TECHGEN-BNC-MODULE2

TECHGEN-BNC-MODULE2

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

a) Physical/chemical (glycol-based liquid).
b) Thermal (use of hot air).
c) Mechanical (pneumatic source which acts by deforming the profiles of the leading edge).
d) Electrical (electrical resistances).

2. During fuelling the automatic fuelling shut off valves will switch off the fuel supply system when:

a) the fuel has reached a predetermined volume or mass.
b) there is fire.
c) the surge vent tank is filled.
d) fuelling system has reached a certain pressure.

3. The main purpose of a Constant Speed Drive unit is to:

a) mechanically protect the alternator drive shaft during coupling.
b) take part in the balancing of reactive loads.
c) take part in the voltage regulation.
d) maintain a constant frequency.

4. When air is compressed for pressurization purposes, the percentage oxygen content is:

a) unaffected.
b) dependent on the degree of pressurisation.
c) decreased.
d) increased.

5. In order to produce an alternating voltage of 400 Hz, the number of pair of poles required in an AC generator running at 6000 rpm is:

a) 4
b) 12
c) 8
d) 24

6. On most modern airliners the cabin pressure is controlled by regulating the:

a) Airflow entering the cabin.
b) RPM of the engine.
c) Airflow leaving the cabin.
d) Bleed air valve.

7. The cabin rate of descent:

a) is always the same as the airplane's rate of descent.
b) results in a cabin pressure increase.
c) results in a cabin pressure decrease.
d) is not possible at constant airplane altitudes.

8. The purpose of the barometric correction in a fuel controller is to:

a) reduce the fuel to air mass ratio when the altitude increases.
b) maintain a constant fuel flow whatever the altitude is.
c) maintain the correct fuel to air mass ratio when the altitude increases.
d) increase the fuel to air mass ratio when the altitude increases.

9. If the maximum operating altitude of an airplane is limited by the pressurized cabin, this limitation is due to the maximum:

a) Negative cabin differential pressure at maximum operating ceiling.
b) Positive cabin differential pressure at maximum cabin altitude.
c) Negative differential pressure at maximum cabin altitude.
d) Positive cabin differential pressure at maximum operating ceiling.

10. The turbine in a cold air unit (air cycle machine):

a) drives the compressor in the unit and causes a pressure increase in the conditioning air.
b) drives the compressor in the unit, creating a temperature drop in the conditioning air.
c) increases the pressure of the air supply to the cabin.
d) drives the compressor which provides pressurisation.

11. In a cabin air conditioning system, equipped with a bootstrap, the mass air flow is routed via the:

a) secondary heat exchanger outlet to the compressor inlet of the cold air unit.
b) turbine outlet of the cold air unit to the primary heat exchanger inlet.
c) compressor outlet of the cold air unit to the primary heat exchanger inlet.
d) secondary heat exchanger outlet to the turbine inlet of the cold air unit.

12. A turbo-fan cold air unit will:

a) not affect the charge air pressure.
b) increase charge air pressure whilst causing the temperature to drop in the heat exchanger.
c) cause a pressure drop as well as an associated temperature drop in the charge air.
d) decrease charge air pressure whilst causing the temperature to rise in the heat exchanger.

13. The cabin heating supply in a heavy jet transport aircraft is obtained from:

a) hot air coming from the engine's compressors.
b) an electrical heater system.
c) a fuel heater system.
d) hot air coming from the engine's turbines.

14. In a bootstrap cooling system the supply air is first:

a) passed across an expansion turbine, then compressed and passed through a heat exchanger.
b) compressed, then passed across an expansion turbine and finally across a heat exchanger.
c) compressed, then goes through a heat exchanger, and across an expansion turbine.
d) passed across an expansion turbine, then directly to the heat exchanger.

15. Concerning electrically powered ice protection devices, the only true statement is:

a) on modern aeroplanes, electrically powered thermal devices are used as de-icing devices for pitot-tubes, static ports, windshield...
b) on modern aeroplanes, electrically powered thermal devices are very efficient, therefore they only need little energy.
c) on modern aeroplanes, electrically powered thermal devices are used to prevent icing on small surfaces (pitot-static, windshield...).
d) on modern aeroplanes, electrical power supply being available in excess, this system is very often used for large surfaces de-icing.

