Tổng hợp câu hỏi trắc nghiệm ôn thi chuyên ngành kỹ thuật hàng không

ATA 71
Which of the following statements is correct about the 2 engine mounts shown here.

1.

a. Both mounts can transfer forces in all 3 directions
b. The forwad mount can only transfer forces in the z and x axes.
c. The aft mount can only transfer forces in the z and y axes.
d. The aft mount can only transfer forces in the z and x axes.
2.
a.
b.
c.
d.

What is the main function of the exhaust nozzle?
Noise reduction.
To decrease fuel consumption.
To generate thrust from the exhaust gas.
To protect the engine turbine against foreign object damage.

3.
a.
b.
c.
d.

Which loads can be transferred by this aft mount?
Only thrust.
Weight and side loads.
Thrust and weight.

Side loads and thrust.

4.
a.
b.
c.
d.

What types of fluid can be collected by the drain system?
Only fuel and oil.
Only oil, fuel and water.
Oil + fuel + hydraulic fluids + water.
Only fuel + water.

5.

What is the task of the drain collector assembly in this drain system ?
a. It connects all drain lines from the accessory drive to one common line routed to the drain
mast.
b. It connects all drain lines of the drain system to one common line routed to the drain mast.
c. It collects fluid leaks from all drain lines.
d. It collects fluid leaks from the accessory drive seals.

6. After landing you find this track on a drain mast. What statement is correct?

a. There was a leakage at the hydraulic pump drive seal. The drive seal must be replaced
before the next flight.
b. There was a leakage at the hydraulic pump drive seal. You must do a leak check.
c. There was a leakage at the hydraulic pump drive seal. You must replace the hydraulic

pump.
d. This is normal, because hydraulic pumps always leak a little bit.
7. How is the oil holding tank of this collector assembly emptied?

a. It is automatically emptied by ram air during each flight.
b. You must open the drain valve to empty the holding tank.
c. Low pressure on the drain mast outlet during flight sucks the fluid out of the holding tank.
d. It is automatically emptied by engine bleed air before each flight.
ATA 72
8. Airlines do not like this of engine design. Why?
a. Because too many special tools are needed to carry out the maintenance on these types of

engine.
b. Because maintance on these engines is too time consuming.
c. Because maintance training for these engine is too expansive.
9. What are 4 typical major modules of a modern turbofan engine?

a. The engine inlet, the compressor, the turbine and the engine exhaust.
b. The low pressure compressor, high pressure compressor, high compressor turbine and low
pressure turbine.
c. The fan module, the core module, the turbine module and the accessory drive
module.
d. The N1 rotor module, the N2 rotor module, the combustor module and the exhaust nozzle
module.
10. Where on the engine do you usually find titanium base alloy material?

a. The low pressure compressor is usually made of titanium base alloy.
b. The fan cases and the engine gearboxes are usually made of titanium base alloy.
c. The high pressure turbine is usually made of titanium base alloy.

d. The N1 driveshaft is usually made of titanium base alloy.
11. What is the purpose of the spiral drawn on the spinner cone?
a. It is just for optical reasons to make the engine look nicer.
b. To show the engine is running.


c. To scare birds away.
d. To improve airflow.
12. What is a labyrinth seal?
a. it is a fluid tight seal between 2 rotating parts which drains any fluid leakage into a labyrinth.
b. It is a gas tight air seal that is between 2 rotating parts which are not in contact with each

other.
c. It is a gas tight air seal that is between 2 parts which are in contact with each other.
d. It is an air seal between 2 rotating parts which are not in contact with each other.
13.
a.
b.
c.

What is the purpose of the airflow splitter fairing?
it splits the airflow from the fan into the primary and secondary airflow.
It splits the airflow from the fan into the LPC airflow and HPC airflow.
It serves as a water separate which prevents that rain can enter the core engine.

14.
a.
b.
c.
d.

What are these holes for?
These are drain holes to prevent water from entering the fan duct.
These holes are used to reduce the noise of the fan.
These holes are used to ventilate the inner surface of the fan case.
These holes are used to improve the airflow in the fan duct by sucking off the boundary layer.

15. Some spinner cones have a soft tip. What is the reason of this soft tip?

a. The soft tip reduces the noise of the inlet airflow.
b. The soft tip reduces the injury danger if somebody is sucked into a running engine.
c. The soft tip is made of a special material that is extremely light to save weight.
d. The soft tip causes a small imbalance during operation to prevent ice built-up at
the spinner cone.
16. Which of the following statements about the attachment of fan blade is correct?
a. Fan blades are always fitted loosely to the fan disc.
b. Fan blades must have a very tight fit because of their large weight.
c. Fan blades are attached in circumferential dovetail slots on the fan disc.
d. Fan blades are attached the fan stator case.
17. Where on the fan module can you find adradable shrouds?

a. On the outer fan stator case.
b. On the inner wall of the fan stator case in the area of the fan blades.
c. In the center hub of the fan frame.
d. On the inner wall of the fan stator case, in the area of the outlet guide vanes.


