AA 3744 then AA 1509 at Boston
Washington National → Boston → Chicago O'Hare
Timetable, Boston time
23:51AA 3744 from Washington National at the gate
07:00AA 1509 to Chicago O'Hare leaves the gate
7 h 09 apart on the timetable, overnight
Boston’s board gives an arrival time for only about 58% of its flights, so many days show no gate time.
The last days
AA 3744 and AA 1509 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.