NIFE - Engine Exam Review
Questions with Correct Detailed
Answers
What are mechanical malfunctions that can lead to a compressor stall? - Answer-FOD,
Failed fuel control unit, vairiable inlet guide vane failure, or variable exhaust nozzle
failure
What's the difference between stall prevention and stall avoidance? - Answer-
Prevention - manufacturer (viarable inlet guide/stator vane, dual spool compressor,
bleed valves, variable exhaust nozzle) Avoidance - pilot can control (avoid erratic/abrupt
PCL movements, avoid severe weather, avoid abrupt changes in attitude, maintain
minimums)
What is interstage bleed air used for? - Answer-Compressor stability
How do you recover from an engine stall? - Answer-Reduce attitude of aircraft, retard
PCL
How do you construct a turbojet? - Answer-Gas generator + inlet + exhaust
What is thrust specific fuel consumption? - Answer-Amount of fuel you need to get 1lb
of thrust. Lower is more efficient.
How is a turbo fan constructed? - Answer-gas generator + ducted fan + exhaust
How does a turbo fan increase its thrust? - Answer-Accelerating more air (increases the
mass portion of the Thrust = m * a)
How can you attach a ducted fan? - Answer-Free power turbine or attached to low-
pressure compressor
What is a bypass ratio? - Answer-Amount of air that goes around the engine to what
goes through. Strike fighter low (1:1), cargo would be high (like 5:1)
Describe turbojet thrust, TSFC and specific weight - Answer-100% of thrust comes from
exhaust. Very high TSFC (inefficient) and lowest specific weight (most simple design)
What happens to the efficiency of a turbo fan with decerase in altitude? - Answer-More
efficient (dense air)
, What is the purpose of the propeller? - Answer-Increases mass of air accelerated over
the wing
What are the components of the propeller? - Answer-Pitch change/dome assembly, hub
assembly, hub, blades
What is the purpose of the reduction gear box? - Answer-Convert low torque/high rpm
of engine to high torque/low RPM of the propeller
What is the purpose of the torquemeter assembly? - Answer-Connect the reduction
gear box to the gas generator, also can measure shaft horsepower.
What are the two sources of AC power? - Answer-AC generator (alternator), Inverter
(DC-->AC power)
If you have a turbojet or turbofan, what do you need to ensure a constant RPM? -
Answer-Constant speed drive
How does a generator work? - Answer-Converts mechanical energy to electrical.
What are our 3 sources of DC power? - Answer-DC Generator, Transformer-rectifier
(AC-->DC), battery
What is a bus? - Answer-Common distribution point for electricity
What are the four types/purposes of each bus? - Answer-Essential: flight safety.
Primary: mission equipment. Monitor/secondary: convenience (cabin lighting). Starter:
starts aircraft engines
How can you menipulate a switch? - Answer-Manually
How can a circuit braker be menipulated? - Answer-Automatic or manually
How is a fuse controlled? - Answer-Automatically
What is Pascal's law? - Answer-Pressure applied to an to an enclosed or confined liquid
is transmitted equally in all directions and acts with equal orce on equal surfaces
What is the tradeoff of force multiplying in hydraulics? - Answer-Linear displacement is
reduced
What is a hydraulic system used for in military aircraft? - Answer-Multiplying force and
giving us a mechanical advantage
What units are used in hydraulics? - Answer-Force - pounds, Area - sq inches, pressure
PSI
Questions with Correct Detailed
Answers
What are mechanical malfunctions that can lead to a compressor stall? - Answer-FOD,
Failed fuel control unit, vairiable inlet guide vane failure, or variable exhaust nozzle
failure
What's the difference between stall prevention and stall avoidance? - Answer-
Prevention - manufacturer (viarable inlet guide/stator vane, dual spool compressor,
bleed valves, variable exhaust nozzle) Avoidance - pilot can control (avoid erratic/abrupt
PCL movements, avoid severe weather, avoid abrupt changes in attitude, maintain
minimums)
What is interstage bleed air used for? - Answer-Compressor stability
How do you recover from an engine stall? - Answer-Reduce attitude of aircraft, retard
PCL
How do you construct a turbojet? - Answer-Gas generator + inlet + exhaust
What is thrust specific fuel consumption? - Answer-Amount of fuel you need to get 1lb
of thrust. Lower is more efficient.
How is a turbo fan constructed? - Answer-gas generator + ducted fan + exhaust
How does a turbo fan increase its thrust? - Answer-Accelerating more air (increases the
mass portion of the Thrust = m * a)
How can you attach a ducted fan? - Answer-Free power turbine or attached to low-
pressure compressor
What is a bypass ratio? - Answer-Amount of air that goes around the engine to what
goes through. Strike fighter low (1:1), cargo would be high (like 5:1)
Describe turbojet thrust, TSFC and specific weight - Answer-100% of thrust comes from
exhaust. Very high TSFC (inefficient) and lowest specific weight (most simple design)
What happens to the efficiency of a turbo fan with decerase in altitude? - Answer-More
efficient (dense air)
, What is the purpose of the propeller? - Answer-Increases mass of air accelerated over
the wing
What are the components of the propeller? - Answer-Pitch change/dome assembly, hub
assembly, hub, blades
What is the purpose of the reduction gear box? - Answer-Convert low torque/high rpm
of engine to high torque/low RPM of the propeller
What is the purpose of the torquemeter assembly? - Answer-Connect the reduction
gear box to the gas generator, also can measure shaft horsepower.
What are the two sources of AC power? - Answer-AC generator (alternator), Inverter
(DC-->AC power)
If you have a turbojet or turbofan, what do you need to ensure a constant RPM? -
Answer-Constant speed drive
How does a generator work? - Answer-Converts mechanical energy to electrical.
What are our 3 sources of DC power? - Answer-DC Generator, Transformer-rectifier
(AC-->DC), battery
What is a bus? - Answer-Common distribution point for electricity
What are the four types/purposes of each bus? - Answer-Essential: flight safety.
Primary: mission equipment. Monitor/secondary: convenience (cabin lighting). Starter:
starts aircraft engines
How can you menipulate a switch? - Answer-Manually
How can a circuit braker be menipulated? - Answer-Automatic or manually
How is a fuse controlled? - Answer-Automatically
What is Pascal's law? - Answer-Pressure applied to an to an enclosed or confined liquid
is transmitted equally in all directions and acts with equal orce on equal surfaces
What is the tradeoff of force multiplying in hydraulics? - Answer-Linear displacement is
reduced
What is a hydraulic system used for in military aircraft? - Answer-Multiplying force and
giving us a mechanical advantage
What units are used in hydraulics? - Answer-Force - pounds, Area - sq inches, pressure
PSI
