Armstrong Siddeley Cheetah

Armstrong Siddeley Cheetah X

The Armstrong Siddeley Cheetah is an aircraft engine that the British manufacturer Armstrong Siddeley built from 1935 to 1948. The 7-cylinder radial engine has a displacement of 13,650 cm³. Early variants of the Cheetah were also initially called Lynx Major .

The Cheetah was often installed in British trainer aircraft such as the Avro Anson or the Airspeed Oxford during World War II .

construction and development

The Cheetah was developed from the earlier Lynx model by using the larger bore cylinders of the Panther model , but maintaining the piston stroke of the Lynx. In the beginning there were only variants with direct drive, later there were also those with reduction gears in different gear ratios. For later variants there were also compressors , both with direct drive through the crankshaft and those with reduction gear.

The basic construction of the Cheetah remained unchanged throughout the construction period. It was the first engine of this type to be certified for 1200 operating hours between overhauls. 37,200 copies were made.

variants

List from: Lumsden

Lynx V (Lynx Major)

1930, 230 bhp (171 kW).

Cheetah V

1935, 270 bhp (201 kW) at 2100 rpm.

Cheetah VA

1935, 285 bhp (212 kW) at 2425 rpm.

Cheetah VI

1935, 307 bhp (229 kW) at 2425 rpm.

Cheetah VIA

1936, as Mark VI, but with Mark IX cylinders.

Cheetah X still preserved

Cheetah IX

1937, 345 bhp (257 kW) at 2425 rpm.

Cheetah X

1938, 375 bhp (280 kW) at 2,300 rpm.

Cheetah XI

345 hp (257 kW) at 2425 / min., Version of the Cheetah X with reduction gear.

Cheetah XII

Like Mark X, adapted for drones.

Cheetah XV

420 bhp (313 kW) at 2425 rpm.

Cheetah XVII

1948, 385 bhp (287 kW) at 2425 rpm.

Cheetah XVIII

385 bhp (287 kW) at 2425 / min., Carburetor adapted for aerobatics.

Cheetah XIX

355 bhp (265 kW) at 2425 rpm.

Cheetah 25

345 bhp (257 kW) at 2425 / min., Cheetah XV increased to 475 bhp (355 kW) at 2700 / min., Modified speed stabilizer.

Cheetah 26

385 bhp (287 kW).

Cheetah 27

1948, 385 bhp (287 kW).

Aircraft with Armstrong Siddeley Cheetah

Airspeed Consul Airspeed Courier Airspeed Envoy Airspeed Oxford Airspeed Queen Wasp Airspeed Viceroy Avro 626 Avro 652 Avro Anson Blackburn Lincock Bristol Bulldog CASA C-201 Alcotán

Avro 626 Prefect de Havilland Hawk Moth Edgar Percival Prospector Handley Page HPR2 Hispano HS-42 IAe.22 DL Kingsford Smith PL.7 Koolhoven FK51 Marinens Flyvebaatfabrikk MF8 Marinens Flyvebaatfabrikk MF10 Percival Provost (prototype) VEF JDA-10M

Surviving engines

By October 2008, there will be at least four Cheetah engines operational. Two Cheetah drive the 17 Anson T21 of the Air Atlantique Classic Flight , and another pair of Cheetah 17 is in an Avro Nineteen, G-AHKX , registered for BAE Systems , but usually from the Shuttleworth Collection installed.

Motors on display

Surviving Armstrong Siddeley Cheetahs can be found on public display in the following museums:

• Arkansas Air and Military Museum
• Aviation Heritage Museum (Western Australia)
• Fleet Air Arm Museum
• Malta Aviation Museum
• Port Elizabeth Branch of the South African Air Force Museum
• Royal Air Force Museum Cosford

Dates (Cheetah IX)

Cheetah engine on an Airspeed Oxford under restoration.

General

• Single-row 7-cylinder radial engine, air-cooled, with compressor
• Bore: 133 mm
• Stroke: 140 mm
• Displacement: 13,650 cm³
• Length: 1342 mm
• Diameter: 1210 mm
• Weight: 289 kg

Components

• Valve train: Two valves with pushrod drive per cylinder
• Compressor: centrifugal, reduction gear 5.4: 1
• Mixture preparation: Carburetor : Claudel-Hobson
• Fuel: gasoline , 87 octane
• Cooling: air
• Reduction gear: no

power

• Takeoff power: 338 bhp (252 kW) at 2100 rpm.
• Continuous output: 345 bhp (257 kW) at 2425 / min. at an altitude of 2400 m
• Output per liter: 18.83 kW / l
• Compression: 6.35: 1
• Specific fuel consumption: 271 g / kW xh
• Specific oil consumption: 9–17 g / kW xh
• Power-to-weight ratio : 1.124 kg / kW

Individual evidence

1. ↑ Lumsden 2003, p.74.
2. ^ ^{A b} Alec Lumsden: British Piston Engines and their Aircraft . Airlife Publishing, Marlborough, Wiltshire 2003. ISBN 1-85310-294-6 . Pp. 74-76.
3. ^ Bill Gunston: World Encyclopedia of Aero Engines . Patrick Stephens, Cambridge 1989. ISBN 1-85260-163-9 . P. 18.
4. ↑ The Cheetah variants start with Mark V.
5. ↑ CAA - G-INFO - G-VROE Accessed February 15, 2009.
6. ↑ CAA - G-INFO - G-AHKX Accessed February 15, 2009.
7. ↑ Engines (21) . RAAF Aviation Heritage Museum. Retrieved November 4, 2014.

literature

• L. Bridgman (Editor): Jane's fighting aircraft of World War II . Crescent. ISBN 978-0-517-67964-7
• Bill Gunston: Development of Piston Aero Engines . Patrick Stephens, Cambridge 2006. ISBN 0-7509-4478-1

Web links

Commons : Armstrong Siddeley Cheetah  - Collection of images, videos and audio files

• Flight Magazine, May 19, 1939 - Introduced the Cheetah X - Flightglobal.com