AA 1725 then AA 3173 at Philadelphia
Chicago O'Hare → Philadelphia → Nashville
Timetable, Philadelphia time
11:42AA 1725 from Chicago O'Hare at the gate
15:35AA 3173 to Nashville leaves the gate
3 h 53 apart on the timetable
The last days
AA 1725 and AA 3173 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.