POWERPLANT ASA TEST PAPER 2025/2026 QUESTIONS
WITH ANSWERS GUARANTEE A+
✔✔A hissing sound from the exhaust stacks when the propeller is being pulled through
manually indicates - ✔✔exhaust valve blow-by.
✔✔If an engine cylinder is to be removed, at what position in the cylinder should the
piston be? - ✔✔Top dead center.
✔✔What is the best indication of worn valve guides? - ✔✔High oil consumption.
✔✔(1) Preignition is caused by improper ignition timing.
(2) Detonation occurs when an area of the combustion chamber becomes incandescent
and ignites the air-fuel mixture in advance of normal timed ignition. - ✔✔neither 1 nor 2
is true.
✔✔Which of the following engine servicing operations generally requires engine pre-
oiling prior to starting the engine? - ✔✔Engine installation.
✔✔During the inspection of an engine control system in which push-pull control rods are
used, the threaded rod ends should - ✔✔be checked for the amount of thread
engagement by means of the inspection holes.
✔✔Which of the following conditions would most likely lead to detonation? - ✔✔Use of
fuel with too low an octane rating.
✔✔How may it be determined that a reciprocating engine with a dry sump is pre-oiled
sufficiently? - ✔✔Oil will flow from the engine return line or indicator port.
✔✔What could cause excessive pressure buildup in the crankcase of a reciprocating
engine? - ✔✔Plugged crankcase breather.
✔✔If air is heard coming from the crankcase breather or oil filler during a differential
compression check, what is this an indication of? - ✔✔Piston ring leakage.
✔✔One cause of afterfiring in an aircraft engine is - ✔✔an excessively rich mixture.
✔✔During overhaul of an engine, a first step of inspection on a crankshaft should be -
✔✔perform a runout check.
✔✔At what point in an axial-flow turbojet engine will the highest gas pressures occur? -
✔✔At the compressor outlet.
,✔✔The abbreviation P17 used in turbine engine terminology means - ✔✔the total
pressure at station 7.
✔✔What turbine engine section provides for proper mixing of the fuel and air? -
✔✔Combustion section.
✔✔Where is the highest gas pressure in a turbojet engine? - ✔✔In the entrance of the
burner section.
✔✔When starting a turbine engine, - ✔✔a hot start is indicated if the exhaust gas
temperature exceeds specified limits.
✔✔What are the 2 basic elements of the turbine section in a turbine engine? - ✔✔Stator
and Rotor.
✔✔How does a dual axial-flow compressor improve the efficiency of a turbojet engine? -
✔✔Higher compression ratios can be obtained.
✔✔Which statement is true regarding aircraft engine propulsion? - ✔✔An engine driven
propeller imparts a relatively small amount of acceleration to a large mass of air.
✔✔An advantage of the centrifugal-flow compressor is its high - ✔✔pressure rise per
stage.
✔✔The highest heat-to-metal contact in a jet engine is the - ✔✔turbine inlet guide
vanes.
✔✔Standard sea level pressure is - ✔✔29.92" Hg.
✔✔Using standard atmospheric conditions, the standard sea level temperature is -
✔✔59°F.
✔✔In a dual axial-flow compressor, the first stage turbine drives - ✔✔N(2) compressor.
✔✔What is the proper starting sequence for a turbojet engine? - ✔✔Starter, ignition,
fuel.
✔✔The velocity of subsonic air as it flows through a convergent nozzle - ✔✔increases.
✔✔The velocity of supersonic air as it flows through a divergent nozzle - ✔✔increases.
✔✔The pressure of subsonic air as it flows through a convergent nozzle -
✔✔decreases.
, ✔✔The pressure of supersonic air as it flows through a divergent nozzle -
✔✔decreases.
✔✔Generally, when starting a turbine engine, the starter should be disengaged -
✔✔after the engine has reached self-accelerating speed.
✔✔What is the primary advantage of an axial-flow compressor over a centrifugal
compressor? - ✔✔Greater pressure ratio.
✔✔A gas turbine engine comprises which three main sections? - ✔✔Turbine,
compressor, and combustion.
✔✔What is the primary factor which controls the pressure ratio of an axial-flow
compressor? - ✔✔Number of stages in compressor.
✔✔The air passing through the combustion chamber of a turbine engine is - ✔✔used to
support combustion and to cool the engine.
✔✔Newton's first law of motion, generally termed the law of inertia, states: - ✔✔Every
body persists in its state of rest, or of motion in a straight line, at the same speed,
unless acted upon by an outside force.
✔✔Newton's Second Law of motion, generally termed the law of momentum, states: -
✔✔Acceleration is produced when a force acts on a mass. The greater the mass, the
greater the amount of force needed.
✔✔Which of the following influences the operation of an automatic fuel control unit on a
turbojet engine? - ✔✔Burner pressure.
✔✔The Brayton cycle is known as the constant - ✔✔pressure cycle.
✔✔If the RPM of an axial-flow compressor remains constant, the angle of attack of the
rotor blades can be changed by - ✔✔changing the velocity of the airflow.
✔✔The compression ratio of an axial-flow compressor is a function of the - ✔✔number
of compressor stages.
✔✔Which of the following variables affect the inlet air density of a turbine engine? -
✔✔Speed of the aircraft, altitude of the aircraft, and ambient temperature.
✔✔Which of the following factors affect the thermal efficiency of a turbine engine? -
✔✔Turbine inlet temperature, compression ratio, and turbine and compressor efficiency.
