The skin friction of the missile at those speeds at those altitudes would melt any metals or nonmetals available. In some descriptions the beast spirals straight up. If you think of the fact that the centrifugal force in a few minutes of such a maneuver would press the crew against the outside, and do likewise to the blood, you see what I mean. There are many occurrences where they have done things that only a pilot could perform but that no human pilot could stand. Fourth, in most of the reports there is a lack of visible jet.
Most observers report units without visible flame . . .
If it would be any known type of jet, rocket, piston engine, or chain-reaction motor, there would be a very clear trail at high altitude. It is from no power unit we know of . . . My opinion for some time has been that they have an extraterrestrial origin. They may not look like us, but I have very strong feelings that they have advanced beyond our mental capabilities. I remember the case in Georgia in the 1950's of a National Guard plane going after a UFO and never returning.