Accidents attributed to powerplant 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.
Precautions against fuel contamination include:
- Proper 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. If water is found in the first sample, drain further samples until no trace of it appears. Suspended water droplets in the fuel can be identified by a cloudy appearance of the fuel, or by the clear separation of water from the coloured fuel, which occurs after the water has settled to the bottom of the tank.
- Replenish the Tanks: Fuel tanks should be filled after each flight or after the last flight of the day to prevent condensation within the tank. To prevent fuel contamination, avoid refuelling from cans and drums.
- Anti-icing Additives: The use of anti-icing additives for some aircraft has been approved as a means of preventing problems with water and ice in AVGAS. Anti-icing additives are in no way a substitute or replacement for carburetor heat.
- Using the Correct Grade of Fuel: Always ensure the correct fuel grade is used.