Rolls-Royce Avon Mk 28-49 Turbojet Engine


Display Status:

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Collection Item Summary:

In 1945, Rolls-Royce started the development of the AJ.65 (axial jet, 28,912 N (6,500 lb) thrust) Avon to replace the Nene, going through several design and test iterations. The first 100-series (RA.3) production engines were delivered in June 1950. For the Comet and Caravelle, the civil RA.29 was produced at 45,592 N (10,250 lb) thrust. The RB.146 300-series was later produced at 76,105 N (17,110 lb) thrust with afterburning.

The Avon powered a variety of military and commercial aircraft: English Electric Canberra, Hawker Hunter, and Vickers-Armstrong Valiant, de Havilland Comet and S.N.C.A.S.E. Caravelle.

This engine, a 44,480 N (10,000 lb) thrust RA.28-49, was manufactured in June 1955 specifically for the Ryan Aeronautical Company in San Diego, California. It powered the Ryan X-13 VTOL Vertijet between 1955 and 1957. In November 1956, the Vertijet, now in the museum's collection, was the first jet-powered VTOL aircraft to demonstrate transition from horizontal to vertical flight and return to horizontal flight.

Collection Item Long Description:

Data Source

National Air and Space Museum

Restrictions & Rights

Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum

Credit Line

Transferred from the U.S. Air Force via the contractor, Ryan Aeronautical Company


Steel, Aluminum, Magnesium, Preservative coating, Stainless Steel, Inconel, Rubber, Paint


Length 287.8 cm (113.3 in.), Diameter 105.4 cm (41.5 in.)

Country of Origin

United Kingdom



Physical Description

  • Type: Turbojet
  • Thrust: 44,480 N (10,000 lb) at 8,000 rpm
  • Compressor: 15-stage compound, 6-stage low pressure and 9-stage high pressure axial
  • Combustor: Cannular
  • Turbine: 2-stage axial
  • Weight: 1,709 kg (3,768 lb) (Approximate)


PROPULSION-Turbines (Jet)

Inventory Number