Rolls-Royce Avon

The engine was initially a private venture put forward for the English Electric Canberra.[3] 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.[4] 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.[4]

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.[4] 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[3] 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.[1] The first application was the Vickers Valiant.

A Mark 122 – The rear fuselage of the Hawker Hunter can be removed for engine maintenance

The engine entered production in 1950 as the RA.3/Mk.101 with 6,500 lbf (29 kN) thrust in the English Electric Canberra B.2.[1] Similar versions were used in the Canberra B.6, Hawker Hunter and Supermarine Swift. Uprated versions followed, the RA.7/Mk.114 with 7,350 lbf (32,700 N) thrust in the de Havilland Comet C.2, the RA.14/Mk.201, 9,500 lbf (42 kN) in the Vickers Valiant and the RA.26, 10,000 lbf (44 kN) 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 12,690 lbf (56,450 N) and 17,110 lbf (72,770 N)[5] 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 17,110 lbf (76,110 N) 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[6] were produced under licence in Belgium by Fabrique Nationale.

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.[4]

Rolls Royce Avon RA.3 Mk.101 at RAF Museum Cosford

AJ65

The original designation, standing for Axial Jet 6,500 lbf thrust

RA.1

Prototype engines for testing and development.

RA.2

Pre-production engines for testing. 6,000 lbf (26.69 kN)

RA.3

Civil designation for the first Avon production mark – 6,500 lbf (28.91 kN).

RA.7

Civil designation for the uprated version of the Avon. – 7,350 lbf (32.69 kN).

RA.7R

The RA.7 with reheat

RA.14

Civil designation for the uprated version of the Avon with can-annular combustion chamber and Sapphire style compressor – 9,500 lbf (42.26 kN).

RA.21

8,050 lbf (35.81 kN) Production engine developed from the RA.7.

RA.24

RA.24R

RA.25

Civil Mk.503

RA.26

Further improvements to the Avon 200 series – Civil Mk.521

RA.28

Second generation variant 10,000 lbf (44.48 kN)

RA.29

Civil designation for the Mk.300 series (used by the Sud Aviation Caravelle)

RA.29/1

RA.29/3

RA.29/6

Mk.100 series

Military designation for the RA.3 Avon – 6,500 lbf (28.91 kN).

Mk.113

Mk.114

Military designation for the RA.7 Avon – 7,350 lbf (32.69 kN).

Mk.115

Mk.117

Mk.118

Mk.200 series

Military designation for the uprated version of the Avon with can-annular combustion chamber and Sapphire style compressor – 9,500 lbf (42.26 kN).

Mk.300 series

Developed after-burning engines for the English Electric Lightning.

RB.146 Mk.301:The ultimate Military Avon for the English Electric Lightning – 12,690 lbf (56.45 kN) dry, 17,110 lbf (76.11 kN) wet.[5]

RB.146 Mk.302:Essentially similar to the Mk.301

Avon 504

Civilian equivalent to military Mk.200 variants.

Avon 506

Civilian equivalent to military Mk.200 variants.

Avon 521

Avon 522

Civilian equivalent to military Mk.200 variants.

Avon 524

Civilian equivalent to military Mk.200 variants.

Avon 524B

Civilian equivalent to military Mk.200 variants.

Avon 525

Civilian equivalent to military Mk.200 variants.

Avon 525B

Civilian equivalent to military Mk.200 variants.

Avon 527

Civilian equivalent to military Mk.200 variants.

Avon 527B

Civilian equivalent to military Mk.200 variants.

Avon 530

Avon 531

Civilian equivalent to military Mk.200 variants.

Avon 531B

Civilian equivalent to military Mk.200 variants.

Avon 532R

Civilian equivalent to military Mk.200 variants.

Avon 532R-B

Civilian equivalent to military Mk.200 variants.

Avon 533R

Civilian equivalent to military Mk.200 variants.

Avon 533R-11A

Civilian equivalent to military Mk.200 variants.

