Oh well, it sure got interesting for a bit!
Time to prepare for the inevitable US next phase, then. I am moving my MMG platoons to a sector just out of line of sight of the US units out there. I have four MMG units, so plenty of Op Fire to fire back. I double check: yes, Opportunity Fire at Helicopters set at Medium range. With a firing range of 5 hexes (1250 meters) for my MMGs, Medium range will fire at them at two, three hex distance. That by the way includes both the distance of the hex a helo is at, and then its flight level:
[*] Helo, two hexes from me, Nap of Earth: 2 hex firing distance
[*] Helo, two hexes from me, Low: 3 hex firing distance
[*] Helo, two hexes from me, High: 4 hex firing distance.
Light arms Fire results at High level are penalised, so don't want to fire at that height anyway. Should be a good setup. (Wish I had SAMs, they excel at High flight level!)
So there's the Anti-aircraft setup I have. Highlighted here with selecting the AA NATO symbol from Toolbar Highlights group. There's plenty of higlight options, from Anti-tank to Engineers to Disrupted or Fixed units, the lot.
That's the end-of-play situation. Spread out, no overstacking anywhere (more than 12SP in a hex), hoping desperately to down a gunship or three next turn!