Originally Posted by Green Giant

Spirit Airlines is a Major Airline by definition. True we are what people would call a LCC; however Spirit is a Major Airline. Spirit is not a Legacy Airline but you don't need to be a Legacy to be a Major. Operating Revenue is the determining factor on how the DOT lists the airline.

"The United States Department of Transportation defines a major carrier or major airline carrier as a U.S.-based airline that posts more than $1 billion in revenue during a fiscal year.[1] The term "major carrier" or "major airline" can also refer to traditional legacy carriers, distinguishing them from startup and low-cost carriers."