AA 2520 then AA 1638 at Phoenix
Houston → Phoenix → Denver
Timetable, Phoenix time
08:39AA 2520 from Houston at the gate
19:09AA 1638 to Denver leaves the gate
10 h 30 apart on the timetable
The last days
AA 2520 and AA 1638 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.