Svenska Flygmotor RM5

Licence production of the RA.3/Mk.109 for the Saab 32 Lansen

Svenska Flygmotor RM5A

Svenska Flygmotor RM6A

Uprated RA.29/Mk.300, with Swedish designed afterburner, for the Saab Draken - 15,000 lbf (66.72 kN) wet.

Svenska Flygmotor RM6B

16,000 lbf (71.17 kN) wet.

Svenska Flygmotor RM6C

17,600 lbf (78.29 kN) wet.

Westinghouse XJ54

Avon 300-series scaled-down by Westinghouse to 105 lb/sec airflow to produce 6,200 lb thrust.[7]

• Several Avon-powered Hawker Hunter aircraft remain airworthy in private ownership in 2010.[8]
• Thunder City in South Africa as of 2011 operated two Avon-powered English Electric Lightnings.[9]

Engines on display

This is the Rolls Royce Avon engine on display at the Temora aviation museum, Australia

• A Mk 524 Avon has been restored at the Museo Nacional de Aeronáutica de Argentina by the Museum Friend's Association in Moron, Argentina and is now on display.
• An Avon Mk.203 was donated by Rolls-Royce to the National Museum of the United States Air Force in July 1986 for public display.[10]
• A Rolls-Royce Avon is on public display at the Midland Air Museum.[11]
• A preserved Rolls-Royce Avon Mk.203 is on display at the Royal Air Force Museum London.[12]
• A partially sectioned Mk.101 Avon is on display at the Royal Air Force Museum Cosford.[13]
• A Rolls-Royce Avon is on display at the Australian National Aviation Museum, Moorabbin, Victoria, Australia
• A Rolls-Royce Avon is on public display at East Midlands Aeropark
• A Rolls-Royce Avon is on display at the Fleet Air Arm Museum at RNAS Yeovilton.
• Several RR Avon engines are on display at the Queensland Air Museum, Caloundra, Australia
• A Rolls-Royce Avon engine is on public display at the Historical Aircraft Restoration Society museum at Illawarra Regional Airport, New South Wales, Australia.
• A Rolls-Royce Avon engine is on public display at the Parkes Aviation Museum in Parkes, New South Wales, Australia.
• A Rolls-Royce Avon is on display at the Classic Flyers Aircraft Museum, Mt Maunganui, Bay of Plenty, New Zealand.
• A Rolls Royce Avon Mk.26 is on display at Mikes Dyno Tuning and Performance Engines, Dandenong, Victoria, Australia
• A Rolls Royce Avon (GAF) is on display at the South Australian Aviation Museum, Port Adelaide, South Australia.

Data from "Lightning F.6 Avon 301R Specs". lightning.org.uk. Archived from the original on 10 April 2008.

General characteristics

• Type: turbojet
• Length: 126 in (3,200 mm)
• Diameter: 35.7 in (907 mm)
• Dry weight: 2,890 lb (1,310 kg)

Components

• Compressor: 15-stage axial flow
• Combustors: cannular, 150 lb/s (68 kg/s)
• Turbine: two-stage axial flow
• Fuel type: kerosene

Performance

• Maximum thrust: 12,690 lbf (56.4 kN) dry, 16,360 lbf (72.8 kN) with reheat
• Overall pressure ratio: 7.45:1
• Specific fuel consumption: 0.932 lb/(lbf⋅h) or 26.4 g/(kN⋅s) (dry); 1.853 lb/(lbf⋅h) or 52.5 g/(kN⋅s) (wet)[14]
• Thrust-to-weight ratio: 5.66

Comparable engines

• Allison J35
• Armstrong Siddeley Sapphire
• Metrovick F.2
• Pratt & Whitney J57
• SNECMA Atar
• Tumansky R-25

Related lists

• List of aircraft engines

Wikimedia Commons has media related to Rolls-Royce Avon.

• The fascinating story of the Rolls Royce Avon turbojet engine, the first Rolls Royce axial flow turbojet
• National Museum of USAF – Avon MK 203 Turbojet
• "Rolls-Royce Avon" a 1955 Flight article on the Avon
• "Rolls-Royce Avon 200 Series" a 1957 Flight article