(FILES) This August 26, 2011 file photo

a blue and orange airplane with a trailer

(FILES) This August 26, 2011 file photo shows a Southwest Airlines jet at the gate at the Minneapolis/St. Paul International Airport. Southwest Airlines announced December 13, 2011 that it has ordered 208 planes from Boeing at a cost of $19 billion USD. AFP PHOTO / KAREN BLEIER (Photo credit should read KAREN BLEIER/AFP/Getty Images)