DRAINS COLLECTOR TANK The drain system has also a drains collector tank / ejector assembly which is installed on the forward face of the external gearbox module and connected to the drains mast too. The tank collects excessive and unused fuel that drains from the fuel manifold when the engine is shut-down or after an engine start abort. The ejector sends the fuel back to the LP fuel system during engine start. If the tank is full, the fuel is discarded overboard via the drains mast.