Armstrong Siddeley Hyena

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