The Air Force is beginning to return B-1B bombers to the air after grounding the entire fleet last month to investigate a fuel system issue. Some Lancers resumed flight operations Monday, about two weeks after Air Force Global Strike Command ordered the fleet of 57 aircraft to stand down for safety inspections. The service declined to say how many were cleared for flight, citing operational sensitivities. “Individual B-1B aircraft will return to flight as inspections and maintenance directed