Main articles: List of United Airlines destinations and List of United Express destinations Days before the internal deadline of Sept 27, the company announced that more than 97% of the US based staff were vaccinated. The company was the first major US airline to announce a vaccine mandate for all staff on Aug 6, at which point over 80% of flight attendants and 90% of pilots had been vaccinated, according to statements of the respective unions. In January 2021, Chief Executive Scott Kirby put forward the possibility for the company to mandate employees to receive the COVID-19 vaccine while cautioning the potential difficulties in implementing the mandate. On June 27, 2019, the parent company's name changed from United Continental Holdings to United Airlines Holdings. On March 3, 2012, United and Continental merged their passenger service systems, frequent-flier programs, and websites, which virtually eliminated the Continental brand with the exception of its logo. The merged airline began operating under a single air operator's certificate from the Federal Aviation Administration on November 30, 2011. The carriers planned to begin merging their operations in 2011. On October 1, 2010, the UAL Corporation changed its name to United Continental Holdings, Inc. The board of directors of Continental and UAL Corporation agreed on May 2, 2010, to combine operations, contingent upon shareholder and regulatory approval. On April 16, 2010, those discussions resumed. In late 2006, Continental Airlines and United had preliminary merger discussions. as a holding company for its airline subsidiaries. On March 28, 1931, UATC formed United Air Lines, Inc. In 1929, Boeing merged his company with Pratt & Whitney to form the United Aircraft and Transport Corporation (UATC) which then set about buying, in the space of just 28 months, Pacific Air Transport, Stout Air Services, VAL, and National Air Transport, as well as numerous equipment manufacturers at the same time. In 1927, William Boeing founded Boeing Air Transport to operate air mail routes under contract with the United States Post Office Department. VAL flew the first privately contracted air mail flight in the U.S. Continental Airlines is the successor to Speed Lanes, which Varney had founded by 1932 and whose name changed to Varney Speed Lines in 1934. United traces its roots to Varney Air Lines (VAL), which Walter Varney founded in 1926 in Boise, Idaho.
United was established by the amalgamation of several airlines in the late 1920s, the oldest of these being Varney Air Lines, which was founded in 1926. Regional service is operated by independent carriers under the brand name United Express. It is a founding member of the Star Alliance, the world's largest airline alliance with a total of 28 member airlines. United has eight hubs, with Chicago–O'Hare being its largest in terms of passengers carried and the number of departures. Measured by fleet size and the number of routes, it is the third-largest airline in the world. United operates a large domestic and international route network spanning cities large and small across the United States and all six continents. (commonly referred to as United) is a major American airline headquartered in Willis Tower in Chicago, Illinois. Gerry Laderman ( chief financial officer).