I’m wondering if some military aircraft do not show. A few times I have heard what sounds like a fighter jet going over a a high speed and they don’t show up in Plane Finder. I just heard a helicopter go over and it is not showing either. I’m positive that the jet was not commercial because I lived in the flight path of an Air Force base. There have been other planes that didn’t show up either. The other day there was a distinctive sound of a vintage aircraft, but nothing in the map.