UA 3902 then AA 4927 at Houston
Toronto → Houston → Phoenix
Timetable, Houston time
08:27UA 3902 from Toronto at the gate
18:15AA 4927 to Phoenix leaves the gate
9 h 48 apart on the timetable
The last days
UA 3902 and AA 4927 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.