My local chapter of IPMS is hosting their 19th annual model contest September 8th. It hosts over 45 categories of plastic models as well as 5 paper model categories. Free admission. Contest is held on the same weekend as the Balloon Races and is held a block away from the National Championship Air Races. Races start the following week but you can wander on the flight line during the contest to see T-6s, Migs and lots of other displays. You can get more info
here.