Gas Turbine Engines

GAS TURBINE ENGINES

FUNDAMENTALS (1)

1. An example of a divergent duct is the....jet pipe at the exit from the turbine

2. A turbo-prop engine derives its thrust from...reaction of the prop-wash

3. On an axial flow, dual compressor forward fan engine, the fan turns the same speed as the....low pressure turbine

4. Jet nozzle is located...at the exhaust

5. Axial flow turbojet engine highest gas pressure occurs at...compressor outlet

6. If LP shaft shears....turbine runaway occurs

7. Density of gas....weight/volume

8. Heat and mechanical energy are mutually convertible and 1 CHU is equal to....1400ft/lbs

9. Turbojet engine gives....large acceleration to a small mass of air

10. ESHP....shaft horsepower + exhaust efflux

11. Engine most likely to have noise suppressor installed....turbojet

12. In a dual axial flow or twin spool compressor system with a free power turbine, Nf would indicate...free power turbine speed

13. The noise suppression system that increases the frequency of sound is termed....multi-lobe type nozzle

14. The accessory gearbox of a high bypass engine is....on the HP compressor housing

15. The purpose of a diffuser is to....increase the static pressure of the air

16. A gas turbine engine comprises 3 main sections....turbine, compressor and combustion

17. The hottest casing is the….HPT

18. Which has the better combination....centrifugal compressor, axial flow turbine, can type combustion chamber

19. Statement that is true for a high bypass ratio turbofan....the compressor assembly is larger and combustion chamber smaller than their turbojet equivalent

20. A waisted drive shaft is primarily to....provide a fuse if the driven component is overloaded

21. A turbojet engine is smoother running that a piston engine because....it has no reciprocating parts

22. Section that provides proper mixing of fuel and efficient burning of the gasses.....combustion section only

23. Unit generally used to measure aircraft noise....effective perceived noise decibels (EPNdB)

24. Core engine or gas generator made up of following components....turbine, combustion chamber, compressor

25. There is no peak pressure in a jet engine because of....continuous flow of air

26. A nozzle is choked when the gas flow through it is....sonic

27. A high bypass engine results in....overall slower airflow and greater propulsive efficiency

28. In a free turbine....there is no mechanical connection with the compressor

29. The advantage of a geared, fan type, dual spool engine is....a geared fan does not need a separate turbine to have a different speed from the compressor and the compressor is not limited to the fan speed

30. If a volume of a mass of air is 546 cubic feet at 273K, at 273K it will be....2 cubic feet greater

31. In a pure jet engine, the rate of pressure rise is greatest at the....compressor stage

32. Ram effect is....conversion of kinetic energy to pressure energy at the face of the compressor

33. Example of a divergent duct....jet pipe at the exit from the exhaust

34. Part of the jet engine has the most potential energy....just before the combustion chamber

ENGINE PERFORMANCE (2)

1. At constant RPM, the pressure ratio of the compressor and the temp rise across the compressor....remains constant irrespective of height

2. Method of comparing engine efficiencies is by comparing....specific fuel consumption

3. Engine section that will produce the most amount of discrete noise....turbine

4. Gas pressure is greatest at the....compressor outlet

5. Thrust rating on a FADEC engine can be changed by....changing the engine rating plug

6. The RPM for max power would be....lower on a colder day

7. As the speed of an aircraft increases, the momentum thrust of an engine will....decrease (momentum thrust is a product of the difference between aircraft speed and the jet efflux speed)

8. Specific fuel consumption for a turbo prop engine....decreases with increase in aircraft speed

9. Reduction in engine efficiency can be caused by....ice formation on air intake

10. Power is adjusted in a gas turbine engine by....increasing air and fuel flow

11. Ram recovery is the point at which intake....total pressure equals ambient pressure

12. The point of maximum velocity in the engine is in the....exhaust exit nozzle

13. Through turbine rotor blades, the pressure....decreases, temp and velocity decreases

14. To maintain the selected RPM of a gas turbine at altitude....the pilot will have to throttle back

15. Ultimate limiting factor of turbine engine operation....turbine inlet temp

16. Ram effect due to aircraft forward speed will cause the thrust of the engine to....remain constant

17. Increasing ram effect with increased speed....increases thrust due to increased maximum airflow

18. Temperature of the mass airflow through a gas turbine engine....increases from the inlet, thru the compressor and the diffuser into the burner and decreases thru the turbine into the exhaust

19. Most engines try to keep a uniform...flame temp

20. If the throttle position remains constant...with increasing OAT, RPM and TGT will increase

21. What happens to thrust as an aircraft climbs with a fixed throttle position....thrust decreases

22. Compressor type that gives the greatest advantage for both starting flexibility and improved high altitude performance....split spool, axial flow

23. Some turbo prop and turbojet engines are equipped with two spool or split compressors. When these engines are operated at high altitudes, the....low pressure rotor will increase in speed as the compressor load decreases in the lower density air

24. Effect of high atmospheric humidity have on the operation of a jet engine....has little or no effect

25. The engine rating plug is.....permanently connected to the engine casing

26. Ram recovery is a measure of....intake efficiency

27. The speed of the low pressure compressor increases as the inlet temp becomes colder because...the fuel controller senses the decreased T2 and schedules an increase in fuel flow to maintain the proper fuel air ratio with the denser air

28. Flat rated thrust is defined as....the thrust at the ambient temperature point above which thrust drops below 100%

29. With an increase in forward speed, the engine thrust...decreases slightly but recover due to ram effect

30. The propulsive efficiency is...high with a low mass flow acceleration

31. At constant RPM, the pressure ratio of the compressor and the temp rise across the compressor....remains constant irrespective of height

32. Across the turbines, there is....a general temp drop

33. Hottest component in a gas turbine engine is the....nozzle guide vanes

34. Statement that is true regarding jet engines....at higher engine speeds, thrust increases rapidly with small increases in RPM

35. Turbine inlet temp is approx....850-1700 degrees celcius

36. What effect does high atmospheric humidity have on the operation of a jet engine....has little or no effect

37. Ram pressure recovery will generally take effect at aircraft speeds of....Mach 0.1-0.2

38. Factor that limits EGT is the....turbine

39. The highest heat to metal contact in a jet engine is....the turbine inlet guide vanes

40. To ensure an engine maintains self sustaining speed....idle increases with density decrease

41. The main factor considered when designing an engine is....maximum turbine temp

INLET (3)

1. Intakes are designed to…decelerate the free air stream flow

2. The inlet door of a variable geometry intake at supersonic speeds will be…closed

3. The inlet door of a variable geometry intake is open at…subsonic speeds

4. A variable geometry intake at subsonic speeds…throat area is increased

5. The purpose of a bellmouth compressor inlet is to…maximize the aerodynamic efficiency of the inlet

6. What is true for a bellmouth intake (is a convergent duct)…velocity increases and pressure decreases

7. An increase in the Ram Ratio of an intake will…increase the temp of the air

8. Intake momentum drag causes…a decrease in thrust at low airspeeds

9. In a variable geometry intake, the velocity of the air on the engine compressor face is controlled by…shock-wave pattern, ramp and spill doors

10. In a subsonic multi-engine aircraft, a normal inlet duct will…increase in size front to rear along the length of the duct

