AA 690 then AA 470 at Philadelphia
Boston → Philadelphia → Chicago O'Hare
Timetable, Philadelphia time
07:37AA 690 from Boston at the gate
15:51AA 470 to Chicago O'Hare leaves the gate
8 h 14 apart on the timetable
The last days
AA 690 and AA 470 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.