WASHINGTON—Airbus said it will continue to build the A380 for at least another decade following a commitment from Emirates Airline to add at least 20 aircraft to its backlog. After months of difficult negotiations and a clash at November’s Dubai Airshow, the airline Jan. 18 signed a memorandum of understanding for an additional 36 aircraft. The preliminary deal consists of 20 firm orders and 16 options. Emirates has yet to make a choice between the Rolls-Royce Trent 900 and ...