Flying Tigers: Shadows Over China

As the achievement states, you need to be on the Raid on Rangoon mission. There are 5 objectives in total, and I believe it’s the 4th where you need to shoot at each bomber in turn until the target on them disappears. Once you have shot at each one, you will be given your final objective.

The achievement will unlock once the mission is completed. I don’t think it can be missed.