Powerplant Systems & Engine Maintenance Flashcards
7 cards from real AMT 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 & Engine Maintenance flashcards as text
What is the purpose of engine baffles on an air-cooled reciprocating engine?
Answer: To direct cooling air around the cylinders in a controlled manner to ensure even temperature distribution
Baffles channel cooling airflow around the cylinder fins in a controlled path, ensuring uniform temperature distribution and preventing hot spots.
An aircraft reciprocating engine has excessive oil consumption with blue smoke in the exhaust. The most likely cause is:
Answer: Worn valve guides or piston rings allowing oil to enter the combustion chamber
Blue exhaust smoke is characteristic of oil burning in the combustion chamber, most commonly caused by worn valve guides or piston rings allowing oil past the seals.
What is the purpose of a turbine engine's fuel heater?
Answer: To prevent ice crystals from forming in the fuel filter and blocking fuel flow
Fuel heaters warm jet fuel to prevent ice crystal formation in the fuel filter, which could restrict fuel flow and cause engine flameout.
When troubleshooting a magneto that is excessively retarded (late timing), the pilot would most likely report:
Answer: Loss of power, high fuel consumption, and high exhaust gas temperatures
Retarded ignition timing causes the fuel-air charge to burn later in the power stroke, reducing power output, wasting fuel, and increasing EGT.
What is the function of the fuel control unit (FCU) on a turbine engine?
Answer: Meters fuel flow to the engine based on power lever position, engine speed, and inlet conditions
The FCU schedules and meters fuel delivery to maintain desired engine speed and prevent overtemperature or overspeed across all operating conditions.
A reciprocating engine exhibits low oil pressure accompanied by high oil temperature. What is the most likely cause?
Answer: Worn bearings providing excessive clearance, allowing oil to bypass and reducing pressure while increasing friction heat
Worn engine bearings increase oil clearances, reducing resistance and pressure while generating additional friction heat, causing the combined low pressure/high temperature symptom.
Which statement about turbine engine thrust reversers is correct?
Answer: Most regulations prohibit use of thrust reversers as the primary means of stopping the aircraft below a minimum groundspeed
At very low groundspeeds, thrust reverser use can cause hot exhaust re-ingestion and aircraft control problems, so regulations typically require discontinuing reverse thrust above idle before a minimum speed.