Flying Tigers: Shadows Over China

This is accessed from the Challenge menu. The achievement description isn’t accurate though, as it only requires me to destroy 15 targets within the time limit. I ended up with 68% accuracy and if I’m honest, I wasn’t very good at this but finished with over 1 minute to spare. So most of you won’t have an issue.

You'll have to destroy x amount of the ground targets in this challenge (SP->Challenge->Ground Attack). I used my machine gun to destroy some targets, and ended up with machinegun accuracy 13% and bomb accuracy 80% and still popped the achievement. You don't have to destroy all of the targets on the ground. I never attacked the ships and there were still 10-15 targets left by the time I had finished the mission. Just fly low over the targets and press to drop a bomb when the circle is over the target. This is not hard at all if you drop the bombs carefully.

The easiest way I found to guarantee a win is as soon as the game starts drop 1 bomb on one target and confirm the kill, once you have done that just use your machine gun and the slow motion to kill 14 more ground targets for the challenge to end and the achievement will pop because of your 100% bombing accuracy.