Powerplant Systems & Maintenance Flashcards
7 cards from real Airframe Mechanic Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Powerplant Systems & Maintenance flashcards as text
An aircraft reciprocating engine is running rough. You find one magneto drops 175 RPM during the mag check. This most likely indicates:
Answer: A fouled spark plug or failed ignition lead on that magneto's circuit
An excessive RPM drop on one magneto suggests a fouled plug or defective ignition lead is preventing complete combustion on that magneto alone.
What is the purpose of a turbine engine's bleed air system?
Answer: Provide air for cabin pressurization, anti-icing, and engine starting
Bleed air extracted from the compressor stages supplies pressurization, anti-icing, pneumatic engine starting, and other aircraft systems.
The P-lead wire on a magneto, when grounded, causes the magneto to:
Answer: Be disabled (switched off)
Grounding the P-lead shorts the primary circuit of the magneto, preventing it from firing and effectively turning it off.
During engine run-up, which condition indicates a possible induction system air leak on a fuel-injected reciprocating engine?
Answer: Engine runs rough and mixture response is abnormal
An induction leak introduces unmetered air, causing rough running and abnormal mixture response because the fuel control cannot account for the extra air.
A turbine engine compressor stall is best described as:
Answer: Disruption of airflow through the compressor causing pressure reversal
A compressor stall occurs when the angle of attack of compressor blades exceeds the critical angle, causing airflow disruption and potential pressure reversal.
What type of oil is used in most turbine engines?
Answer: Synthetic ester-based oil
Turbine engines require synthetic ester-based oils that withstand the extreme temperatures and provide adequate lubrication at high altitudes.
When is it permissible to use automotive gasoline (MOGAS) in an aircraft engine?
Answer: Only when approved by an STC for that specific aircraft/engine combination
MOGAS may only be used when an FAA-approved Supplemental Type Certificate (STC) authorizes its use for that specific aircraft and engine combination.