The only thing I have heard is the Airport Authority using 154.235 one time a few years ago, but it was during a normal day, no airshow. Not sure now if that's their frequency, or they were just using a fire frequency for another agency..Might want to monitor the Mattoon Pd and FD freqs too, for they'll probably be there. Hope it's a good time! I will be at work the day of the show..