Look at this exemple.
Enter the zone, you get message "in zone".
Leave the zone, message "out zone" and you can repeat each time you enter/leave the zone.
Should work as you need. in_out_zone.miz
As Yurgon said, Caucasus, Mind Voldy, all parking spot.
Your script works well anyway, all helos spawn.
I just tried with Mozdok; same problem.
I don't fall, it's just like i spawn on the static. swapr_TEST.miz