Engine
What is the flat rated shaft horsepower output of the PT6A-68 engine
1100
What is the capacity of the oil system
18.5 quarts
What is the function of the reduction gearbox
To reduce the power turbine output of 30,000 RPM to propeller operation speed off 2000 RPM
The propeller system is designed to maintain a constant speed of _____ during most flight conditions
2000 RPM (100% Np)
During an auto start or normal operations with the ignition set to NORM, the ____ will energize and de-energize the igniters as required.
PMU
What are the two sections of the T-6’s engine
Gas generation section and the power turbine section
What components does the oil system supply filtered oil to
Engine Bearings
Reduction Gears
Accessory Drives
Propeller
What drives the RGB?
Hot Gases impinging on the 2-Stage Power Turbine
At 100% indicated torque, the engine is producing approx _____ foot pounds of torque at the prop shaft
2,900 ft-lbs
Power for the START control is provided through a circuit breaker placarded START, located on the ________ bus circuit breaker panel in the front cockpit.
Battery
What components make up the gas generator section of the engine? (aft half)
4 Stage Axial Flow Compressor
Single-Stage centrifugal flow compressor
Combustion Chamber
Single-Stage Compressor Turbine
What are the components of the oil system
Pressure System
Scavenge System
Cooling System
Breather System
What does a red CHIP annunciator indicate
Contaminated
What are the three basic conditions of propeller pitch
Feathered
low pitch (flat or fine)
high pitch (coarse)
During an auto start or normal operation with the IGNITION switch set to _________, the PMU will energize and de-energize the igniters as required.
NORM
What components make up the Power Turbine section
2 Stage Axial Flow Power Turbine
Reduction Gearbox
When must oil be checked and where to get an accurate reading
Within 30 minutes of engine shutdown and using the dipstick, not the sight gauge.
T or F: the RGB is mechanically connected to the gas generator section of the engine
- False – No Mechanical Connection to the Gas Generator Section
Approximately what is the blade angle of the propeller at low pitch
15 Degree
Power for the IGNITION system is provided through a circuit breaker, placarded IGN, located on the _______ bus circuit breaker panel in the front cockpit.
Battery
Briefly describe the flow of air into and through the engine
Air enters the intake cowling beneath the prop and flows first through an inertial separator. It then turns 180 deg and passes through a 4 stage axial compressor and a single stage centrifugal compressor. From there, it enters the combustion chamber, is mixed with fuel and is lit. The expanding air first passes over the compressor turbine, making the engine self-sustaining, and then passes over the two power turbines before passing through the exhaust ports and diverted rearward by the exhaust stacks.
The engine oil pressure indicator may display oil pressures up to __ psi with the engine shut down due to the design of the oil pressure transmitter.
4 PSI
What accessories are mounted on the reduction gearbox
Prop interface unit (PIU), torque probe, Permanent magnetic alternator (PMA) (on top), and the air conditioning compressor (belt driven) (on right side)
With the PMU functioning, the _______________ will modulate oil pressure to the prop pitch change piston to limit Np to 106%, while electronic governor will keep Np at 100%.
mechanical overspeed governor
T/F If the IGN SEL EICAS message remains continuously illuminated, notify maintenance personnel after the mission.
True