DALLAS (AP) — The CEO of discount carrier Spirit Airlines says he isn't worried about competing against new, cheaper fares from American and United. The "basic economy" fares from American and United are designed to attract the kind of thrifty fliers that have helped Spirit double in revenue in four years. Spirit has always been known as a low-fare, high-fees carrier — the fees made it one of the most complained-about airlines in the industry. At least Spirit passengers know what they're getting for what the airline calls a "bare fare," CEO Robert Fornaro said Wednesday.Read more on NewsOK.com