Update: Paramedics examined, and discharged, 6 people who fell ill on Los Angeles-bound American Airlines flight forced to return London's Heathrow Airport; unclear what caused patients to feel sick; crews investigating plane found no evidence of hazardous substances, authorities say - ABC News
American Airlines, Inc. (AA) is a major American airline headquartered in Fort Worth, Texas. Operating an extensive international and domestic network, American Airlines is the world's largest airline by fleet size and revenue, and the second largest by number of destinations served, after United Airlines. It operates from its main hub at Dallas/Fort Worth, and its hubs at Charlotte, Los Angeles, New York-JFK, New York-LaGuardia, Miami, Chicago-O'Hare, Philadelphia, Phoenix, and Washington, D.C., while its primary maintenance base is at Tulsa International Airport. Its primary competitors are United Airlines, Delta Air Lines, and Southwest Airlines.
American Airlines is a founding member of the Oneworld airline alliance, and coordinates fares, services, and scheduling with British Airways, Iberia, and Finnair in the transatlantic market and with Japan Airlines in the transpacific market. Regional service is operated by independent and subsidiary carriers under the brand name American Eagle.