You will see the Nakhon Ratchasima (Korat) Airport mentioned on hotel brochures, websites and road signs. However, it was closed to scheduled flights in 2004!
From time to time, their are rumours that it will open again but it seems unlikely. The travelling time from Bangkok to Korat is between 3 and 4 hours and that is probably quicker than the time, door to door, by air. Journeys to more distant places, such as Chiang Mai, would be quicker but the volume of traffic may be too low to make such an operation viable. In any case, you will see more of real Thailand from the road!