd. pp. 64–65.
  3. ^ Wilkinson, Paul H. (1957). Aircraft engines of the World 1957 (15th ed.). London: Sir Isaac Pitman & Sons Ltd. pp. 74–75.

Further reading

  • Kay, Anthony L. (2007). Turbojet History and Development 1930-1960 Volume 2:USSR, USA, Japan, France, Canada, Sweden, Switzerland, Italy and Hungary (1st ed.). Ramsbury: The Crowood Press. ISBN 978-1861269393.
  • "Aero Engines 1957". Flight and Aircraft Engineer. 72 (2531): 111–143. 26 July 1957. Retrieved 16 March 2019.
  • "J71 Allison's Big Axial Turbojet". Flight and Aircraft Engineer. 67 (2418): 733. 27 May 1955. Retrieved 16 March 2019.

External links

  • "Allison J71 Turbojet". Archived from the original on 19 October 2006. Retrieved 16 March 2019.
  • "J71 Allison, USA". (in Czech). Prague. Retrieved 16 March 2019.