How do you complete mition #5?

First of all I don't know about the Autobot version, this only works for the Decepticon version. The weapons I would go with are the PLASMA RIFLE and the RPG, if you have the mark2 versions select them if not, just take the regulars. You start by having to destroy the generators, to move quickly between them use vehicle mode. Start by destroying the turrets guarding the generators with the PLASMA RIFLE, the destroy the generator with the RPG. Repeat this process for all four generators, using vehicle mode to move between them. Move to the yellow marker, destroying the tanks as you go. Then move towards the cargo plane to grab the bomb. Take the bomb back to the yellow marker, then destroy the Autobot reinforcements that arrive. Then track down the escaping Autobot, and destroy him.
(Please note that for all ranged combat I prefer to use the PLASMA RIFLE, and strafe quickly to the right or left; alternating direction for difficult enemies.)