AIRCRAFT GENERAL KNOWLEDGE

C. A. T
APRIL 2020.
PPL
1. The term “Bootstrap” when used to identify a cabin air conditioning and
pressurization system refers to the:

A. Cold air unit (air cycle machine) arrangement.

B. Source of the charge air.
C. Change air across the inter- cooled heat exchanger.
D. Means by which pressurization is controlled.

2. With regard to an aircraft structure, what is “fail safe”?

A. One in which the load is carried by other components if a part of structure fails.
B. Easily manufactured.
C. Only used for a limited time.
D. One which takes precedence over all other parts.

3. What is the purpose of an elevator trim tab?

A. Adjust the speed tail load for different airspeeds in flight allowing neutral
control.
B. Provide horizontal balance as airspeed is increased to enable hands-off flight.
C. Modify the downward tail load for various airspeeds in flight eliminating flight
control pressures.

4. The cross-feed fuel system enables:

A. Supply jet engine outboard tanks first.

B. The supply of the jet engines mounted on a wing from any fuel tank within that
wing.
C. The supply of any jet engine from any fuel tank.
D. Only the transfer from the centre tank to the wing tip tanks

5. In a fire detection system with a single loop continuous components ( with no fault
protection), if the inner core contacts the outer casing:

A. There will be no effect on the system.

B. The fire alarm is triggered .
C. The main engine fire extinguisher is automatically activated.
D. The power supply is cut off automatically.
6. The component that transforms the hydraulic pressure into linear motion is
called:

A. A pressure regulator.
B. A hydraulic pump.
C. An actuator.
D. An accumulator.

7. Assuming cabin differential pressure has attained the required value in flight
Conditions, if the flight altitude is maintained:

A. A constant mass airflow is permitted through the cabin.

B. The outflow valves will move to the fully open position.
C. The pressurization system ceases to function until leakage reduces the
pressure.
D. The outflow valves will move to the fully closed position.

8. A smoke mask is a:

A. Mask with flow on request and covers only the nose and the mouth.
B. Mask with flow on request and covers the whole face.
C. Continuous flow mask and covers the whole face.
D. Continuous flow mask and only covers the nose and mouth.

9. What is the purpose of stringers?

A. Withstand the shear stresses.

B. Provide thermal and sound isolation.
C. Assist the skin in absorbing the longitudinal traction-compression stresses.
D. Integrate the strains due to pressurization to which the skin is subjected and
convert them into a tensile stress.

10. In a hydraulic system, the reservoir is pressurized in order to:

A. Provide a positive fluid pressure at the pump inlet.

B. Prevent air bubbles forming at high altitudes.
C. All the above.

11. In the pneumatic supply system of a modern transport aircraft, the air pressure is
regulated. This pressure regulation occurs just before the manifold by the:

A. Fan bleed air valve.

B. High pressure bleed air valve.
C. Low pressure bleed air valve.
D. Intermediate pressure check-valve.
12. The cabin rate of descent is:

A. Always the same as the airplane’s rate of descent.

B. Not possible at constant airplane altitudes.
C. A cabin pressure decrease.
D. A cabin pressure increase.

13. On most transport aircraft, the low pressure pumps of the fuel system are:

A. Piston pumps.
B. Gear type pumps.
C. Diaphragm pumps.
D. Centrifugal pumps.

14. On a transport type aircraft the fuel tank system is vented through:

A. A pressure regulator in the wing tip.

B. Bleed air from the engines.
C. Ram air scoops on the underside of the wing.
D. The return lines of the fuel pumps.

15. In a steep turn to the left, when using the spoilers:

A. The right aileron will ascend, the left one will descend, the right spoiler will
retract and the left one will extend.
B. The right aileron will descend, left will ascend, right spoiler will retract and the
left spoiler will extend.
C. The right aileron will descend, left will ascend, right spoiler will extend as the
left spoiler retracts.
D. The right aileron will ascend, left aileron will descend, right spoiler will extend
as the left spoiler retracts.

16. A non-cantilever wing is:

A. A low wing configuration.

B. A high wing configuration.
C. A wing platform other than rectangular.
D. A wing supported by braces or a strut connected to the fuselage.

17. Thermal plugs are installed in:

A. Wheel rims.
B. Fire warning systems.
C. Cabin windows.
D. Cargo compartments.
18. If the pressure in the cabin tends to become lower tan the OAT the:

A. Air cycle machine will stop.

B. Outflow valve open completely.
C. Negative PRV will open.
D. Negative PRV will close.

19. What is the purpose of an anti-servo tab?

A. Reduce control forces by deflecting in the proper direction to move a primary

flight control.
B. Prevents a control surface from moving to a full deflection position due to
Aerodynamic forces.
C. Move the flight controls in the event of manual reversion.

