AA 3299 then AA 3978 at Phoenix
Burbank → Phoenix → Denver
Timetable, Phoenix time
11:46AA 3299 from Burbank at the gate
15:15AA 3978 to Denver leaves the gate
3 h 29 apart on the timetable
The last days
AA 3299 and AA 3978 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.