Legacy carrier

In the United States, a legacy carrier is an airline that was once economically regulated by the Civil Aeronautics Board (CAB) during the period of airline regulation 1938–1978 or can trace its origin to one that did. The CAB was a now defunct federal agency that tightly controlled almost all US commercial air transport during that period. As related below, many features associated with the legacy airline business model were actually developed not during the regulated era, but instead in the first decade or so of the deregulated era, as legacy carriers adapted to an unfamiliar competitive environment.

As of 2024 there are five surviving legacy carriers, but note that Alaska and Hawaiian are currently seeking approval for a merger:^[1]

• Alaska Airlines
• American Airlines
• Delta Air Lines
• Hawaiian Airlines
• United Airlines

Legacy carriers do not include:

• Any airline founded after the regulated era. A few prominent examples of such carriers include America West Airlines, ValuJet, JetBlue and Spirit Airlines.
• Any US airline with a pre-1979 origin which was not regulated by the CAB. There are two significant US airlines today that operated pre-1979 but were not regulated by the CAB. The most prominent is Southwest Airlines, which started operations in 1971 but was never subject to CAB regulation because it was an intrastate airline and thus was subject to less regulation. For that reason, Southwest has never been counted as a legacy carrier. As related below, the term "intrastate airline" meant more than simply operating within a single state. Prior to 1979, Hawaiian Airlines operated only within the state of Hawaii, yet was CAB-regulated.

While the term "legacy carrier" is most often used in a US context, it is possible to speak of legacy carriers elsewhere, since tight airline regulation was once the global norm and following US airline deregulation, many other countries went through some kind of airline deregulation. Non-US carriers with origins that precede liberalization can be viewed as legacy carriers. For instance, in Europe, flag carriers such as British Airways, Lufthansa and Air France (with origins well before the liberalized era) can be viewed as legacy carriers in contrast to airlines such as Ryanair, Wizz Air and so forth.