Propellers (Turbine, Aux, Maintenance) Flashcards
What are the types of turboprop engines?
Single shaft.
Free turbine.
Types of control levers on a TPE331:
Power lever.
Condition/speed lever.
Power lever positions on a TPE331:
Reverse.
Ground idle.
Flight idle.
Maximum.
Condition lever positions for a TPE331:
Emergency shutoff.
Low RPM.
High RPM.
When does the power lever of a TPE331 control the prop pitch angle?
During ground operations.
Instruments to monitor on a TPE331:
Tachometer.
Torquemeter.
Fuel flow meter.
EGT indicator.
Define flat rated engine.
Turboprop engine whose allowable output is less than the engine is capable of producing.
Max power that a TPE331 is allowed to develop is limited by:
Amount of torque that airframe structure can accommodate.
Maximum temps turbine blades can withstand.
Range of operation of a turboprop powerplant normally used for in-flight approach and ground operations:
Beta mode
Flight operating mode for a turboprop powerplant from takeoff through landing:
Alpha mode.
Moving the TPE331 power lever forward has what effect on the prop?
Drains prop oil and increases pitch.
Moving the TPE331 power lever rearward has what effect on the prop?
Directs oil into the prop, decreasing pitch.
What component of a TPE331 automatically operates the feathering valve?
NTS (negative torque sensor)
Which turboprop propeller is allowed to go into its feather position when the engine is shut down?
PT6.
Why must the TPE331 propeller be held in low pitch when the engine is shut down?
To minimize the load on the starter due to its single shaft construction.
Why is the PT6 propeller allowed to feather when the engine is shut down?
The starter only rotates the gas generator turbine and is not loaded by the propeller.
What are the controls on the PT6?
Power control lever.
Propeller control lever.
Condition lever.
Full aft position of a PT6 propeller control lever does what?
Feathers the prop.
What are the settings of the PT6 condition lever?
Cutoff.
Idle.
Run.
Three types of reciprocating engine prop mounts:
Flanged.
Tapered.
Splined.
Safest propeller stopping position for hand-propping.
10 and 4.
Functions of a spinner:
Engine aerodynamics streamlined.
Directs cooling air into cowlings.
Components of the spinner assembly:
Spinner.
Spinner support.
Donut (shim)
Spinner bulkhead.
How is the propeller hub centered on the shaft?
With two cones.
The term used to describe the contact between the step of the cone taper and the internal propeller splines.
Bottoming.
How much dye surface coverage is required to verify proper propeller seating on a tapered shaft?
No less than 70%
What lever controls RPMs on a PT6?
Prop lever
What lever adjusts idle speeds on the PT6?
Condition lever.
What are the settings for the power lever on a PT6?
Reverse.
Ground idle.
Flight idle.
Takeoff.
What does the Torquemeter measure?
Horsepower
What should be done after shutting down the TPE331?
Spin prop by hand to force cool air through.
The TPE331 idles at _____ and holds at _____ throughout flight.
95%.
100%
TPE331 takeoff lever settings are what?
Power - max
Condition - high
When is reverse required?
Slowing on descent.
Power backing.
Turning.
Stopping.
Benefits of composite blades:
Lighter.
Wider variety of shapes.
Tolerates bending.
Disadvantages of composite blades:
Expensive repair and manufacturing.
4 ways to correct blade imbalance:
Add weights to cuffs.
Remove material from blade.
Pack lead into dowel pin holes.
Add weight to bulkhead.
What should be inspected on a wood prop?
Looks for cracks across grain.
Look for laminate separations.
Warping.
What is the RPM difference allowed between engines by the synchronizers?
150 RPMs
How is synchrophasing achieved?
By slowing one prop via blade pitch.
Components of an anti icing system:
Rheostat switch, pump, slinger ring, feed shoe.
Places where anti icing may be used:
Propeller.
Windshield.
Carburetor.
Heating sequence for de-icing of propeller:
Root to tip (prevents ice “run-back”)
At what power percentage range does a PT6 operate?
50-100%
Name the most common composite materials used to manufacture propeller blades.
Glass.
Graphite.
Kevlar.
Where can the torque values for the propeller attaching nuts be found?
In the AIRFRAME maintenance manual.
What must be done if the rear cone bottoms.
Tip of the cone must be machined off.
What must be done if the front cone bottoms?
A spacer must be placed on the propeller shaft behind the rear cone.
Most props installed on tapered shafts are what type?
Wood.
What is used on the propeller hub to fit it to the tapered shaft?
A lapping compound (if dye test is failed)
Two sources of propeller induced vibration:
Out-of-track condition.
Out-of-balance condition.
If the prop edge is nicked, what should the length of the repair area be?
10 times the depth of the nick.
