Airframe Mechanic Certification Powerplant Systems & Maintenance 3

Question 1

An aircraft reciprocating engine is running rough. You find one magneto drops 175 RPM during the mag check. This most likely indicates:

Accepted Answer

A fouled spark plug or failed ignition lead on that magneto's circuit

Answer

An excessive RPM drop on one magneto suggests a fouled plug or defective ignition lead is preventing complete combustion on that magneto alone.

Question 2

What is the purpose of a turbine engine's bleed air system?

Accepted Answer

Provide air for cabin pressurization, anti-icing, and engine starting

Answer

Bleed air extracted from the compressor stages supplies pressurization, anti-icing, pneumatic engine starting, and other aircraft systems.

Question 3

The P-lead wire on a magneto, when grounded, causes the magneto to:

Accepted Answer

Be disabled (switched off)

Answer

Grounding the P-lead shorts the primary circuit of the magneto, preventing it from firing and effectively turning it off.

Question 4

During engine run-up, which condition indicates a possible induction system air leak on a fuel-injected reciprocating engine?

Accepted Answer

Engine runs rough and mixture response is abnormal

Answer

An induction leak introduces unmetered air, causing rough running and abnormal mixture response because the fuel control cannot account for the extra air.

Question 5

A turbine engine compressor stall is best described as:

Accepted Answer

Disruption of airflow through the compressor causing pressure reversal

Answer

A compressor stall occurs when the angle of attack of compressor blades exceeds the critical angle, causing airflow disruption and potential pressure reversal.

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Powerplant Systems & Maintenance 3