With Guard and AFRES, you know your plane before you start pilot training. So if you are hired by a unit and sent to school, you can be 100% certain you will fly fixed wing, assuming you graduate and your unti does not fall to any future BRACS. I have heard that there are some reqs for some of the fighter units, where they want you to be in the top X% of the class. In my class, we had 2 helo slots that went to non-vols. Some classes have folks that want helos which makes the rest of the class happy. There was a class that had 3 people that wanted 2 slots. YMMV. BTW, this info was brought to by an active duty AF, heavy pilot. Good luck.