Heard a loud dull roar in the air and after looking around seen 6 aircraft in formation flying. Pulled up flightaware app and seen 4 of them were t6 Texans painted as japanese aircraft and broadcasting their ads-b data, all labeled as "tora/toratoratora". 1 was a bomber and couldnt tell the other but it was a multi engine aircraft as they were up there pretty good, but no adsb being broadcast on those. They were flying east over southern il. Around 920am. Even off at a distance on approach, they were by far the loudest things in the sky
