USAF civilian for 15 years. At least in my position there was a lot of intermixing of civilian and military personnel, and I always had some military personnel working for me in addition to civilians. Everything was always on a first-name basis, nobody used rank much, enlisted or officer. Main difference was some people wore uniforms, others didn't. At the time I left, there were quite a few formerly military positions being taken over by civilians. At some bases, there are more civilians than military, and in some places, base personnel are largely civilian. But I don't think there are any civilian pilots yet.