The Boeing 787-9 Dreamliner is one of the most widely used long-haul aircraft of its generation, combining a large twin-engine widebody cabin with the range needed for routes that can stretch across oceans. However, putting a single hourly operating figure on the aircraft is harder than it might initially appear, because the cost of flying a 787-9 depends on many factors, including fuel prices, maintenance arrangements, crew expenses, airport charges, aircraft utilization, and the way an airline accounts for ownership.