11. With an electrical ice protection system, the heating elements operate…part continuous-part intermittent

12. A bellmouth compressor inlet is used on…helicopters

13. Variable Ramp Intakes restrict airflow by…creating shock-waves in the intake

14. The most efficient engine intake on subsonic or low supersonic aircraft is…pitot

15. A turboprop engine inlet anti-ice system operates….continuously

16. An aircraft flying at supersonic speed, to reduce the air velocity at the compressor, the variable intake….throat area is decreased

17. The cycling speed of the electrical de-icing mat….is affected by weather conditions

18. Ram Ratio in regard to air intakes is the relationship between….ambient pressure and compressor inlet pressure

19. Vortex dissipaters prevent engine FOD by…a stream of engine bleed air blown toward the ground ahead of the engine

20. Pitot type intakes are used in…subsonic aircraft

21. As an aircraft approaches the transonic range, the aerodynamic efficiency of a pitot type intake….decreases due to the shock wave

22. Electrical de-icing operates….continuously and intermittently

23. A well designed intake will take advantage of forward speed by…converting kinetic energy into pressure energy

24. The variable inlet guide vanes are operated….by fuel pressure

25. If an inlet is choked then the velocity….decreases and pressure increases

COMPRESSORS (4)

1. In a turbine engine with a dual spool compressor, the low speed compressor….seeks its own best operating speed

2. In flight, failure of compressor bleed valve (jammed open) will make engine run at….lower RPM than normal

3. In a dual compressor, the low pressure compressor (LPC) speed tends to change with….the CIT of LPC

4. On which blade type may a mid-span shroud most likely be used….long, narrow chord type blades

5. Advantage of centrifugal flow compressor is its high….pressure rise per stage

6. 2 types of centrifugal compressor impellers are….single entry and double entry

7. Pressure rise across a single spool axial flow compressor is in the order of….up to 15:1

8. During low RPM range, variable intake guide vanes and bleed valves area at….maximum swirl position and bleed valves open

9. Advantage of a multi-spool compressor is….quicker acceleration and better control of stall characteristics

10. Engine bleed at high speed is….sometimes open

11. Centrifugal compressor produces a compression ratio….lower than the axial flow compressor

12. Why in an axial flow compressor is the cross sectional area of the compressor air duct reduced at each stage….to maintain the velocity of the air under rising pressure

13. On a high bypass ratio engine, what medium operates the VBV….fuel pressure

14. Abradable lining around the fan is to….strengthen the EPR value

15. Compressor surge is caused by….over fuelling

16. Purpose of stator blades in the compressor section….control the direction of the airflow

17. Inlet guide vanes are fitted to….control the angle of airflow into the compressor

18. Type of combustion chamber is most suited for centrifugal compressors….multiple-can type

19. Surge margin of an axial flow compressors….the margin between the compressor working line and the surge line

20. A bleed valve….relieves compressor choking at low RPM

21. What is the function of the stator vane assembly at the discharge end of a typical axial flow compressor….to straighten airflow to eliminate turbulence

22. Which of the following can cause fan blade shingling in a turbofan engine….large, rapid throttle movements and FOD

23. Advantage of an axial flow over a centrifugal flow gas turbine engine….high peak efficiencies

24. What is the profile of a compressor blade….a cut out that reduces blade tip thickness

25. How does a dual axial flow compressor improve the efficiency of a turbojet engine….higher compression ratios can be obtained

26. The stator vanes in an axial-flow compressor….convert velocity energy into pressure energy

27. A function of a cascade vanes in a turbojet engine compressor section….to remove air swirl before the combustion chamber

28. Stall will occur in the high pressure stages of an axial flow compressor because….air mass flow is reduced when the compressor is turning at high speed

29. Purpose of bleed valve, located at the beginning stages of the compressor is to….vent some of the air overboard to prevent a compressor stall

30. No damage is permissible on….a shroud-fillet area

31. Air thru the compressor, before entering the combustion chamber passes….thru divergent passage to increase the pressure

32. Purpose of rotating guide vanes on a centrifugal compressor is to….direct the air smoothly into the impeller

33. Variable inlet guide vanes prevent….compressor stalling

34. The diffuser after the compressor, before the combustion chamber….decreases velocity, pressure increases

35. Cascade vanes in the intake of a centrifugal compressor are to….provide a pre-swirl to incoming air

36. A function of the cascade vane in a turbojet engine compressor section….to remove air swirl before the combustion chamber

37. Purpose of the diffuser vanes of a centrifugal compressor serve….to convert kinetic energy into pressure energy

38. An axial flow compressor surges when….all stages are stalled

39. Phase of engine operation will bleed valves be fully open….rapid deceleration

40. Compressor stage….one rotor plus one stator

41. Tip speed of a centrifugal compressor can reach….Mach 1.2 / 1.3

42. An axial flow compressor compresses the air by….diffusion

43. ‘Cascade Effect’ is related to….axial flow compressors

44. What is the normal pressure rise across each compressor stage of an axial flow compressor….1.2:1

45. Diffuser vanes are used in jet engines to convert….kinetic energy into potential energy thru divergence

46. Stator vanes in an axial-flow compressor….convert velocity energy into pressure energy

47. A compressor stage stalls when….smooth airflow is disrupted

48. Purpose of a counter-rotating spool in some dual or triple-spool compressors is….dampening gyroscopic effects

49. The optimum air speed for entrance into the compressor is approx….Mach 0.4

50. The effect of different stages in an axial flow compressor is….to multiply the pressure by each succeeding stage

51. An axial compressor case annulus is….convergent

52. 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

53. Compressor stalls may be eliminated by using which of the following systems….compressor bleed-air system and variable vane system

54. The fan speed of a twin spool axial compressor engine is the same as the….low pressure compressor

55. The vanes of a diffuser in a centrifugal compressor….are tangential to the impeller

56. Primary factor which controls the pressure ratio of an axial flow compressor….number of stages in compressor

57. The compression ratio of an axial flow compressor is a function of….number of compressor stages

58. What units in a gas turbine engine aid in guiding the airflow during low thrust engine operations….inlet guide vanes

59. For any given power lever setting, the speed of the high pressure compressor is held constant by….the fuel control governor

60. Compressor stall is caused by….a high angle of attack airflow thru the first stages of compression

61. Energy changes that take place in the impeller of a centrifugal compressor are….pressure increase, velocity increase, temp increase

62. Compressor blades reduce in length….from LP to HP section to maintain uniform velocity in compressor

63. A bypass engine LP compressor….supplies more air than is required for combustion

64. Severe rubbing of turbine engine compressor blades will usually cause….galling

65. Stagger angle is used on the compressor blades to….maintain exit velocity of airflow at the same value along blade length

66. An axial compressor case annulus is….convergent (all axial flow compressor case annulus are convergent to maintain a constant axial velocity thru the compressor)

67. In an axial flow compressor is the cross sectional area of the compressor air duct reduced at each stage….to maintain the velocity of the air under rising pressure

68. The root of the compressor blades are loosely fitted to the compressor disks. This is because….it aids easy blade assembly and it provides a vibration damping effect

COMBUSTION SECTION (5)

