Message posted by Peter Merlin on December 02, 2016 at 7:42:45 PST:
WWW621 is a Janet identifier. I learned that for the first time in the early 1990s when I watched a Janet 737 land at Burbank Airport. The screen in the control tower identified the aircraft with a flight number beginning with WWW. That three-letter code has since been verified by others.
In Reply to: curious flightradar activity posted by jklier on December 02, 2016 at 7:30:30 PST: