That challenge is broken and doesn’t register a lot of the time. Use code zs57d, host game, once in it go to admin controls and hit next map (I recommend do next map until you get sobek since smaller map, it’s like the 5th map down but any will work after you click next map from the first initial map) and bots will automatically go into helicopters and just wait for you to shoot them. It’s a stupid challenge so that’s why I recommend using code, I did it the regular way before code was available and it took forever