Module 15 Gas Turbine Engine 100 Important Sentences for Revision

 1. Basic Principles

1. A gas turbine engine operates on the Brayton cycle.
2. The Brayton cycle consists of intake, compression, combustion, expansion, and exhaust.
3. Thrust is produced by accelerating a mass of air rearward.
4. Newton’s third law is the basis of jet propulsion.
5. The faster the exhaust gases, the greater the thrust.
6. The main sections of a gas turbine are intake, compressor, combustion, turbine, and exhaust.
7. Air enters through the intake with minimum pressure loss.
8. The compressor raises the air pressure.
9. The combustion section adds heat to the compressed air.
10. The turbine extracts energy from hot gases to drive the compressor.

2. Engine Components

11. The intake directs air smoothly into the compressor.
12. The compressor may be centrifugal, axial, or mixed-flow.
13. Centrifugal compressors are common in small engines.
14. Axial compressors are used in large engines for higher pressure ratios.
15. The diffuser slows down air to increase static pressure.
16. The combustion chamber burns fuel continuously.
17. The turbine converts heat energy into mechanical work.
18. The exhaust nozzle accelerates gases to produce thrust.
19. Bearings support rotating shafts.
20. Accessory gearboxes drive pumps and generators.

3. Compressor Section

21. Compressors increase air pressure and temperature.
22. Axial compressors consist of rotating and stationary blades.
23. Rotor blades accelerate the air.
24. Stator blades convert velocity into pressure.
25. Multi-stage axial compressors achieve high pressure ratios.
26. Centrifugal compressors use impeller and diffuser action.
27. Compressor efficiency affects overall engine performance.
28. Surge is a total breakdown of airflow through the compressor.
29. Stall occurs when air separates from the blade surface.
30. Variable stator vanes and bleed valves prevent stall and surge.

4. Combustion Section

31. Combustion occurs at nearly constant pressure.
32. The air-fuel ratio must be correct for complete burning.
33. There are three types of combustion chambers: can, annular, and can-annular.
34. Igniters provide spark during engine start.
35. Fuel injectors atomize and mix fuel with air.
36. The liner directs flame and protects casing from heat.
37. Cooling air flows through liner holes to reduce temperature.
38. Combustion efficiency affects thrust and fuel economy.
39. Flameout occurs when the flame is extinguished during operation.
40. Relight systems restart combustion after flameout.

5. Turbine Section

41. The turbine extracts energy from hot gases.
42. It drives the compressor and accessories.
43. A turbine consists of rotor blades and stator vanes.
44. The stator guides gas flow onto rotor blades.
45. The high-pressure turbine drives the compressor.
46. The low-pressure turbine drives the fan or propeller.
47. Turbine blades are made of nickel-based superalloys.
48. Blade cooling prevents overheating.
49. Cooling air passes through internal passages and holes.
50. Blade creep occurs from long-term high temperatures.

6. Exhaust and Thrust

51. The exhaust system directs gases rearward efficiently.
52. Thrust is created by high-velocity gas exiting the nozzle.
53. Convergent nozzles are used on subsonic engines.
54. Convergent-divergent nozzles are used for supersonic speeds.
55. Afterburners add fuel to the exhaust for extra thrust.
56. Thrust reversers help decelerate the aircraft after landing.
57. Reversers operate hydraulically or pneumatically.
58. Bucket, cascade, and clamshell are main types of reversers.
59. Reverse thrust should not be used in flight.
60. EGT (Exhaust Gas Temperature) is an important performance indicator.

7. Engine Starting and Ignition

61. Starting provides rotation for initial air compression.
62. Air turbine starters are common in large engines.
63. Electrical starters are used on small turbine engines.
64. Ignition systems provide spark for combustion start.
65. Two igniters are used for reliability and redundancy.
66. Igniters use high-voltage discharge.
67. Ignition is required during start and for relight.
68. Exciters store and discharge energy to igniters.
69. After engine self-sustains, the starter disengages.
70. Starter cutout occurs automatically after light-up.

