What does "fuel tank sumping" involve?

Fuel tank sumping is a critical procedure that involves checking for contaminants such as water and debris in the fuel tank. This process is essential because water can cause engine performance issues, and contaminants can lead to corrosion or other damage to the fuel system. By sampling fuel from the lowest point of the tank, technicians can ensure that any separated water or sediment is removed before flight operations, thereby enhancing safety and reliability.

The importance of this practice stems from the fact that water is denser than fuel and tends to settle at the bottom of fuel tanks. Regularly performing sumping helps maintain fuel quality and prevents potential engine failures that could arise from contaminated fuel.