You do realize that we're talking about a false flag op here, don't you?
It is supposed to look like goofballs are flying these planes.
So you want the crazed hijackers to look like professional pilots, for some reason?
It sure is and building aircraft in secret doesn't mean there are no records for such aircraft. I hope you didn't t think there were no records for the SR-71,. A-12, and the YF-12. I might add that the A-12 was faster and flew higher than the SR-71 and the YF-12.
And yet, even those aircraft have tail, part and serial numbers, flight and maintenance records.
The records could have been completely destroyed, if need be. Which means it never existed to
you or me. Get the point here? It existed. They had records. But it's up to them when/if we know about it's existence,
It's not hard to dispose of their records, if they want to.