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, producing 20,000 lbf "dry", and 27,000 lbf 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. Major Frank Bernard Halford, (1894–1955), was an aircraft engine designer. ... Turbojets are the simplest and oldest kind of general purpose jet engine. ... Until 1920, Geoffrey de Havillands de Havilland Aircraft Company had been known as Airco, where he was owner and chief designer. ... For other uses of afterburner, see Afterburner (disambiguation). ...

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. An axial compressor is the name used in the aircraft industry to refer to a particular type of compressor used in jet engines. ... A cutaway example of an early jet engine showing the centrifugal compressor A centrifugal compressor, also called a radial blower, squirrel cage, or squirrel wheel compressor, consists of a cylindrical assembly of compressor blades mounted on an axle. ... Air Commodore Sir Frank Whittle, OM, KBE FRS (1 June 1907–9 August 1996) was a Royal Air Force officer who invented the jet engine. ... Cutaway Goblin II A cutaway diagram of the internal workings of the de Havilland Goblin, as fitted to the Vampire. ... The De Havilland Ghost was a turbojet engine. ... It has been suggested that hypersonic be merged into this article or section. ...

The Gyron first ran in 1953. Flight testing started in 1955 on modified Short Sperrins (a bomber design that was instead turned into an experimental aircraft), replacing the lower two Rolls-Royce Avons with the much larger Gyrons. This is a list of aviation-related events from 1953: Events The first year in which the worlds airlines carried more than 50 million people (ICAO statement, 29 December) January January 26 - The first meeting of the Experimental Aircraft Association takes place at Milwaukee, Wisconsins Curtis-Wright Field. ... The Short SA.4 Sperrin was a British jet bomber design of the early 1950s built by Short Brothers of Belfast. ... The Rolls-Royce Avon turbojet was developed by Cyril Lovesey who had previously been in charge of Merlin development at Rolls-Royce. ...

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. Sixteen Hunters of the RAF Black Arrows perform aerobatics at the Farnborough Air Show, England. ... The Operation Requirement F.155 was an identified need by the British Ministry of Supply for an interceptor aircraft for the defence of the United Kingdom. ... The Rolls-Royce RB.106 was an advanced military turbojet engine design of the 1950s by Rolls Royce Ltd. ... The 1957 White Paper on Defence was a British white paper setting forth the future as seen of the British military. ...

An example of the Gyron is held by the Science Museum[1], another was held by the de Havilland Heritage Museum, St Albans [2] A typical exhibit at a modern science museum. ...