AMT Powerplant Systems & Engine Maintenance 2

Question 1

What is the primary purpose of an aircraft engine's intercooler?

Accepted Answer

To cool the compressed induction air between the supercharger and the intake manifold

Answer

An intercooler cools supercharged or turbocharged induction air between the compressor and the intake manifold, increasing air density for better combustion.

Question 2

When inspecting a turbine engine for a hot-section inspection, which component is most susceptible to thermal fatigue cracking?

Accepted Answer

Turbine blades and nozzle guide vanes

Answer

Turbine blades and nozzle guide vanes operate at the highest temperatures in the engine and are most susceptible to thermal fatigue cracking.

Question 3

A reciprocating engine is running rough and backfiring through the induction system. The most likely cause is:

Accepted Answer

Excessively lean mixture causing early ignition

Answer

An excessively lean mixture can cause slow or late combustion that continues into the induction cycle, causing backfiring through the intake.

Question 4

What does the term 'critical altitude' refer to in a turbocharged engine?

Accepted Answer

The highest altitude at which the turbocharger can maintain rated manifold pressure

Answer

Critical altitude is the maximum altitude at which the turbocharger can maintain the rated manifold pressure; above this, manifold pressure begins to drop.

Question 5

During a compression check on a reciprocating engine, a low reading that improves significantly when oil is squirted into the cylinder indicates:

Accepted Answer

Worn or broken piston rings

Answer

Oil temporarily seals piston ring gaps, so a low reading that improves with oil injection points to worn or damaged piston rings as the source of leakage.

(AMT) Aviation Maintenance Technician Practice Test

(AMT) Aviation Maintenance Technician Practice Test

AMT Powerplant Systems & Engine Maintenance 2