Hello... I am thinking there is something borked with the CH-21c models and the Z offset (and maybe other offsets) ... it seems to be reporting a +5m Z when on flat ground in the Virtual Arsenal and Spawns underground often in there as well.
Other evidence I was getting of the issue.... when landed on ground I still had options to "rappel" that should only come up while heli is reporting being in the air...
also the script that detects the landed heli to become a respawn point in our mission, will not work with that heli as it never "seems to land".