MODULE 15 JUNE 2026
- EGT is directly proportional to:
A. TIT (Turbine Inlet Temperature)
B. TOT (Turbine Outlet Temperature)
C. CDP (Compressor Discharge Pressure)
D. All of the above - Which bearing uses a thin film of oil around the outer race to reduce vibraƟon?
A. Ball Bearing
B. Roller Bearing
C. Slipper Bearing
D. Hydraulic Bearing - In a Fenwal fire detector system, the sensing element is:
A. Wired in parallel
B. Wired in series
C. Connected through relays only
D. Independently connected - Glow-type igniter plugs are generally used in:
A. Small engines
B. Large engines
C. Auxiliary engines
D. Turbofan engines - An advantage of a can-annular combusƟon chamber is:
A. Greater structural integrity
B. Larger frontal area
C. Lower heat resistance
D. Reduced combusƟon efficiency - The hoƩest area in a gas turbine engine is:
A. In and around the turbine secƟon
B. Inlet secƟon
C. Compressor secƟon - Turbine shaŌs are commonly manufactured from:
A. Nickel alloys
B. Aluminium alloys
C. Steel only
D. Magnesium alloys - Ball bearings can support:
A. Axial loads only
B. Radial loads only
C. Both axial and radial loads
D. Thrust loads only - The type of oil normally used in gas turbine engines is:
A. SyntheƟc oil
B. Mineral oil
C. Both syntheƟc and mineral oil - A fuel control system primarily senses:
A. Compressor discharge pressure
B. Turbine outlet temperature
C. Compressor inlet pressure only - The funcƟon of an overrunning (free-wheel) clutch is:
A. Free rotaƟon of the driven member
B. Prevent rotaƟon in both direcƟons
C. Increase shaŌ speed
D. Reduce gearbox load - Water injecƟon can increase engine thrust by approximately:
A. 20%
B. 30%
C. 40%
D. 50%
13.EPR is measured by:
A. Electromechanical transmiƩer
B. Mechanical transmiƩer
C. Electronic transmiƩer
- During engine start, the following must be monitored:
