AA 387 then AA 1828 at Charlotte
Detroit → Charlotte → Boston
Timetable, Charlotte time
08:06AA 387 from Detroit at the gate
17:59AA 1828 to Boston leaves the gate
9 h 53 apart on the timetable
The last days
AA 387 and AA 1828 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.