AA 2870 then AA 3046 at Seattle
Philadelphia → Seattle → Chicago O'Hare
Timetable, Seattle time
12:09AA 2870 from Philadelphia at the gate
17:24AA 3046 to Chicago O'Hare leaves the gate
5 h 15 apart on the timetable
Seattle’s board gives a departure time for only about 57% of its flights, so many days show no gate time.
The last days
AA 2870 and AA 3046 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.