When You're being shot at from behind, go to 3rd person view, and if the bullets are grouped together mostly around one of your wings, then tilt your plane accordingly, it may not save you, but every one of the enemy's missed bullets is one wasted and probably not going into your friends' planes. Also, when you're doing the gunning, turn down the throttle, you'll be more accurate and less likely to overshoot and become the hunted yourself if they slow down. this also allows you to put more bullets into the zeppilin before needing to turn off, in fact in zeppilin games, climb way up above at least 1.5-2,000 ft up it and kill the engine. Then, you'll get a lot of time to light it up on the way down.
And finally, if you want,the enemy to waste some bullets, corkscrew while going up and down ( EXTREMELY DIFFICULT AT LOW ALTITUDES)