FAA Aviation Mechanic Airframe (AMA)Fuel, Cabin and Ice Control SystemsHard
A technician is troubleshooting a fuel vent system on a transport-category aircraft wing and locates a small chamber near the wingtip that is not part of the usable fuel volume. Its purpose is to collect fuel that expands due to thermal changes or sloshes during maneuvers, preventing fuel from escaping through the vent outlet. This chamber is called the:
- ASurge tank
- BCollector tank
- CSump tank
- DExpansion bladder
Show answer & explanationAnswer & explanation
Correct answer: A. Surge tank
A surge tank is an unpressurized, normally empty chamber near the wingtip that captures fuel displaced by thermal expansion or sloshing before it can escape overboard through the vent system, then allows it to drain back into the main tank.
Why the other options are wrong
- B. A collector tank gathers fuel from multiple tank bays to ensure a reliable supply to the engine pump, a different function.
- C. A sump tank collects water and contaminants at the low point of a tank for drainage, unrelated to venting.
- D. An expansion bladder is not a standard fuel system component; bladders are used as flexible tank liners.
Surge Tank
An empty vent-system chamber, usually near the wingtip, that catches fuel displaced by expansion or sloshing before it reaches the vent outlet, then drains it back into the main tank.
- Not part of usable fuel volume
- Prevents fuel loss through vent outlet
- Drains collected fuel back to main tank
Memory trick: Surge tank = 'catch-all' for fuel surges before it escapes