It depends.
It would be possible, I think, to slip in undetected.
Fly over the radar. Which would mean the upper atmosphere, but Clark can do that.
Then you come straight down at high speed. If you time it so that the radar dish(es) is/are looking in the other direction, you could zoom in without being spotted.
Leaving, you could do the reverse. Zoom straight up, then go over and out of range.
Or yeah. Might be able to get away as a strange possibly bird-like blip, I'd think.
Paul
