I have tested this, when the mortar is spawned (VIRTUAL artillery module)to perform the firemission it fires one round (sometimes a couple) then backflips and 'crashes'. The mortar crewman doesnt perform any animations to change the elevation of the weapons, the whole model tilts back on the axis of the crewmans back foot lifting the whole weapon in the air. It does work with a placed, crewed mortar using the 'artillery module' though.

It works/breaks the same for OPFOR helo and troops, I found it flew over and I got the supplies delivered text (without getting any supplies) but it kept flying without stopping then vanished.