General Electric J73

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.

"J73" redirects here. For other uses, see J73 (disambiguation).
J73
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
Unit cost $145,000
Developed from General Electric J47
Developed into General Electric J79

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]

Variants
F-86H Sabre
J73-GE-1
J73-GE-3
9,200 lbf (40.92 kN) for the North American F-86H Sabre.
J73-GE-5
Variant intended for a proposed Advanced F-89.[4]

Applications
YF-84J Thunderstreak
  • North American F-86H Sabre
  • Republic YF-84J Thunderstreak, two prototypes

Specifications (J73-GE-3)

Data from Flight 9 April 1954 : Aero Engines 1954[5], Aircraft engines of the World 1953[6]

General characteristics

  • Type: non-afterburning turbojet
J73-GE-5 with afterburning
  • Length: 200 in (5,080 mm)
  • Diameter: 39.5 in (1,003 mm)
  • Dry weight: 3,600 lb (1,630 kg)

Components

  • Compressor: 12 stage, axial flow, variable inlet guide vanes
  • Combustors: 10 cannular combustion chambers
  • Turbine: 2 stage axial turbine
  • Fuel type: MIL-F-5624A / JP-4
  • Oil system: dry sump, pressure spray with gear pumps

Performance

  • Maximum thrust: 9,000 lbf (40 kN)::::J73-GE-5 - 9,500 lbf (42 kN) dry, 12,500 lbf (56 kN) with afterburner
  • Overall pressure ratio: 7.5:1
  • Air mass flow: 155 lb/s (70 kg/s)
  • Specific fuel consumption: 0.9 lb/(lbf⋅h) or 25 g/(kN⋅s)
  • Thrust-to-weight ratio: 2.5
J73-GE-5 - 2.64 dry, 3.47 with afterburner

See also

Related development

Comparable engines

Related lists

References
  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. Retrieved 24 February 2019.
  3. Seven Decades of Progress: A Heritage of Aircraft Turbine Technology. Fallbrook: Aero Publishers. 1979. p. 82. ISBN 9780816883554.
  4. "Standard Aircraft Characteristics: Advanced F-89" (PDF). US Air Force. 3 December 1951. Retrieved 30 December 2018.
  5. "Aero Engines 1954 : The World's Leading Aero-engine Constructors and their Products Reviewed". 9 April 1954: 457. Retrieved 24 February 2019. Cite journal requires |journal= (help)
  6. Wilkinson, Paul H. (1953). Aircraft engines of the World 1953 (11th ed.). London: Sir Isaac Pitman & Sons Ltd. pp. 82–83.

Further reading
  • Gunston, Bill (2006). World Encyclopedia of Aero Engines, 5th Edition. Phoenix Mill, Gloucestershire, England, UK: Sutton Publishing Limited. ISBN 0-7509-4479-X.
  • Kay, Anthony L. (2007). Turbojet History and Development 1930֪–1960 Volume 2:USSR, USA, Japan, France, Canada, Sweden, Switzerland, Italy and Hungary (1st ed.). Ramsbury: The Crowood Press. ISBN 978-1861269393.
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