AA 6430 then UA 3911 at San Francisco
Phoenix → San Francisco → Denver
Timetable, San Francisco time
10:01AA 6430 from Phoenix at the gatealso QR 7617
17:00UA 3911 to Denver leaves the gate
6 h 59 apart on the timetable
The last days
AA 6430 and UA 3911 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.