Airframe Mechanic Certification Powerplant Systems & Maintenance 2

Question 1

What is the primary purpose of an engine's magneto impulse coupling?

Accepted Answer

Retard ignition timing during starting to prevent kickback

Answer

Impulse couplings retard and then rapidly release to produce a hot spark at low engine RPM during starting, preventing kickback.

Question 2

When inspecting a turbine engine's compressor blades, a nick that exceeds allowable limits requires:

Accepted Answer

Repair per the manufacturer's structural repair manual

Answer

Damage exceeding allowable limits must be repaired per the manufacturer's structural repair manual or the engine must be removed.

Question 3

In a reciprocating engine, detonation differs from pre-ignition in that detonation:

Accepted Answer

Results from fuel-air mixture auto-igniting after normal spark ignition

Answer

Detonation is explosive auto-ignition of the end charge after normal spark ignition, whereas pre-ignition occurs before the spark plug fires.

Question 4

Which statement about turbine engine oil systems is correct?

Accepted Answer

Most turbine engines use a dry sump oil system

Answer

Turbine engines use a dry sump system where oil is stored in a separate tank rather than the engine sump.

Question 5

A fuel control unit (FCU) on a turbine engine primarily schedules fuel flow based on:

Accepted Answer

Compressor inlet temperature and pressure, throttle position, and RPM

Answer

The FCU uses multiple inputs including compressor inlet conditions, throttle position, and RPM to schedule the correct fuel flow.

Airframe Mechanic Certification Practice Test