United Airlines and United Express operate approximately 4,500 flights a day to 337 airports across five continents. In 2016, United and United Express operated more than 1.6 million flights carrying more than 143 million customers. United is proud to have the world's most comprehensive route network, including U.S. mainland hubs in Chicago, Denver, Houston, Los Angeles, New York/Newark, San Francisco and Washington, D.C. United operates 743 mainline aircraft and the airline's United Express partners operate 478 regional aircraft. The airline is a founding member of Star Alliance, which provides service to 190 countries via 28 member airlines. For more information, visit united.com, follow @United on Twitter or connect on Facebook. The common stock of United's parent, United Continental Holdings, Inc., is traded on the NYSE under the symbol "UAL".