The T74 is a light-weight, free-power turbine engine designed for use in fixed-wing aircraft.
It has two independent turbines, one driving a compressor in the gas generator section, and the second
driving a reduction gearing for a propeller installation.
The different engine sections bolt together at flanges, which are identified by letters.
Numbers are used to identify locations or stations on the engine.
The compressor is a three-stage axial rotor, which is housed in the gas generator case.
Located forward of the compressor is the combustion chamber. The combustion chamber is of the
annular reverse-flow type. Fourteen fuel nozzles are mounted at the front end of the combustion
chamber liner. The two single-stage turbine rotors are located in the center of the annular combustion
chamber. The compressor turbine assembly is splined to the compressor front hub. The power turbine
rotor drives the reduction gearing through the power turbine shaft.
Ahead of the combustor and turbine assemblies is the exhaust duct. The duct is attached to
the front flange of the gas generator.
Located at the front of the engine are the reduction gearbox and propeller shaft. The
accessory drive gearbox is attached to the aft flange of the compressor inlet case at the rear of the
The engine has four main bearings. Numbers 1 and 4 are ball bearings, and 2 and 3 are
Section II. Major Engine Systems
The T74-CP-702 has four major engine systems: the bleed air system, lubrication system, fuel
system, and instrumentation and ignition system. Each of these systems is essential for safe engine
operation. The section discusses each system in detail in the paragraphs that follow.
BLEED AIR SYSTEMS
The engine has three separate bleed air systems: a compressor bleed air control, a bearing
compartment airseal, and a turbine