Cutaway of a J73 at the NMUSAF
Type Turbojet
National origin United States
Manufacturer General Electric
Major applications North American F-86H Sabre
Number built 870
Developed from General Electric J47
Developed into General Electric J79

The General Electric J73 turbojet was developed by General Electric from the earlier J47 engine. Its original USAF designation was J47-21, but with innovative features including variable inlet guide vanes, double-shell (inner and outer) combustor case, and 50% greater airflow was redesignated J73. Its only operational use was in the North American F-86H.

Design and development

An engine, uprated from the J47, was required for the F-86H. The mass flow was increased by relocating accessories from the centre of the compressor inlet to the underside of the engine. This allowed a reduction in blade hub diameter, which together with an increase in tip diameter, gave a bigger area for air to enter the compressor. The area through the combustion chambers also had to be increased. This was done by replacing the multiple individual chambers with a single annular casing with individual flame tubes or cans known as cannular.[1]

The pressure ratio was increased and variable inlet guide vanes fitted to prevent low-RPM problems (rotating stall/blade flutter) with the higher design pressure ratio. A 2-stage turbine was required.[2][3]

A low boost (10% at take-off) afterburner was fitted. It was known as a tailpipe augmentation (TPA) system.[3]

Nuclear powered

Four J73 engines were converted to produce thrust using nuclear energy instead of jet fuel. Testing was done in 1957 at the Atomic Energy Commission's National Reactor testing station. The engines were modified to pass the compressor air through a heat exchanger, in which heat was transferred from a nuclear reactor, before entering the compressor turbine at 1,400 degrees F.[4]


F-86H Sabre
9,200 lbf (40.92 kN) for the North American F-86H Sabre.
Variant intended for a proposed Advanced F-89.[5]


YF-84J Thunderstreak

Specifications (J73-GE-3)

Data from Flight 9 April 1954 : Aero Engines 1954,[6] Aircraft engines of the World 1953[7]

General characteristics

J73-GE-5 with afterburning



J73-GE-5 - 9,500 lbf (42 kN) dry, 12,500 lbf (56 kN) with afterburner
J73-GE-5 - 2.64 dry, 3.47 with afterburner

See also

Related development

Comparable engines

Related lists


  1. ^ "Aero Engines 1957". Flight: 133. 26 July 1957.
  2. ^ Johnsen, Irving A.; Bullock, Robert 0. (1965). NASA SP-36 : AERODYNAMIC DESIGN OF AXIAL-FLOW COMPRESSORS (PDF). Washington D.C.: NASA. pp. 27a, 44. Archived from the original (PDF) on 20 July 2018. Retrieved 24 February 2019.((cite book)): CS1 maint: numeric names: authors list (link)
  3. ^ a b Seven Decades of Progress: A Heritage of Aircraft Turbine Technology. Fallbrook: Aero Publishers. 1979. p. 82. ISBN 9780816883554.
  4. ^ https://archive.org/details/Aviation_Week_1957-03-18/page/n13/mode/2up, p.27
  5. ^ "Standard Aircraft Characteristics: Advanced F-89" (PDF). US Air Force. 3 December 1951. Retrieved 30 December 2018.
  6. ^ "Aero Engines 1954 : The World's Leading Aero-engine Constructors and their Products Reviewed". 9 April 1954: 457. Retrieved 24 February 2019. ((cite journal)): Cite journal requires |journal= (help)
  7. ^ Wilkinson, Paul H. (1953). Aircraft engines of the World 1953 (11th ed.). London: Sir Isaac Pitman & Sons Ltd. pp. 82–83.

Further reading