1. A tubo-annular gas turbine combustion system consists of….a number of flame tubes in an annular air casing

2. Dilution air is placed….in the dilution zone of the combustion chamber after the primary zone

3. Why is it necessary to have a combustion chamber drain….to allow unburnt fuel to drain away….to prevent initial over-fuelling on start-up or hot start

4. A torodial vortex is….a region in the combustion chamber of low velocity recirculation

5. The main purpose of combustion is to….increase gas velocity

6. What is a cannular combustion system….a set of flame tubes, enclosed in a common air casing

7. Another name for a cannular combustion chamber is….can-annular

8. Duplex burners have….two calibrated outlets…one for low speed, second for high speed

9. Combustion sections used in turbine engines….multiple can, annular and can annular

10. Component that creates a vortex in a gas turbine flame tube….swirl vanes

11. In a turbo prop engine, combustion takes place at constant….pressure

12. Air thru the combustion chamber retains a constant….pressure

13. Percentage mass airflow taken by flame tube snout….18%

14. Percentage mass airflow which bypasses the flame tube snout….82%

15. A combustion chamber has a….divergent inlet, convergent outlet

16. The purpose of the nose or snout in a combustion chamber….to act as a diffuser to slow the airflow down

17. Combustion chamber drain valve closed….by combustion chamber gas pressure

18. Combustor air that is not used to support combustion….will film cool the liner and dilute combustion chamber exit temp

19. Air used for combustion is….primary

20. Overall air/fuel ration of a combustion chamber can vary between….45:1 and 130:1

21. Air passing thru the combustion section of a jet engine is….most used for cooling

22. In the combustion chamber….static pressure decreases slighty and volume increases

23. Flame stabilization in a combustion chamber is achieved by….the airflow pattern

24. At high rotational speed at sea level, a duple burner would be passing fuel via the….primary and the main nozzle

25. When light-up takes place….interconnectors spread the heat to adjacent flame tubes

26. Combustion liner walls cooled in a gas turbine engine….by secondary air flowing thru the combustion chamber

27. In an annular combustor (thru flow)….it requires less cooling air due to its minimal surface area

28. Fuel entering the combustion chamber from an atomizer spray nozzle enters as….a fuel/air mixture

29. A duplex burner uses….small burner at low rpm and both burners at high rpm

30. Component that creates a vortex in a gas turbine flame tube….swirl vanes

31. Hot spots in the combustion section of a turbojet engine are possibly due to….malfunctioning fuel nozzles

32. A shroud placed around fuel nozzles….prevents carbon build up

33. In which type of turbine engine combustion chamber is the case and liner removed and installed as one unit during routine maintenance….annular

34. Purpose of swirl vanes in the combustion chamber is to produce….gas re-circulation

TURBINE (6)

1. Turbine disks are attached to the shat in a gas turbine engine....bolted

2. Impulse-reaction turbine blades form....tip half reaction, root half impulse

3. Material used for LPT shaft in modern turbofan engines....Marage-250

4. Impulse blades operate cooler than reaction blades because....the airflow has a higher velocity thru an impulse turbine NGV

5. A nozzle guide vane is....hollow in construction to allow for flow of cooling air

6. Hot section inspections for many turbine engines are required....on a time cycle basis

7. The turbine section....converts dynamic pressure into mechanical energy

8. As hot gasses flow thru an impulse turbine blading, the velocity....remains constant

9. An impulse turbine blade arrangement forms....constant passage

10. A slow constant growth in a turbine blade is known as....secondary creep

11. The passage between adjacent nozzle guide vanes forms....convergent duct

12. Turbine engine components are never manufactured by....gas welding

13. Impulse turbine blades run cooler than reaction blades because....temperature drop across NGV is greater

14. Fir tree turbine blade attachment locates the blade....allows slight movement

15. Stress rupture cracks usually appear on turbine blades at....across he leading or trailing edge at the right angle to the edge

16. What is meant by a shrouded turbine....the turbine blades are shaped so that their ends forma a band or shroud

17. ‘hot streaking’ is caused by....a partially clogged fuel nozzle

18. Creep of turbine blades is....due to thermal and centrifugal forces

19. Nozzle guide vanes are fitted to....increase velocity of gas flow

20. Temperature thru the turbine stages generally....decreases

21. As the hot gasses flow thru an impulse turbine blading, the velocity....remains constant

22. Nozzle guide vane bow is an indication of....engine overheat

23. Turbine nozzle diaphragms located on the upstream side of each turbine wheel are used....to increase the velocity of the heated gasses flowing past this point

24. Alloys used for gas turbine nozzles are....inconel, nimonic and GMR-235

25. Turbine disk growth is due to.... a permanent change in disk diameter

26. Dirt particles in the air going into the compressor of a turbine engine will form a coating on all except the....turbine blades

27. How is a radial turbine driven....by change of momentum and angle of airflow

28. The forces driving a turbine round are due to....impulse and reaction

EXHAUST (7)

1. The jet pipe of a gas turbine engine….protects the airframe from heat damage

2. Lobe type exhaust noise suppressors are made from…heat resistant alloy

3. A supersonic duct is…convergent then divergent along its length

4. When should thrust reversers be used…low RPM and low forward speed

5. The purpose of a propelling nozzle (convergence) is to…increase the velocity of the air and increase thrust

6. If the exit area of the nozzle is too large, the effect is….exit velocity lower causing loss of thrust

7. As air flows out at the outflow of a choked nozzle….velocity increases and pressure decreases (convergent duct-exhaust)

8. Exhaust noise can be reduced by….increasing the mixing rate

9. A convergent exhaust nozzle produces mainly….momentum thrust

10. To have minimum friction in the jet pipe, it should be….long and small diameter

11. A convergent-divergent nozzle….makes maximum use of pressure thrust

12. The purpose of a propelling nozzle of a gas turbine engine is designed….to increase the velocity and decrease the pressure of the gas stream leaving the nozzle (increase thrust)

13. The exhaust section is designed to….impart a high exit velocity to the exhaust gasses

14. The struts on the exhaust cone….supports the exhaust cone and straighten the gas airflow

15. On front fan engines, to obtain thrust reversal…cold stream is reversed

16. Reverse thrust can only be selected when the throttle is….closed

17. Thrust reversers utilizing pneumatics actuating system receives operating pressure from….engine bleed air system

18. An exhaust cone placed aft of the turbine in a jet engine will cause the pressure in the first part of the exhaust duct to….increase and velocity to decrease

19. The function of the exhaust cone assy of a turbine engine is to….straighten and collect the exhaust gasses into a solid exhaust jet

20. Hot spots on the tail cone of a turbine engine are possible indicators of a malfunctioning fuel nozzle or….a faulty combustion chamber

21. A nozzle is ‘choked’ when the engine inlet airflow is….subsonic and supersonic

22. What is the proper operating sequence of using thrust reversers…..retard thrust levers to grd idle, select reverse thrust, then advance power levers as required, and then retard thrust reverser levers to grd idle

23. Noise from a jet wake when untreated by suppression is…low freq, high decibel

24. A choked nozzle…increases thrust

BEARINGS AND SEALS (8)

