Not everyone in the Air Force is a pilot, he more than likely has a technical or mechanical job. Pilots have to be college grads and the best out of their class from military academies or ROTC to even get a chance to try to be one. That being said, I know a special forces operator with a stutter. I work in a well known government agency (think FBI/DEA type deal) with a stutter. Don’t let it limit you.