Here is some news about UFO/UAP sightings by the Navy

Or it would be really dangerous to have a civil aviation ...
Accidents happen and usually because of human mistakes.

About UFO sights it's the same: not all pilots chase planet Venus! At least I hope so ...
Statistically it happens that a pilot thinks to see something while he's seeing something else [this happens not only to pilots, obviously].

 

But what happens when a fleet of them appear on radar and other sensors? Are those illusions as well?

 

An order to scramble comes.
Air Forces are taking really seriously UFO sights: they cannot accept that unknown objects fly in the air space of their countries.
So [at least this is what I collected when I was an investigative ufologist, so in a different geological era!] UFO reports obtain a great attention.

About my homeland, we have got a particular base: the base where they assembly F35. I'm still in contact with the environment of ufology and it happens I take a look. Italian Air Force tests the new planes in this area. A common persuasion of ufologists is that near so "sensitive" bases UFOs are not rarely spotted.
This is true also here. In Italy it's not so difficult for an ufologist to obtain information about the timing of the test of a military plane.
In some occasions tests corresponded with UFO sights [so witnesses saw F35 fighters, not UFOs], but in some occasions they didn't correspond.

 

I believe that one was determined to be a balloon. Scroll down and you'll see the source is RT, which, I believe, is a Russian sponsored source, no?

 

Another "much ado about nothing"?

'NASA’s UFO Research Team to Brief the Public'
'The panel is identifying data that may help researchers learn more about mysterious flying objects'

snip:

"The public meeting will be livestreamed Wednesday at 10:30 a.m. ET. Separately, the team is expected to publish a report on their findings this summer.

The meeting comes after U.S. defense officials released videos of unidentified flying objects last year during the first congressional hearing on the subject in more than half a century. "

"The team of 16 researchers, with backgrounds in astrophysics, oceanography, astronomy and other fields, have focused on identifying data that can potentially be analyzed to learn more about UAP. The nine-month study focused on unclassified data and considered what information can be gathered from civilian government entities and the private sector.'

link to livestream
https://archive.is/GIclH

 

Another live link NASA

https://www.nasa.gov/nasalive