Abstract: A method and system for measuring the mass quantity and volume of fuel in an aircraft fuel tank is disclosed. A pressure assembly (124) is disposed proximate the lowest portion of each fuel tank on an aircraft (60), with respect to a wing tank (100). The pressure sensor assembly includes a temperature probe (126) having a plurality of temperature sensors (128) mounted therein at spaced apart elevations within the fuel tank. Also included is an attitude sensor (150) in which are provided a roll sensor (156) and a pitch sensor (160) for respectively determining the roll and pitch angles of the fuel surface with respect to a vertical reference axis on the aircraft. The reference axis is aligned with an acceleration-sensitive axis of an accelerometer (164), which is operative to determine the acceleration acting upon fuel within the wing tank, and using the roll and pitch angles, the acceleration normal to the upper surface of the fuel.