18. What is the purpose of the mid-span shrouds on the fan blades?

a. Mid-span shrouds serve as enforcements for the fan blades, to better withstand the

centrifugal loads.
b. The shrouds help to keep the fan blade deflection within safe limits if very heavy
loads act on them.
c. The shrouds help to split the inlet airflow into primary and secondary airflow.
d. The mid-span shrouds help to scare birds away.
19.
a.
b.
c.

What function does the fan frame carry out?
It supports the bearing at the front end of the HP compressor rotor.
It supports the stator vanes of the compressor.
It supports the rear bearing of the compressor rotor.

20.
a.
b.
c.
d.

What happens when the rotor blade of a running engine makes contact with the lining?
the blade bends and gets out of shape.
The lining material is scraped off.
The blade tip material is scraped off.
The blade tip breaks off.

21. Which design method is used for this compressor rotor?

a. This is a disc type compressor rotor.

b. This is a drum type compressor rotor.
c. This is a combined compressor rotor made of 1 drum and 3 discs.
d. This is a combined compressor rotor made of 2 drums and 2 discs.
22. How many stages of this compressor rotor have axial dovetail slots to fit the rotor blades?

a. Only the first stage has axial dovetail slots for the rotor blades.
b. The first 2 stages have axial dovetail slots for the rotor blades.
c. The first 3 stages have axial dovetail slots for the rotor blades.
d. All 9 stages have axial dovetail slots to fit the rotor blades.
23. What is the purpose of the diffuser in the combustion case?
a. It increases the air velocity into the combustion chmber and therefore increases the air

pressure.


b. It decreases the air velocity into the combustion chamber and therefore increases

the air pressure.
c. It splits the airflow into the combustion chamber into primary airflow and scondary airflow.
d. It guides all the air from the high pressure compressor into the primary combustion zone.
24. What do you think is the purpose of the interstage seal?
a. It prevents gas flow through the gap between the turbine stator and the turbine

rotor.
b. It prevents the cooling airflow from entering the main gas flow.
c. It prevent oil from leaking into the main gas flow.
25. What is the name of this rotor blade attachment?

a. Dove tail attachment.
b. Fir tree attachment.

c. Lemon tree attachment.
d. Fir tail attachment.
26.
a.
b.
c.

What is the main disadvantage of fan mounted gearboxes?
The weight of the gearbox moves the center of gravity of the engine too far to the front.
The gearbox on the fan case increases the frontal area of the engine.
This design puts too much extra weight on the engine.

27. What is the advantage of a V-clamp or QAD-ring attachment?
a. V-clamp or QAD-ring attachments transmit higher loads.
b. V-clamp or QAD-ring attachments permit quick and easy removal and installation of

the accessory units.
c. They are used if there is no room for the necessary number of bolts on the mounting pad.
28. What is the advantage of tangential struts compared with radial struts used in the turbine

frame?
a. Tangential struts minimize the stress on the frame hub caused by thermal expansion.
b. Tangential struts are lighter than radial struts.
c. Tangential struts are cheaper to manufacture than radial struts.
d. Tangential struts look better than radial struts.
29. What is the advantage of core mounted gearboxes compared with fan case mounted

gearboxes?
a. Core mounted gearboxes are more compact and therefore lighter than fan case mounted
gearboxes.

b. Core mounted gearboxes are easier to access than fan case mounted gearboxes.
c. Engines with core mounted gearboxes have a smaller frontal area than fan case
mounted gearboxes.
30. Which rotor of this turbofan engine has a triple bearing system?
a. HP rotor.
b. LP rotor.
31. Which kind of loads can be transmitted by a floating bearing?

a. Weight loads, shock loads, thermal loads and thrust loads.
b. Weight loads and centrifugal loads.
c. Weight loads, centrifugal loads and thrust loads.
d. Weight loads only.
32. What is pressure balancing?
a. Pressure balancing is a method of reducing axial loads on fixed bearings in an
engine.
b. Pressure balancing is a method to reduce axial loads on floating bearings in an engine.
c. Pressure balancing is a method to reduce radial loads on fixed bearings in an engine.
d. Pressure balancing is a method to reduce the oil pressure at the lubrication nozzle.


