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.
and American Flagship Service cater to the medium-haul transcontinental business segment.
An airline carrier's collective bargaining agreement with flight crews stipulates the maximum seating capacity of regional aircraft; as such, any aircraft that exceeds this capacity must operate as a mainline flight.
3 These independent airlines operate regional aircraft under codeshare agreements with a mainline carrier.