1. A carbon seal has which type of sealing arrangement....full contact with race

2. Some labyrinth seals...control the outflow of air at the turbine (can be air seals or oil seals)

3. An abradable lining in the fan case...provides acoustic medium

4. Why are oil seals pressurized...to ensure minimum oil loss

5. The highest turbine bearing temp takes place...at shut-down

6. Seals on gas turbine engine restrict leakage of oil by...air pressure

7. What is the purpose of pressure balance seal...to ensure the location bearing is adequately loaded throughout the engine thrust range

8. The function of labyrinth seals is to create...a restricted leakage of air between fixed and rotating components

9. If ball or roller bearings found with magnetism...degaussed before use

10. Main bearing oil seals used with turbine engines are usually...labyrinth and/or carbon

11. The bearings of a compressor rotor are usually….ball and roller

12. In a jet engine, the rotating assembly oil seals are maintained oil tight by means of...air pressure

13. Which of the following is true about ball and roller bearings...a ball bearing has less friction than any other type

LUBRICANTS AND FUELS (9)

1. Advantage of mineral base lube over vegetable based lube…chemical stability

2. Desirable characteristics of turbine engine oil…high flash point

3. Reid Vapour pressure…38 degrees Celsius

4. Factors that determines the proper grade of oil to use in a particular engine…operating speeds of bearings

5. High tooth pressures and high rubbing velocities in spur type gears require the use of…an EP lubricant

6. The result of operating an engine in extremely high temp using lubricant meant for much lower temp…oil pressure will be lower than normal

7. Upon what quality or characteristics of a lubricating oil is its viscosity index based…its rate of change in viscosity with temp change

8. The specific gravity of fuel affects…aircraft range

9. In addition to lubricating, engine oil…cools, seals, prevents corrosion and cushions shock loads

10. Calorific value is the…amount of heat or energy in 1 pound of fuel

11. Compared to reciprocating engine oils, the types of oils used in turbine engines…have less tendency to produce lacquer or coke

12. DERD 2494…kerosene

13. Types of water present in aviation fuel are…free and entrained both harmful

14. Ignition of fuel depends on…both volatility and atomisation

LUBRICATION SYSTEM (10)

1. The purpose of a pressure filter in a lubrication system is to….protect the oil jets

2. In a jet engine which uses a fuel oil heat exchanger, the oil temp is controlled by a thermostatic valve that regulates the flow of….oil thru the heat exchanger

3. The oil dampened main bearing utilized in some turbine engines is used to….provide an oil film between the outer race and the bearing housing in order to reduce vibration tendencies in the rotor system, and to allow for slight misalignment

4. Oil pressure and scavenge pumps are usually….spur gear pumps

5. What will happen to the return oil if the oil line between the scavenger pump and the oil cooler separates….the return oil will be pumped overboard

6. Oil pressure in the cooler is….higher than the fuel pressure

7. The possible cause when a turbine engine indicates no change in power settings parameters, but oil temp is high….engine main bearing distress

8. At cruise RPM, some oil will flow thru the relief valve of a gear type engine oil pump. This is normal as the relief valve is set at a pressure which is….lower than the pressure pump capabilities

9. The possible combined output from all the scavenge pumps in a lubrication system will be….greater than the pressure pump output

10. ‘Last chance’ filters in a lubrication system are serviced during….engine overhaul

11. What is the primary purpose of the hopper located in the oil supply tank of some dry sump engine installations….to reduce the time required to warm the oil to operating temp

12. Primary purpose of the oil breather pressurization system that is used on turbine engines….provides a proper oil spray pattern from the main bearing oil jets

13. A thread type oil seal in a lubrication system….has a thread on a stationary portion to prevent fluid leaks

14. What would be the probable result if the oil system pressure relief valve should stick in the open position on a turbine engine….insufficient lubrication

15. What determines the minimum particle size which will be excluded or filtered by a cuno type filter….the spacer thickness

16. In order to relieve excessive pump pressure in an engine’s internal oil system, most engines are equipped with a….relief valve

17. Manufacturers normally require turbine engine oil servicing within a short time after engine shut down primarily to….prevent over servicing

18. When rotating, the gerotor type oil pump….draws oil into the pump and carries it round between the gear teeth and idler

19. What filters are used to protect oil pressure spray jets….in-line thread filters

20. Low oil pressure can be detrimental to the internal engine components. however high oil pressure….should be limited to the engine manufacturer’s recommendation

21. What is the purpose of the last chance filters….to prevent damage to the oil spray nozzle

22. A turbine engine dry sump lubrication system of the self contained, high pressure design….consists of pressure, breather and scavenge subsystems

23. A full flow oil system has….a variable oil pressure dependant upon throttle setting

24. When rotating, the gear type oil pump….draws oil into the pump and carries it round between the gear teeth and casing

25. What is the primary purpose of the oil breather pressurization system that is used on turbine engines….provides a proper oil spray pattern from the main bearing oil jets

26. The air-cooled-oil-cooler has an anti-surge valve in order to….protect the cooler

27. A vane type oil pump output is controlled by….outlet pressure against spring pressure

28. Possible failure related ferrous metal particles in turbine engine oil causes an electrical indicating type magnetic chip detector to indicate their presence by….bridging the gap between the detector centre (positive) electrode and the ground electrode

29. The teeth of the gears in the accessory section of an engine normally lubricated by….splashed or sprayed oil

30. Type of oil system is usually found on turbine engines….dry sump, pressure and spray

31. A jet engine gear box breather is prevented from leaking oil to atmosphere by the action of….impeller and centrifugal force

32. Type of oil pumps most commonly used on turbine engines are….positive displacement

33. A scavenge filter is incorporated in a gas turbine lubrication system to….protect the pressure pump

34. The identification of a lubrication fluid line is the word ‘lubrication’….followed by squares

35. After making a welded repair to a pressurized type turbine engine oil tank, the tank should be pressure checked to….not less than 5psi plus the maximum operating pressure of the tank

36. Oil pressure in the cooler is….higher than the fuel pressure

37. Typical operating pressure of an oil pump in a a gas turbine lubrication system….30psi

38. What is the cause of high oil temp….a blocked pressure filter

39. Oil system generally used on most modern turboprop engines is….dry sump type

40. A spur gear pump operating in a lubrication system promotes….high flow at low pressure

41. The possible combined output from all the scavenge pumps in a lubrication system will be….greater than the pressure pump output

42. Sump pressure is maintained by the…breather system

FUEL (11)

1. What are float switches used for in the fuel system….to control refuel/defuel valves

2. To what condition does the fuel flow respond during aircraft acceleration….mass airflow rate thru the engine

3. An EEC is powered in flight by….N2 tachogenerator

4. To stabilize cams, springs and linkages within the fuel control, manufacturers generally recommend that all final turbine engine trim adjustments be made in the….increase direction

5. The maximum RPM of a turbine engine is limited by….reduction of the fuel pump stroke by a spill valve sensitive to centrifugally generated fuel pressure

6. Kinetic valves are used because….they are more sensitive

7. When a throttle is selected to increase power, the pressure drop across the Fuel Control Unit throttle orifice….drops then increases due to increasing pump output

8. During any stabilised running condition, the spill or half ball valve is….lightly seated

9. With a decrease in fuel SG, what is the result when the engine is fitted with an uncompensated fuel governor….maximum RPM increases

