[Ref. Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 7-27, 7-28]
Accidents attributed to powerplant (engine) failure from fuel contamination have often been traced to :
- Inadequate preflight inspection by the pilot
- Servicing aircraft with improperly filtered fuel from small tanks or drums
- Storing aircraft with partially filled fuel tanks
- Lack of proper maintenance
Water is the principal fuel contaminant
Suspended water droplets in the fuel can be identified by a cloudy appearance of the fuel – they cannot be mixed with fuel, so the clear separation of water from the colored fuel is a good indicator of water contamination.
To prevent fuel contamination :
- Preflight inspection – fuel should be drained from the fuel strainer quick drain and from each fuel tank sump into a transparent container and then checked for dirt and water
(Notes: If water or other contaminants are found in the first sample, drain further samples until no trace appears.) - Avoid refueling from cans and drums
(Notes: In remote areas or in emergency situations, there may be no alternative to refueling from sources with inadequate anti-contamination systems, a chamois skin and funnel may be the only possible means of filtering fuel) - Fuel tanks should be filled after each flight or after the last flight of the day to prevent moisture condensation within the tank
- Proper maintenance