B.A. had a b747-400 take off from Nirita and an engine went bang.The crew made sure everything was safe and flew onto Helisinki.This is because the the aircraft burns more fuel on three engines than four.Maybe someone can tell me why this is.It wasthen 3 eng ferried back to LHR with the engine siezed so there was no windmilling but apparently this was safe to do so.