Allison J71

J71
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-1 SeaMasters were also fitted with the engine.

Variants

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

J71-A-1

J71-A-2

Powered the McDonnell F3H Demon

J71-A-2B

J71-A-2E

9,700 lbf (43.15 kN) thrust (14,000 lbf (62.28 kN) thrust with afterburner), for the McDonnell F3H-2 Demon.

YJ71-A-3

7,000 lbf (31.14 kN) thrust (9,500 lbf (42.26 kN) thrust with afterburner)

J71-A-4

Afterburning turbojet engines for the Martin XP6M-1 Seamaster flying boat prototypes.

J71-A-6

Afterburning turbojet engines for the Martin YP6M-1 Seamaster pre-production flying boats.

J71-A-7

14,000 lbf (62.28 kN) thrust with afterburner

J71-A-9

Powered the Douglas RB-66 Destroyer

J71-A-11

10,200 lbf (45.37 kN) thrust

J71-A-13

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)

Components

• 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)

Performance

• Maximum thrust: take-off, dry 10,000 lbf (44,000 N); take-off, wet 14,000 lbf (62.28 kN)
• Overall pressure ratio: 8.0:1
• Air mass flow: 160 lb/s (73 kg/s) at 6,100 rpm (static)
• Specific fuel consumption: 1.8 lb/(lbf⋅h) (51 g/(kN⋅s)) with afterburner (wet)
• Thrust-to-weight ratio: 2.857

See also

Related development

• Allison J35

Related lists

• List of aircraft engines

References

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