A&P POWERPLANT ORAL NEWEST
ACTUAL EXAM WITH ACTUAL EXAM
QUESTIONS AND CORRECT ANSWERS
RATED A+
What should a thermocouple-type cylinder head temperature
indicator read when the engine is not operating?
the temperature of the outside air
How does a torquemeter actually measure the torque
produced by an engine?
the torquemeter is actually an oil pressure gauge. the pressure it
measures is produced in a torque sensor and is proportional to
the amount of strain in the torsional shaft that drives the reduction
gears of the turboprop engine
*** what two pressures are measured to get the engine
pressure ratio of a turbojet engine?
the turbine discharge total pressure and the compressor inlet total
pressure
*** of what two materials are the thermocouples made that
are used in a turbine engine exhaust gas temperature
system?
chromel and alumel
,What kind of mechanism is normally used to measure oil
pressure in a reciprocating engine?
a bourdon tube mechanism
what is measured by the tachometers used in a two spool
gas turbine engine?
the N1 tachometer shows the RPM of the low pressure
compressor, and the N2 tachometer shows the RPM of the high-
pressure compressor
does the tachometer of a geared reciprocating engine
indicate the speed of the crankshaft or of the propeller shaft?
the speed of the crankshaft
*** can a thermal switch-type fire detection system indicate a
general overheat condition?
no, this is a spot-type fire detection, and it cannot indicate an
overheat condition
*** can a thermocouple-type fire detection system indicate a
general overheat condition?
no, this is a rate-of-temperature-rise-type of system, an it cannot
indicate a general overheat condition
How is a thermocouple-type fire detection system checked
for operation?
current is sent through the heater in the thermal test unit. this
heats the thermocouple, which produces enough current to close
the sensitive relay. current through the contacts of the sensitive
relay closes the slave relay and turns on the fire warning light
,Does a break in a continuous-loop fire detection system keep
the system from detecting a fire?
no, the unit will show a fault when it is tested, but it will still warn
of a fire.
*** Does the pressure-type continuous-element fire detector
system detect a general overheat condition, as well as a fire?
yes, a high temperature on a small portion or the sensor or a
lower temperature over the entire sensor will cause it to releases
enough gas to close the diaphragm switch and warn a fire
*** what are two most commonly used fire extinguishing
agents used for engine fires?
halogenated hydrocarbon, such as Halon 1301, and carbon
dioxide
*** what extinguishing agent is used in the high-rate-
discharge fire extinguishing systems installed in most
turbojet engine installations?
Halon 1301
*** what happens when the pilot pulls the fire-pull T-handle in
the cockpit of a jet transport airplane?
the bottle discharge switch is uncovered and armed, the
generator field relay is tripped, fuel is shutoff to the engine,
hydraulic fluid is shut off, and the hydraulic pump low-pressure
lights are deactivated
how can a mechanic determine the state of charge of the
HRD bottles of fire extinguishing agent?
, a pressure gauge on the bottle shows the pressure of the
contents of the bottle
what method is used to discharge an HRD bottle in a turbine
engine installation?
An electrically ignited powder charge blows a knife through the
seal on the bottle and discharges the contents.
*** which type of fire detection system operates on the rate of
temperature rise?
the thermocouple system
*** what is indicated if the yellow blow-out plug of the fire
extinguisher system on the side of the engine nacelle is
blown out?
the built-in fire extinguishing system has been discharged by
normal operation.
