Psyops
Have always felt this was being used to cover up US black ops/skunkworks shenanigan's
I remember reading that back in the 1960's at a public briefing on UFO's a US government official claimed they didn't exist, immediately followed by a UFO "expert" who claimed they did (later to be revealed as someone from a US intelligence agency specialising in psychological warfare).
The SR71 Blackbird first flew in 1964, the first pilot to fly it was said to have walked into the hanger, looked at it, and then walked out and was said to be just shaking his head in wonder for a while just trying to believe what he had just seen.
The F117 Nighthawk first flew in 1981, both it and the SR71 have been cited as being responsible for some UFO sightings particularly those around Nevada.
Just try to imagine the technology the US Airforce may be playing with now, almost certainly drones at this point, which don't have so much problem with G forces that would kill a human pilot.
Why do these UFO's like to play around US military installations or aircraft?, (probably assessing personnel / pilots reactions).
How is it that spy satellite technology that allegedly can read car licence plates and recognise the faces of someone looking up hasn't translated to US Navy aircraft cameras that seem to generate footage of UFO's that's worse than that from WW2 fighter gun camera footage?
Sorry I just don't buy it, I think it's a good way to keep secrets secret, and maybe make potentially hostile foreign powers hesitate from shooting the latest toys down "Don't shoot Dimitry, do you want to start an interstellar war?!!"
Mitchell and Webb said it best:
https://www.youtube.com/watch?v=lTHB8iC1C0E