Well them's the facts. Yes, the aircraft will turn without BGS, but not as quickly or sharply and in this case not quickly or sharply enough. Yesterday the BGS failed and the crew taken unawares (no EICAS messages) could not make the turn at the end of the runway. On departure the crew had to use differential braking and engine thrust to turn the aircraft, which apparently is not the norm at that airport (under Cargolux SOP's anyway).