Exam 1

Question 1

Turbine fuel with a civilian classification Jet A1 is known as \_\_ in the United States and has the military classification \_\_. 
A JP-5 F-35
B JP-8 F-80
C JP-40 F-45
D JP-4 F-40

Answer 1

A

Question 2

Why is Specific Gravity (SG) considered when loading AVTUR into an aircraft?
A Because the cost of fuel is determined by its SG, and airline accounting departments require this information for invoice reconciliation.
B Because AVTUR is more susceptible to SG changes than other fuels, with a consequent change in its volatility.
C Because fuel is loaded from the ground facility by volume (gallons or litres) and to convert volume to weight/mass (pound or kilograms) its SG is needed.
D In order to calculate the temperature of the fuel to ensure fuel icing does not become a problem later in flight.

Answer 2

C.

Question 3

How does the temperature, density, pressure and velocity of a gas flow vary through a divergent duct at supersonic speed?
A Temperature, density and pressure both decrease, while velocity increases.
B Temperature, density, pressure and velocity all increase.
C Temperature, density, pressure and velocity all decrease.
D Temperature and pressure both increase, while velocity and density decreases.

Answer 3

A.

Question 4

In what ways are turbine engines and reciprocating (piston) engines similar?
A Both types of engine use the same lubricating oil.
B Both types of engine are internal combustion.
C Both types of engine use the same fuel.
D Both types of engine have the same power to weight ratio.

Answer 4

B.

Question 5

How do clamshell reversers function?
A By blocker doors external to the exhaust duct moving to blank off the hot exhaust gases redirecting them forward.
B By blocker doors in the bypass duct moving to blank off the cold fan air redirecting it forward.
C By blocker doors inside the exhaust duct moving to blank off the hot exhaust gases redirecting them forward.
D By cascade vanes in the nacelle surrounding the bypass duct opening to allow the cold fan air to flow outward and forward.

Answer 5

C.

Question 6

There are three general types of combustion chamber. The most easily serviced is totally external to the engine, the second is a dual ring system and the third is an efficient combination of the two others. Which of the following lists the three types, in the order described? 
A Can, Can-annular and Annular.
B Can, Annular and Can-annular.
C Can-annular, Annular and Can.
D Can-annular, Can and Annular.

Answer 6

.B

Question 7

In which one of the following ways does AVTUR differ from AVGAS?
A AVGAS has better self lubricating properties.
B AVTUR has a higher calorific value.
C AVTUR is more volatile.
D AVGAS has a higher specific gravity.

Answer 7

B.

Question 8

Turbine blades used in modern turbine engines are generally: 
A fir leaf.
B impulse.
C impulse-reaction.
D reaction.

Answer 8

C.

Question 9

The primary function of a turbine engine’s lubrication system is to:
A clean metal particles from the turbine shaft bearings.
B protect the turbine blades from corrosion.
C cool the internal bearings.
D prevent metal to metal contact.

Answer 9

D.

Question 10

With respect to the mechanical efficiency, how do turbine engines differ from reciprocating (piston) engines?
A The reciprocating engine is more mechanically efficient.
B The respective mechanical efficiency of the two engine types depends on the prevailing operating environment.
C There is no difference between the two engine types with respect to mechanical efficiency.
D The turbine engine is more mechanically efficient.

Answer 10

D.

Question 11

Which of the gas flows from a turbofan engine is used to generate reverse thrust?
A The hot exhaust gas from the core flow.
B The cold stream flow from the bypass duct.
C Compressor flow by reversing the angle of the fan blades.
D Combustion gases from reverse flow engines.

Answer 11

B.

Question 12

What acronym is used to describe the ratio of turbine outlet pressure to compressor inlet pressure? 
A EGT.
B TIT.
C EPT.
D EPR.

Answer 12

D.

Question 13

What is the name given to the permanent lengthening (elongation) of turbine blades? 
A Stretch.
B Creep.
C Rubbing.
D Distension.

Answer 13

B.

Question 14

How is the residual temperature of the exhaust gases utilised?
A On turboprops the temperature of the exhaust gases can contribute to forward thrust, but on helicopters they serve no useful purpose.
B Exhaust gases are used for engine ice protection systems.
C Exhaust gases are used for airframe ice protection systems.
D It is not used at all, but rather it is lost to the atmosphere.

Answer 14

D.

Question 15

A similarity between turbine and reciprocating engines is that:
A both engines have a continuous gas flow.
B both engines use the same type of fuel.
C both engines use the same type of lubricating oil.
D both are internal combustion engines.

Answer 15

D.