10. An increase in fuel S.G. will cause….a reduction in maximum RPM

11. What power supplies the EEC during normal operation….a dedicated generator

12. A FADEC system takes measurements from engine speed….temperature and pressure

13. If the knife-edge blade in a kinetic valve is fully in….servo pressure is being bled off

14. A fuel heater prevents….entrained water in fuel freezing

15. A fuel heater prevents….LP filter icing

16. In a FADEC system, how are the power supply windings for channel A and channel B wound….on one generator with 2 separate windings

17. Out of the following thrust lever resolver angles, which one is the forward idle setting….40 degrees

18. When the EEC supervisory circuit senses a fault on the engine, the fault annunciator light will be on and the EEC will….remove fuel, down trimming signal immediately

19. BPC controls the FCU by….pressure sensing

20. What is the primary purpose for trimming a turbine engine fuel control unit…to obtain maximum thrust output when desired

21. What would be the effect on the engine if the BPC half ball valve in the servo line sticks open….a reduction in fuel flow, therefore a decrease in RPM

22. A kinetic valve is a device used to control HP pump output. This is achieved by movement of a…..knife blade

23. Which of the following inputs does the fuel control system combine to operate a gas turbine engine….engine speed, altitude, exhaust temperature and throttle position

24. In a FADEC system, the signal to the HMC is the difference between….actual N1 and computed N1

25. Purpose of a fuel flow divider in a turbine engine duplex fuel nozzle….creates the primary and secondary fuel supplies

26. Purpose of the LP fuel pump is to….ensure the HP fuel pump does not cavitate

27. Purpose of a silver strip on a fuel filter….to detect sulphur in fuel

28. On approach….RPM should be above the minimum idle for maximum acceleration

29. Why is the high pressure fuel pump fitted in a gas turbine engine….to provide the majority of the fuel pressure to the engine

30. How is servo pressure, which is used to control fuel pump ‘swash plate’ angle obtained….from pump delivery pressure through a fixed restriction

31. During acceleration, the fuel flow is increased at a controlled rate in order to….prevent surge and the risk of flame-out

32. Where is the engine fuel shutoff valve usually located…downstream of the engine driven fuel pump

33. Why is it necessary to control fuel supply to the engine during rapid acceleration….to prevent excessively high EGT and possible compressor surge

34. What moves the swash plate away from the minimum stroke position….a spring

35. During aerobatic manoeuvres, what prevents fuel form spilling out of fuel tank vents….float operated valves

36. Which of the following influences the operation of an automatic fuel control unit on a turbojet engine….burner pressure

37. The basic concept of an HP fuel control is….constant adjustment of the swash plate angle of the HP fuel pump

38. A FADEC consists of….electronic controls (EEC), sensors and an HMU

39. During acceleration, the fuel flow is increased at a controlled rate in order to….prevent surge and the risk of flame out

40. A fuel trimmer unit is adjusted at altitude….automatically via a fuel trim unit

41. The fuel trimmer on a turbo-prop engine is operated….automatically controlled in conjunction with FCU

42. When considering a centrifugal type engine speed governor, n increase in fuel S.G. will cause….a reduction in maximum RPM

43. A barometric pressure controller controls….fuel flow to suit atmospheric pressure changes

44. The burner fuel flow is at a maximum at….I.S.A. sea level

45. What must be done after the FCU has been replaced…..retrim the engine

46. On an engine powered by a FADEC, each engine has….1 FADEC with one channel active and the other channel monitoring with its output drivers de-energised

47. The position of fuel heater in fuel system is….before the LP fuel filter

48. HMU receives signals form….EEC

49. The EEC receives its primary power from….separate permanent magnet alternator

50. In a FADEC system, what is the result of channel A failing to recive information from a sensor….channel A will take the info from channel B

51. Why is an ACU fitted to a gas turbine engine…..it limits the rate of increase in fuel flow during sudden acceleration

52. The swash plate in a fuel pump when static is….in the maximum position

53. When trimming a turbine engine, the fuel control is adjusted to….set idle RPM and maximum speed or EPR

54. In flight, the engine EEC controls….fuel flow

55. To prevent compressor surge and overheating of the combustion chamber due to over fuelling…..an acceleration control unit (ACU) is fitted

56. In a FADEC system, what determines which channel is in control….whichever is the best channel

57. What are the positions of the pressurization valve and the dump valve in a jet engine fuel system when the engine is shut down….pressurization valve closed, dump valve open

58. What would be the effect on the engine if the BPC half ball valve in the servo line sticks open….a reduction of fuel flow, therefore a decrease in RPM

59. Why is a hydro-mechanical governor fitted to a gas turbine engine fuel pump….to enable the engine to operate over a wide range of SGs

60. The density of air is very important when mixing fuel and air to obtain a correct fuel to air ratio. Which of the following weighs the most….100 parts of dry air

61. What causes the fuel divider valve to open in a turbine engine duplex fuel nozzle….fuel pressure

62. Baffles in a rigid fuel tank….prevents surge

63. Why is the barometric pressure controller (BPC) fitted in a turbo-shaft engine fuel system….to vary pressure pump output in relation to the pressure variation at the intake

64. Which valve ensures the adequate fuel flow….the fuel metering valve

65. Specific fuel consumption at altitude will….remain constant

66. If the swash plate of a positive displacement swash plate pump is perpendicular to the axis of the pump, the flow will be….zero

67. What are the principal advantages of the duplex fuel nozzle used in many turbine engines….provides better atomization and uniform flow pattern

68. After a bag tank replacement, where would you disconnect the system to carry out the flow checks….at the engine

69. What is the purpose of the attenuator fitted between the HP fuel pump and the BPC in a fuel system….it damps out pulsations in the fuel delivery to the BPC

70. Conditions when trimming of a turbine engine be most accurate….no wind and low moisture

71. Opening of fuel valve after shut down will cause….risk of fire in turbine

72. When a re-light is required in flight on a FADEC engine….igniter is selected automatically

AIR SYSTEMS (12)

1. Bleed air pressure and shut-off cock pressure is...200psi

2. Turbine case cooling utilizes...fan air

3. If air is taken from the compressor for air cond / anti-icing...thrust will decrease, EGT will increase

4. Engine anti-ice is taken from...HP compressor

5. In an axial flow turbine engine, compressor bleed air is sometimes used to aid in cooling the... turbine, vanes, blades and bearings

6. Air bleed for an anti-ice system is...sent through a pressure regulator

7. When electrical anti-icing is on...power decreases

8. Anti-ice bleed is controlled by...regulator valve

9. On a gas turbine engine, thermal wing de-icing system derives air...through a pressure regulating shut-off valve (PRSOV)

10. Inlet for cooling air for the 1st stage turbine blades are fed via the...blade root

STARTING AND IGNITION SYSTEMS (13)

1. In a gas turbine engine dc capacitor discharge ignition system, where are the high voltage pulses formed…at the triggering transformer

2. In the HEIU the choke….prolongs the discharge

3. A hot start is associated with….high EGT

4. A safety feature usually employed in pneumatic starters that is used to prevent the starter from reaching burst speed if inlet air does not terminate on schedule is the…..stator nozzle design that chokes airflow and stabilizes turbine wheel speed

