The Bristol Type 146 was a British single-seat, eight-gun fighter monoplane prototype built to a mid-1930s Air Ministry contract. Powered by a radial engine, it was outclassed by Merlin-engined fighters, and only one was built.

The Bristol Mercury is a British nine-cylinder, air-cooled, single-row, piston radial engine. Designed by Roy Fedden of the Bristol Aeroplane Company it was used to power both civil and military aircraft of the 1930s and 1940s. Developed from the earlier Jupiter engine, later variants could produce 800 horsepower (600 kW) from its capacity of 1,500 cubic inches by use of a geared supercharger.