Armstrong Siddeley Heritage Trust
Armstrong Siddeley Jaguar Aero-Engines
This range of Armstrong Siddeley aero-engines were all descended from an engine designed at the Royal Aircraft Factory in 1916, known as the R.A.F. 8. This engine, designed by Sidney Heron, was an air-cooled radial engine with fourteen cylinders arranged in two staggered rows. In 1917, Heron was transferred to work on the engine at the Siddeley-Deasy company; however, this work was deferred due to issues with the Siddely Puma engine.
Jaguar Front view Rear View Side View
In 1919, Siddeley-Deasy was acquired by Armstrong Whitworth, with the company name changing to Armstrong Siddeley. A Government contract to develop the R.A.F.8 was awarded to Armstrong Siddeley in June 1919, who named it the Jaguar. The Mk I Jaguar's first test run took place in June 1920, when it produced a disappointing 300 hp. The second engine in the Jaguar series had the stroke increased from 5" to 5.5"; this change gave a satisfactory output of 365hp. This version was ordered into production by the Air Ministry.
Between 1923 and 1929, there were many variants of the Jaguar, including direct-drive, geared, and supercharged models. The Jaguar was the first production aero-engine in the world to be supercharged, which gave increased performance up to 11,500 feet. Engine power varied from 385hp to 470hp.
The Jaguar was fitted to over forty different types of aircraft. By 1929, the engine was falling behind some of its competitors, and the Armstrong Siddeley Panther superseded it.
Danish Dankok with Jaguar IV
Hawker Hoopoe with Jaguar Credit AirHistoryNet
Savenska A B with a Geared Jaguar
Heinkle HE VIII
Fairy Flycatcher
Armstrong Whitworth Argosy
Avro 642
Siskins with Jaguar III or IV engines
Farman Goliath
Jaguar Publicity Photograph
Jaguar Mk IV Mounted
Reconditioned Jaguar on a test bed
Alan Cobham became the first person to fly from England to South Africa and back in his Jaguar-powered de Havilland D.H. 50J biplane, which was built for the purpose of investigating the possibilities of aviation in Africa.
He began his epic flight at Stag Lane Aerodrome in Edgware, London, on 16 November 1925. The outward journey spanned 94 days and 8,125 miles, and he reached Cape Town, South Africa, on 17 February 1926.
On 26 February 1926, he left for London, reaching Stag Lane Aerodrome only 16 days later on 13 March 1926. Immediately after landing, King George V invited him to Buckingham Palace.
For this impressive pioneering flight, Cobham was awarded the Air Force Cross.
These images are best viewed when enlarged. The left-hand image shows Sir Alan Cobham with photographer B. W. G. Emmott, who took cinematograph equipment to make a film of the flight, and his flight engineer, Elliot. If you look closely at the right-hand image, you can see the photographer and camera in front of the pilot. The legend on the side of the aeroplane reads "Imperial Airways Air Route Survey". The engine is a Jaguar Mk IV.
For the interest of the technically minded, here is an Air Ministry test sheet for a Jaguar Mk IV from 1929. Apologies for the cropping and poor quality of this almost 100-year-old document. Click on the document to enlarge.
