## Chapter 2 Engine Fuel and Fuel Metering Systems 

## Fuel System Requirements 

The engine fuel system must supply fuel to the engine’s fuel metering device under all conditions of ground and air operation. It must function properly at constantly changing altitudes and in any climate. The most common fuels are AVGAS for reciprocating engines and Jet A for turbine engines. AVGAS is generally either 80 (red) or 100LL (blue) octane. The LL stands for low lead although it contains four times the lead of 80 octane AVGAS. Jet A is a kerosene-based fuel that is clear to straw in color. 

