AA 1809 then AS 257 at Boston
Charlotte → Boston → Seattle
Timetable, Boston time
12:35AA 1809 from Charlotte at the gate
16:33AS 257 to Seattle leaves the gate
3 h 58 apart on the timetable
The last days
AA 1809 and AS 257 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.