AMT Powerplant Theory and Maintenance 2

Question 1

What is the purpose of the intercooler in a turbocharged reciprocating engine?

Accepted Answer

To reduce the temperature of compressed induction air

Answer

To cool the oil before it enters the engine

Answer

To cool exhaust gases before they enter the turbocharger

Answer

To regulate the temperature of the magneto

Question 2

A reciprocating engine is said to be 'detonating' when:

Accepted Answer

The fuel-air mixture explodes instantaneously rather than burning progressively

Answer

The fuel-air mixture ignites too late in the power stroke

Answer

The magneto fires both plugs simultaneously

Answer

Excessive oil enters the combustion chamber

Question 3

Which turbine engine component is most susceptible to thermal fatigue and oxidation?

Accepted Answer

High-pressure turbine blades

Answer

Compressor inlet guide vanes

Answer

Accessory gearbox housing

Answer

Fan blade leading edges

Question 4

When performing a differential compression test on a reciprocating engine cylinder, a reading of 72/80 psi is obtained. What does this indicate?

Accepted Answer

The cylinder is serviceable; the leakage is within acceptable limits

Answer

The cylinder is unserviceable and must be removed immediately

Answer

The piston rings are completely failed

Answer

The intake valve is stuck open

Question 5

In a gas turbine engine, the primary function of the diffuser section is to:

Accepted Answer

Convert air velocity into static pressure

Answer

Accelerate airflow into the combustion chamber

Answer

Mix fuel with compressed air

Answer

Direct exhaust gases to the turbine

Question 6

Which type of oil system is commonly used in dry-sump aircraft engines?

Accepted Answer

A pressure pump and scavenge pump transfer oil to and from an external tank

Answer

A single pump circulates oil from a sump built into the crankcase

Answer

Oil is gravity-fed from a header tank with no pump required

Answer

A centrifugal pump draws oil directly from the accessory gearbox

Question 7

What is the role of the fuel control unit (FCU) on a turbine engine?

Accepted Answer

To meter fuel flow based on power lever position and engine parameters

Answer

To ignite the fuel-air mixture during start

Answer

To pressurize the fuel before it enters the combustion liner

Answer

To filter fuel contaminants before they reach the fuel nozzles