WITH ANSWERS GUARANTEE A+
✔✔A hissing sound from the exhaust stacks when the propeller is being pulled through
manually indicates - ✔✔exhaust valve blow-by.
✔✔If an engine cylinder is to be removed, at what position in the cylinder should the
piston be? - ✔✔Top dead center.
✔✔What is the best indication of worn valve guides? - ✔✔High oil consumption.
✔✔(1) Preignition is caused by improper ignition timing.
(2) Detonation occurs when an area of the combustion chamber becomes incandescent
and ignites the air-fuel mixture in advance of normal timed ignition. - ✔✔neither 1 nor 2
is true.
✔✔Which of the following engine servicing operations generally requires engine pre-
oiling prior to starting the engine? - ✔✔Engine installation.
✔✔During the inspection of an engine control system in which push-pull control rods are
used, the threaded rod ends should - ✔✔be checked for the amount of thread
engagement by means of the inspection holes.
✔✔Which of the following conditions would most likely lead to detonation? - ✔✔Use of
fuel with too low an octane rating.
✔✔How may it be determined that a reciprocating engine with a dry sump is pre-oiled
sufficiently? - ✔✔Oil will flow from the engine return line or indicator port.
✔✔What could cause excessive pressure buildup in the crankcase of a reciprocating
engine? - ✔✔Plugged crankcase breather.
✔✔If air is heard coming from the crankcase breather or oil filler during a differential
compression check, what is this an indication of? - ✔✔Piston ring leakage.
✔✔One cause of afterfiring in an aircraft engine is - ✔✔an excessively rich mixture.
✔✔During overhaul of an engine, a first step of inspection on a crankshaft should be -
✔✔perform a runout check.
✔✔At what point in an axial-flow turbojet engine will the highest gas pressures occur? -
✔✔At the compressor outlet.
,✔✔The abbreviation P17 used in turbine engine terminology means - ✔✔the total
pressure at station 7.
✔✔What turbine engine section provides for proper mixing of the fuel and air? -
✔✔Combustion section.
✔✔Where is the highest gas pressure in a turbojet engine? - ✔✔In the entrance of the
burner section.
✔✔When starting a turbine engine, - ✔✔a hot start is indicated if the exhaust gas
temperature exceeds specified limits.
✔✔What are the 2 basic elements of the turbine section in a turbine engine? - ✔✔Stator
and Rotor.
✔✔How does a dual axial-flow compressor improve the efficiency of a turbojet engine? -
✔✔Higher compression ratios can be obtained.
✔✔Which statement is true regarding aircraft engine propulsion? - ✔✔An engine driven
propeller imparts a relatively small amount of acceleration to a large mass of air.
✔✔An advantage of the centrifugal-flow compressor is its high - ✔✔pressure rise per
stage.
✔✔The highest heat-to-metal contact in a jet engine is the - ✔✔turbine inlet guide
vanes.
✔✔Standard sea level pressure is - ✔✔29.92" Hg.
✔✔Using standard atmospheric conditions, the standard sea level temperature is -
✔✔59°F.
✔✔In a dual axial-flow compressor, the first stage turbine drives - ✔✔N(2) compressor.
✔✔What is the proper starting sequence for a turbojet engine? - ✔✔Starter, ignition,
fuel.
✔✔The velocity of subsonic air as it flows through a convergent nozzle - ✔✔increases.
✔✔The velocity of supersonic air as it flows through a divergent nozzle - ✔✔increases.
✔✔The pressure of subsonic air as it flows through a convergent nozzle -
✔✔decreases.
, ✔✔The pressure of supersonic air as it flows through a divergent nozzle -
✔✔decreases.
✔✔Generally, when starting a turbine engine, the starter should be disengaged -
✔✔after the engine has reached self-accelerating speed.
✔✔What is the primary advantage of an axial-flow compressor over a centrifugal
compressor? - ✔✔Greater pressure ratio.
✔✔A gas turbine engine comprises which three main sections? - ✔✔Turbine,
compressor, and combustion.
✔✔What is the primary factor which controls the pressure ratio of an axial-flow
compressor? - ✔✔Number of stages in compressor.
✔✔The air passing through the combustion chamber of a turbine engine is - ✔✔used to
support combustion and to cool the engine.
✔✔Newton's first law of motion, generally termed the law of inertia, states: - ✔✔Every
body persists in its state of rest, or of motion in a straight line, at the same speed,
unless acted upon by an outside force.
✔✔Newton's Second Law of motion, generally termed the law of momentum, states: -
✔✔Acceleration is produced when a force acts on a mass. The greater the mass, the
greater the amount of force needed.
✔✔Which of the following influences the operation of an automatic fuel control unit on a
turbojet engine? - ✔✔Burner pressure.
✔✔The Brayton cycle is known as the constant - ✔✔pressure cycle.
✔✔If the RPM of an axial-flow compressor remains constant, the angle of attack of the
rotor blades can be changed by - ✔✔changing the velocity of the airflow.
✔✔The compression ratio of an axial-flow compressor is a function of the - ✔✔number
of compressor stages.
✔✔Which of the following variables affect the inlet air density of a turbine engine? -
✔✔Speed of the aircraft, altitude of the aircraft, and ambient temperature.
✔✔Which of the following factors affect the thermal efficiency of a turbine engine? -
✔✔Turbine inlet temperature, compression ratio, and turbine and compressor efficiency.
