- De Havilland Gyron
The PS.23 or PS.52 Gyron, also known as the Halford H-4, was
Frank Halford 's lastturbojet design while working forde 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 withafterburner ("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.The Gyron was Halford's first
axial-flow design, a complete departure from his earliercentrifugal-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 forsupersonic 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 twoRolls-Royce Avon s with the much larger Gyrons.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 theHawker Hunter . However, this project was eventually cancelled. Another design potentially based on the Gyron was theOperational Requirement F.155 interceptor, which optionally used theRolls-Royce RB.106 . F.155 was also cancelled, part of the1957 Defence White Paper .An example of the Gyron is held by the
Science Museum [http://www.sciencemuseum.org.uk/wroughton/introduction.asp] , another was held by the de Havilland Heritage Museum, St Albans [http://futurshox.net/aeroview.php?level=image&id=256]The Gyron Junior was the initial powerplant of the
Blackburn Buccaneer before the type was re-engined with theRolls-Royce Spey , and it was also used in theBristol 188 supersonic research aircraft.pecifications (Gyron)
jetspecs
type=Turbojet
length=
diameter=
weight=4,200 lb
compressor=Seven stage axial flow
combustion=
turbine=Two-stage
fueltype=
oilsystem=
power=
thrust=15,000 lb
compression=5.6
aircon=285 lb/sec
turbinetemp=
fuelcon=
specfuelcon=
power/weight=
thrust/weight=External links
* [http://www.aoxj32.dsl.pipex.com/NewFiles/deHaviland.html "British Jet Engine Website" entry]
* [http://www.airmuseumsuk.org/museum/dhengine/800/pages/109%20DH%20Gyron%20Junior.htm Photo of DH Gyron Junior]
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