15.16 Flashcards
(28 cards)
What is the most efficient speed for a turbo prop
300 to 450 mph
What percentage of engine power drive the propeller in a turbo prop
95%
How much residual thrust does a turbo prop generate
10 to 15%
What skate core of a turbo prop know as
Gas generator
How is high shaft houres power created
Extra turbines
What is a free power turbine
It is not connected to core (gas generator)
Aerodynamic connection instead
What are the advantages of a free power turbine
Vibration not transmitted form gearbox and gas chamber
Engine easy to start when cold
Prop can be a lower rpm when taximjng and completely stop. This is when the engine can be used as an apu
What is true about the speed of a direct coupled turbine
Constant engine and propeller speed
What type of oil does a turbo fan need
High viscosity oil
What is true of propeller tip speed
Needs to be bellow speed of sound
Straight cut parallel spur gear
Low friction low noise
Helical cut parallel spur gear
Gradual onset of power and quieter
Needs tapered bearing
What direction does the propeller of a fixed annulus epicyclic gear box spin
Same direction as engine
What direction does the propeller of a rotating annulus epicyclic gear box spin
Opposite form engine rotation
Alpha phase
Flight condition of turbo prop engine
Beta phase
Ground configuration of a turbo prop
What does a propeller control unit govern
Engine rpm
Where is a dual lever found
Free turbine turboprops
What does the trust lever schedule
Fuel
How does PCU select the required RPM
applying or releasing pressure on governor control unit
What is a control lock used for
Turbo props
Prevent flight control fluter
How can an over speed turbo prop be prevented
Change prop angle
Centrifugal twisting motion causes what on a turbo prop and how is it reduced
The blades to return to zero. Feathering stops this
What will happen if oil to the blades stop
The prop will auto feather
