
click to enlarge
Use the machine gun to pick off any other stragglers inside the base. You might need to hop off of it for a minute to officially trigger the objective and launch. You should have a sniper rifle and some bombs in your inventory after this happens. Use the rifle to shoot at the mass of incoming Germans. Put 2 rounds into any of the hydrogen tanks to blow up the entire camp when Dexter gives you the order.
Okay, this zeppelin ride is interesting. Your setup is pretty straightforward. You can drop bombs by switching to them in the inventory. You can hold ten at time. The only trick is that you need to aim a bit above the railing to get them to fall properly outside of the gondola. They won't blow up if they fall inside, but they'll stay inactive until they roll out and hit the ground uselessly. You also have a sniper rifle. You can get more ammo by walking up to the box by Dexter and hitting “e.” There are also 2 machine guns to use. If you are ever wounded, fall back to the steel plated area by Dexter and crouch to heal in safety.
The zeppelin's health appears in the corner. Only machine guns and rockets can damage it. It's also pretty hearty and regenerates. I know from my first run that you can be fairly incompetent and still survive just fine. You can actually ignore all of the soldiers if you want. They can not hurt the zeppelin, and the steel tends to protect you fairly well. Feel free to enjoy the shooting gallery though. I'll highlight all of the spots you need to watch carefully. Shooting any of the other Germans is optional, so feel free to snipe and bomb to your heart's content.
After you take off, you should be pretty safe. Just keep an eye out for more soldiers who want to take a shot at you. Keep your head low to avoid them. Your first challenge isn't until you reach the end of the village and the crew complain about taking rounds in the cabin. Look for a lone machine gunner by the last house. Snipe him.
After that, just keep your eyes open. If you nail the hydrogen tank in the back of the moving truck ahead, it will cause the one behind it to crash. That's kinda cool. You can also drop a bomb and kill off the whole group of Germans moving along the hill.