33. Which lubrication method is shown in this graphic?

a. The direct lubrication method.
b. The indirect lubrication method.
c. A combination of a direct and an under-race lubrication method.
d. The outer-race lubrication method.
34. What must you do if one fan blade is damaged and has to be replaced?

a. This is not allowed as you cannot replace just one blade. You must always replace the whole
set.
b. First remove all the fan blades and calculate a new distribution with the new blade.
c. You must replace the damaged blade with a new blade which has the exactly same moent
weight.
d. You must adjust the change in the moment weight by adding balance weights.
35. Assume that during blending 20 gram of blade material has been removed. What has to be

done to the blade so that it can be put on the fan rotor again?
a. You must add a balance weight of 20 gram on the spinner.
b. You must blend 20 gram of material at the tip of the opposite blade.
c. You must measure the new moment weight, calculate the required balance weight
and add it to the spinner.
d. You must always perform a complete computerized rebalancing of the fan rotor.
36. In this example which components of the high pressure compressor can be inspected by a

rigid borescope?
a. All the stator vances of all compressor stages.
b. All the rotor blades of all compressor stages.
c. Some rotor blades of all stages and all stator vanes of all stages.
d. You can only inspect the rotor blades of stage 1 to 4, stage 6 and 7 and of stage 9 and 10.
37. How do you rotate the N2 rotor system for a borescope inspection?

a. Use the shaft of the borescope and push on the rotor blades.
b. Rotate the N1 rotor fast enough so that the N2 rotor will follow.


c. Motorize the engine with the pneumatic starter motor at a very low speed.
d. By a cranking device connected to the accessory gearbox or transfer gearbox.
ATA 73

38.
a.
b.
c.
d.

What is this component in the fuel system?
The fuel filter.
The fuel control unit.
The oil cooler.
The fuel flow transmitter.

39. Why do we need a positive fuel pressure at the inlet of the high pressure fuel pump?
a. Because the gear type HP pump cannot create sufficient suction to get the fuel from the tanks.
b. Because the pressure decreases too much when the fuel passes through the oil cooler and fuel

filter.

c. Because the high pressure pump cannot create sufficient pressure without the low pressure

pump.
d. Because cavitation occurs at the inlet of the high pressure pump if it has to draw the
fuel by suction.
40. What can be the disadvantage in the fuel system if there is an IDG oil cooler in the fuel bypass

return line?
a. The hot bypass fuel reduces the efficiency of the engine oil cooler.
b. The IDG oil cooler needs too much fuel for its operation therefore the engine speed decreases.
c. The IDG oil cannot be cooled sufficiently at a high power setting when all fuel is needed for
combustion.

41.
a.
b.
c.
d.

What is a shroud?
a shroud is an extra strong pipe wall of a high pressure fuel line.
A shroud is a pipe, which forms a sealed ring space around an inner pipe.
A shroud is a protective silicone coating on a high pressure fuel line.
A shroud is a second outer pipe wall which improve the strength of the primary inner pipe
wall.

42. Where can you find a flow divider valve in an engine fuel system?

a. On engines with duplex fuel nozzles inside each nozzle.
b. Only on engines with 2 fuel manifolds.
c. On all engines with airspray nozzles.
d. Only on modern turbofan engines.


43. What is the name and the task of the highlighted fuel line in the engine fuel system?

a. It is the fuel bypass return line. It returns the fuel that is not needed for combustion to the
tank.
b. It is the fuel bypass return line. It returns the fuel that is not needed for
combustion to the fuel pump.
c. It is the fuel bypass return line. It returns the fuel to the oil cooler if it is too cold for
combustion.
d. It is the fuel recirculation line. It recirculates the fuel back to the tank if it is too hot for

combustion.
44. What is the main difference between plunger type fuel pumps and gear type fuel pumps?

a. Plunger type pumps can also be used to meter the fuel, but they cannot supply high fuel
pressures.
b. Gear type pumps can supply higher fuel pressures than plunger type pumps.
c. Gear type pumps can also be used to meter the fuel, but plunger type pumps can supply
higher fuel pressures.
d. Plunger type pumps can also be used to meter the fuel and they can supply higher
fuel pressures.
45. What is a wash screen in the fuel system?

a. It is a filter element, that can be washed out during engine maintenance.
b. It is a very fine filter screen for the servo fuel flow that is continuously cleaned by
the main fuel flow.
c. It is a screen which washes away the particles that are caught in the main filter element.
d. It is a screen that can be used to wash high pressure filter elements.
46. Which type of fuel nozzle is always a single flow nozzle?

a. Airspray nozzles are always single flow nozzles.
b. Fuel spray nozzles are always single flow nozzles.
c. The duplex nozzle is a single flow nozzle.


47. Where do you find shrouds in the fuel system of modern engines?

a. All fuel lines of the engine fuel system are shrouded lines.
b. The fuel supply line between the tank and the low pressure fuel pump is usually a shrouded
line.
c. Only the fuel line couplings of the high pressure fuel system are usually shrouded.

