united airlines and united express operate more than 4,500 flights a day to 339 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 737 mainline aircraft and the airline's united express partners operate 483 regional aircraft. for more information, visit united.com. also follow united on hub.united.com, twitter (@united), facebook, youtube and instagram.