Aircraft Fuel Systems Flashcards
7 cards from real A&P practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Aircraft Fuel Systems flashcards as text
When should fuel sump drains be checked by sampling fuel from the aircraft?
Answer: Before each flight, after refueling, and after the aircraft has sat overnight or longer
Fuel sumps should be sampled before each flight, after refueling, and after any extended parking period to detect water and sediment contamination before it can cause engine failure.
What is the most common cause of water contamination in aircraft fuel tanks?
Answer: Water condensation forming when moist air in partially filled tanks cools
Water condensation is the most common fuel contaminant, occurring when humid air trapped in partially filled tanks condenses as ambient temperatures drop overnight.
What is the correct action if water is found during a fuel sump drain check?
Answer: Continue draining until only clean fuel flows; ground the aircraft if water persists and have a mechanic inspect
The correct procedure is to continue draining until only clean, uncontaminated fuel flows; if water continues to appear, the aircraft must be grounded and inspected by an A&P mechanic.
What is the purpose of a fuel primer in an aircraft?
Answer: To deliver raw fuel directly to the engine intake system to enrich the mixture for cold engine starting
A fuel primer injects raw fuel directly into the engine's intake ports or cylinders, providing the rich mixture necessary to start a cold engine when the carburetor alone cannot deliver adequate fuel.
What is the function of a motive flow (jet) pump in an aircraft fuel system?
Answer: To transfer fuel from auxiliary or tip tanks to the main feed tank using engine fuel pressure and venturi effect
A motive flow pump uses the venturi effect, powered by high-pressure fuel from the engine, to transfer fuel from auxiliary tanks to the main feed tank without requiring electrical power or moving parts.
What indicates a clogged or restricted aircraft fuel filter?
Answer: Low fuel pressure downstream of the filter and a differential pressure warning indication
A restricted fuel filter creates high pressure upstream and reduced pressure downstream; many aircraft are equipped with differential pressure switches that illuminate a cockpit warning when the restriction becomes critical.
Under FAR Part 43, the aircraft fuel system is inspected as part of which required inspection interval?
Answer: Every 100 hours as part of the 100-hour inspection
Under FAR Part 43, the fuel system is included in the required 100-hour inspection, during which all aircraft systems and components are checked for airworthiness.