|This article's factual accuracy may be compromised due to out-of-date information. (August 2012)|
A mainline flight is a flight operated by an airline's main operating unit, rather than by regional alliances, regional code-shares or regional subsidiaries. In the USA, examples of mainline passenger airline flights include those operated by American Airlines, Delta Air Lines, United Airlines, and US Airways but it would not include flights operated by regional airlines American Eagle Airlines, Executive Airlines, Piedmont Airlines, or PSA Airlines with Regional jets or the services of mainline "non-airline" regional airline marketing brands such as AmericanConnection, Delta Connection, United Express, or US Airways Express aboard lower-capacity narrowbody jets and turboprop aircraft, such as those produced by Embraer or Bombardier, that do not have transcontinental range.
Often US mainline airline carriers operate in-house brands such as United p.s. to cater to business segments such as the short-range air shuttle, low-cost, or premium-service flights which normally would not support the traffic or revenue yield needed for the traditional operation of larger mainline aircraft with over 100 passenger seats between selected city pairs.
All of the - mainline legacy - airlines listed below operate international, intercontinental, or transoceanic airline services using jet airliners. Additionally, all the - mainline legacy - carriers listed happen to be within the group of United States airline carriers known to statistically be major carriers.
All of the following airlines in some form operate in association with a regional component. All legacy carriers are among the group of US airlines known as "mainline" carriers.
(*) These airlines operate mainline equipment but do not wholly "own" regional airlines or have "non-owned" regional affiliates.
||This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. (April 2009)|
- , AA and early references to mainline, regional and B-scale