16. Cabin altitude means the:

a) cabin pressure expressed as altitude.
b) flight level the aircraft is flying at.
c) flight level altitude at maximum differential pressure.
d) difference in height between the cabin floor and ceiling.

17. Cabin air for modern aircraft is usually taken from:

a) the second fan stage.
b) the low pressure compressor.
c) the high pressure compressor.
d) the low pressure compressor and from the high pressure compressor if necessary.

18. The automatic fuelling shut off valve:

a) cuts off the fuel in case of engine fire.
b) stops fuelling as soon as the fuel spills into the vent line.
c) stops fuelling as soon as a certain fuel level is reached inside the tank.
d) stops fuelling as soon as a certain pressure is reached.

19. Cabin air for a large airplane, during flight:

a) has an increased oxygen ratio.
b) has a constant oxygen ratio regulated to a preset value.
c) has a reduced oxygen ratio.
d) is temperature controlled.

20. When the AC generators are connected in parallel, the reactive loads are balanced by means of the:

a) energizing current.
b) frequency.
c) torque of the Constant Speed Drive (CSD).
d) voltage.

21. If one of the 12 cells of a lead-acid battery is dead, the battery:

a) is unserviceable.
b) has 1/12 less voltage, but can still be used.
c) has 1/12 less voltage and less capacity, but can still be used.
d) has 1/12 less capacity, but can still be used.

22. The elements specifically protected against icing on transport aircraft are: 1) engine air intake and pod. 2) front glass shield. 3) radome. 4) pitot tubes and waste water exhaust masts. 5) leading edge of wing. 6) cabin windows. 7) trailing edge of wings. 8) electronic equipment compartment. The combination regrouping all the correct statements is:

a) 1, 2, 3, 8
b) 1, 2, 5, 6
c) 1, 4, 5, 7
d) 1, 2, 4, 5

23. The "cabin differential pressure" is:

a) the pressure differential between the air entering and leaving the cabin.
b) cabin pressure minus ambient pressure.
c) approximately 5 psi at maximum.
d) approximately 15 psi at maximum.

24. In a fuel system, the oil to fuel heat exchanger allows:

a) fuel cooling so as to prevent vapour creation likely to unprime nozzles.
b) jet engine oil cooling through thermal exchange with fuel flowing from tanks.
c) automatic fuel heating by the engine oil so as to prevent icing in fuel filter.
d) fuel heating as required whenever fuel filter clogging is detected.

25. The fuel supply system on a jet engine includes a fuel heating device, upstream of the main fuel filter so as to:

a) prevent, at low fuel temperature, the risk of ice formation from water contained in the fuel.
b) prevent fuel from freezing in fuel pipes due to low temperatures at high altitude.
c) maintain and improve fuel heating power.
d) ease low pressure pumps work by increasing fuel fluidity.

26. In an aircraft air conditioning system the air cannot be treated for:

a) purity.
b) temperature.
c) pressure.
d) humidity.

27. A static inverter is a:

a) filter against radio interference.
b) device for reversing the polarity of the static charge.
c) static discharger.
d) transistorized unit used to convert DC into AC.

28. On a modern large pressurized transport aircraft, the maximum cabin differential pressure is approximately:

a) 13 - 15 psi
b) 7 - 9 psi
c) 22 psi
d) 3 - 5 psi

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

a) mechanically driven by the engine's accessory gearbox.
b) centrifugal pumps, driven by an electric motor.
c) electro-mechanical wobble pumps, with self-regulated pressure.
d) removable only after the associated tank has been emptied.

30. The pack cooling fan provides:

a) air to the eyeball outlets at the Passenger Service Unit (PSU).
b) cooling air to the pre-cooler.
c) cooling air to the primary and secondary heat exchanger during cruise.
d) cooling air to the primary and secondary heat exchanger during slow flight and ground operation.

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

a) Water.
b) Freon.
c) CO2.
d) Powder.

32. On modern transport aircraft, cockpit windows are protected against icing by:

a) Electric heating.
b) Rain repellent system.
c) Anti-icing fluid.
d) Vinyl coating.

33. In large modern aircraft, in the air conditioning system, reduction of air temperature and pressure is achieved by:

a) a compressor.
b) an evaporator.
c) an expansion turbine.
d) a condenser.