8. Engine Control Systems

71. Engine thrust is controlled by fuel flow.
72. The fuel control unit (FCU) meters correct fuel quantity.
73. FADEC stands for Full Authority Digital Engine Control.
74. FADEC controls fuel and engine parameters electronically.
75. FADEC removes mechanical control cables.
76. Manual reversion may be used in older systems.
77. Power levers command thrust setting to FADEC.
78. Engine control prevents over-speed and over-temperature.
79. EPR (Engine Pressure Ratio) indicates engine thrust.
80. N1 and N2 show compressor spool speeds.

9. Lubrication and Fuel Systems

81. The oil system lubricates and cools engine bearings.
82. Dry sump systems are common in turbine engines.
83. Scavenge pumps return oil to the tank.
84. Filters remove dirt and metal particles.
85. Chip detectors signal metal contamination.
86. Oil coolers maintain correct temperature.
87. The fuel system delivers fuel from tanks to combustion.
88. Boost pumps supply fuel to the engine pumps.
89. Fuel filters remove contaminants.
90. The FCU meters fuel according to throttle position and conditions.

10. Fire Protection, Performance, and Maintenance

91. Fire detection systems use continuous loops or thermal sensors.
92. Overheat detection warns of rising temperature before fire.
93. Fire extinguishing systems use Halon or clean agents.
94. Engine performance is measured by EPR, N1, and fuel flow.
95. Specific fuel consumption defines fuel efficiency.
96. Vibration monitoring detects rotor imbalance.
97. Engine trend monitoring helps predict maintenance needs.
98. Borescope inspection checks internal parts.
99. Engine removal is required for major overhauls.
100. Proper maintenance ensures reliability, safety, and efficiency.

 

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All types of AMEL Modules Questions quantity and Time information

 Modules Questions and time information

MODULE 1 MATHEMATICS

1. Category A:    16 multi-choice Time allowed 20 minutes.
2. Category B1:  32 multi-choice Time allowed 40 minutes.
3. Category B2:  32 multi-choice Time allowed 40 minutes.
4. Category B3:  28 multi-choice Time allowed 35 minutes. 

MODULE 2 PHYSICS

1. Category A:    32 multi-choice Time allowed 40 minutes.
2. Category B1:  52 multi-choice Time allowed 65 minutes.
3. Category B2:  52 multi-choice Time allowed 65 minutes.
4. Category B3:  28 multi-choice Time allowed 35 minutes.

MODULE 3 ELECTRICAL FUNDAMENTALS

1. Category A:    20 multi-choice Time allowed 25 minutes.
2. Category B1:  52 multi-choice Time allowed 65 minutes.
3. Category B2:  52 multi-choice Time allowed 65 minutes.
4. Category B3:  24 multi-choice Time allowed 30 minutes.

MODULE 4 ELECTRONIC FUNDAMENTALS

1. Category B1:   20 multi-choice Time allowed 25 minutes.
2. Category B2:   40 multi-choice Time allowed 50 minutes.
3. Category B3:   8 multi-choice Time allowed 10 minutes.

MODULE 5 DIGITAL TECHNIQUES

1. Category A:         16 multi-choice Time allowed 20 minutes.
2. Category B1.1:    40 multi-choice Time allowed 50 minutes.
3. Category B1.3:    40 multi-choice Time allowed 50 minutes
4. Category B1.2:    20 multi-choice Time allowed 25 minutes.
5. Category B1.4:    20 multi-choice Time allowed 25 minutes.
6. Category B2:       72 multi-choice Time allowed 90 minutes.
7. Category B3:       16 multi-choice Time allowed 20 minutes.

MODULE 6 MATERIALS AND HARDWARE

1. Category A:    52 multi-choice Time allowed 65 minutes.
2. Category B1:  72 multi-choice Time allowed 90 minutes.
3. Category B2:  60 multi-choice Time allowed 75 minutes.
4. Category B3:  60 multi-choice Time allowed 75 minutes.

MODULE 7A MAINTENANCE PRACTICES

1. Category A:    72 multi-choice and 2 essay questions. Time allowed 90 mins plus 40 mins. 
2. Category B1:  80 multi-choice and 2 essay questions. Time allowed 100 mins plus 40 mins.
3. Category B2:  60 multi-choice and 2 essay questions. Time allowed 75 mins plus 40 mins.