48.
a.
b.
c.

Where do you think the FCU gets the actual N2 from?
From the N2 speed indicator in the cookpit.
Form the mechanical drive of the FCU via the accessory gearbox.
From the N2 speed sensor on the engine.

49. What happens to the engine if too much fuel is suddenly supplied to the combustion chamber
a.
b.
c.
d.

for acceleration?
The engine can overboost.
The engine gets into a dangerous overtemperature condition.
The high pressure compressor of the engine stalls.
The engine gets into an overspeed condition.

50.
a.
b.
c.
d.

Which signal uses the FCU to bring the engine back to the demanded speed?
The compressor inlet temperature signal CIT.

The compressor discharge pressure signal CDP.
The fan speed signal N1.
The core engine speed signal N2.

51. Can the engine always supply a constant thrust if the fan speed is kept constantly at 90%?
a. Yes, because the N1 is always in a fixed relation to the thrust of the engine.
b. No, because even with a constant speed the thrust changes if the ambient conditions

change.
c. No, because with 90% N1 the thrust in flight is much higher than on ground.
d. No, only if it is flat rated to 90%.
52. Which signals does the fuel control unit need for constant speed control?

a. N1 and N2 signals from engine.
b. N2 signal from the engine and N2 command signal from the cockpit.
c. N2, CIT and CDP signal from the engine.
d. N1 signal from the engine, N2 command signal from the cockpit and aircraft configuration
signals.
53. What is the difference between minimum idle and approach idle?
a. Approach idle speed is higher than minimum idle speed.


b. Minimum idle speed is higher than approach idle speed.
c. For approach idle the thrust lever must be pushed a little bit out of the idle position.
d. For approach idle the CIT signal is needed but not for minimum idle.
54. What happens to the N1 during the climb flight phase on a constant thrust controlled engine?

a. Nothing, the N1 remains constant until a new power setting is selected.
b. The N1 decreases because the density decreases.
c. The N1 increases because the density decreases.

d. The N1 increases because the density increases.
73.3
55.
a.
b.
c.

Which 1 of these examples has the highest fuel flow?
Condition A.
Condition B.
None, the 2 example have the same flow across the valve.

56.
a.
b.
c.
d.

Which signals are necessary for the density compensation?
CIT and CDP.
Ambient pressure and temperature.
CIT and N2.
Ambient temperature and CIT.

57. Which of the following parameters is usually kept constant for fuel metering?

a. The flow area of the fuel metering valve.
b. The pump supply pressure.
c. The differential pressure across the fuel metering valve.
d. The differential pressure across the bypass valve.

58. Which hydromechanical component converts a speed controlled fuel control unit into a thrust

controlled fuel control unit?
a. The density compensation.
b. The power management computer.
c. The torque moter at the fuel control unit.
59. Which input signals are needed by the limiting section of the fuel control unit?
a. CIT, CDP and N2.
b. CIT, CDP and N1.


c. CDP and CIT.
d. CIT, CDP, N1 and thrust lever angle (TLA).
60. What happens to the engine in this condition?

a. The engine continues to accelerate.
b. The engine keeps the selected speed.
c. The engine decelerates.
d. The engine shuts down.
73.4
61.
a.
b.
c.

What is the relation between aircraft speed and thrust?
At a given engine speed, the thrust decreases when the aircraft speed increases.
At a given engine speed, the thrust increases when the aircraft speed increases.
The thrust of the engine increases when the aircraft is faster than mach 1.

62.
a.
b.
c.

How can this overspeed governor reduce the fuel flow?
It closes the fuel metering valve.
It closes the HP shut-off valve.
It opens the bypass valve.

63. What happens first if the N2 rotor reaches an overspeed condition?
a. The ECU tries to close the fuel metering valve by changing the signal to the torque

motor.
b. The ECU opens the bypass valve to reduce the fuel flow across the fuel metering valve.
c. The overspeed governor opens the bypass valve to reduce the fuel flow across the fuel
metering valve.
d. The pilot receives an overspeed warning and has to select a lower power setting to decrease
the N2.
64.
a.
b.
c.

Where does the ECU get its second power supply from?
From an internal battery in the ECU.
From the integrated drive generators (ISD) on the engine.
From permanent magnet alternator at the engine accessory gearbox.

