Manchester–Boston Regional Airport a "tag-on" for United flights heading from Bangor and Portland, Maine, to Chicago, but the carrier no longer serves either city with mainline aircraft. In the early 1990s, United Airlines began flights between Manchester and Washington Dulles International Airport near Washington, D.C. But creation of a north–south hub at Dulles did not work for United, and heavy competition in this market led to a quick exit. The Boeing 737 was used for this short-lived service, which comprised about four daily circuits between the two airports. US Airways started service at Manchester in early 1986, by connecting their hubs at Pittsburgh
Washington Dulles International Airport mezzanine with more room for lines. A new train system, dubbed AeroTrain and developed by Mitsubishi, began in 2010 to transport passengers between the concourses and the main terminal. The system, which uses rubber tires and travels along a fixed underground guideway, is similar to the people mover systems at Singapore Changi Airport, Hartsfield–Jackson Atlanta International Airport, and Denver International Airport. The train is intended to replace the mobile lounges, which many passengers found crowded and inconvenient. The initial phase includes the main terminal station, a permanent Concourse A station, a permanent Concourse B station, a permanent midfield concourse station