I just self-destructed the Adams AFB and after sitting inside the Vertibird for about 10 seconds, it goes back to the landing pad and doesn't let me activate the Vertibird again. I've reloaded a couple times and still get this bug.
EDIT: Okay that fixed itself quickly. I waited for Sarah and the two generic soldiers to get bored and walk back to the Vertibird and I activated it again. That worked, so everything is fine.