5. Advantage of pneumatic starter over electric starters is….high power-to-weight ratio

6. An igniter plug for a large gas turbine takes the form of a….surface discharge plug

7. When removing turbine engine igniter plug, to eliminate possibility of receiving a lethal shock, the ignition switch is turned off and…..the transformer exciter input lead is disconnected and the centre electrode grounded to the engine after disconnecting the igniter lead from the plug and waiting the prescribed time

8. Pneumatic starters are usually designed with what types of airflow impingement systems….redial inward flow turbine and axial-flow turbine

9. Voltage at the igniter plug depends on….gap in the ignition system box

10. A starter has 2 hole to check the….level of oil

11. A glow plug may be used in place of a spark plug on….small engines

12. An electrical starter-generator is….series wound with high torque

13. On a gas turbine engine DC starting circuit, if there is an open circuit on the contact of the over speed relay….no supply is connected to the starter motor

14. To avoid lethal electric shock from ignition system, ground….the ignition lead

15. A ‘hot start’ with excessive temperatures may be caused by….throttle partly open

16. High energy ignition is required because of the….high flash point of the fuel

17. The resistor in a DC starter motor….prevents current surge when motor is at low rpm

18. Purpose of the current limiting resistor in a starter circuit….is to prevent an initial current surge

19. On a low energy dual ignition system (<3 joules), if a relight is necessary….pilot selects both igniters

20. Airflow to the pneumatic starter from a ground unit is normally prevented from causing starter overspeed during engine start by….activation of a flyweight cutout switch

21. A HEIU is rated in…joules

22. A DC starter motor disconnects due to….current decreasing switching off an overspeed relay

23. Why do turbine engine ignition systems require high energy….to ignite the fuel under conditions of high altitude and low temp

24. A clicking sound heard at engine coast-down in a pneumatic starter incorporating a sprag clutch ratchet assembly is a n indication of….the pawls re-contacting and riding on the ratchet gear

25. Air turbine starters are generally designed so that reduction gear distress or damage may be detected by….inspection of a magnetic chip detector

26. In the HEIU, the discharge resistors….allows the capacitors to discharge when the unit is switched off

27. When is ignition used….for relight and start up

28. Type used on turbine engine….capacitor discharge

29. A safety feature usually employed in pneumatic starters that is used if the clutch does not release from the engine drive at the proper time during start is the….drive shaft shear point

30. A dry motoring cycle would be required to….clear engine after a wet start

31. A glow plug….operates electrically….used on small engines

32. Caution when handling damaged hermetically sealed turbine igniter transformer because….some contain radioactive material

33. A HEIU works by….a discharging capacitor

34. When an engine being started by an air starter reaches self sustaining speed….the starter valve is disconnected by the fly weight cut-out switch in the starter

35. After an unsuccessful start of a n engine….unburnt fuel can be evacuated by motoring the engine with HP cock closed

36. Voltage at the igniter plug is….governed by the air gap in the HEIU box

37. In a gas turbine engine DC capacitor discharge ignition system where are the high voltage pulses formed….at the triggering transformer

38. The field of the DC starter motor used on gas turbine engine is….series or compound

39. The purpose of an under current relay in a starter-generator system is to….disconnect power from the starter-generator and ignition when sufficient engine speed is reached

40. In an electrical starting system, the slow start resistor is short circuited by the….time switch

41. First instrument indication of a successful start of a turbine engine….a rise in the exhaust gas temp

42. Inspection of pneumatic starters by maintenance technicians usually includes checking the….oil level and magnetic drain plug condition

43. Turbine blade is most commonly used in air starter motors….impulse

44. If the engine fails to light-up, the starter cycle is cancelled by….a time switch

ENGINE INDICATING SYSTEMS (14)

1. In what units are gas turbine engine tachometers calibrated….percent of engine RPM

2. Fuel flow is measured in…. lbs/hrs or kg/hrs

3. Instruments that measure relatively high fluid pressures, such as oil pressure gauges are usually what type….bourdon tube

4. A common type of electrically operated oil temp gauge utilizes….either a wheatstone bridge or ratiometer circuit

5. EGT indicator on a gas turbine engine provides a relative indication of the….turbine inlet temp

6. Engine pressure ration is the total pressure ratio between the…front of the compressor and the rear of the turbine

7. What happens when bulb type thermometer resistive element goes open circuit….reads more than ambient

8. In a thermocouple temp sensing system, what is the purpose of the compensating resistor….to correct for varying ambient temp at the cold junction

9. What power supply is required for a thermocouple system work….neither of the above

10. Thermocouple metals most frequently used are….constantan and copper

11. Regarding an engine EGT detection system, which of the following statements is true….chromel is positive and alumel is negative

12. How are EGT thermocouples connected….parallel

13. Motor driven impeller and turbine fuel flow transmitted are designed to transmit data….using aircraft electrical system power

14. Fuel flow indication is taken from….after either HP pump or LP pump

15. In a tachometer generator….frequency output is proportional to engine speed

16. A thermocouple indicator is basically a….milivoltmeter

17. Instruments that provide readings of low or negative pressure, such as manifold pressure gauges are usually….diaphragm and bellows type

18. The gauge on a bulb type temp indicator shows zero. This could be caused by….two cables shorting together by the sensor

19. What unit in a tachometer system sends information to the indicator….3 phase AC generator

20. In a multi-thermocouple loop, if one thermocouple goes open circuit, the indication…..will have no effect on temp indication

21. Vibration signals when picked up….the frequencies are filtered to exclude unwanted frequencies

22. A tachogenerator to indicate revs/min requires….no power

23. N2 is taken from….a tachometer on the accessory gearbox

24. A thermocouple indicator is connected to the….cold junction

25. EGT gauge indication….needs NO POWER, it is self generating

26. When testing an EGT system….the OAT is always taken into consideration

27. What instrument on a gas turbine engine should be monitored to minimize the possibility of a ‘Hot Start’….turbine inlet temp

28. The indication on a thermocouple-type EGT indicator is produced by….a current generated by the temp difference between dissimilar metal hot and cold junctions

29. On an aircraft turbine engine operating at a constant power, the application of engine anti-icing will result in….noticeable shift in EPR

30. What will the EPR reading be if the P1 sensor probe becomes blocked on take-off….EPR reading higher than actual

31. Thrust in a high bypass fan engine is indicated by….N1 RPM or EPR

32. What indication is available to show that thrust reverser has been selected….an amber ‘reverser unlocked’ light illuminates

33. Torsional deflection in a turboprop engine shaft is an indication of what variable….horsepower

34. Thrust in a high bypass engine….is not indicated in flight

35. A ballast resistor is fitted…in series, to give identical resistance values to all airframe

36. Torque pressure is usually read from a….direct reading pressure gauge

37. Modern oil pressure servo transmitters sense….differential pressure

38. Engine oil temp gauges indicate the temp of the oil….at the oil cooler

39. On an EGT thermocouple system, the hot junction….placed downstream of the combustion chamber

40. Motor driven impeller and turbine fuel flow transmitters are designed to transmit data….using aircraft electrical system power

41. EGT is displayed in….degrees celsius

42. Torque measurement in a gas turbine engine is….required only when the turbine drives a propeller

43. EGT thermocouples are usually made of….chromel and alumel

44. Oil temp thermocouples are usually constructed of…iron constantan

45. A red triangle, dot or diamond mark on an engine instrument face or glass indicates….the maximum limit for high transients such as starting

