CNN  —  United Airlines passengers flying on new Boeing 787-9s will find a new “Elevated” aircraft interior when the fresh design debuts on international flights next year. The Dreamliner aircraft interior, which was unveiled on Tuesday, features new luxury United Polaris Studio suites for some business class travelers, sliding doors and 19-inch screens for standard United Polaris seats and improvements across classes of service in this “nose-to-tail transformation.” “This is just one more step,