FAA Aviation Mechanic Powerplant (AMP)Fuel, Induction and LubricationEasy
A mechanic is performing a pre-flight inspection on a reciprocating engine aircraft. What is the primary reason for draining a small amount of fuel from the fuel tank sumps and fuel strainer drain?
- ATo verify the specific gravity of the fuel.
- BTo check for water and sediment contamination.
- CTo ensure proper fuel system pressurization.
- DTo measure the exact fuel quantity in the tanks.
Show answer & explanationAnswer & explanation
Correct answer: B. To check for water and sediment contamination.
Water and sediment are denser than aviation fuel and will settle at the lowest points (sumps and strainers) in the fuel system. Draining these points allows a visual check for these contaminants, which can cause engine power loss or failure.
Why the other options are wrong
- A. Verifying specific gravity requires specialized equipment and is not a routine pre-flight check performed by draining a small sample.
- C. Fuel system pressurization is not typically checked by draining fuel; it's more relevant to turbine engines or specific boost pump operations.
- D. A small drain sample is insufficient to measure the exact fuel quantity; this is done via fuel gauges or dipstick methods.
Fuel Sump Drain Check
A pre-flight procedure where a small amount of fuel is drained from low points in the fuel system to check for water and sediment contamination.
- Water is denser than fuel and settles at the bottom.
- Sediment can clog filters and fuel nozzles.
- Essential for preventing engine malfunctions due to contaminated fuel.
Memory trick: Drain for Dirt and Drops