Armstrong Siddeley Hyena

The Armstrong Siddeley Hyena was a British aero engine developed by Armstrong Siddeley. Designed in the 1930s, it was an unusual experimental radial engine with inline cylinder banks.[1] It was flown using an Armstrong Whitworth A.W.16 fighter aircraft as a test bed. Unresolved problems with cooling of the rear cylinders prevented the engine from going into production.[2] Few details of this engine survive as company records were lost.[3]

Type Radial engine
Manufacturer Armstrong Siddeley
First run 1933
Major applications Armstrong Whitworth A.W.16

Armstrong Siddely in-line radial engines

The Hyena arrangement of cylinder banks arranged as a radial engine was continued with further designs, but with little commercial success. Only the Deerhound and Hyena being built.

15 cylinders (5 banks of 3 cyl.)
14 cylinders (7 banks of 2 cyl.)
21 cylinders (7 banks of 3 cyl.)
28 cylinders (7 banks of 4 cyl.)
24 cylinders (6 banks of 4 cyl.)
36 cylinders (9 banks of 4 cyl.)

Specifications (Hyena)

Data from Lumsden.[3]

General characteristics

  • Type: 15-cylinder 3-row radial engine with inline banks.[1]
  • Bore: 5.3 in (137 mm)
  • Stroke: 4.88 in (125 mm)
  • Displacement: 1,615.58 cu in (26.6 L)



  • Power output: 618 hp at 2,000 rpm at sea level

See also

Comparable engines

Related lists



  1. Gunston, Bill (1986). World Encyclopedia of Aero Engines. Guild Publishing. p. 18. 3-row radials
  2. Pearce, William. "Armstrong Siddeley 'Dog' Aircraft Engines". Retrieved 9 May 2016.
  3. Lumsden 2003, p.76.


  • Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.