1940s British turbojet aircraft engine
The Rolls-Royce Avon was the first axial flow jet engine designed and produced by Rolls-Royce. Introduced in 1950, the engine went on to become one of their most successful post-World War II engine designs. It was used in a wide variety of aircraft, both military and civilian, as well as versions for stationary and maritime power.
An English Electric Canberra powered by two Avons made the first un-refuelled non-stop transatlantic flight by a jet, and a BOAC de Havilland Comet 4 powered by four Avons made the first scheduled transatlantic crossing by a jet airliner.
Production of the Avon aero engine version ended after 24 years in 1974. Production of the Avon-derived industrial version continues to this day, by Siemens since 2015.
The current version of the Avon, the Avon 200, is an industrial gas generator that is rated at . As of 2011, 1,200 Industrial Avons have been sold, and the type has established a 60,000,000 hour record for its class.
Design and development.
The engine was initially a private venture put forward for the English Electric Canberra. Originally known as the AJ.65 for "Axial Jet, 6,500 lbf" the engine was based on an initial project concept by Alan Arnold Griffith. which combined an axial compressor with a combustion system and single-stage turbine using principles proven in the Rolls-Royce Nene engine.
Design work began in 1945. The Avon design team was initially headed by Stanley Hooker assisted by Geoff Wilde. Development of the engine was moved from Barnoldswick to Derby in 1948 and Hooker subsequently left the company, moving to Bristol Engines.
The first engine ran on 25 March 1947, with a 12-stage compressor. The engine was difficult to start, would not accelerate and broke first-stage blades. Two-position inlet guide vanes and compressor bleed were among the design changes which allowed the engine, as the RA.2, to run a 25-hour test and fly in the two outboard positions on the converted Avro Lancastrian military serial "VM732", from Hucknall on 15 August 1948.
The first production engine, which needed a two-stage turbine, was the RA.3, or Avon Mk 101. Several modified versions of this design were produced in the Mk. 100 series.
The Avon 200 series was a complete redesign having very little in common with earlier Marks. Differences included a completely new combustion section and a 15-stage compressor based on that of the Armstrong-Siddeley Sapphire. The first application was the Vickers Valiant.
Operational history.
The engine entered production in 1950 as the RA.3/Mk.101 with thrust in the English Electric Canberra B.2. Similar versions were used in the Canberra B.6, Hawker Hunter and Supermarine Swift. Uprated versions followed, the RA.7/Mk.114 with thrust in the de Havilland Comet C.2, the RA.14/Mk.201, in the Vickers Valiant and the RA.26, used in the Comet C.3 and Hawker Hunter F.6. An Avon-powered de Havilland Comet 4 flew the first scheduled transatlantic jet service in 1958. The highest thrust version was the RA.29 Mk.301/2 (RB.146) used in later versions of the English Electric Lightning. It produced with afterburning. Other aircraft to use the Avon included the de Havilland Sea Vixen, Supermarine Scimitar and Fairey Delta2.
The RA.3/Mk.109 was produced under licence by Svenska Flygmotor as the RM5, and an uprated RA.29 as the RM6 with thrust. The RM5 powered the Saab 32 Lansen and the RM6 powered the Saab 35 Draken and all-weather fighter version of the Lansen (J 32B).
300 Avon 113s, and a larger number of Avon 203s were produced under licence in Belgium by Fabrique Nationale Division Moteurs .
In the US the RA.28-49 was used in the VTOL Ryan X-13 Vertijet aircraft.
In Australia, the Avon was used by Commonwealth Aircraft Corporation in the CA-27 Avon-Sabre.
The Avon continued in production for the Sud Aviation Caravelle and English Electric (BAC) Lightning until 1974, by which time over 11,000 had been built. It remained in operational service with the RAF until 23 June 2006 in the English Electric Canberra PR.9.
Initial design work was done on the 2-spool RB.106/RB.128 as an Avon successor for large supersonic fighters.
Variants and designations.
Avon Series 100.
Avon Series 100 are early military versions of the Avon.
Avon Series 200.
Avon Series 200 are uprated military versions of the Avon with can-annular combustion chamber and Sapphire style compressor.
Avon Series 300.
Avon Series 300 are further developed military after-burning versions of the Avon for the English Electric Lightning.
Avon Series 500.
Avon Series 500 are civilian equivalents to the military Avon Series 200 variants.
Specifications (Avon 301R).
General characteristics
Components
Performance
References.
Notes.
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Bibliography.
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