AA 4642 then DL 878 at Boston
Columbus (Ohio) → Boston → Washington National
Timetable, Boston time
10:03AA 4642 from Columbus (Ohio) at the gate
20:05DL 878 to Washington National leaves the gate
10 h 02 apart on the timetable
The last days
AA 4642 and DL 878 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.