The major airlines in the United States include American Airlines, Alaska Airlines, Continental and Delta Airlines. Other familiar companies are Frontier Airlines, Jet Blue Airways, Southwest Airlines and U.S Airways.
A number of bankruptcies and mergers over the course of the last 12 years have condensed what used to be 10 major U.S. carriers into four mega-carriers. American Airlines acquired TWA, America West and U.S. Airways, and only the latter airline kept its name in this merger. Delta merged with Northwest Airlines, and United and Continental combined, as did Southwest and AirTran.
The top five airlines in 2015, according to the annual Airline Quality Report, are listed in order from one to five as Virgin America, Hawaiian Airlines, Delta, Jet Blue and Alaska Airlines. The findings in this report were measured in four areas, including on-time percent, denied boardings, mishandled baggage and customer complaints. The report also notes that airline quality has gone down overall, with numbers as low as those in 2009.
Lost luggage and flight delays are a common issue when mergers occur. Issues with integrating computer systems are cited as the main problem during a merger. In addition, passengers often fear increases in air travel rates when major airlines merge; however, this actually doesn't occur.