20. In addition to energy storage, the accumulator of the hydraulic system is used:

A. For fluid storage.

B. For damping pressure surges in the system.
C. As a PRV.
D. For pressure storage.

21. The pneumatic system is useful:

A. To eliminate the fluid pressure variations.

B. To eliminate the fluid flow variations.
C. In emergency cases.
D. To offset for the starting of some devices.

22. The octane rating of a fuel characterizes the:

A. Fuel volatility.
B. Fuel electrical conductivity.
C. Quantity of heat generated by its combustion.
D. The anti-knock capability.

23. A gaseous sensor/ responder tube fire is tested by:

A. Checking the sensor with pressurized gas.

B. Checking the wiring harness for faults but not the sensor.
C. Checking continuity of the system with a test switch.
D. Heating up the sensor with the test power connection.

24. The trim tab:

A. Increases hinge moment and control surface efficiency.
B. Reduces hinge moment and increases control surface efficiency.
 C. Increases hinge moment and reduces control surface efficiency.
D. Reduces hinge moment and control surface efficiency.

25. A torsion link assembly is installed on the landing gear to:

A. Absorb the spring tension.

B. Control the wheels.
C. Lock the landing gear.
D. Avoid rotation of the piston rod relative to the gear oleo strut.

26. Generally, on modern jet transport aircraft, how can the landing gearbe
extended if there is a complete hydraulic system failure.
A. Mechanically
B. Electrically.
C. Pneumatically.
D. By hydraulic accumulators.

27. Pneumatic mechanical ice protection system are mainly used for:

A. Windscreens
B. Propellers.
C. Wings.
D. Pitot tubes

28. The type of brake unit found on most transport aeroplanes is a:

A. Single disk brake.

B. Drum type disk brake.
C. Belt brake.
D. Multiple disk brake.

29. In flight, the most commonly used anti-icing method for the wings of modern
commercial aircraft fitted with turbo-jet units is:

A. Thermal (use of hot air).

B. Physical/chemical (glycol-based liquid).
C. Electrical (electrical resistances).
D. Mechanical (pneumatic source which acts by deforming the profiles of
the leading edge).

30. The most common extinguishing agent used in gas turbine engine fire
protection system is:

A. Water.
B. Freon.
C. Carbon Dioxide.
 D. Powder.

31. Hydraulic fluids must have the following characteristics:

1. thermal stability
2. low emulsifying characteristics
3. corrosion resistant
4. good resistance to combustion
5. high compressibility
6. high volatility
7. high viscosity
The combination regrouping all the correct statements is:

A. 1, 2, 3, 4
B. 1, 2, 5, 7
C. 2, 3, 4, 5
D. 1, 3, 4, 6

32. In a hydraulic braking system, an accumulator is pre-charged to 1200 psi.

An electrically driven hydraulic pump is started and provides a system
pressure of 3000 psi.
The hydraulic pressure gauge which is connected to the gas section of the
accumulator, reads:

A. 4200 psi
B. 1200 psi
C. 3000 psi
D. 1800 psi
33. When a part of a continuous loop fire detection system is heated:
1. Its resistance decreases.
2. Its resistance increases.
3. The leakage current increases.
4. The leakage current decreases.
The combination regrouping all the correct statements is:
A. 1, 3
B. 2, 3
C. 1, 4
D.2, 4

34. Hydraulic fluids used in systems of large modern airliners are:

A. Water base fluids.
B. Phosphate ester base fluids.
C. Vegetable base fluids.
D. Mineral base fluids.

35. Regarding fire detection, Ion detectors are used to detect:

 A. Fire.
B. Over temperature.
C. Over temperature and fire.
D. Smoke.
36. The purpose of the cabin pressure controller, in the automatic mode, is to
perform the following functions:
1. control of cabin altitude,
2. control of cabin altitude rate-of-change,
3. limitation of differential pressure
4. balancing aircraft altitude with cabin altitude
5. cabin ventilation
6. keeping a constant differential pressure throughout all the flight phases.
The combination regrouping all the correct statements is:
A. 4,5,3
B. 1,2,3
C. 5,6,1
D. 2,6,4
37. The purpose of the cabin pressure controller, in the automatic mode, is to
perform the following functions:
1. control of cabin altitude,
2. control of cabin altitude rate-of-change,
3. limitation of differential pressure
4. balancing aircraft altitude with cabin altitude
5. cabin ventilation
6. keeping a constant differential pressure throughout all the flight phases.
The combination regrouping all the correct statements is:
A. 1,2,3
B. 2,6,4
C. 4,5,3
D. 5,6,1
38. When a landing gear wheel is hydroplaning, its friction factor is equal to:
A. 0.1
B. 1
C. 0
D. 0.5
39. The colour of fresh synthetic hydraulic fluid is:
A. Pink.
B. Purple.
C. Red.
D. Blue.
40. Under normal conditions the cabin pressure altitude is not allowed to
exceed:
A. 10,000 ft
B. 8,000ft
C. 6,000ft
D. 4,000ft