AA 4599 then AS 288 at Boston
Philadelphia → Boston → Seattle
Timetable, Boston time
15:43AA 4599 from Philadelphia at the gate
16:58AS 288 to Seattle leaves the gate
1 h 15 apart on the timetable
The last days
AA 4599 and AS 288 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.