Legacy airlines, or legacy carriers, are commercial airlines that have been providing flight services along established interstate routes before the Airline Deregulation Act of 1978. This legislation removed the federal government’s control over airfare, routes, and led to the market entry of many new airlines.
Through the shifts of this legislation, legacy carriers underwent a substantial transition that did not impact new airlines. In addition to their long-time operations, legacy air carriers have been associated with a full-service flight experience with more amenities. Legacy carriers will usually offer first class and business class seating in addition to coach.
Customers of these carriers are sometimes given access to private airport lounges, frequent-flyer programs, and other perks that encourage customer loyalty. The more comfortable and accommodating experience is one of the primary reasons why customers choose to fly legacy aviation carriers.
Legacy carriers in the United States are somewhat comparable to flag carriers. Outside of the U.S., flag carriers are owned or affiliated with national governments.
None of the legacy airlines operated in the U.S is an official flag carrier airline, but before its bankruptcy in the early 1990s, international legacy carrier, Pan Am was considered an unofficial flag carrier airline for the U.S.

Which Airlines Are Legacy Carriers?
The current legacy carriers in the United States are Delta Air Lines, United Airlines, American Airlines, Alaska Airlines, and Hawaiian Airlines. These are the remaining carriers following a series of mergers in the 2010s, as well as Chapter 11 bankruptcy filings that ended four legacy carriers in 2005.
In the past, the big four domestic carriers were American Airlines, Eastern Air Lines, TWA, and United Airlines. Other major transcontinental legacy carriers were USAir, Continental, and Northwest. After various mergers and incorporations, these carriers are now defunct.
Legacy Carriers Vs. Low-Cost Carriers
In the commercial aviation industry, low-cost carriers are those airlines that were not affected by the Airline Deregulation Act of 1978. Low-cost carriers are also associated with budget rates and minimal amenities. These companies are typically focused on reducing operational costs and serving as many passengers as possible.
Not all low-cost carriers have adopted this approach, however, as some of these airlines still offer premium cabins, assigned seating, as well as in-flight refreshments and entertainment. Low-cost carriers that do not offer these amenities are sometimes called ultra-low-cost carriers.
Low-cost carriers also may not operate or offer as many direct flights to major airports and/or destination cities. Also called no-frills, budget, or discount airlines, low-cost carriers have become more frequented by passengers in North America, particularly in the United States.
This is mainly due to the affordability of fares compared to legacy air travel. Additional factors include recovering trends in leisure travel while business travel rates have not yet returned to pre-COVID numbers.
Low-cost carriers are expected to thrive, as they may be able to better retain their profits through cost-cutting measures and reduced amenities, whereas legacy carriers, may not be able to compete through reduced ticket prices.
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