It looks as if US Airways and American Airlines are going to merge very soon. That merger would put them ahead of Delta (that purchased Northeast, then merged with Western, bought Pan Am routes, and finally merged with Northwest) and United (that kept it simple and just merged with Capital with Continental).
This new, combined airline would create the US's biggest airline, bringing the number of major airlines down to only 3 main carriers and a handful of budget carriers. And a bunch of regionals. And while the consolidations have resulted in service cuts in certain markets, the airlines have also become more profitable.
According to our 2013 Customer Loyalty Engagement Index, here's how the airline brands currently rank. FYI, strength relates to how well the brands have managed to create real levels of emotional engagement between themselves their passengers (this is versus a category Ideal, calculated to be 100%). If you think that the percentages posted below are lower than you might expect, try and remember back to your last flight, and conjure up how pleased you were. Just landing safely, close to on-time, doesn't count.
American is currently the 3rd largest airline (having gotten there by buying Trans Caribbean, Air California, Reno Air, and TWA) and US Airways is the 4th (which used to be All American Aviation who changed their name to Allegheny Airlines, that bought Mohawk, changed their name again to US Air, bought Pacific Southwest and Piedmont, which was bought by American West [who, when they existed, were #1 on our CLEI list] and then officially kept the US Airways brand, so good call there). But while size certainly counts in terms of routes, it's emotional engagement that counts when it comes to engendering loyalty. Oh and not screwing up the merged reservation systems. You really, really don't want to do that.
As to the name, it turns out that the merged company would be called "American Airlines" (who spent 2 years and a gabillion dollars on a new logo, so they must figure, why let that go to waste?), would be based in Fort Worth, TX, with 94,000 employees and 950 planes.
Which works out to a lot of people and planes that could take you to an awful lot of places. Although, given the merger talks, the most important – and successful – trip the brands may take, is the one where they actually manage to meet each other halfway.