MODULE 7B MAINTENANCE PRACTICES

1. Category B3:  60 multi-choice and 2 essay questions. Time allowed 75 mins plus 40 mins.

MODULE 8 BASIC AERODYNAMICS

1. Category A:    20 multi-choice Time allowed 25 minutes.
2. Category B1:  20 multi-choice Time allowed 25 minutes.
3. Category B2:  20 multi-choice Time allowed 25 minutes.
4. Category B3:  20 multi-choice Time allowed 25 minutes.

MODULE 9A HUMAN FACTORS

1. Category A:     20 multi-choice and 1 essay question. Time allowed 25 mins plus 20 mins.
2. Category B1:   20 multi-choice and 1 essay question. Time allowed 25 mins plus 20 mins.
3. Category B2:   20 multi-choice and 1 essay question. Time allowed 25 mins plus 20 mins.

MODULE 9B — HUMAN FACTORS

1. Category B3:  16 multi-choice and 1 essay questions. Time allowed 20 mins plus 20 mins.

MODULE 10 AVIATION LEGISLATION

1. Category A:    32 multi-choice and 1 essay question. Time allowed 40 mins plus 20 mins.
2. Category B1:  40 multi-choice and 1 essay question. Time allowed 50 mins plus 20 mins.
3. Category B2:  40 multi-choice and 1 essay question. Time allowed 50 mins plus 20 mins.
4. Category B3:  32 multi-choice and 1 essay questions. Time allowed 40 mins plus 20 mins.

MODULE 11A TURBINE AEROPLANE STRUCTURES & SYS

1. Category A:    108 multi-choice Time allowed 135 minutes. 
2. Category B1:  140 multi-choice Time allowed 175 minutes.

MODULE 11B — PISTON AEROPLANE AERODYNAMICS, STRUCTURES & SYS

1. Category A:    72 multi-choice Time allowed 90 minutes.
2. Category B1:  100 multi-choice Time allowed 125 minutes.

 MODULE 11C — PISTON AEROPLANE, STRUCTURES AND SYSTEMS 

1. Category B3:   60 multi-choice Time allowed 75 minutes.

MODULE 12 HELICOPTER AERODYNAMICS, STRUCTURES AND SYS

1. Category A:    100 multi-choice Time allowed 125 minutes.
2. Category B1:  128 multi-choice Time allowed 160 minutes.

MODULE 13 AIRCRAFT STRUCTURES AND SYSTEMS

1. Category B2:   180 multi-choice Time allowed 225 minutes.

MODULE 14 PROPULSION 

1. Category B2:    24 multi-choice Time allowed 30 minutes.

MODULE 15 GAS TURBINE ENGINE

1. Category A:    60 multi-choice Time allowed 75 minutes.
2. Category B1:  92 multi-choice Time allowed 115 minutes.

MODULE 16 PISTON ENGINE

1. Category A:    52 multi-choice Time allowed 65 minutes.
2. Category B1:  72 multi-choice Time allowed 90 minutes.
3. Category B3:  68 multi-choice Time allowed 85 minutes.

MODULE 17A PROPELLER

1. Category A:    20 multi-choice Time allowed 25 minutes.
2. Category B1:  32 multi-choice Time allowed 40 minutes.

MODULE 17B PROPELLER

1. Category B3:   28 multi-choice Time allowed 35 minutes

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M-15 Gas Turbine Engine Final Practice Test [92 Question and 115 Minutes]

Module 15 : Gas Turbine Engine

Final Practice Test

  

 

