United Airlines' largest expansion comes with new seating option for economy travelers

United Airlines will add a paid “extra space” seat option to some international flights starting next year, as part of what it calls the largest expansion in its history. For eligible passengers on new aircraft, the airline’s custom Economy Plus seats will block some middle seats, creating more room. United first teased the concept in July and formally unveiled it Tuesday alongside the announcement of 10 new routes across Europe and Asia. Some services will use the A321XLR single-aisle. On each XLR, one row features large custom tables spanning armrest to armrest across the open middle seats, permanently fixed with two cup indentations. Tickets for the 10 nonstops—including Okinawa, Ibiza, Terceira and Catania—go on sale Tuesday.