Patent ID: 8109470

Claim:
An aircraft fuel tank assembly, comprising: a first fuel tank, a second fuel tank, and a tank-to-tank overpressure protector, wherein the overpressure protector has a closed state for substantially preventing fluid communication between said first fuel tank and said second fuel tank through the overpressure protector, and an open state for enabling fluid communication between said first fuel tank and said second fuel tank through the overpressure protector to provide pressure relief, wherein the fuel tank assembly further comprises a mechanical indicator for indicating whether the overpressure protector is in the open or closed state, wherein said indicator comprises a follower element which is moveable dependent on the state of the overpressure protector, wherein the indication of the indicator is generated dependent on the position of the follower element, and wherein said open or closed state indication of the indicator is sensed at a location outside of the first and second fuel tanks.