The Kenneth Arnold UFO sighting in 1947

Of course the Kenneth_Arnold_UFO_sighting wasn't the first. These UFO sightings are part of a phenomenon that has been going on since ancient times, perhaps even going much further back.

https://en.wikipedia.org/wiki/Kenneth_Arnold_UFO_sighting#Arnold_shares_the_story

http://www.project1947.com/fig/kamurrow.htm Today and even several decades ago, if you are a pilot and you see a moving object that doesn't resemble or behave like any known conventional craft, you have a dilemma.

https://www.seattletimes.com/seattle-news/northwest/flying-saucers-became-a-thing-70-years-ago-saturday-with-sighting-near-mount-rainier/

Any pilot that reports a UFO or highly advanced craft, they risk becoming grounded, as well as ridiculed.

https://www.theatlantic.com/technology/archive/2014/06/the-man-who-introduced-the-world-to-flying-saucers/372732/

https://www.spokesman.com/stories/2017/jun/25/flying-saucers-still-evasive-70-years-after-pilots/

https://en.wikipedia.org/wiki/1947_flying_disc_craze

https://en.wikipedia.org/wiki/1947_flying_disc_craze#Events_of_Summer_1947

https://www.ancient-origins.net/unexplained-phenomena/what-did-ancients-see-unidentified-flying-objects-made-impact-early-history-021327

https://www.livescience.com/20645-ufo-sightings.html