Heavy Fire: Afghanistan

Here is a video guide that shows how to do the method described by DrevinKnight:

Chain kills are basically simultaneous kills. So an example of a chain kill of 5 is killing 5 enemies at once with a grenade. There is a high likelihood that you will unlock the Chain A and Chain B trophies while progressing through the game. Chain C is much more difficult though.

The best place to get Chain C is at the beginning of the 11th mission. The name of the mission is Hawk Eyes – The Escort. In this mission you are the gunner an impenetrable attack helicopter with unlimited ammo and missiles. About 30 seconds into the mission you will come to a small village. You will hear your character telling his convoy not to enter the village because it is full of enemies. You’ll see 3 small groups of insurgents on the ground, kill them or not, it really doesn’t make a difference.

The chopper will circle the village once and return to the starting position. The chopper will be facing down a street. To the right of the street are buildings, just to the north of those buildings there is a large Semi-truck. A large group of hostiles will emerge from behind this truck. Once they are in front of the truck fire a missile into the truck. Immediately fire another missile into the group of enemies in the center of the street next to building with hostiles on the roof. Also fire your last missile into the group on the left side of the street. If done correctly you will get a chain of at least 10 kills