The Armstrong Siddeley Double Mamba is a turboprop engine design developed in the late 1940s of around 3,000–4,000 hp (2,200–3,000 kW).

It was used mostly on the Fairey Gannet anti-submarine aircraft developed for the Fleet Air Arm of the Royal Navy.

[1] Engine starting was by cartridge, however, forced air restart was achieved in flight.

The Double Mamba engine was also proposed for the Westland Westminster, a 30-seat helicopter that was later built as a prototype powered by a pair of Napier Eland E220 turboshaft engines.

Preserved Double Mamba engines are on public display at the: Data from Flight[2] Related development