Originally Posted by
rickair7777
Tower flybys, down the centerline, are fine. That's a normal-ish maneuver.
Ad hoc inflight inspections by other random aircraft are definitely not OK. You need to do some planning and coordination for formation flying of any sort, and participants need to be trained.
Exception for mil, since they do form flying as a matter of course.
No kidding. Unplanned formation - especially by dissimilar aircraft - is significantly hazardous. And yeah, most ex military will pull it off nicely, assuming the target aircraft flies straight and level, but it’s dicier than most people suspect.