1. A jet engine derives its thrust by ?
   1.   reaction of the propelling gases
   2.   impingement of the propelling gases on the outside air
   3.   drawing air into the compressor
2. The working fluid of a gas turbine engine is ?
   1.   kerosene
   2.   air
   3.   gasoline
3. In a twin spool compressor system, the first stage turbine drives the ?
   1.   N1 and N2 compressors
   2.   N2 compressor
   3.   N1 compressor
4. The term Pt7 means ?
   1.   the total pressure at station No. 7
   2.   the total inlet pressure
   3.   pressure and temperature at station No. 7
5. The pressure of supersonic air as it flows through a divergent nozzle?
   1.   is inversely proportional to the temperature
   2.   increases
   3.   decreases
6. A gas turbine engine comprises which three main sections?
   1.   Compressor, diffuser, and stator
   2.   Turbine, compressor, and combustion
   3.   Turbine, combustion, and stator
7. In what section of a turbojet engine is the jet nozzle located ?
   1.   Turbine
   2.   Exhaust
   3.   Combustion
8. The Brayton cycle is known as the constant ?
   1.   mass cycle
   2.   pressure cycle
   3.   temperature cycle
9. Standard sea level pressure is ?
   1.   29.00 inches Hg
   2.   29.29 inches Hg
   3.   29.92 inches Hg
10. A turboprop engine derives its thrust by ?
    1.   reaction of the prop-wash
    2.   reaction of the propulsion gases
    3.   impingement of the prop-wash on the outside air
11. Adiabatic compression is ?
    1.   one where there is no loss or gain of heat
    2.   one where there is an increase in kinetic energy
    3.   an isothermal process
12. In a ducted fan engine, the fan is driven by the ?
    1.   air passing over the compressor
    2.   turbine
    3.   accessory gearbox
13. On a gas turbine engine, what is the fan driven by?
    1.   I P turbine
    2.   H P turbine
    3.   LP turbine
14. The density of gas may be expressed as ?
    1.   volume/weight
    2.   pressure/volume
    3.   weight/volume
15. A divergent duct will cause subsonic flow to decrease in ?
    1.   velocity, pressure remains constant
    2.   velocity, increase pressure
    3.   pressure, increase velocity
16. The purpose of a diffuser is to ?
    1.   induce a swirl to the air prior to combustion
    2.   increase the static pressure of the air
    3.   increase the kinetic energy of the air
17. On a triple spool engine, the first stage of turbines drive ?
    1.   the LP compressor
    2.   the I P compressor
    3.   the HP compressor
18. What type of oil is used in a gas turbine engine?
    1.   Phosphate Ester
    2.   Synthetic
    3.   Mineral
19. The hottest casing is the ?
    1.   combustion chamber
    2.   L.PT
    3.   H.PT
20. Oil pressure and scavenge pumps are usually ?
    1.   multi-plunger pumps
    2.   spur gear pumps
    3.   diaphragm pumps
21. After placing an engine into storage, details would be recorded in ?
    1.   Engine log book
    2.   Technical Log
    3.   Aircraft log book
22. Installed engines must be re-preserved after preservation at least every ?
    1.   six weeks
    2.   six days
    3.   six months
23. What would be indicative of a hung start?
    1.   High E.G.T
    2.   Engine would fail to reach self sustaining speed
    3.   Starter would fail to disengage
24. A rotation pad on an accessory drive gear box is provided for ?
    1.   N2 rotation
    2.   Alternate tachogenerator fitment
    3.   F1 rotation
25. During start, if a bleed valve is stuck closed ?
    1.   E.G.T is unaffected
    2.   E.G.T will be higher than normal
    3.   E.G.T will be lower than normal
26. Galling is a condition caused by excessive?
    1.   scoring
    2.   chafing
    3.   temperatures
27. If a compressor surge occurs, it is recognized by ?
    1.   coughing in the compressor and vibration
    2.   fluctuating RPM and fuel flow
    3.   fluctuating E.G.T and thrust
28. A hot start refers to?
    1.   too much fuel being supplied
    2.   early ignition
    3.   high E.G.T before idle RPM is achieved
29. What may be an indication of a bleed valve stuck in the closed position?
    1.   Compressor stalling at low RPM
    2.   Low E.G.T reading
    3.   Over speed
30. Engine oil sampling analysis is taken?
    1.   after engine shut down
    2.   when oil level is high
    3.   at specific time after engine shut down
31. Methyl Bromide fire extinguisher are installed with neck ?
    1.   at the bottom
    2.   at the top
    3.   horizontal
32. The most satisfactory extinguishing agent for an electrical fire is?
