FAA Aviation Mechanic Airframe (AMA)Fuel, Cabin and Ice Control SystemsEasy
A line technician drains the fuel filter/water separator sump on a turbine aircraft before flight and finds a small amount of water. What is the primary purpose of this component?
- ATo remove water and particulate contamination from fuel before it reaches the engine-driven fuel pump
- BTo regulate fuel pressure delivered to the fuel control unit
- CTo measure the total fuel quantity remaining in the tank
- DTo mix fuel system icing inhibitor uniformly into the fuel
Show answer & explanationAnswer & explanation
Correct answer: A. To remove water and particulate contamination from fuel before it reaches the engine-driven fuel pump
A fuel filter/water separator removes free water and solid contaminants from the fuel supply, protecting downstream components such as the engine-driven pump and fuel control unit from damage and ice formation.
Why the other options are wrong
- B. Pressure regulation is performed by other fuel system components.
- C. That function belongs to fuel quantity indicating systems.
- D. FSII is typically added during refueling, not mixed by the filter.
Fuel Filter/Water Separator
A component installed in the fuel system that removes water and solid contaminants from fuel before it reaches the engine.
- Has a drainable sump for removing collected water
- Prevents ice formation and pump/injector damage
- Should be drained regularly per maintenance schedule
Memory trick: Filter/separator is the fuel system's water trap.