65. What is the difference between an ECU and an EIU?

a. There is no difference in function. ECU and EIU are just different names for the same
component.
b. The EIU controls the engine and the ECU performs the fuel metering.
c. There are 2 EIUs on an aircraft but only 1 ECU because the ECU has 2 channels.


d. The ECU controls the engine and the EIU is used on some aircraft as an interface
between aircraft and engine.
66. What is the purpose of the flyweight governor in this HMU?

a. The governor is used to control the fuel metering valve.
b. The governor is used as an overspeed protection.
c. The governor is used to control the N2 speed of the engine.
d. The governor is necessary for engine starting until the PMA supplies sufficient power for
the ECU.
67. Which adjustments are necessary after replacement of a fuel metering unit (FMU) on a

FADEC controlled engine?
a. Idle adjustment and part power adjustment.
b. Idle adjustment only.
c. Gravity adjustment only.
d. No adjustments are necessary.
68. When does the ECU use the power supply from the aircraft?

a. Always during normal engine operation because this is the normal power supply for the
ECU.
b. The ECU uses the power supply from the aircraft when the PMA fails and at the
beginning of the engine start.
c. The ECU uses the power supply from the aircraft only in flight if the PMA fails.

d. The ECU uses the power supply from the aircraft only if it is ised for maintenance tests on
ground.
69. Most engine sensors have 2 signal lines, 1 for each channel in the ECU. Why is there only 1

signal line from the pressure sensor Po, Ps12 and Ps3?
a. Because the pressure signals are less important for engine control.
b. Because the ECU of 1 engine can use the respective pressure signals of the other engines on
the aircraft.
c. Because the 2 channels receive the pressure signals from pressure transducers in


the ECU.
d. Because the ECU calculates the Ps12 and Ps3 based on the Po and the engine speed N2.
70. What is the purpose of the thrust rating plug in the FADEC system?

a. From the thrust rating plug the ECU gets the maximum permissible rotor speed of the
engine.
b. The rating plug limits the throttle movement in the forward direction.
c. From the rating plug the ECU gets the maximum permissible operating hours from the
engine.
d. From the rating plug the ECU gets the maximum T/O thrust information for the
engine.
ATA 74
74.1
71.
a.
b.
c.

In what condition is continuous igition necessary?

In cold temperatures.
At high altitudes.
In heavy snow or rain.

72.
a.
b.
c.
d.

Which of these situations can active the ignition?
Engine anti-ice system is switched on.
Maximum engine thrust selected.
Outside air temperature below 0 degree celsius.
Windshield wiper switched on.

73. Is it safe for you to touch the output of an ignition exciter 10 minutes after switching off the

system?
a. Yes, I can be sure that there is no longer any voltage at the output.
b. Yes, even if there is a voltage at the output, with no input power this is not dangerous.
c. No, even after hours there can be a dangerous voltage at the output.
74. Which of the following statements about an ignition system is correct?

a. The ignition system must be switched on all the time to keep the engine running.
b. The ignition system is only switched on during engine start.
c. The ignition system must always be switched on manually.
d. The ignition system is used for engine start and for continuous ignition.

75. Which of the following statements about an ignition exciter is correct?

a. The ignition exciter mainly has a transformer that generates an outout voltage of about
2000 V AC.
b. The ignition exciter has capacitors that can store a very high electrical energy for
a long time.
c. The output voltage is always 0 volts when you switch off the input voltage.
76. Which statement is correct about the highlighted area of the plug connector?

a. This is an electrical contact that is always connected to ground.
b. This is part of the connector insulation.
c. This contact gives the electrical energy to the plug. You can touch it when the system is
switched off.
d. This contact gives the electrical energy to the plug. You must never touch it even
when the system is off.
77. What statement is correct about the 2 igniter plugs you can find on each engine?

a. Each plug has its own ignition exciter and 1 or 2 plugs work at a time dependent
on the mode of operation.
b. Both plugs are supplied from the same ignition exciter and always work at the same time.
c. Each plug has its own ignition exciter, but both plugs always work at the same time.
d. Both plugs are supplied from 1 ignition exciter. The second box becomes active when the
first box fails.
74.2
78.
a.
b.
c.
d.

What does starter duty time mean?
The time given to a starter that is fitted to a engine before it is replace.
The total number of operating hours that a starter is permitted to remain in service.
The number of subsequent engine starts a starter is permitted to perform.
The time that a starter can continuously operate before it must be stopped in order
for it to cool down.

