This is done by destroying a helicopter in the PvE modes either Co-op or Spec-ops. I’d recommend trying to do this in the Co-op category as they are typically much shorter and easier than Spec-ops. What you want to do is find a mission that has a picture of a helicopter and also has a description of destroying a helicopter or something about a chopper. Here is a picture below showing what to look for. This particular day just happed to have 3 missions with a helicopter but that is not typical. These 5 missions will change out daily so keep checking back until you find one that has a helicopter.
Once you find a mission you will have to be the one that deals the final blow to unlock the achievement. The helicopter can only be damaged by the SA-16 rocket launchers that will be found near the helicopter which have a gold icon next to them. The helicopter will take 6 shots to destroy and will show flames and smoke when it has one shot left. Also just to add the launchers DO NOT lock on meaning that you will have to lead the shot or wait for the helicopter to hover in one spot to hit it. If you didn’t score the final hit just reload and try again.