UA 3901 then AF 2519 at San Francisco
Los Angeles → San Francisco → Seattle
Timetable, San Francisco time
09:36UA 3901 from Los Angeles at the gate
10:31AF 2519 to Seattle leaves the gate
55 min apart on the timetable
The last days
UA 3901 and AF 2519 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.