79. Which component of the start system is activated by the engine master switch during engine

start?
a. The pneumatic starter motor.
b. The clutch in the pneumatic starter motor.


c. The N2 rotor shaft.
d. The starter shut-off valve.
80. Where do you usually find the starter valve on a turbofan engine?

a. Always in the 6 o’clock position at the transfer gearbox.
b. In the lower area of the engine so that it is easily accessible on ground.
c. In the engine pylon at the beginning of the starter duct.
81. What is the meaning of the term “Starter cool down time”?

a. This term describes the time that a starter can operate continuously before it must be
stopped to cool it down.
b. This term describes the time that a starter must cool down after operation before
it can be used again.
c. This term describes the number of subsequent start sequences that a starter is permitted to
do.
d. This term describes the time that it takes to cool the starter down to ambient temperature

after operation.
74.3
82. What do you think, is the difference between wet and dry motoring?
a. Wet motoring means that the fuel tanks are filled. For dry motoring the fuel tanks are empty.
b. Wet motoring: Fuel will be sprayed into the combustion chamber. Dry motoring: No

fuel is used.
c. Wet motoring: You spart water into the engine inlet to clean the compressor. Dry motoring:
No water is used.
83.
a.
b.
c.

What is the motoring speed?
The motoring speed is the idle speed of the engine.
The motoring speed is the maximum speed before starter cut-out.
The motoring speed is the maximum speed that occurs without light up of the

engine.
d. The motoring speed is the maximum speed allowed during engine motoring.
84.
a.
b.
c.
d.

What do you think is necessary before the next start attempt?
The ECU must switch to star mode with reduce fuel flow.
The ECU makes a dry motoring.

The ECU checks the fuel for water contamination.
You open the engine cowlings to repair the ignition system.


85. Have you can see the the indications and switch positions during a maintenance action. Find
a.
b.
c.
d.

out what action it is.
Dry motoring.
Engine manual start.
Wet motoring.
An auto start.

86. Have you see the cockpit indications during a manual start. What must you do when you see

these cockpit indications?

a. Nothing, because the engine start will be monitored by the ECU.
b. You must abort the start sequence by moving the mode selector to normal, because the engine

could overheat.
c. Set the engine master switch to off. This closes the starter valve and prevents an overheat of
the engine.
d. You must abort the start sequence by moving the engine master switch to off.
ATA 75
75.1 air systems overview
87.

a.
b.
c.
d.

How many stages with variable stator vanes has this this engine?
Two HP compressor stages have variable stator vanes.
Three HP compressor stages have variable stator vanes.
Four HP compressor stages have variable stator vanes.
All 9 HP compressor stages have variable stator vanes.

88.
a.
b.
c.

What is meant by the term “ Tip clearance”?
The tip clearance is the distamce between the root and the tip of a rotor blade.
The tip clearance is the distance between 2 rotor blades measured at the tip of the blades.
The tip clearance is the distance between a rotor blade and a stator vane measured at the tip

of the blades.
d. The tip clearance is the gap between the tip of a rotor blade and the inner wall of the
stator case.
89. What is the purpose of the variable bleed valves system?

a. It controls cooling air from the LP compressor into the core compartment.
b. It protects the LP compressor against stall and surge.
c. It protects the HP compressor against stall and surge.
d. It controls cooling air from the LP compressor into the fan compartment.

90. What is the difference between a turbine clearance control system and a compressor

clearance control system?
a. Turbine clearance control is either active or passive, but compressor clearance control is
always passive.
b. Turbine clearance control uses HPC bleed air, but compressor clearance control uses fan
air.
c. Turbine clearance control uses air for cooling, but compressor clearance control
uses air for heating.
d. Turbine clearance control is always passive, but compressor clearance control is active or
passive.
91. Which air is usually used for cooling of the engine core compartment?

a. Ram air.
b. Fan air.
c. LPC bleed air.
d. HPC bleed air.
75.2 compressor control system
92.
a.
b.
c.
d.

Which component is used as the control unit for compressor control on a FADEC engine?
The hydromechanical unit (HMU).
The engine interface unit (EIU).
The engine control unit (ECU) or electronic engine control (EEC).

The power management computer (PMC).

93.
a.
b.
c.
d.

In which positions are the VSVs and VBVs on an engine that is not running?
The VSVs are in closed and the VBVs are in open.
The VSVs are in open and the VBVs are in closed.
The VSVs and the VBVs are in open.
The VSVs and VBVs are in closed.

94. When does this HP bleed valve close?
a. It closes when the Ps3 pressure becomes stronger than the spring force.
b. It closes when the pressure at the compressor stage no.5 becomes stronger than the

spring force.

c. It closes when the engine is not running.
d. It cannot close, because of the vent hole in the valve plate.