46. On an RPM system using a synchronous generator, the pointer is deflected by….an AC servometer

47. On an aircraft turbine engine operating at a constant power, the application of engine anti-icing will result in….noticeable shift in EPR

48. A CIT sensor is made up of….platinum-rhodium

49. Why do helicopters require a minimum of two synchronous tachometer systems….one indicates engine RPM and the other main rotor RPM

50. In addition to fuel quantity, a computerized fuel system (CFS) with a totalizer indicator provides indication of how many of the following….fuel flow rate, fuel used since reset or initial start up, fuel time remaining at current power setting

51. If the thermocouple leads were inadvertently crossed at installation, what would the EGT gauge pointer indicate….moves off scale on the zero side of the meter

52. Thermocouple leads….are designed for a specific installation and may not be altered

53. The fuel flow indication data sent from motor driven impeller and turbine, and motorless type fuel flow transmitters is a measure of….fuel mass flow

54. Engine pressure ration is determined by….dividing turbine outlet total pressure by engine inlet total pressure

55. In a capacitive type fuel quantity indicating system the tank units are connected….in parallel

56. The resistance of a temp bulb is….increases with an increase in temp

57. The indicator of a tachometer system is responsive to change in….frequency

58. The RPM indication of a synchronous AC motor tachometer is governed by the generator….frequency

59. How is the N! and N2 measured on a triple spool engine….pulse type speed probes

60. The compensation device on an EGT system…..does not need calibration

61. Integrating fuel flow gives….total fuel consumed

62. In a thermocouple system, the size of the EMF that is produced is a result of….the difference between the hot and cold junction

63. What is the primary purpose of the tachometer on an axial compressor turbine engine….monitor engine RPM during starting and to indicate overspeed conditions

64. Engine vibration is monitored using….piezoelectric accelerometer

65. The turbine discharge pressure indicator sensor is located….immediately aft of the last turbine stage

66. Where is Turbine Outlet Temperature (TOT) measured….downstream of the turbine

67. If there is a restriction in the oil pressure line, the gauge will….read low

68. A bourdon tube instrument may be used to indicate….pressure and temperature

69. Vibration pick-ups are located….on both fan and turbine cases

70. On an EGT thermocouple system, the hot junction….is placed downstream of the combustion chamber

71. thrust in a bypass engine….is not indicated in flight

72. The fuel flow indicator rotor and needle for a motor impeller and turbine indicating system is driven by….an electrical signal

POWER AUGMENTATION SYSTEMS (15)

1. Water methanol injection is used…at a combination of higher than normal air temp & high altitude take off conditions

2. During operation of the engine equipped with water injection system, the metering of the coolant to the system is…due to atmospheric pressure

3. When reheat is selected and in operation, the mass gas flow…remains the same

4. The main reason for adding methanol to the water is to…prevent mixture freezing

5. Methanol is added to water when augmenting thrust in order to…reclaim lost heat at the turbines

6. Water used in a thrust augmentation system should be demineralised to prevent…fouling the blades and vanes

7. When reheat is used, EPR…remains constant

8. On a turboprop engine, water methanol for cooling is injected into the…compressor inlet or outlet

9. Water/methanol is injected…at high temp or high altitudes

10. Afterburning is initiated in order to…increase the local speed of sound at the jet nozzle

11. When using water methanol in an axial flow compressor, it is injected into the…compressor inlet or burner section

12. How is the flame stabilised in the reheat system of a gas turbine engine…by ensuring that the gas velocity is grater than the flame velocity

13. Injection of water/methanol into compressor inlet causes…increase in power without the need for burning extra fuel

14. Water methanol injection will increase thrust by up to…30%

15. Screech liners in the afterburning jet pipe…prevents cyclic vibrations of large amplitude

16. The primary purpose of water injection is to…cool the turbine

17. Water or water/methanol injected into the combustion chamber inlet increases…mass airflow through the turbine

18. Reheat is the term used to describe…adding fuel in the exhaust section

19. The reheat ignition system which incorporates a platinum/rhodium element is known as…catalytic ignition

TURBO-PROP ENGINES (16)

1.If an EPR gauge is installed on turbofans as a measure of power output, what is used on a turbo-prop…torque meter

2. What type of reduction gear is used on most turboprop modern engines…epicyclic reduction gear

3. In a turboprop the propellers produce…75-85% of total thrust

4. Torque measurement is taken from the…reduction gearbox

5. A free turbine is usually found on a…turbo-prop

6. A free turbine is…connected directly to the power output shaft

7. A direct drive turboprop engine…uses a reduction gearbox to reduce RPM of propeller

8. A turboprop reduction gear is normally…10:1

9. What controls the fuel trimmer on a turboprop engine…Engine Speed Governer

10. A propeller engine oil has…higher viscosity than turbojets

11. The fuel flow in a turboprop engine within the constant speed range is controlled…automatically

12. Fuel trimming on a turboprop engine is…governer controlled

TURBO-SHAFT (17)

1. On a twin spool turbo-shaft engine, the free turbine is connected to the...output gearbox

2. A turbo-shaft engine has...a power shaft which is not connected to the compressor

3. In the majority of helicopters, the thrust generated by the gas generator is absorbed by the...free power turbine

4. Which type of torquemeters are used on turbo-shaft engines...electro-mechanical and oil

5. A curvic coupling...accurately aligns the driving and driven shafts

APU (18)

1. Usually most of the load placed on an APU occurs when…the bleed air valve is opened

2. The function of an APU air inlet plenum is to…stabilize the pressure of the air before it enters the compressor

3. 2 most important signals when monitoring APU…EGT and oil pressure

4. An APU shut down is initiated by…low oil pressure, fire warning, hot oil temp

5. Electrical speed control switches on an APU are set at…35%, 95% and 100%

6. An APU start cycle is completed at…95%

7. An APU consists of…a power compressor and a load compressor

8. An APU is usually rotated during start by…an electric starter

9. One of the accessories driven from the APU gearbox is a centrifugal switch, the purpose of which is to…cancel the ignition circuits and arm the overspeed protection circuits

10. APU cooling before shutdown may be accomplished by…closing the bleed air valve

11. Generally, when maximum APU shaft output power is being used in conjunction with pneumatic power…pneumatic loading will be automatically modulated to maintain safe EGT

12. What initiates APU shutdown…fire detection, low oil pressure, high oil temperature

POWERPLANT INSTALLATION (19)

1. Feeders are…heavy duty electrical generator cables

2. The spring back and cushion on an engine power lever is…used to prevent the controls hitting the fuel control stops

3. Fibrous metallic lining for noise suppression is used…in hot area

4. Rubber anti-vibration pads are fitted to engine…pylons to prevent vibration thru the airframe

5. The minimum bend radius for a continuous loop type fire wire…1 inch

6. Forward engine mounts take which loads…thrust, vertical and shear loads

7. What are installed in an engine mounting to tune out the worst engine vibrations…rubber encased wire-mesh vibration isolators

8. Engine thrust is transmitted thru mountings that…allows for radial and axial expansion

9. Acoustic linings made from composite materials used on engine …cold section only

10. Rubber clips which hold the electrical wires are used for…heat absorption

11. When checking the effect of inertia on the engine after heavy landing, check the…module alignment first

FIRE PROTECTION SYSTEMS (20)