A. EGT
B. Oil pressure
C. Engine speed (RPM)
D. All of the above - Propeller RPM is measured using:
A. Tachometer
B. Manometer
C. EPR indicator
D. Thermocouple - Crystal-type thermocouples are used for:
A. Temperature sensing
B. Pressure sensing
C. VibraƟon sensing
D. Fuel flow sensing - The compressor diffuser used in helicopters is generally:
A. Convergent type
B. Divergent type
C. Parallel type
D. Venturi type - Low-volaƟlity fuel is used to:
A. Prevent vapour lock
B. Resist evaporaƟon
C. Both A and B
D. Increase octane raƟng - To expel residual fuel aŌer a fire, the engine should be:
A. Restarted immediately
B. Motored
C. Accelerated rapidly
D. Should not restart - If a fuel metering valve sƟcks, the effect may be:
A. Rich mixture
B. Lean mixture
C. Engine malfuncƟon
D. All of the above - The purpose of swirl vanes is to:
A. Provide beƩer mixing of fuel and air
B. Increase air velocity
C. Increase flame velocity
D. All of the above - In cold weather, fuel volaƟlity should be:
A. Low
B. High
C. Medium
D. Unaffected by temperature - A newly stored engine should be checked:
A. AŌer 24 hours with pink indicaƟon
B. Within 24 hours with pink indicaƟon
C. Within 24 hours with blue indicaƟon
D. AŌer 24 hours with blue indicaƟon - A mechanical thrust reverser operates by:
A. Blocking the exhaust path
B. DiverƟng airflow to oppose thrust
C. Both A and B - Newton’s Third Law relates to:
A. AcceleraƟon and moƟon
B. MoƟon only
C. GravitaƟon only
D. AcƟon and reacƟon forces - Oil temperature indicaƟon is normally taken from:
A. Inlet of the pressure pump
B. Outlet of the pressure pump
C. Scavenge subsystem
D. Oil tank - Factors affecƟng inlet condiƟons include:
A. AircraŌ speed, aircraŌ aƫtude and ambient air condiƟons
B. StagnaƟon density only
C. Both A and B
D. Compressor RPM only - CharacterisƟcs of a bell-mouth compressor intake include:
A. High duct efficiency
B. Increased drag
C. Decreased velocity
D. All of the above - MTCS discharge indicator:
A. Red disk indicates thermal discharge
B. Yellow disk indicates crew/system discharge
C. Both A and B
D. Yellow indicates normal discharge - In a pressure relief valve system:
A. The relief valve is spring-loaded to open posiƟon
B. The relief valve is spring-loaded to closed posiƟon
C. Both A and B - An APU load compressor supplies:
A. Electrical power only
B. PneumaƟc power only
C. Both electrical and pneumaƟc power
D. Hydraulic power - AŌer a fire has been exƟnguished by the engine fire exƟnguisher:
A. Restart immediately
B. Restart aŌer 10 minutes
C. Do not aƩempt a restart
D. Restart aŌer inspecƟon only - If one turbine blade is damaged:
A. N2 speed increases
B. N2 speed decreases
C. EGT increases
D. Both B and C - EPR is measured using:
A. Electrical transmiƩer
B. Electromechanical transmiƩer
C. Both A and B
D. PneumaƟc transmiƩer - Regarding MTCS air cooling:
A. Compressor shaŌs do not require cooling
B. Bearings do not require cooling
C. Combustor and turbine secƟons principally require cooling
D. EnƟre engine requires equal cooling - An advantage of a can-annular combusƟon chamber is:
A. Greater structural stability
B. Smaller frontal area
C. High heat resistance
D. All of the above - The major advantage of a turboshaŌ engine is:
A. High reliability, small size, and light weight
B. High power output, small size, heavy weight
C. Less power, small size, light weight
D. Low reliability and low weight - An APU can provide:
A. Engine starƟng on the ground only
B. PneumaƟc power only
C. Engine starƟng in flight
D. Both ground and in-flight support - Why are turboshaŌ engines ideal for helicopters?
A. Free-wheeling or overrunning clutch unit permits autorotaƟon during power loss
B. Overrunning or free-wheeling Assists twin-engine transmission systems
C. Helps in starƟng and single engine operaƟon in economy cruise mode - The primary purpose of the fuel metering secƟon of a hydromechanical FCU is:
A. AutomaƟcally stop fuel aŌer flameout
B. Meter the correct amount of fuel to the combusƟon chamber
C. Maintain constant pressure at all speeds
D. All of the above - A fan located ahead of the compressor:
A. Reduces FOD suscepƟbility
B. Increases compressor temperature
C. Decreases engine efficiency
D. None of the above - Marking in combusƟon chambers and hot secƟons should be done using:
A. Layout dye, chalk, or felt-Ɵp marker
B. Wax marking pencil
C. Metal pencil or graphite pencil
D. Centre punch - Desiccant should be replaced when humidity exceeds:
A. 20%
B. 25%
C. 30%
D. 50% - Turbine cooling air passing through porous holes is known as:
A. TranspiraƟon cooling
B. Film cooling
C. Impingement cooling
D. ConvecƟon cooling - Fenwal fire detector systems:
A. Can withstand one fault only
B. ConƟnuous loops are connected in series
C. Both A and B
D. Connected in parallel - For an engine stored in a shipping case, the humidity indicator should be checked:
A. Every 10 days
B. Every 30 days
C. Every 90 days
D. Every 180 days - Which type of gas turbine engine consists of a fan and two independent rotaƟng assemblies?
A. Dual Spool
B. Single Spool
C. Dual Spool with Fan - If FADEC fails, the engine reverts to:
A. EPR Mode
B. N1 Mode
C. Manual Fuel Mode
D. N2 Mode - Compared with a propeller engine, a forward-fan (turbofan) engine:
A. Has less acceleraƟon
B. Produces lower jet velociƟes
C. Does not prevent shock waves
D. Both A and B - Turbine engine igniƟon systems require a large amount of energy because:
A. IgniƟon is required for a longer period
B. A high voltage is required
C. Constant output is required
D. None of the above - TurboshaŌ engines are primarily used in:
A. Helicopters
B. APUs
C. Both A and B - Which of the following statements regarding wire bundles is correct (MTCS)?
A. The minimum bend radius should not be less than 10 Ɵmes the outside diameter of the wire
group.
B. Wire groups should normally not exceed ½ inch deflecƟon between support points by their own
weight.
C. A wire bundle should not contain more than 80 wires and should not exceed 2.5 inches in
diameter.
D. All of the above - In an aŌerburner, the:
A. Pressure increases
B. Volume increases
C. Pressure decreases and volume increases
D. Temperature decreases - A boroscope is:
A. A flexible and/or rigid opƟcal instrument used to inspect the inside of an engine
B. A rigid tube only
C. A flexible hose used to inspect the outside of an engine
D. A pressure measuring device - Turbine blade shrouds are provided to:
A. Reduce blade vibraƟon and Ɵp leakage
B. Increase blade angle at the Ɵp
C. Act as a diffuser
D. Increase fuel flow - Regarding aŌerburners:
A. Pressure increases
B. Velocity decreases
C. A flame holder is required
D. A flame holder is not required - The power secƟon of a turboshaŌ engine includes:
A. Compressor, combusƟon chamber, turbine and exhaust
B. The later turbine stages and output shaŌ
C. Compressor and accessory gearbox only
D. ReducƟon gearbox only - Compressor washing is performed for:
A. EnƟre gas-path cleaning
B. LubricaƟon of compressor blades
C. Blade balancing
D. VibraƟon reducƟon only - Thermocouple assemblies:
A. Consist of wires of different metals and lengths
B. Are painted yellow
C. Require insulaƟon between conductors
D. All of the above - During engine start, acceleraƟon temperature is excessively high. A possible cause is:
A. Fuel control acceleraƟon cam incorrectly adjusted
B. Fuel control bypass valve sƟcking closed
C. Low fuel pressure
D. Faulty thermocouple - During engine start, acceleraƟon temperature is too low. A possible cause is:
A. Fuel control acceleraƟon cam incorrectly adjusted
B. Fuel nozzle blockage
C. Excessive fuel flow
D. Faulty igniter - Water injecƟon systems:
A. Reduce specific fuel consumpƟon
B. Increase specific fuel consumpƟon and are therefore used only for short periods
C. Have no effect on fuel consumpƟon
D. Eliminate compressor stall - Compared with gasoline, aviaƟon kerosene has:
A. A lower boiling point
B. A higher boiling point
C. The same boiling point
D. Extremely high volaƟlity - A fuel flow indicator generally:
A. Measures fuel pressure only
B. Indicates fuel flow rate
C. May indicate fuel quanƟty in gallons
D. Both B and C - Lean die-out occurs when:
A. The fuel-air mixture becomes excessively rich
B. The fuel-air mixture becomes excessively lean to sustain combusƟon
C. Compressor speed becomes too high
D. IgniƟon energy becomes excessive