I hear them when we have the Indy 500 or the Brickyard 400 with just a rubber duck antenna on a scanner from 79Th and Michigan Road in my backyard on the Northwest side of Indy since 2010. I also hear the PA for the Speedway ON 455.1375
125.275 control tower and fly over coordination
123.450 air to air chatter
123.050 helicopters downtown traffic
123.025 helicopters air to air
118.675 indy ATC
155.160 Lifeline helicopter and Methodist Hospital Control. (hopefully not needed.)
Unfortunately, I was not able to find the Black Diamonds air to air yesterday
or their ground coordinator during Saturdays flyover. I was searching AM /FM VHF 118-136 and Mil 225-400 both no joy. Their website is stuck in last year and did not even list this weekend on their schedule.
Happy listening it is a beautiful day for a motor car race!!!