1. What are the types of continuous fire detection system….capacitance and resistance

2. What is used as an extinguishant in fire bottles….halogenated hydrocarbons

3. Electrical fire….use carbon dioxide

4. A fire detection system that operates on the rate of temp rise is a….theromocouple system

5. Co2 extinguish fire by….contact with the air converts the liquid into snow and gas which smothers the flame

6. Rubber clips supporting a firewire is to….insulate from engine vibration

7. In a resistance type firewire, when hot….resistance decreases

8. A fire detection system operates on the principle of a buildup of gas pressure within a tube proportional to temperature. Which of the following systems does this statement define….Lindberg continuous element system

9. The following fire detection systems uses heat in the normal testing of the system….the thermocouple system and the Lindberg system

10. The safest fire extinguishing agent to use from a standpoint of toxicity and corrosion hazards….bromotriflouromethane (Halon 1301)

11. Fenwall fire detection system use spot detectors wired in parallel between two separate circuits….so that a single fault may exist in the system without sounding a false alarm

12. When pulling fire handle….closes fuel shut-off valve, hydraulic shut-off valve, disconnects the generator field and arms the fire extinguishing system

13. The following fire detection systems will detect a fire when an element is inoperative but will not test when the test circuit is energized….the Kidde system and the Fenwall system

14. A continuous loop fire detector is what type of detector….overheat detector

15. Fire extinguishing agent distributed in the engine section….spray nozzles and perforated tubing

16. The most satisfactory extinguishing agent for an intake fire is….dry chemical

17. When testing a two pin fire bottle connector….short two pins together

18. Fire extinguishing systems activated by….electrically discharged cartridges

19. After a fire is extinguished or overheat condition removed in aircraft equipped with a Systron-Donner fire detector, the detection system….automatically resets

20. The fire detection system that uses two wires imbedded in a ceramic core within a tube is the….Kidde system

21. The test switch of a continuous loop detector gives a…..continuity check…it is a overheat detector

22. A fuel or oil fire is defined as a….Class B fire

23. A fire involving energized electrical equipment is defined as a….Class E fire

24. Gas type firewires operate by utilising….the change in the gas pressure

25. Methyl bromide fire extinguisher are installed with neck….at the bottom

26. Principle of operation of the continuous loop fire detector system sensor….core resistance material which prevents current flow at normal temp

27. Kidde fault free fire detection system has….2 internal wires in the sensing element

28. The fire detection system that uses a single wire surrounded by a continuous string of ceramic beads in a tube is the….Fenwall system

29. The explosive cartridge in the discharge valve of a fire extinguisher container is….a life dated unit

30. The operating principle of the spot detector sensor in a fire detection system….a bimetallic theromoswitch that closes when heated to a high temp

31. When testing a squib on a fire bottle, you use a…..low current ohmmeter

32. Which of the following fire detectors are commonly used in the power section of an engine nacelle….rate of temp rise detectors

33. Fire wire clips have rubber in them to….support the wire…insulate from engine vibration

34. For fire detection and extinguishing purposes, aircraft powerplant areas are divided into fire zones based on………the volume and smoothness of the airflow thru engine compartments

35. Two continuous-loop fire detection systems that will not test due to a broken detector element are the…Kidde and Fenwall System

36. The use of water on Class D fires….will cause the fire to burn more violently and can cause explosions

37. When testing an installed fire bottle….a safety ohmmeter is used

38. On a fire bottle, if the indicator pin was protruding, this would indicate….extinguisher had been fired

39. Omission of crushable washer on engine fire-wire connector will….allow moisture ingress

40. Extinguisher spray rings checked for freedom from obstruction….by blowing thru with compressed air

41. When testing a squib on a fire bottle, use a….low current ohmmeter

42. In a Fenwall fire detection system….the tube is inconel and wire is nickel

43. What retains the nitrogen charge and fire extinguishing agent in a high rate of discharge (HRD) container….breakable disk or fusible disk

ENGINE MONITORING AND GROUND OPERATIONS (21)

1. Which of the following is the least likely indication of a main bearing failure…high oil pressure

2. First engine instrument indication of a successful start of a turbine engine….a rise in the exhaust gas temp

3. Galling is a condition caused by excessive….chafing

4. If a burner was down, in a multi-can system, the engine would tend to….surge

5. A ‘Hot Start’ refers to….high EGT before idle RPM is achieved

6. Which engine variables is the most critical during turbine engine operation….turbine inlet temp

7. Possible cause if a gas turbine engine has high exhaust gas temp, high fuel flow and low RPM at all engine power settings….turbine damage or loss of turbine efficiency

8. After shutdown, flames are present in the exhaust pipe. The probable cause is….a defective pressurizing and dump valve

9. A cool-off period prior to shutdown of a turbine engine is done to….allow the turbine wheel to cool before the case contracts around it

10. The recurrent ingestion of dust or other fine airborne particulates into an engine can result in….erosion damage to the compressor and turbine sections

11. If the run down time is less than the minimum stated for a given engine….the rotating assembly is being restricted

12. In the event of stall occurring….close throttle

13. Run down time is indicative of….the freedom of rotation of the compressor

14. In regard to using a turbine engine oil analysis program, which is not true….generally, an accurate trend forecast may be made after an engine’s first oil sample analysis

15. A rotation pad on an accessory drive gearbox is provided for….N2 rotation

16. A ‘Hung Start’ is indicated by….failure to reach idle RPM

17. When the engine will not run up to idle after reaching starting speed, the likely fault is….FCU

18. The blending of blades and vanes in a turbine engine….should be performed parallel to the length of the blade using smooth contours to minimize stress points

19. During start, if a bleed valve is stuck closed….EGT will be lower than normal

20. Starting an engine with a bleed valve stuck closed would cause….possible stalling of the engine

21. If a turbine engine is unable to reach take off EPR before its EGT limit is reached, this is an indication that the….compressor may be contaminated or damaged

22. If a compressor surge occurs…coughing in the compressor and vibration occurs

23. Flame-out (lean) occurs due to….low pressure at low engine speeds

24. After an engine fails to light on start, u…may carry out a dry motor after a period of time prior to another start attempt

25. What should be done initially if a turbine engine catches fire when starting….turn off the fuel and continue engine rotation with the starter

26. A ‘Wet Start’ is indicated by….no temperature indication (due to lack of ignition)

27. What must not be used during an engine compressor wash….chlorine

28. Mark turbine components only with….layout dye, commercial felt tip marker or chalk

ENGINE STORAGE & PRESERVATION (22)

1. Fuel system inhibiting oil is...mineral oil

2. Which part of the engine is most likely fatal if hydraulic fluid was to leak on it...CPU

3. Installed engine must be re-preserved after preservation at least every...6 months

4. To inhibit the fuel system of an installed engine...pump oil into the engine when stationary

5. When removing engine for long-term storage, bleed valves should be...open but blanked

6. Small cuts in a MVP engine storage bag can be repaired...with adhesive PVC tape

UNVERIFIED (23)

1. Normal gas turbine engine stating sequence...starter, ignition, fuel

2. Which material is used for gas turbine engine fuel lines...stainless steel