Get the long range SA-15’s first, the ones that display the biggest range rings on your radar. Take some sidearms depending on how many you need to clear out. Find a spot on the map where you will have a good pop-up place just inside or barely outside that ring.
Slow come up until you start getting ping by it’s radar. They should not be able to lock onto you. I usually set waypoints during the mission planning directly ontop of the SA-15’s so during flight I can target their locations easily. I fly to waypoint 1 my hiding place then cycle up to waypoint 2 which is an SA-15 target and the waypoint marker in the HUD is right on top on him.
Now count the seconds between the pings. If your not getting pinged increase altitude or clsoe some range to a new hiding place. Take off two seconds. Say it was 11 seconds. Point the helicopter at the missile, wait for a ping then count off 9 seconds.
Fire your missile at that 9 second mark (my X-52 Pro HOTAS has a stopwarch function I use or just count off in your head). This does a couple of things it launches the missile and gets it up an going and then it is hit almost immediately with a radar ping from your INTENDED target to lock on.
Remember the sidearm will lock on to the FIRST radar ping it gets which may not be your intended target so you don’t want it just out their flying for 10 seconds without having locked on to your target.
Duck back down in in about 10 seconds if you hit the SA-15 you should see that range ring disappear. Pop back up and use the MFD to scan that direction and you should see a pillar of smoke.