UA 3904 then LY 4489 at San Francisco
Portland (Oregon) → San Francisco → Los Angeles
Timetable, San Francisco time
07:53UA 3904 from Portland (Oregon) at the gate
18:28LY 4489 to Los Angeles leaves the gate
10 h 35 apart on the timetable
The last days
UA 3904 and LY 4489 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.