SAMS Questions (other) Flashcards
A free turbine is usually found on a
Turboprop aircraft
A free turbine is
A gas turbine engine with a turbine stage on a shaft independent of the shaft used to drive the compressor
The fuel flow in a turboprop engine within the constant speed range is controlled by
FADEC System
(Full Authority Digital Engine Control)
Torque measurement is taken from the
main shaft
(instrument = Torquemeter)
Fuel trimming on a turboprop engine is controlled by
Fuel Control Unit (FCU)
*Automatically regulates fuel flow
What is the purpose of the reduction gear on a propeller driven engine
Slows propeller down
If an E.P.R gauge is installed on turbofans as a measure of power output, what is used on a turboprop
Tachometer: Shows the RPM of the compressor in percentage of its rated speed
What type of reduction gear is used on most turboprop modern engines
Epicyclic / Planetary gear train
A turbo-shaft engine has what type of spool system
Twin spool system
(??????????)
On a twin spool turbo-shaft engine, the free turbine is connected to the
Power Output shaft
(On helicopters, this goes through reduction gear system to rotate rotor blades)
In the majority of helicopters, the thrust generated by the gas generator is absorbed by the
Turbine
An A.P.U automatic shut down is initiated by
ECB = Electronic Control Box
An A.P.U start cycle is completed at ___% RPM
95% RPM
An A.P.U power lever is located
trick question
APU is a constant speed engine and has no power lever
An A.P.U consists of what type of compressors
Centrifugal and axial load compressors
When necessary, A.P.U engine cooling before shutdown may be accomplished by
Opening surge control valve
(Normally used to prevent APU compressor stall)
An A.P.U is usually rotated during start by
Ground Pneumatics
(Electric starter motor)
In a large commercial passenger transport aircraft the A.P.U supplies
Up to 10’000 ft
Both Electrical and Pneumatic power can be used
10’000 ft to 17’000 ft
Either Electrical OR Pneumatic power can be used
17’000 ft to 35’000 ft
Electrical Power only
(BEE)
When in operation, the speed of an A.P.U ____________ regardless of the load condition
is constant
When is the A.P.U at it’s greatest load
When using both electronic and pneumatic power
(only permittable sea level up to 10’000 ft)
What is the most important signal when monitoring an A.P.U
EGT
Exhaust Gas Temperature
(This is also one of the factors that will cause automatic APU shutdown if EGT goes too high)
