United Airlines is preparing to put one of its most anticipated new aircraft into passenger service, and the Airbus A321XLR is shaping up to be considerably more than a long-range replacement for the carrier’s aging Boeing 757 fleet. Designed as United Airlines’ most premium narrowbody for international flying, the aircraft brings lie-flat suites, premium economy, large seatback screens, and other features more commonly associated with widebody aircraft into a single-aisle cabin.