FREE AMT Turbine Engine Principles Questions and Answers

Question 1

Which of the following describes the primary function of the diffuser section in a gas turbine engine?

Accepted Answer

To increase the pressure and reduce the velocity of the air leaving the compressor.

Answer

The diffuser is a divergent duct located between the compressor section and the combustion section. Its purpose is to slow down the high-velocity air from the compressor and increase its pressure before it enters the combustion chambers, ensuring stable combustion.

Question 2

A turbofan engine has a bypass ratio of 5:1. What does this indicate?

Accepted Answer

For every 1 part of air that goes through the engine core, 5 parts of air are bypassed around the core.

Answer

Bypass ratio is a fundamental parameter of a turbofan engine. It is the ratio of the mass flow rate of the air that is bypassed around the engine core to the mass flow rate of the air that passes through the core. A 5:1 ratio means five times more air goes around the core than through it.

Question 3

During a routine inspection of a turbine engine, a technician finds minor pitting and small nicks on the leading edges of the first-stage compressor blades. According to typical maintenance standards, what is the most likely cause?

Accepted Answer

Foreign Object Damage (FOD)

Answer

Small nicks, dents, and pitting on the front-facing compressor blades are classic signs of Foreign Object Damage (FOD). This occurs when small, hard particles (like sand, ice, or runway debris) are ingested into the engine inlet and strike the rotating blades.

Question 4

What is the primary thermodynamic cycle upon which all gas turbine engines operate?

Accepted Answer

The Brayton cycle

Answer

The Brayton cycle is the thermodynamic model that describes the operation of a gas turbine engine. It consists of four processes: isentropic compression (in the compressor), constant-pressure heat addition (in the combustor), isentropic expansion (in the turbine), and constant-pressure heat rejection (exhaust).

Question 5

In a dual-spool, axial-flow compressor, how is the low-pressure compressor (N1) typically connected to its corresponding turbine?

Accepted Answer

Via a concentric shaft that passes through the hollow high-pressure (N2) shaft.

Answer

Dual-spool engines have two independent rotating assemblies. The low-pressure compressor (N1) is connected to the low-pressure turbine by a shaft that runs through the center of the hollow high-pressure (N2) shaft, which connects the high-pressure compressor and high-pressure turbine. This allows each spool to rotate at its own optimal speed.

(AMT) Aviation Maintenance Technician Practice Test

(AMT) Aviation Maintenance Technician Practice Test

FREE AMT Turbine Engine Principles Questions and Answers