AA 426 then AA 2878 at Philadelphia
Dallas-Fort Worth → Philadelphia → Denver
Timetable, Philadelphia time
11:34AA 426 from Dallas-Fort Worth at the gate
16:00AA 2878 to Denver leaves the gate
4 h 26 apart on the timetable
The last days
AA 426 and AA 2878 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.