A&P Turbine Engine Theory Questions and Answers

Question 1

In a gas turbine engine, what is the primary function of the diffuser section located between the compressor and the combustor?

Accepted Answer

To decrease the velocity and increase the static pressure of the air.

Answer

To increase the velocity and decrease the static pressure of the air.

Answer

To mix fuel with the compressed air for ignition.

Answer

To extract bleed air for cabin pressurization and anti-ice systems.

Question 2

Which of the following statements most accurately describes the primary source of thrust in a high-bypass turbofan engine?

Accepted Answer

The majority of thrust is produced by the large fan section accelerating a mass of ducted air that bypasses the engine core.

Answer

Thrust is generated almost exclusively by the high-velocity exhaust gases exiting the core engine.

Answer

Thrust is equally divided between the fan section and the core exhaust gases.

Answer

All thrust is generated by the expansion of hot gases in the turbine section driving the fan.

Question 3

A pilot reports hearing a loud bang from the engine, followed by a rapid rise in Exhaust Gas Temperature (EGT) and a loss of thrust. These symptoms are most indicative of which condition?

Accepted Answer

Compressor stall or surge

Answer

Flameout

Answer

Hot start

Answer

Hung start

Question 4

What is the primary purpose of the "fir-tree" root design commonly used to attach turbine blades to the turbine disk?

Accepted Answer

To securely attach the blade while accommodating thermal expansion and high centrifugal loads.

Answer

To simplify the manufacturing and machining of the turbine disk.

Answer

To act as a heat sink, drawing heat away from the blade airfoil.

Answer

To create a lightweight connection that reduces rotational mass.

Question 5

The continuous thermodynamic cycle of intake, compression, constant-pressure combustion, and exhaust that describes the operation of a gas turbine engine is known as the:

Accepted Answer

Brayton cycle

Answer

Otto cycle

Answer

Diesel cycle

Answer

Rankine cycle

Question 6

A technician is troubleshooting an aircraft's inoperative wing anti-icing and cabin pressurization systems. Which turbine engine system is the most likely common source for both of these issues?

Accepted Answer

The compressor bleed air system.

Answer

The engine fuel control unit.

Answer

The accessory gearbox.

Answer

The engine lubrication system.