34. In a compressor stage of a jet engine, the sequence is:

a) rotor - rotor - stator
b) stator - stator - rotor
c) stator - rotor
d) rotor - stator

35. What is the purpose of the pack cooling fans in the air conditioning system?

a) Supplying the heat exchangers with cooling air during cruise flight.
b) Supplying the heat exchangers with cooling air during slow flights and ground operation.
c) Supplying the Passenger Service Unit (PSU) with fresh air.
d) Cooling of the APU compartment.

36. The pressure usually produced by the Boost Pumps (BP) of the fuel supply system of a large jet transport airplane is within the following range:

a) 5 to 10 psi
b) 20 to 50 psi
c) 3000 to 5000 psi
d) 300 to 500 psi

37. On a jet aircraft fuel heaters are:

a) Located on the engines.
b) Installed in each tank.
c) not necessary at all.
d) Installed only in the centre tank.

38. The maximum differential pressure of a transonic transport category airplane is approximately:

a) 9.0 psi
b) 13.5 psi
c) 3.5 psi
d) 15.5 psi

39. In a generator, the Constant Speed Drive (CSD): 1- may be disconnected from the engine shaft. 2- may be disconnected from the generator. 3- is a hydro-mechanical system. 4- is an electronic system. 5- may not be disconnected in flight. 6- may be disconnected in flight. The combination regrouping all the correct statements is:

a) 1, 3, 6
b) 1, 2, 5
c) 1, 4, 5
d) 2, 3, 4

40. The term "bootstrap", when used to identify a cabin air conditioning and pressurisation system, refers to the:

a) source of the charge air.
b) cold air unit (air cycle machine) arrangement.
c) means by which pressurisation is controlled.
d) charge air across the inter-cooler heat exchanger.

41. Generally, for large aeroplanes, electrical heating for ice protection is used on:

a) Fin leading edges.
b) Elevator leading edges.
c) Slat leading edges.
d) Pitot tubes.

42. Engine bleed air used for air conditioning and pressurization in turbo-jet aeroplanes is usually taken from the:

a) compressor section.
b) by-pass ducting.
c) fan section.
d) turbine section.

43. In flight, the cabin air for modern airplanes with jet engines is usually supplied by:

a) ram air intakes.
b) single radial compressors.
c) piston compressors.
d) engine compressors.

44. On most transport jet aircraft, the low pressure pumps of the fuel system are supplied with electric power of the following type:

a) 28 V AC
b) 28 V DC
c) 115 V DC
d) 115 V AC

45. The fuel cross-feed system:

a) is only used to feed an engine from the tank of the opposite wing.
b) allows feeding of any engine from any fuel tank.
c) is only used on the ground for fuel transfer from one tank to another.
d) is only used in flight for fuel transfer from one tank to another.

46. (For this question use annex 021-980A) The diagram shown in annex represents a jet fuel system. The fuel-flow measurement is carried out:

a) after high pressure pump first stage (item 2).
b) after low pressure valve (item 1).
c) after high pressure valve (item 4).
d) in the fuel control unit (item 3).

47. With regard to the pneumatic mechanical devices which afford protection against the formation of ice, the only correct statement is:

a) The inflatable de-ice boots of the pneumatic mechanical device are arranged perpendicular to the leading edges.
b) The pneumatic mechanical device can only be used as an anti-icing device.
c) The pneumatic mechanical device is used a lot on modern aircraft as it is inexpensive and easy to maintain.
d) The pneumatic mechanical device can only be used as a de-icing device.

48. The pneumatic ice protection system is mainly used for:

a) pitot tubes.
b) engine intakes.
c) wings.
d) propellers.

49. The heating facility for the windshield of an aircraft is:

a) Only used when hot-air demisting is insufficient.
b) Harmful to the integrity of the windows in the event of a bird strike.
c) Used only at low altitudes where there is a risk of ice formation.
d) Used on a continual basis as it reduces the thermal gradients which adversely affect the useful life of the components.

50. In a "bootstrap" cooling system, the charge air is first compressed in the cold air unit to:

a) ensure an adequate pressure and temperature drop across the cooling turbine.
b) increase the cabin air supply pressure when the charge pressure is too low.
c) maintain a constant cabin mass air flow.
d) ensure an adequate charge air flow across the inter-cooler heat exchanger.

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