    1.   carbon tetrachloride
    2.   methyl bromide
    3.   carbon dioxide
33. A continuous loop fire detector is what type of detector?
    1.   Overheat detector
    2.   Spot detector
    3.   Rate of temperature rise detector
34. How is the fire extinguishing agent distributed in the engine section ?
    1.   Nitrogen pressure and slinger rings
    2.   Spray nozzles and fluid pumps
    3.   Spray nozzles and perforated tubing
35. A fuel or oil fire is defined as a ?
    1.   class C fire
    2.   class B fire
    3.   class A fire
36. Forward engine mounts take which loads ?
    1.   Thrust, vertical and shear loads
    2.   Centrifugal, thrust and axial
    3.   Thrust, vertical and impact
37. Auxiliary power units provide?
    1.   pneumatic and electrical power
    2.   hydraulic and pneumatic power
    3.   hydraulic and electrical power
38. An A.P.U is?
    1.   a self contained variable speed gas turbine engine
    2.   a reserved engine in case of a main engine failure
    3.   a self contained constant speed gas turbine engine
39. On a twin spool turbo-shaft engine, the free turbine is connected to the ?
    1.   L.P gearbox
    2.   Output gearbox
    3.   H.P gearbox
40. What type of reduction gear is used on most turboprop modern engines ?
    1.   Helical cut parallel spur gears
    2.   Straight cut parallel spur gears
    3.   Epicyclic reduction gear
41. Fuel trimming on a turboprop engine is?
    1.   governor controlled
    2.   automatic
    3.   pilot controlled
42. Water or water/methanol injected into the combustion chamber inlet increases?
    1.   combustion chamber outlet temperatures
    2.   mass airflow through the turbine
    3.   fuel to air ratio by up to 20%
43. Water methanol injection will increase thrust by up to?
    1.   70%
    2.   50%
    3.   30%
44. Integrating fuel flow gives ?
    1.   total fuel consumed
    2.   fuel flow and acceleration
    3.   average fuel flow
45. E.G.T thermocouples are usually made of?
    1.   chromel and platinum
    2.   chromel and alumel
    3.   nickel and platinum
46. A thermocouple indicator is basically a ?
    1.   milliohmeter
    2.   milliammeter
    3.   millivoltmeter
47. Where is Turbine Outlet Temperature (T.O.T) measured?
    1.   Downstream of the turbine
    2.   Upstream of the turbine
    3.   In the combustion chamber
48. oil temperature thermocouples are usually constructed of ?
    1.   alumel constantan
    2.   iron constantan
    3.   chromel alumel
49. What power is required for E.G.T gauge indication?
    1.   115V AC
    2.   28V DC
    3.   No power - it is self generating
50. Fuel flow indication is taken from ?
    1.   after the LP pump
    2.   after the H.P pump
    3.   after either H.P Pump or LP Pump
51. The resistor in a D.C. starter motor?
    1.   prevents over speed
    2.   prevents current surge when motor is at low rpm
    3.   used when D.C. motor fails
52. An aircraft flying through heavy rain may use, as a precaution?
    1.   continuous ignition
    2.   engine intake deicing
    3.   airframe deicing
53. The field of the D.C. starter motor used on gas turbine engine is ?
    1.   shunt or compound
    2.   series or compound
    3.   series only
54. The type of ignition system used on most turbine aircraft engines is?
    1.   low tension
    2.   capacitor discharge
    3.   high resistance
55. What type of turbine blade is most commonly used in air starter motors?
    1.   Impulse-reaction
    2.   Reaction
    3.   Impulse
56. As air is bled off the engine, EGT will?
    1.   increase
    2.   decrease
    3.   remain constant
57. Turbine case cooling utilizes?
    1.   LP compressor air
    2.   Fan air
    3.   HP compressor air
58. Engine anti-ice is taken AIR from the ?
    1.   Turbine
    2.   LP compressor
    3.   HP compressor
59. When does E.E.C channel change over occur?
    1.   On fault
    2.   On engine shut down
    3.   On engine start up
60. Fuel boost pumps are cooled using?
    1.   Fuel pumps do not require cooling
    2.   Fuel
    3.   Ram air
61. When FADEC is in normal mode ?
    1.   channel A or B will be in command
    2.   channel A will be in command
    3.   channel B will be in command
62. In-Flight the engine E.E.C controls ?
    1.   EGT
    2.   Throttle position
    3.   Fuel flow
63. Which of the following turbine fuel filters has the greatest filtering action?
    1.   Small wire mesh
    2.   Micron
    3.   Stacked charcoal
