AA 4103 then AA 2548 at O'Hare
Detroit → Chicago → Philadelphia
Timetable, Chicago time
11:00AA 4103 from Detroit at the gate
19:20AA 2548 to Philadelphia leaves the gate
8 h 20 apart on the timetable
The last days
AA 4103 and AA 2548 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.