95. How are the VSVs usually actuated?

a. By individual torque motors on each variable stator vane.
b. By 2 hydraulic actuators. VSVs on the left by the LH actuator and VSVs on the right by the
RH actuator.
c. By 1 or 2 hydraulic actuators that are supplied by engine driven hydraulic pumps.

d. By 1 or 2 hydraulic actuators driven by high pressure fuel from the engine fuel
system.
96. Which statement is correct about this engine without a FADEC system? When the engine is

not running…
a. … the VSVs are open and the VBVs are closed.
b. … the VSVs are closed and the VBVs are open.
c. … the VSVs and the VBVs are closed.
d. … the VSVs and the VBVs are open.
97. Which signals are necessary for this main engine control to control the VSVs and VBS?

a. The N2, the CIT and the VSV and VBV feedback signals.
b. The N2, the CIT, the CDP and the VSV and VBV feedback signals.
c. The CIT, the CDP and the VSV and VBV feedback signals.
d. The N2 and the VSV and VBV feedback signals.
98. How are the HP compressor bleed valves usually actuated?

a. By fuel pressure from the HMU.
b. By hydraulic pressure from the engine drive hydraulic pumps.
c. By internal springs.
d. By air pressure from the aft stages of the HPC.
99. The CIT sensor is also called T25 sensor. Where is this CIT sensor usually located on an

engine?
a. The CIT sensor is usually installed in the engine intake in front of the fan.
b. The CIT sensor is usually installed in the fan frame in front of the HP compressor.


c. The CIT sensor is usually installed in the fan exhaust duct behind the variable bleed valves.
d. The CIT sensor is usually installed in the fan frame in front of the LP compressor.

75.3 clearance control
100.
For which operating condition is a clearance control system most effective?
a. Idle power operation.
b. Take-off power operation.
c. Climb and cruise power operation.
d. Descent and approach.
101.

What is the difference between a turbine clearance control system and a compressor

clearance control system?
a. Turbine clearance control is always a passive system, but compressor clearance control is an
active system.
b. Turbine clearance control cools the cases, but compressor clearance control heats
the rotor.
c. Turbine clearance control heats the cases, but compressor clearance control cools the rotor.
d. Turbine clearance control always uses fan air, but compressor clearance control uses HPC
bleed air.
102.

Which of these turbines has an active clearance control system?

a. The HP turbine only.
b. The LP turbine only.
c. The HP turbine and the LP turbine.
103.

Which signals are minimum to activate an active clearance control system during

cruise?
a. The flight altitude and the turbine case temperature.
b. The rotor speeds N1 and N2.
c. The flight altitude and the rotor speed N2.
d. The turbine case temperature, the turbine case diameter and the rotor size.
104.

How are clearance control valves usually operated?

a. By air pressure from the HP turbine.
b. By fuel pressure from the HMU.


c. By electric actuators and gear drives.
d. By air pressure from the LP compressor.
75.4 cooling system
105.
Which air do you think is used for external cooling of the fan compartment?
a. Fan air.
b. Ambient ram air.
c. Discharge air form the LP compressor.
106.
Which critical situation can happen to the engine during cooling after it is shut down?
a. The thermal stress between the upper and lower parts of the engine cases can become too

high.
b. The rotors can contact the engine cases because the engine bends due to the
temperature difference.
c. Warm air can cause a fire because it can enter the pylon area.
d. The engine cooling process is too slow because the warm air cannot escape fast enough.

107.

Which air is usually used as sealing air for the bearing compartments?

a. Fan air.
b. LPC discharge air.
c. HPC discharge air.
d. HPC intermediate pressure.
108.

When can the engine get to a bowed rotor condition?

a. During operation when the cooling airflow for the core compartment is not sufficient.
b. During operation when the cooling airflow for the core and for the fan compartment is not
sufficient.
c. After engine shut-down when the cooling airflow for the core and for the fan compartment
is not sufficient.
d. After engine shut-down when the lower half of the engine becomes colder than the
upper half.
ATA76
76.1
109.

Which component on this engine start system is mechanically controlled?

a. The LP fuel valve.
b. The HP fuel shut-off valve.


c. The igniter plugs.

d. The metering valve in the fuel control unit.
110.

What is controlled by the highlighted engine control lever?

a. The rotational speed of the engine.
b. The rotational reverse speed of the engine.
c. The activation of the thrust reverser and the rotational speed of the engine.
d. The activation of the thrust reverser.
The engine is not running. What happens to the servovable if you pull the highlighted

111.

circuit breaker of the engine start system?
a. Nothing.
b. The solenoid of the servovable is de-energized and the pressurizing valve opens.
c. The solenoid of the servovable is energized and the pressurizing valve opens.
d. The solenoid of the servovable is de-energized but the pressurizing valve remains
closed.
76.2
112.
What happens to the thrust lever if the pilots hands are removed?
a. The levers move to the IDLE position.
b. The levers move to the TAKE-OFF (fail-safe) position.
c. The levers remain in the selected position.
113.

What kind if transmission system is used on this fuel control unit?

a. A mechanical rack and pinion transmission.

b. A mechanical crank lever transmission.
c. An electrical motor driven worm gear transmission.
114.

