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FOR SIMULATION USE ONLY ā NOT A TRAINING AID
ENGINE
Figure 1-7 Engine
The PT6A-68 is a free-turbine turboprop engine (Figure 1-7) flat rated to produce
1100 shaft horsepower (SHP) as installed in the aircraft. The engine is a reverse-
flow design with two independent sections: the gas generator section and the
power turbine section.
The gas generator section (the aft half of the engine) consists of the four-stage
axial flow compressor, single-stage centrifugal flow compressor, combustion
chamber, and single-stage compressor turbine.
The power section (the forward half of the engine) consists of the two-stage axial-
flow power turbine, exhaust case, and reduction gearbox.
Oil System
The oil system has a capacity of 18.5 U.S. quarts and provides a constant supply of
filtered oil to the engine bearings, reduction gears, accessory drives, and propeller
throughout normal and aerobatic flight manoeuvres.
Components include pressure, scavenge, cooling, and breather systems.
The pressure system incorporates two oil pickup elements. One element, normally
submerged in oil, picks up oil near the centre of the tank, and a second element
picks up oil near the top of the tank to prevent loss of oil pressure during inverted
flight.
The scavenging system incorporates two dual-element gear type pumps. The
pumps, one located inside, and one outside the accessory gearbox, return
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