Powerplant ACS Oral Exam Questions And
Answers
How can you tell if a turbofan or turbojet is out of trim -
correct answer ✅EGT will be high and the idle and max power will
be off
Why are wires bonded on powerplant installations -
correct answer ✅To provide a current return path for electrical
accessories, and to prevent static discharge.
What is the P-lead and how does it function? -
correct answer ✅The P-lead connects the ignition switch to the
primary circuit of the magneto. When the ignition switch is turned
off, the P-leads on both magnetos are grounded. When the ignition
switch is turned to the "LEFT" position, the right magneto is
grounded, so that only the left magneto operates, and visa versa.
What purpose do turbine engine fuel control units serve? -
correct answer ✅they automatically meter fuel to the engine
What are the different engine indications used for trimming a
turbine engine -
correct answer ✅Engine pressure ratio or RPM
,Powerplant ACS Oral Exam Questions And
Answers
What type of pump can vary the amount of fuel discharged
regardless of speed? -
correct answer ✅a variable displacement pump
What is a commonly used type of fuel boost pump? -
correct answer ✅The centrifugal type.
When performing an external inspection of an engine-driven fuel
pump, what should you look for? -
correct answer ✅leaks and security of mounting
What is the purpose of duplex fuel nozzles -
correct answer ✅provides different spray patterns, wider during
start up and acceleration and narrower when engine speeds above
idle
What is the purpose of a by-pass valve in an engine fuel system
micron filter -
correct answer ✅allows unfiltered fuel into the engine if the filter
becomes blocked
, Powerplant ACS Oral Exam Questions And
Answers
What purpose do fuel selector valves serve -
correct answer ✅they allow tank and engine selection and provide
a means of shutting off fuel flow
What could happen if the induction system becomes obstructed -
correct answer ✅the engine may not be able to produce its rated
power, or it may not be able to run at all. this can also be an
indication of dirty air inlet filter
what are the most common ways to control wastegate actuator
power -
correct answer ✅Mechanically with linkages attached to the
throttle or or a separate control hydraulically by an actuator thats
driven by oil pressure
in the turbocharger system what is used to limit the amount of
airflow used for cabin pressurization -
correct answer ✅sonic venturi
what is an indication of exhaust gas leak -
correct answer ✅flat gray or sooty black deposit in area of leak
Answers
How can you tell if a turbofan or turbojet is out of trim -
correct answer ✅EGT will be high and the idle and max power will
be off
Why are wires bonded on powerplant installations -
correct answer ✅To provide a current return path for electrical
accessories, and to prevent static discharge.
What is the P-lead and how does it function? -
correct answer ✅The P-lead connects the ignition switch to the
primary circuit of the magneto. When the ignition switch is turned
off, the P-leads on both magnetos are grounded. When the ignition
switch is turned to the "LEFT" position, the right magneto is
grounded, so that only the left magneto operates, and visa versa.
What purpose do turbine engine fuel control units serve? -
correct answer ✅they automatically meter fuel to the engine
What are the different engine indications used for trimming a
turbine engine -
correct answer ✅Engine pressure ratio or RPM
,Powerplant ACS Oral Exam Questions And
Answers
What type of pump can vary the amount of fuel discharged
regardless of speed? -
correct answer ✅a variable displacement pump
What is a commonly used type of fuel boost pump? -
correct answer ✅The centrifugal type.
When performing an external inspection of an engine-driven fuel
pump, what should you look for? -
correct answer ✅leaks and security of mounting
What is the purpose of duplex fuel nozzles -
correct answer ✅provides different spray patterns, wider during
start up and acceleration and narrower when engine speeds above
idle
What is the purpose of a by-pass valve in an engine fuel system
micron filter -
correct answer ✅allows unfiltered fuel into the engine if the filter
becomes blocked
, Powerplant ACS Oral Exam Questions And
Answers
What purpose do fuel selector valves serve -
correct answer ✅they allow tank and engine selection and provide
a means of shutting off fuel flow
What could happen if the induction system becomes obstructed -
correct answer ✅the engine may not be able to produce its rated
power, or it may not be able to run at all. this can also be an
indication of dirty air inlet filter
what are the most common ways to control wastegate actuator
power -
correct answer ✅Mechanically with linkages attached to the
throttle or or a separate control hydraulically by an actuator thats
driven by oil pressure
in the turbocharger system what is used to limit the amount of
airflow used for cabin pressurization -
correct answer ✅sonic venturi
what is an indication of exhaust gas leak -
correct answer ✅flat gray or sooty black deposit in area of leak
