Pilots and crew members wave from the door of an Airbus A350-1000 twin-jet passenger plane, following its first flight from the Airbus factory in Toulouse, France, on November 24. The plane is the biggest version of Airbus’s A350 wide-body jet, swelling the twin-engine model’s capacity. Bloomberg reports its introduction casts doubt on the future of four-turbine planes, including Airbus’s own A380.