The Armstrong Siddeley Mongoose is a British five-cylinder radialaero engine produced by Armstrong Siddeley. Developed in the mid-1920s it was used in the Hawker Tomtit trainer and Parnall Peto seaplane amongst others. With a displacement of 540 cubic inches (9 litres) the Mongoose had a maximum power output of 155 horsepower (115 kilowatts).
A Mongoose engine powers the sole remaining airworthy Hawker Tomtit, based at Old Warden.
Design and development
The Mongoose is a five-cylinder, single-row, air-cooled radial piston engine. The engine features twin forward-mounted ignition magnetos and enclosed valve rockers, the cylinders being the same as those used for the earlier Jaguar engine.[1] An unusual feature of the Mongoose is the vertical position of the lower cylinder, a design thought likely to promote oil fouling of the spark plugs.[2]
Built in several variants, power output ranged between 135 and 155 hp (100-115 kW).
An Armstrong Siddeley Mongoose IIIC powers the sole remaining airworthy Hawker Tomtit, K1786/G-AFTA, owned and operated by the Shuttleworth Collection this aircraft flies regularly throughout the summer months.[5]
