Ive just heard that BA's LCY-JFK flights using a A318 will have a fuel stop in BHD for every flight.
It's going through Shannon Westbound as the runway at London City is too short for the fuel load required to go direct. The runway at Belfast City isn't ideal for transatlantic weights and fuel I suspect, as even Ryanair are load constrained operating across to Prestwick on a B737.