de Havilland Gyron

de Havilland Gyron
de Havilland Gyron at the de Havilland Aircraft Heritage Centre
Type Turbojet
Manufacturer de Havilland Engine Company
First run 1953
Major applications Hawker P.1121 (not built)
Developed into de Havilland Gyron Junior

The de Havilland PS.23 or PS.52 Gyron, originally the Halford H-4, was Frank Halford's last turbojet design while working for de Havilland. Intended to outpower any design then under construction, the Gyron was the most powerful engine of its era, producing 20,000 lbf (89 kN) "dry", and 27,000 lbf (120 kN) with afterburner ("reheat" in British terminology). The engine was actually too large for most roles and saw no production use. It was later scaled down to 45% of its original size to produce the de Havilland Gyron Junior, which was somewhat more successful.[1]


Design and development

The Gyron was Halford's first axial-flow design, a complete departure from his earlier centrifugal-flow engines based on Whittle-like designs, the Goblin (H-1) and Ghost (H-2). The Gyron was also one of the first engines designed specifically for supersonic flight.

The Gyron first ran in 1953. Flight testing started in 1955 on a modified Short Sperrin (a bomber design that was instead turned into an experimental aircraft), replacing the lower two Rolls-Royce Avons with the much larger Gyrons. Flight rating was 18,000 lbf (80,000 N). In 1955 the DGy.1 received an official rating of 15,000 lbf (67,000 N).[2] Addition of a reheat section boosted output to 20,000 lbf (89,000 N) and then 25,000 lbf (110,000 N) in the Dgy.2

The Gyron was selected for a number of projects, most notably the Hawker P.1121 (sometimes referred to as the Hurricane) supersonic attack aircraft that was to have been the replacement for the Hawker Hunter. However, this project was eventually cancelled. Another design potentially based on the Gyron was the Operational Requirement F.155 interceptor, which optionally used the Rolls-Royce RB.106. F.155 was also cancelled, part of the 1957 Defence White Paper. Government financial support of the Gyron project itself was cancelled in March 1957, at a reported total cost of £ 3.4 million.[3][4]

Engines on display

An example of the Gyron is held by the Science Museum (London),[5] another is on public display at the de Havilland Aircraft Heritage Centre, St Albans.

Specifications (Gyron D.Gy.1.)

General characteristics

  • Type: Turbojet
  • Length: 155.5 in
  • Diameter: 55.2 in
  • Dry weight: 4,270 lb


  • Compressor: Seven stage axial flow
  • Turbine: Two-stage


See also

Related development

Comparable engines
Related lists




  • Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9

External links

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • De Havilland Gyron — The PS.23 or PS.52 Gyron, also known as the Halford H 4, was Frank Halford s last turbojet design while working for de Havilland. Intended to outpower any design then under construction, the Gyron was the most powerful engine of its era,… …   Wikipedia

  • de Havilland Gyron Junior — Gyron Junior de Havilland Gyron Junior at the de Havilland Aircraft Heritage Centre Type Turb …   Wikipedia

  • de Havilland Aircraft Heritage Centre — Established 1959 Location London Colney, Hertfordshire, UK …   Wikipedia

  • de Havilland Engine Company — Industry Aerospace engineering Fate Merged with Bristol Siddeley Successor Bristol Siddeley Founded 1944 Defunct 1961 Headquarters …   Wikipedia

  • De Havilland — Infobox Defunct Company company name = de Havilland Aircraft Company company slogan = fate = incorporated into Hawker Siddeley successor = foundation = 1920 defunct = 1964 location = Hatfield, Hertfordshire, England industry = aerospace key… …   Wikipedia

  • De Havilland Spectre — Spectre Spectre rocket engine …   Wikipedia

  • de Havilland Gipsy — Gipsy Gipsy II Type Air cooled 4 cylinder inline piston engine …   Wikipedia

  • de Havilland Ghost — Ghost A Swedish licensed built de Havilland Ghost, the RM 2 Type Turbojet …   Wikipedia

  • de Havilland Gipsy Major — Gipsy Major Preserved Gipsy Major. Type Piston inline aero engine Manufac …   Wikipedia

  • de Havilland Gipsy Six — Gipsy Six Preserved Gipsy Six Type Piston inline aero engine …   Wikipedia