https://x.com/DakotaSidwell/status/1870243442694967802

Also

Each year, the Federal Aviation Administration (FAA) issues a special Notice to Air Missions (NOTAM) authorizing Santa Claus to operate his reindeer-powered sleigh in U.S. airspace on Christmas Eve. This tradition underscores the agency's commitment to safety and adds a festive touch to the holiday season.

In 2020, the FAA granted Santa special operating authority for interstate air-cargo delivery directly to rooftops across the United States. Additionally, for the first time, Santa received a special commercial space license for a crewed mission to the International Space Station using his StarSleigh-1 space capsule powered by the Rudolph Rocket.

Australia has embraced a similar tradition. Airservices Australia allocates Santa the call sign "SLEIGH RIDER ONE" and issues a NOTAM advising aircraft to maintain clearances as he delivers presents across the country on Christmas Eve.

In the United Kingdom, NATS (formerly National Air Traffic Services) coordinates with Santa to ensure his safe passage through UK airspace. They issue a special NOTAM, sometimes referred to as a "SANTAM," to notify other airspace users of Santa's flight on December 24th.

These annual NOTAMs not only ensure Santa's safe journey but also engage the public in aviation traditions during the festive season.

For those interested in tracking Santa's progress, the North American Aerospace Defense Command (NORAD) provides real-time updates on his location during Christmas Eve.

And while it is not an established tradition and not every pilot chooses to do this in their career, but it is generally considered acceptable by air traffic control for pilots flying transatlantic and trans-pacific routes to contact ATC and inform them that they saw Santa's sleigh. I was told by one airline captain with about 30 years flying experience that he did it once just to get it out of his system, he said, and that ATC took the joke very well.