64. The swash plate in a fuel pump, when static is?
    1.   at some intermediate position
    2.   in the minimum position
    3.   in the maximum position
65. A fuel heater prevents?
    1.   HP filter icing
    2.   LP filter icing
    3.   Neither
66. The fuel pump plungers are lubricated by?
    1.   synthetic anti-freeze oil
    2.   grease packed bearings
    3.   the Fuel
67. Specific fuel consumption at altitude will?
    1.   decrease
    2.   remain constant
    3.   increase
68. A spur gear pump operating in a lubrication system promotes?
    1.   low flow at high pressure
    2.   low flow at low pressure
    3.   high flow at low pressure
69. A full flow oil system has?
    1.   a hot and cold oil pressure limit
    2.   a variable oil pressure dependant upon throttle setting
    3.   a single fixed minimum oil pressure
70. What type of oil system is usually found on turbine engines?
    1.   Dry sump, dip, and splash
    2.   Wet sump, spray, and splash
    3.   Dry sump, pressure, and spray
71. Which of the following is a function of the fuel oil heat exchanger on a turbojet engine?
    1.   Increases fuel temperature
    2.   Aerates the fuel
    3.   Emulsifies the oil
72. Calorific value is the?
    1.   vaporisation point of fuel
    2.   amount of heat or energy in one pound of fuel
    3.   fuel boiling temperature
73. A fuel system icing inhibitor is a fuel additive which?
    1.   prevents the water in the fuel freezing
    2.   prevents the fuel from freezing
    3.   prevents both the water and the fuel freezing
74. Kerosene will burn effectively at an air/fuel ratio of ?
    1.   45:1
    2.   150:1
    3.   15:1
75. Taper roller bearings accept loads in which direction ?
    1.   Radial and axial in both directions
    2.   Radial and axial in one direction only
    3.   Axial loads only
76. Indentations on bearing races caused by high static loads are known as ?
    1.   brinelling
    2.   galling
    3.   fretting
77. A carbon seal has which type of sealing arrangement ?
    1.   Full contact with casing
    2.   Full contact with race
    3.   Full contact with labyrinth
78. On a Clamshell door type thrust reverser, The Clamshell doors redirect the exhaust gas stream?
    1.   45 degrees to the thrust line
    2.   90 degrees to the thrust line
    3.   0 degrees to the thrust line
79. A convergent exhaust nozzle produces mainly ?
    1.   momentum and pressure thrust
    2.   momentum thrust
    3.   pressure thrust
80. Exhaust noise can be reduced by ?
    1.   lowering the vibration frequency
    2.   increasing the jet velocity
    3.   increasing the mixing rate
81. A Convergent-Divergent nozzle ?
    1.   requires the aircraft to be travelling at supersonic speeds
    2.   makes maximum use of Pressure thrust
    3.   produces a type of thrust known as kinetic thrust
82. A choked nozzle ?
    1.   has no effect on the thrust
    2.   increases thrust
    3.   decreases thrust
83. A slow constant growth in a turbine blade is known as?
    1.   primary creep
    2.   secondary creep
    3.   tertiary creep
84. Turbine engine components are never manufactured by ?
    1.   electrical resistance welding
    2.   argon arc welding
    3.   gas welding
85. What are blue and golden deposits evidence of, on a turbine blade ?
    1.   Titanium
    2.   Aluminium
    3.   Magnesium
86. An increase in turbine diameter is caused by ?
    1.   prolonged high temperatures and centrifugal loads
    2.   products of combustion
    3.   over speed
87. Creep, overall ?
    1.   has no effect on turbine diameter
    2.   decreases turbine diameter
    3.   increases turbine diameter
88. Why are nozzle guide vanes fitted ?
    1.   To increase velocity of the air flow
    2.   To increase velocity of the gas flow
    3.   To decrease velocity of the gas flow
89. The three main types of turbine blades are ?
    1.   impulse, vector, and impulse-vector
    2.   reaction, converging, and diverging
    3.   impulse, reaction, and impulse-reaction
90. A combustion chamber has a ?
    1.   convergent inlet, divergent outlet
    2.   convergent inlet, convergent outlet
    3.   divergent inlet, convergent outlet
91. Fuel nozzles are cleaned ?
    1.   in-situ with detergent solution
    2.   in-situ with carbon solution
    3.   with a rag and solvent
92. Secondary air in the combustion chamber is used for ?
    1.   cooling
    2.   combustion
    3.   increasing axial velocity of gases

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