Planetary Defence Force

From publisher blurb: You supplemented your colonist's income with a role as a part-time gunship pilot. After all, there was no chance you would ever have to actually fight in the thing. The planet is a backwater, and those jalopies can barely fly. Imagine what a mess it would be if them, and you, were the only things that stood in the way of an invasion by a hostile power. Ha ha. Well, crap.