So, this isn't a dream per se, but a daydream I have semi-frequently, usually while driving home from Newark Airport on the NJ Turnpike.
As you're driving, for the first mile or two you are directly under the approach path for planes landing on one of the runways. Oftentimes you will have a plane flying directly over you, and can see a line of three or four more planes extending in a line off into the distance.
Anyway, the daydream I have is pretty simple. I fantasize that terrorists are out in the middle of Newark or Elizabeth, and they shoot a ground-to-air missile at one of the planes. I see the smoky contrails of the missile go from ground up to sky.
My fantasy isn't really concerned about the plane, oddly -- I usually don't even consider whether or not the missile hit the plane. But in my fantasy I immediately pull over and get a line of sight visual on the location from where the missile was fired. I then call 911, get in touch with the state police, and help them triangulate the position of the bad guys in time to catch them.