The Armstrong Siddeley Leopard was a British 14-cylinder twin-row air-cooled

radial Radial is a geometric term of location which may refer to: Mathematics and Direction * Vector (geometric), a line * Radius, adjective form of * Radial distance, a directional coordinate in a polar coordinate system * Radial set * A bearing f ...

aero engine developed in 1927 by

Armstrong Siddeley Armstrong Siddeley was a British engineering group that operated during the first half of the 20th century. It was formed in 1919 and is best known for the production of luxury vehicles and aircraft engines. The company was created following t ...

. It was the most powerful radial engine in the world when introduced.

Variants

;Leopard I :700 hp, medium supercharged. Direct drive propeller. ;Leopard II :700 hp, geared epicyclic drive. ;Leopard III :800 hp, two-valve cylinder head, direct drive. ;Leopard IIIA :800 hp, geared epicyclic drive.

Applications

Blackburn Iris The Blackburn Iris was a British three-engined biplane flying boat of the 1920s. Although only five Irises were built, it was used as a long-range maritime reconnaissance aircraft by the Royal Air Force, where it equipped a squadron for four yea ...

Junkers Ju 52 The Junkers Ju 52/3m (nicknamed ''Tante Ju'' ("Aunt Ju") and ''Iron Annie'') is a transport aircraft that was designed and manufactured by German aviation company Junkers. Development of the Ju 52 commenced during 1930, headed by German aero ...

Hawker Dantorp The Hawker Dantorp H.B. III was a Danish single-engined biplane bomber of the 1930s. The aircraft was a development of the British Hawker Horsley designed for the Danish Navy, but differed in being powered by a radial engine and having a third c ...

Hawker Horsley The Hawker Horsley was a British single-engined biplane bomber of the 1920s. It was the last all-wooden aircraft built by Hawker Aircraft, and served as a medium day bomber and torpedo bomber with Britain's Royal Air Force between 1926 and 1935 ...

Mason 1991, p. 138.

Specifications (Leopard I)

References

Notes

Bibliography

* Lumsden, Alec. ''British Piston Engines and their Aircraft''. Marlborough, Wiltshire: Airlife Publishing, 2003. . * Mason, Francis K. Hawker Aircraft since 1920 (third ed.). London: Putnam, 1991. . * Smith, Herschel. ''Aircraft Piston Engines''. New York, New York: McGraw-Hill, 1981. . {{ASaeroengines 1920s aircraft piston engines Aircraft air-cooled radial piston engines