The General Electric J73

turbojet The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, a ...

was developed by

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from the earlier

J47 The General Electric J47 turbojet (GE company designation TG-190) was developed by General Electric from its earlier J35. It first flew in May 1948. The J47 was the first axial-flow turbojet approved for commercial use in the United States. I ...

engine. Its original USAF designation was J47-21, but with innovative features including variable inlet guide vanes, double-shell (inner and outer) combustor case, and 50% greater airflow was redesignated J73. Its only operational use was in the North American F-86H.

Design and development

An engine, uprated from the J47, was required for the F-86H. The mass flow was increased by relocating

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from the centre of the compressor inlet to the underside of the engine. This allowed a reduction in blade hub diameter, which together with an increase in tip diameter, gave a bigger area for air to enter the compressor. The area through the combustion chambers also had to be increased. This was done by replacing the multiple individual chambers with a single annular casing with individual flame tubes or cans known as cannular. The pressure ratio was increased and variable inlet guide vanes fitted to prevent low-RPM problems (rotating stall/blade flutter) with the higher design pressure ratio. A 2-stage turbine was required. A low boost (10% at take-off)

afterburner An afterburner (or reheat in British English) is an additional combustion component used on some jet engines, mostly those on military supersonic aircraft. Its purpose is to increase thrust, usually for supersonic flight, takeoff, and c ...

was fitted. It was known as a tailpipe augmentation (TPA) system.

Nuclear powered

Four J73 engines were converted to produce thrust using nuclear energy instead of jet fuel. Testing was done in 1957 at the Atomic Energy Commission's National Reactor testing station. The engines were modified to pass the compressor air through a heat exchanger, in which heat was transferred from a nuclear reactor, before entering the compressor turbine at 1,400 degrees F.https://archive.org/details/Aviation_Week_1957-03-18/page/n13/mode/2up, p.27

Variants

;J73-GE-1: ;J73-GE-3: for the

North American F-86H Sabre The North American F-86 Sabre, sometimes called the Sabrejet, is a transonic jet fighter aircraft. Produced by North American Aviation, the Sabre is best known as the United States' first swept-wing fighter that could counter the swept-wing Sov ...

. ;J73-GE-5: Variant intended for a proposed Advanced F-89.

Applications

* Republic YF-84J Thunderstreak, two prototypes

Specifications (J73-GE-3)

References

External links

General Electric J73 Turbojet
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National Museum of the United States Air Force The National Museum of the United States Air Force (formerly the United States Air Force Museum) is the official museum of the United States Air Force located at Wright-Patterson Air Force Base, northeast of Dayton, Ohio. The NMUSAF is the ...

{{USAF gas turbine engines J73 1950s turbojet engines F-86 Sabre