Question 16

All other factors remaining the same, which of the following conditions will increase thrust or torque from a turbine engine? 
A An increase in density altitude.
B An increase in air intake temperature.
C A decrease in intake air density.
D An increase in air intake pressure.

Answer 16

D.

Question 17

How is RPM typically measured in a turboshaft engine?
A By utilising a sensor which measures fan blade passage over a pick-up.
B By utilising an AC generator, three phase independent electrical system and synchronous motor.
C By utilising an electronic counter which measures the ignition pulses.
D By measuring compressor outlet pressure, since compressor outlet pressure is proportional to engine RPM.

Answer 17

B.

Question 18

Typically the lubrication systems of high bypass turbofan engines is \_\_\_\_\_\_\_ pressure \_\_\_\_\_ sump. 
A low wet
B low dry
C high wet
D high dry

Answer 18

D.

Question 19

Which of the following is an advantage of an axial flow compressor, compared to a centrifugal compressor?
A An axial flow compressor is more resistant to FOD.
B An axial flow compressor is less prone to compressor stall/surge.
C An axial flow compressor allows for a smaller engine diameter for a given mass flow capacity.
D An axial flow compressor is more robust and easier to manufacture.

Answer 19

C.

Question 20

Which of the following statements regarding Specific Fuel Consumption (SFC) is correct?
A SFC is a measure of engine efficiency. When SFC is high, engine efficiency and therefore fuel economy is high.
B SFC decreases if the compressor is dirty or damaged.
C SFC is a measure of engine efficiency. When SFC is low, engine efficiency and therefore fuel economy is high.
D SFC increases with altitude, since RPM is increased to maintain a given thrust.

Answer 20

C.

Question 21

In a turbine engine, which of the following is an advantage applicable to an axial flow compressor when compared to a centrifugal compressor?
A It can achieve higher compression ratios more efficiently.
B It is better able to handle foreign object ingestion.
C It is not as prone to stalling and surging.
D It is more robust and easier to manufacture.

Answer 21

A.

Question 22

Which of the following best describes self sustaining RPM during start?
A The RPM at which the engine has settled at ground idle.
B The RPM at which the turbine is generating enough torque to accelerate on its own.
C The RPM at which the starter has created a steady acceleration of the engine core.
D The RPM at which the gas temperature starts to reduce.

Answer 22

B.

Question 23

The source of bleed air in a turbine engine is normally from the: 
A turbine.
B combustion chamber.
C exhaust.
D compressor.

Answer 23

D.

Question 24

The turbine temperature rising rapidly (unusually fast) towards the specified limit, is an indication of: 
A a wet start.
B a hung (or false) start.
C a hot start.
D torching on start.

Answer 24

C.

Question 25

How are modern turbine blades cooled in a turbofan engine?
A Secondary combustion air is blown over and through them.
B Oil is splashed over them.
C Bleed air from the compressor is blown over and/or through them.
D Fan air is blown over and through them.

Answer 25

C.

Question 26

What does the term reverse flow mean when used to describe the combustion section of a turbine engine?
A Reverse flow means that combustion gases are directed through a cooling section so that the fan can be mounted externally at the rear of the engine.
B Reverse flow means that raw fuel is injected into the combustion gases for reheat (after burning).
C Reverse flow means that the gas reverses its direction during the combustion process.
D Reverse flow means that the combustion gases are vectored forward to aid deceleration during landing or on a rejected takeoff.

Answer 26

C.

Question 27

What are the two main types of intake on turbofan engined aircraft? 
A Centreline and offset.
B Shielded and unshielded.
C Divided and pitot.
D Convergent and divergent.

Answer 27

C.

Question 28

Multiple, separate interconnected chambers within a common air casing, encircling the turbine shaft, describes: 
A an annular combustion chamber.
B can-annular combustion chamber.
C a can combustion chamber.
D axial flow combustion chamber.

Answer 28

B.

Question 29

Which of the following additives are commonly used in Jet A1? 
A Anti-microbiocodal.
B Anti-inflammatory.
C Anti-serum.
D Anti-toxin.

Answer 29

A.

Question 30

How does the pressure, temperature and velocity change across a stage of an axial compressor?
A Pressure, temperature and velocity all decreases across both the rotor and the stator.
B Pressure, temperature and velocity all increases across both the rotor and the stator.
C Pressure and temperature both decrease across both the rotor and the stator, while velocity increases across the stator and decreases across the rotor.
D Pressure and temperature both increase across both the rotor and the stator, while velocity decreases across the stator and increases across the rotor.

Answer 30

D.