The ATPL BGT Quiz assesses key knowledge areas in jet engine mechanics, focusing on gas velocity, pressure, and temperature within turbojet engines. Essential for aerospace engineering students and professionals, it evaluates understanding of engine core components and performance factors.
Lower pressure and lower temperature
Raise pressure and lower velocity
Raise velocity and lower temperature
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Thrust increases as air temperature increases
Thrust decreases as air temperature increases
Thrust increases as humidity increases
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In the jet pipe
At the end of the compressor
In the combustion chamber
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In the diffuser
At the last stage of the turbine
At the inlet of the compressor
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The fan
The compressor, combustion chambers, turbines and exhaust
The accessory drive shaft
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A decrease in ambient air temperature
A decrease in ambient air pressure
A decrease in ambient air density
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It will stall more readily
Discharge pressure will increase
RPM will increase
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A bypass ratio less than 1:1
A bypass ratio more than 1:1
No bypass air
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A convergent duct
A divergent duct
A helical duct
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Lowers the efficiency of a jet engine as aircraft speed increases
Raises the thrust output of a jet engine as aircraft speed increases
Cools the air as it enters the engine intake
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Gas pressure, velocity and temperature all decrease
Gas pressure increases, velocity falls and temperature increases
Gas pressure reduces, velocity increases and temperature decreases
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Blade creep experienced on the test bench by the manufacturer
Normal blade creep over the life of the engine
Blade creep to the point where it would be detrimental to continue to run the engine
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Prolonged ground running with the air intake guard screens fitted
An unserviceable igniter plug
An unstable airflow through the compressor
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Within the combustion chamber
At the entry to the exhaust unit
At the compressor exit
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At MSL under ISA conditions
At high altitudes
At MSL under ISA plus temperatures
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The compressor ceases to rotate
The smooth flow of air over the blading breaks away and causes an interruption of airflow through the engine
The fuel flow burners will cease immediately
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Prevent turbine blade stall at high engine RPM
Prevent compressor blade stall during operation off design RPM
Prevent excessive cooling due to large mass air flow through the engine
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The decrease in mass airflow permits an increased fuel/air ratio
The higher ambient temperature results in a greater pressure rise through the engine
The engine can operate at design RPM to maintain an efficient wing angle of attack
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An increase in the gas temperature, reduced thrust and an increase in SFC
An increase in thrust since less air will be mixed with fuel in the combustion chambers
An increase in RPM and a decrease in gas temperature
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Between the final compressor stage and the inlet to the combustion chamber
In the exhaust unit
At the downstream end of the combustion chamber
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To prevent overheating of the turbine
To prevent burning of the thermocouples
To prevent a thermal runaway
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Raise the pressure and reduce the velocity of the gases
Increase the density and reduce the temperature of the gases
Increase the volume and velocity of the gases
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Nozzles designed to increase velocity of the air
Divergent ducts which lower the velocity and raise the pressure of the air
Special passages which drop the pressure of the air before combustion occurs
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Leave the fuel filler caps off
Keep the tanks as full as possible
Fill the tank airspace with carbon dioxide
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Both the HP and LP turbines
Only the front HP turbines
Only the rear LP turbines
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Open the throttle and watch RPM increase to optimum range
Close the throttle and manually operate the bleed valves
Shut off the fuel supply and maintain starter motor rotation
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Units of fuel used per unit of thrust per hour
Distance travelled per unit of fuel
Amount of fuel used in a specified engine RPM range
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Prevent blade tups rubbing against the shroud ring on expansion
Prevent gas leaking past blade tips, increase rigidity and reduce vibration
Prevent hot gases distorting the turbine blades
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Temperature increases
Pressure increases
Velocity increases
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Open from idling to nearly design RPM, then closed up to max RPM
Closed for idling to nearly design RPM, then opened up to max RPM
Open over the entire RPM range, unless compressor stall occurs
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Of compressibility effects on the blades
Blade interference increases
Blade angle of attack becomes too great
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All events are occurring at the same time
The engine is open from end to end
The cycle can start and stop at any time
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Of intake choking
Combustion chamber back-pressure increasing
The difference between exhaust and intake velocities is reduced
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Rises steadily
Is constant or falls slightly
Rises initially and then falls steadily
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Water
Fuel
Air
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Engine compressor inlet pressure to propelling nozzle pressure
Engine compressor outlet pressure to jet pipe pressure
Engine compressor inlet pressure to jet pipe pressure
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RPM
EPR
EGT
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Reaction to impingement of exhaust gases on the outside atmosphere
Reaction to the pressure difference between exhaust and intake air pressures
The force required to accelerate a mass of air through the engine
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The accessory housing
The fuel tanks
The fuel control unit
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The allows the compressors to run closer to their ideal RPM
Manufacturing is made simpler and cheaper
Shaft strength is increased
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No turbulence and pressure lower than ambient
No turbulence and velocity higher than ambient
No turbulence and pressure higher than ambient
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Goes to the rear of the combustion chamber for cooling purposes
Does not pass through the compressor
Is used to drive the air turbine
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Reduce combustion chamber back pressure
Give a balance to the air losses
Precent compressor stall and surge when operating off design RPM
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Stop the swirl that would otherwise form
Convert kinetic energy into pressure energy
Increase the velocity of the air
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It accelerates a relatively large mass of air to a relatively low velocity
It accelerates a relatively small mass of air to a relatively high velocity
It accelerates a relatively large mass of air to a relatively high velocity
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These engines have intake screens
Most of the air bypasses the engine
Most foreign objects are smaller than the blades
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A lower air mass accelerated to a higher velocity
A higher air mass accelerated to a higher velocity
A higher air mass accelerated to a lower velocity
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Inadequate power output
Gearbox RPM limitations
Shockwaves at the propeller blade tips at high Mach number
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Quiz Review Timeline (Updated): Mar 20, 2023 +
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