So, I may or may not sound like a crazy person here but...

I fully believe that something that has been called the 'TR-3b' is absolutely real, and is such a highly classified craft... though different people use different names.

I've seen this thing multiple times, once hovering only a hundred feet or so over ... whatever the exact building/hangar near the 'Fly Away Cafe' at Boeing Field in Seattle is.

Large, equilateral triangular craft. Basically the size of that entire hangar, if you want to measure it on google maps or something.

Has a thruster near each point of the triangle, and a larger ... glowing something or other in the center.

The theory is that it uses some kind of extremely advanced, exotic method to ... not entirely negate gravity, but functionally reduce the weight and this felt inertia of the craft by about 90%.

This enables it to hover and loiter for extremely long periods of time, and also make sudden accelerations... as, if this is theory is true.... it functionally has a star trek style inertial dampener.

https://www.defencestreet.com/tr-3-black-manta/

https://www.military.com/video/aircraft/military-aircraft/tr-3b-aurora-anti-gravity-spacecrafts/2860314511001

This is of course an artist rendition, but it most accurately captures what I've seen (though every time I saw it, it was hovering level, the tilt here is so you can get a good grasp of what it looks like)

Of course, if you look into this, take everything you read with an entire fistful of salt.

Not only are there tons of cranks and wannabe ufologists adding in nonsense details, but it has been shown that the military will absolutely engane in intentional disinformation to keep things even more confused.

https://m.youtube.com/watch?v=SSTsW_wFn_U&pp=ygUOcGF1bCBiZW5uZXdpdHo%3D