This SAE Aerospace Standard (AS) defines the maximum allowable free opening dimensions for airframe fueling ports on civil aircraft that require the exclusive use of gasoline as an engine fuel, and the minimum free opening dimensions for airframe fueling ports on civil aircraft that operate with turbine fuels as the primary fuel type and with gasoline as the emergency fuel type. This SAE Aerospace Standard (AS) also defines the features and dimensions for airframe refueling ports on civil aircraft that require the exclusive use of turbine fuel as an engine fuel.