A Tempe, Ariz. airline is one of the busiest in the world when it comes to domestic flights.
According to the Huffington Post, US Airways was ranked number nine in the top ten busiest airlines in the world.
"Airlines are ranked in terms of international, domestic and total scheduled passenger numbers and passenger-kilometres."
Southwest Airlines ranked number one nationally with 112 million customers in 2012. Rounding out the top five busiest national airlines were Delta Air Lines, China Southern Airlines, United Airlines and China Eastern Airlines, respectively.
Take a look at the top 10 busiest airlines both national and international.