BLEEP BLOOP: I just saw an aircraft with callsign #UAL710 (ICAO code #AA4C3E) flying at 316 kt at altitude 8550 feet MSL at coordinates 34.1980,-118.4564.

They must have had a 50 knots tail wind.

https://globe.theairtraffic.com//?icao=aa4c3e
https://globe.adsbexchange.com/?icao=aa4c3e
https://www.openstreetmap.org/?mlat=34.1980&mlon=-118.4564#map=15/34.1980/-118.4564