The GTCP85 air compressor/shaft power engine in its many variants is an ubiquitous engine, used as airborne APU in many famous aircraft such as the Boeing 737, KC135, Breguet Atlantic, Transall to name just a few. Moreover, it has been utilized in several ground power/support units, some also providing heating/cooling functions for field hospitals or the like. Combined power (air/shaft) of most units is in the region of 200hp at a shaft speed slightly above 40,000 RPM.
Garrett AiResearch started design of this engine in the early 1950s but later on, several improvements have been added. The basic design of the GTCP85 is similar on all the versions, featuring a two-stage radial compressor, a single stage radial turbine and a single, reverse flow, can-type, tangentially mounted combustion chamber with a single duplex fuel nozzle to atomize the fuel. One peculiar detail of this engine is the double-entry first stage radial compressor, requiring an assembly of individual air ducts from the first stage compressor discharge to the second stage compressor inducer plenum. This is necessary to permit air flowing to the rear intake of the first stage compressor.
85-129H
85-129K
85-129J
85-129CKB
85-129CKA
85-129C
85-129D
85-129E
85-98DHF
85-98DCB
