APP TUT Chpt 9-17 (MCQ)

• TUT 9: Lubrication:

  Qns 1: Modern Gas turbine engine oil system generally used?

  Ans: Synthetic oil
• TUT 9: Lubrication:

  Qns 2: In the event of inadvertent mixing of two different types of oil in a lubricating system?

  Ans: The system must be drained and flushed
• TUT 9: Lubrication:

  Qns 3: Servicing of oil should be done

  Ans: Within a short time after engine shut down
• TUT 9: Lubrication:

  Qns 4: Which oil system parameter will less likely lead to an engine shutdown when the parameter indicates?

  Ans: High oil pressure
• TUT 9: Lubrication:

  Qns 5: Which following of the components are lubricated by the oil system in an aircraft engine?

  Options:

  1. Reduction gearbox
  2. Accessory gearbox
  3. Bearings
  4. All of the above

  Ans: All of the above
• TUT 9: Lubrication:

  Qns 6: The ___ pump will supply oil to the various components in the oil system and the ___ pump will direct oil back to the oil tank

  Ans: Pressure, scavenge
• TUT 9: Lubrication:

  Qns 7: The magnetic chip detectors are located on the oil ___ line

  Ans: scavenge
• TUT 9: Lubrication:

  Qns 8: Which Engine component will normally experience a sudden increase in metal wear of a Gas Turbine Engine during long operation?

  Ans: Engine bearing
• TUT 9: Lubrication:

  Qns 9: During an oil analysis program, what is indicated by a sudden increase in wear content of a particular type?

  Ans: the amount of metal content/element found in the oil
• TUT 9: Lubrication:

  Qns 10: What are the 4 main roles of a lubrication system in a typical gas turbine engine?

  Ans: lubrication of mating parts, cleaning of moving parts, cooling of hot parts, act as oil damper
• TUT 9: Lubrication:

  Qns 11: Which of the following best describe the function of the oil damper?

  Ans: reduce vibration from transferring to engine case
• TUT 9: Lubrication:

  Qns 12: What is the most common method to check the oil level in an oil tank of a turbofan engine?

  Ans: Oil sight glass
• TUT 9: Lubrication:

  Qns 13: What is the purpose of the non-wired magnetic chip detector in the lubrication system?

  Ans: To inform service crew of trapped metal particles that could come from bearings
• TUT 9: Lubrication:

  Qns 14: What are the basic requirements for aviation lubrication oil?

  Ans: Low volatility, Anti-forming characteristics, Excellent film strength qualities of cohesion and adhesion
• TUT 9: Lubrication:

  Qns 15: What is the main difference between the dry sump oil system and the wet sump oil system?

  Ans: Wet Sump lubricates parts by immersing partially or fully in a bath of oil while Dry Sump uses main oil supply which is carried in a tank mounted integrally within the engine or externally on the engine
• TUT 9: Lubrication:

  Qns 16: What will happen to the oil flow when the pressure between the inlet and outlet of the filter is high?

  Ans: When the Differential Pressure Switch senses the pressure is high, the oil will go through the Bypass valve instead of the filter to lubricate the bearings
• TUT 9: Lubrication:

  Qns 17: What is the purpose of the Centrifugal Breather?

  Ans: It is to separate air from oil
• TUT 9: Lubrication:

  Qns 18: Define Full Flow type oil system

  Ans: The full flow system supplies the oil flow rates based on maximum engine speed from engine start to engine stop
• TUT 10: Fuel system:

  Qns 1: What is the purpose of a fuel and oil heat exchanger?

  Ans: To prevent water content in the fuel from ice formation
• TUT 10: Fuel system:

  Qns 2: What is the function of the Variable Stator Vane (VSV) actuator?

  Ans: To prevent compressor surge
• TUT 10: Fuel system:

  Qns 3: The fuel and heat exchanger is located?

  Ans: downstream of the low pressure fuel pump
• TUT 10: Fuel system:

  Qns 4: List 2 problems associated with the presence of water in the fuel

  Ans: Fuel icing or gelling & Microorganism
• TUT 10: Fuel system:

  Qns 5: Which of the following engine conditions or parameters can be sensed by gas- turbine engine system controller for fuel control unit (FCU)

  Options:

  1. Thrust lever position & Inlet total pressure
  2. Inlet temperature & Shaft rpm (N1, N2 and N3)
  3. Burner pressure or Compressor Discharge Pressure & Exhaust Gas Temperature
  4. All of the above

  Ans: All of the above
• TUT 10: Fuel system:

  Qns 6: Which of the following best explains the function of dump valve and high pressure shut-off valve in a fuel system?

