More like an interop radio ID. I've heard the chopper on here, but I've also heard the weekly radio checks with a local police dept. use the ID as well. I'm pretty sure I've also heard other interoperational stuff use that ID at different times also like with a command post on a tac etc..
I've labelled it OPP - InterOp/Air Unit Patch. I'm in Zone 2 Fleetnet area.