After finalizing its merger with Northwest, Atlanta-based Delta Air Lines has become the world's largest airline, flying to over 368 destinations in 66 countries. Delta operates under a hub system, where it gathers and distributes passengers across the globe through key locations in Atlanta, Cincinnati, New York, Salt Lake City, and newly acquired Detroit and Minneapolis-St. Paul. Delta generates $30 billion in annual revenue with a fleet of nearly 1,000 aircraft.