Avon engine

Avon engine. The Rolls-Royce Avon is a British axial-flow turbojet engine that became one of the most successful and influential jet powerplants of the mid-20th century. Developed by Rolls-Royce Limited as a successor to the centrifugal-flow Rolls-Royce Nene, it powered a wide array of military and civilian aircraft across several nations. Its robust design and continuous development led to numerous variants with increasing thrust, securing its place in aviation history.

Development and design

The Avon's development began in the immediate post-war period, with the first prototype running in 1945. Engineers at Rolls-Royce Limited, led by figures like Adrian Lombard, pursued an axial-flow compressor design for greater efficiency and potential compared to their earlier centrifugal engines. The initial design, the RA.3, featured a 12-stage compressor and a single-stage turbine, drawing on advanced German research captured after World War II. Subsequent development, including work at the National Gas Turbine Establishment, focused on overcoming early combustion issues and incorporating new materials like Nimonic alloys for high-temperature components. This evolutionary process yielded significant increases in thrust and reliability across the engine's long production life.

Operational history

The Avon entered service in 1950 with the Royal Air Force, powering the English Electric Canberra B.2 bomber. It quickly proved its worth, providing superior performance and reliability that cemented its reputation. The engine saw extensive combat use, notably in the Hawker Hunter during conflicts like the Suez Crisis and the Indo-Pakistani War of 1965. Its adaptability was further demonstrated when it was selected for the record-breaking Fairey Delta 2, which captured the World Air Speed Record in 1956. The Avon's service life extended for decades, with engines remaining in use on types like the English Electric Lightning interceptor through the Cold War era, a testament to its foundational design.

Variants

The Avon family was extensively developed, resulting in numerous major variants. The early Series 100 (RA.3/RA.7) engines powered initial production aircraft like the de Havilland Comet 2 and the Supermarine Swift. The more powerful Series 200 introduced a revised compressor and was used in the English Electric Lightning and Saab 32 Lansen. The Series 300 represented a significant thrust increase and was fitted to later marks of the Hawker Hunter and the Sud Aviation Caravelle airliner. Specialized versions included the RA.29 used in the BAC TSR-2 prototype and the RA.24 for the Fokker F28 Fellowship. Licensed production was undertaken by companies including Fabrique Nationale de Herstal in Belgium and Commonwealth Aircraft Corporation in Australia.

Applications

The Avon's applications were remarkably diverse, spanning fighters, bombers, reconnaissance aircraft, and airliners. Key military aircraft included the English Electric Lightning, Hawker Hunter, Gloster Javelin, and the Vickers Valiant. It also powered important export designs like the Saab 32 Lansen and the IAR 93. In civil aviation, it was the powerplant for the first jet airliner to enter transatlantic service, the de Havilland Comet 4, and notably the Sud Aviation Caravelle. Other significant uses were on the Fairey Delta 2 research aircraft and the BAC One-Eleven prototype.

Specifications (representative variant)

Avon Series 300 (RA.29): * Type: Turbojet * Length: 3,175 mm (125 in) * Diameter: 1,032 mm (40.6 in) * Dry weight: 1,950 kg (4,300 lb) * Compressor: 15-stage axial flow * Combustors: 10 x can-type combustion chambers * Turbine: 2-stage axial * Maximum thrust: 75.6 kN (17,000 lbf) * Specific fuel consumption: 0.95 lb/(lbf·h) * Thrust-to-weight ratio: 3.95:1

Category:Aircraft engines Category:Rolls-Royce engines