B777 Fuel tank vent system
Hi,
I was just reading through the BA B777-200 incident where thrust are lost on both engines due to ice accretion, the report talked about the fuel tank vent system. I can't seem to find detailed explanation other than the surge tank in FCOM. Can someone with the knowledge care to share and educate the purpose of the vent system?
Quote: Fuel tank vent system
Each tank is vented to atmosphere through channels in the roof of the fuel tanks, which are connected to surge tanks mounted outboard of each of the main tanks. The surge tanks are vented to atmosphere through a flame arrestor and a scoop mounted on the lower surface of each wing. Should the flame arrestor or scoop become blocked, a pressure relief valve will operate and prevent the tanks from becoming over, or under, pressurised.
Thanks