AA 1487 then AA 1998 at Seattle
Dallas-Fort Worth → Seattle → Phoenix
Timetable, Seattle time
00:10AA 1487 from Dallas-Fort Worth at the gate
06:20AA 1998 to Phoenix leaves the gate
6 h 10 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 1487 and AA 1998 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.