  Ans: Dump valve removes residing/dripping fuel from fuel manifold & fuel nozzle after engine shut down while HP shut-off valve cuts the supply of fuel to the fuel manifold & fuel nozzle after engine shut down
• TUT 10: Fuel system:

  Qns 7: Explain the function of fuel flow transmitter

  Ans: Indicate fuel flow rate in the cockpit and monitor excessive fuel flow to prevent high EGT condition
• TUT 10: Fuel system:

  Qns 8: List the functions/components that the EEC controls

  Options:

  1. Compressor bleeds & Variable stator vanes
  2. Cooling airflows & Engine oil cooling
  3. IDG oil cooling & Fuel heating
  4. All of the above

  Ans: All of the above
• TUT 10: Fuel system:

  Qns 9: What are the inputs which the EEC Control reads?

  Options:

  1. Exhaust total pressure, Shaft RPM N1,N2,N3, Burner pressure
  2. Thrust lever position, Ambient pressure & Inlet total pressure, EGT
  3. Start lever/switch position, Ignition switch selection, VSV position, Inlet Temperature
  4. All of the above

  Ans: All of the above
• TUT 10: Fuel system:

  Qns 10: An airplane fitted with turbofan engines is cruising at 37000ft altitude, producing net thrust of 3000 lbt at a fuel flow rate of 1200 lbf/hr. Find the thrust specific fuel consumption in lbf/lbt.hr.

  Ans: 0.4 lbf/lbt.hr.
• TUT 10: Fuel system:

  Qns 11: If the sector fuel for B777 is 48000kg and the specific gravity of fuel is 0.805. Find the total fuel in liters

  Ans: 59627L
• TUT 10: Fuel system:

  Qns 12: An A320 in a flight lasting 4.5hrs has consumed 16000kg of fuel. Determine the average fuel consumption rate per engine

  Ans: 1778kg/hr
• TUT 10: Fuel system:

  Qns 13: An A340-500 aircraft takes off with 180000kg of fuel. Duration of this flight is 17hrs. At destination the fuel remaining is 10000kg. Find the average fuel consumption per engine for this airplane

  Ans: 2500kg/hr
• TUT 10: Fuel system:

  Qns 14: An airplane is fitted with four turbofan engines is to be refueled. The reserve fuel for the flight is 16000kg. The specific gravity of the fuel is 0.785. The duration of theflight is 13hrs and the average fuel flow rate of each engine is 2650kg/hr. find the amount of total fuel in liters to be top-up, if the airplane arrived with 12000Kg of fuel remaining in the aircraft

  Ans: 180637L
• TUT 10: Fuel system:

  Qns 15: A BOEING 777 aircraft is to fly from Singapore, Hong Kong.

  • Estimated duration of flight: 4 hrs 30 min
  • Average fuel consumption: 3 liters per passenger per 100 km
  • Flying distant between airports: 5,465 km
  • Maximum seating capacity: 500 seats
  • Reserve fuel for the flight: 5% of the total sector fuel
  • Alternate fuel required: min. 30 minutes flight time
  • Specific gravity of fuel: 0.78

  If the aircraft tanks held 20000 kg before refueling, determine the total fuel uplift in liters with maximum sitting capacity

  Ans: 69541.05L
• TUT 11: Air system:

  Qns 1: Hot temperature from the gas touches the turbine blade is undesirable. What will happen to the turbine blade after a long duration?

  Ans: Overheating which lead to unwanted thermal expansion & fatigue
• TUT 11: Air system:

  Qns 2: Propose ways to reduce heat on the turbine blade

  Ans: By providing continuous supply of cooling air from the compressor into the turbine disc to lower the temperature of the turbine blade
• TUT 11: Air system:

  Qns 3: Why is nacelle’s ventilation critical?

  Ans: To avoid accumulation of fluid and fuel vapor that can potentially self-ignite
• TUT 11: Air system:

  Qns 4: What are the 2 sources of air used for nacelle’s ventilation and cooling?

  Ans: Fan air and ram air
• TUT 11: Air system:

  Qns 5: What are the 2 disadvantages of tapping air for ventilation?

  Ans: Tapping air for ventilation will have an effect on the loss of engine performance such as thrust and create additional drag
• TUT 11: Air system:

  Qns 6: State the important functions of air on the EXTERNAL air system of a turbofan engine

  Options:

  1. Customer bleed for air-conditioning & Nacelle anti-icing
  2. Thrust reverser operation & Active clearance control
  3. Accessories cooling & Nacelle ventilation
  4. All of the above

  Ans: All of the above
• TUT 11: Air system:

  Qns 7: What is the working principle of "Active Clearance Control"?

  Ans: To use cold air to cool the turbine casing of a turbofan engine to minimise loss of air between the turbine blades and turbine casing