its really easy actually and there is no tactics involved... well there are but nothing no one doesn't already know. u just have to kill loads of bombers. kill every bomber that you see and dont let them get to the building... thats all u need to do and there really aren't many ways of going about it.
Thanks for the info, I was really hoping that there was a cool trick that someone could show me. Looks like it'll be a while before I get through this stage LOL. Thanks again, Russ