UFOs do not aliens make. The flying distance from Houston to Homey Airport, Nevada is about 1,450 miles. The flying distance from Houston to the nearest star system is about 26 trillion miles, real Obama numbers. And the closest inhabited star system is probably at least ten times that distance away.
So the odds favor any UFO being USAF.
Yes, the critters taught us how to build our own. Some have been seen with NASA markings and some with USAF markings.
Certainly AirForce personnel have been seen working around some of the craft and on some of the critters mother ship craft.
There IS, however, a BIG DIFFERENCE . . . in our crews and craft and THEIR crews and craft.