← All explained questions · Supplemental · II — Preflight Procedures
When sumping fuel during preflight, the pilot finds clear water droplets settled at the bottom of the sample. The correct action is to
Choices
ignore the water — small amounts are normal.
Any water requires complete removal.
✓ continue draining sumps until samples are completely free of water and contaminants.correct
Keep draining the sumps until the samples are completely free of water and contaminants, then re-sump after the airplane has been moved to redistribute any residual water. Water in fuel must be completely drained — repeat sumping until samples are clean. Water can re-pool from undrained low spots after the airplane is moved, so a second sump after positioning is good practice. Water in fuel will cause engine roughness or stoppage, especially at altitude where it freezes.
add fuel-system de-icer and depart immediately.
Fuel additives don't substitute for proper draining.
rock the wings vigorously to break up the water.
Rocking won't make water acceptable in the fuel system.
Why
Keep draining the sumps until the samples are completely free of water and contaminants, then re-sump after the airplane has been moved to redistribute any residual water. Water in fuel must be completely drained — repeat sumping until samples are clean. Water can re-pool from undrained low spots after the airplane is moved, so a second sump after positioning is good practice. Water in fuel will cause engine roughness or stoppage, especially at altitude where it freezes.
FAA source: FAA-H-8083-3C, AFH Ch. 2, preflight / fuel contamination inspection; aircraft POH/AFMbrowse the reference library →
Try 10 more questions on this topic →Free, no signup needed to start.
Original study question written for this course — representative of FAA knowledge-test topics, not an actual current FAA exam question. Reviewed by a panel of three CFIs + AI review.