Locherbie, exactly. They did not go down with the plane, they fell free of it. They were blown out of the pressurized cabin when the plane broke up. Decompression is not explosive (there is a recent thread on breathing vaccum). A human falling reaches terminal velocity after appr. 100 meters (about 250kph), the rest of the way down just takes time, it doesn't add to the destruction.
I'm not talking about putative aliens, I'm talking about the ones allegedly found at Roswell, you know the ones they later cut open in front of a camara with normal knives. Distinctly no tougher than humans.
I am taking about the internal logic of the Rosswell myth, not any old putative UFO crash.
Hans