What is the purpose of a friction brake in the engine control system?

a. It prevents very rapid throttle movements.
b. It stops the movement of the control system when the autothrottle servo motor is active.
c. It removes the internal friction in the mechanical transmission system.
d. It makes sure that the throttle remains in the selected position when the pilot
takes his hand off.


115.

Where do you normally find the mechanical components for the lever lock function of

the engine control system?
a. On the throttle levers at the control stand.
b. At the thrust control drum in the engine pylon area.
c. At the fuel control unit on the engine.
d. In the autothrottle servo mechanism.
116.

What is the purpose of the throttle interlock mechanism in the engine control system?

a. It makes sure that the forward thrust and the reverse thrust lever can not be activated at
the same time.
b. It locks the power lever on the fuel control unit when the reverser is fully deployed.
c. It locks the reverse thrust lever in reverse idle until the reverser is fully deployed.

d. It locks the forward and reverser thrust levers in idle if the autothrottle computer is
switched on.
76.3
117.
a.
b.
c.
d.

What happens to the power lever if you operate the forward thrust lever and the

reverse thrust lever at the same time?
The reverse thrust signal overrides the forward thrust signal and the engine stops.
The reverse thrust signal opposes the forward thrust signal.
Nothing, because the forward thrust signal always has priority over the reverse thrust signal.
The engine will accelerate because both signals will add up.

118.
The friction brake…
a. …stops the thrust levers if the system fails due to an autothrottle runaway.
b. …removes the friction from the mechanical thrust control system.
c. …blocks the thrust levers so that only the autothrottle servo can move them.
d. …makes sure that the thrust levers remain in any selected position.
119.

Where do you usually find throttle interlock actuators on electrically controlled

aircraft?
a. Nowhere. There are no throttle interlocks on electrically controlled aircraft.
b. At the thrust reverser feedback mechanism in the engine pylon area.

c. Below the center pedestal in the mechanical section of the engine controls.
d. At the HMU on the engine.


120.

What is the purpose of the 2 resolvers in the throttle control unit shown on this

graphic?
a. The resolvers activate the thrust reversers. There is 1 resolver for each engine.
b. The resolvers convert the thrust lever deflection into signals for the ECU – 1
resolver for each channel.
c. The resolvers convert the thrust lever deflection into signals for the ECU – 1 resolver for
each engine.
d. The resolvers activate the thrust reversers. There is 1 resolver for each channel.
ATA 77
77.1
121.
Which of these statements is correct about the use of analog and digital indications.
a. Analog indications allow minitoring of trends and digital indications give you exact

values.
b. With digital indications you can easily monitor increasing and decreasing data.
c. With analog indications you can easily read exact values.
122.
Which parameter is used to set the engine thrust on this aircraft?
a. EPR.
b. N1.
c. EGT.
d. N2.

123.

Which indication is used to set engine thrust in this example?

a. EPR.
b. N1.
c. N2.
d. EGT.
124.

Which statement is correct about engine trend monitoring?

a. It gives an indication to the pilot about the trend of the engine speed and temperature.
b. It shows the pilot the trends for the engine performance.
c. It analyzes engine data on the ground to detect engine parameters that indicate a
trend towards a limit.
d. It only analyzes engine data in order to show when the engine has to be changed.
77.2


125.
What is the value of N1 for engine number 2 shown here?
a. About 100%, an exact value is ont readable on the analog indication.
b. 95.8%
c. 96.1%
d. 99.9%
126.
Which rotor speed is measured on the gearbox of the engine shown here?
a. The N2 rotor speed.
b. The N1 rotor speed.

c. N1 or N2 depending on the engine speed.
d. N1 and N2.
127.
What do you think is the main advantage of this type of rotor speed indication?
a. The rotor speed indication is very precise.
b. This indication system does not need any power supply.
c. Information from the indication is also useful for engine trend monitoring.
128.
What happens when the actual N1 exceeds this red line limit?
a. The turbine inlet temperature become too high.
b. The pressure in the compressor becomes too high.
c. The centrifugal forces that act on the rotor system become too high.
d. The engine shuts down automatically.
129.

How does this type of speed sensor work?

a. The phonic wheel changes the magnetic field of the variable reluctance speed
sensor.
b. The compressor shaft drives the tachometer generator, which generates a voltage
proportional to the speed.
c. The phonic wheel moves a coil inside the variable reluctance speed sensor, which generates
a voltage.
d. The phonic wheel reflects light which is sent by the speed sensor.
130.

How does the tachometer generator operate?

a. It generates an AC which has a voltage that is proportional to the input speed.
b. It generates an AC which has a frequency that is proportional to the input speed.

c. It generates a DC which has a voltage that is proportional to the input speed.
d. It generates pulses with a pulse rate that is proportional to the input speed.