*** what is indicated if the red blow-out plug of the fire
extinguisher system on the side of the nacelle is blown out?
the built-in fire extinguishing system has been discharged by a
high temperature condition
*** how is a low pressure-type continuous-element fire
detection system checked for operation?
low-voltage alternating current is sent through the sheath of the
detector element. this heats the element, and it releases enough
gas to close the diaphragm switch
Why is stranded wire used rather than solid wire, in most
powerplant electrical systems?
solid wire is likely to break when it is subjected to vibration
ACTUAL EXAM WITH ACTUAL EXAM
QUESTIONS AND CORRECT ANSWERS
RATED A+
What should a thermocouple-type cylinder head temperature
indicator read when the engine is not operating?
the temperature of the outside air
How does a torquemeter actually measure the torque
produced by an engine?
the torquemeter is actually an oil pressure gauge. the pressure it
measures is produced in a torque sensor and is proportional to
the amount of strain in the torsional shaft that drives the reduction
gears of the turboprop engine
*** what two pressures are measured to get the engine
pressure ratio of a turbojet engine?
the turbine discharge total pressure and the compressor inlet total
pressure
*** of what two materials are the thermocouples made that
are used in a turbine engine exhaust gas temperature
system?
chromel and alumel
,What kind of mechanism is normally used to measure oil
pressure in a reciprocating engine?
a bourdon tube mechanism
what is measured by the tachometers used in a two spool
gas turbine engine?
the N1 tachometer shows the RPM of the low pressure
compressor, and the N2 tachometer shows the RPM of the high-
pressure compressor
does the tachometer of a geared reciprocating engine
indicate the speed of the crankshaft or of the propeller shaft?
the speed of the crankshaft
*** can a thermal switch-type fire detection system indicate a
general overheat condition?
no, this is a spot-type fire detection, and it cannot indicate an
overheat condition
*** can a thermocouple-type fire detection system indicate a
general overheat condition?
no, this is a rate-of-temperature-rise-type of system, an it cannot
indicate a general overheat condition
How is a thermocouple-type fire detection system checked
for operation?
current is sent through the heater in the thermal test unit. this
heats the thermocouple, which produces enough current to close
the sensitive relay. current through the contacts of the sensitive
relay closes the slave relay and turns on the fire warning light
,Does a break in a continuous-loop fire detection system keep
the system from detecting a fire?
no, the unit will show a fault when it is tested, but it will still warn
of a fire.
*** Does the pressure-type continuous-element fire detector
system detect a general overheat condition, as well as a fire?
yes, a high temperature on a small portion or the sensor or a
lower temperature over the entire sensor will cause it to releases
enough gas to close the diaphragm switch and warn a fire
*** what are two most commonly used fire extinguishing
agents used for engine fires?
halogenated hydrocarbon, such as Halon 1301, and carbon
dioxide
*** what extinguishing agent is used in the high-rate-
discharge fire extinguishing systems installed in most
turbojet engine installations?
Halon 1301
*** what happens when the pilot pulls the fire-pull T-handle in
the cockpit of a jet transport airplane?
the bottle discharge switch is uncovered and armed, the
generator field relay is tripped, fuel is shutoff to the engine,
hydraulic fluid is shut off, and the hydraulic pump low-pressure
lights are deactivated
how can a mechanic determine the state of charge of the
HRD bottles of fire extinguishing agent?
, a pressure gauge on the bottle shows the pressure of the
contents of the bottle
what method is used to discharge an HRD bottle in a turbine
engine installation?
An electrically ignited powder charge blows a knife through the
seal on the bottle and discharges the contents.
*** which type of fire detection system operates on the rate of
temperature rise?
the thermocouple system
*** what is indicated if the yellow blow-out plug of the fire
extinguisher system on the side of the engine nacelle is
blown out?
the built-in fire extinguishing system has been discharged by
normal operation.
*** what is indicated if the red blow-out plug of the fire
extinguisher system on the side of the nacelle is blown out?
the built-in fire extinguishing system has been discharged by a
high temperature condition
*** how is a low pressure-type continuous-element fire
detection system checked for operation?
low-voltage alternating current is sent through the sheath of the
detector element. this heats the element, and it releases enough
gas to close the diaphragm switch
Why is stranded wire used rather than solid wire, in most
powerplant electrical systems?
solid wire is likely to break when it is subjected to vibration
