Mainline (air travel)

Airline industry term A mainline flight by a United Airlines Boeing 777-200ER landing at Amsterdam Schiphol Airport in February 2011. JetBlue Airbus A320 and Embraer E190 at John F. Kennedy International Airport in March 2006. Unlike many other airlines, JetBlue's mainline equipment included the Embraer E190 until September 2025. On traditional legacy carriers, such operations on the smaller aircraft are mostly outsourced to smaller, usually independently owned regional airlines. A mainline flight is a flight operated by an airline's main operating unit, rather than by regional alliances, regional code-shares, regional subsidiaries, or wholly owned subsidiaries offering low-cost operations. Mainline carriers typically operate between hub airports within their network and on international or long-haul services, using narrow-body and wide-body aircraft. This is in contrast to regional airlines, providing feeder services to hub airports operating smaller turboprop or regional jet aircraft, or low-cost carrier subsidiaries serving leisure markets. In the United States, examples of mainline passenger airline flights include those operated by American Airlines, Delta Air Lines, and Unite