AA 3544 then UA 545 at O'Hare
Detroit → Chicago → Philadelphia
Timetable, Chicago time
17:05AA 3544 from Detroit at the gate
19:45UA 545 to Philadelphia leaves the gate
2 h 40 apart on the timetable
The last days
AA 3544 and UA 545 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.