General Electric J73


The General Electric J73 turbojet was developed by General Electric from the earlier J47 engine. Its original USAF designation was J47-21, but with innovative features including variable inlet guide vanes, double-shell 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 accessories 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 with the higher design pressure ratio. A 2-stage turbine was required.
A low boost afterburner was fitted. It was known as a tailpipe augmentation system.

Variants

;J73-GE-1:
;J73-GE-3: for the North American F-86H Sabre.
;J73-GE-5: Variant intended for a proposed Advanced F-89.

Applications