AA 9953 then AA 2404 at Philadelphia
Atlanta → Philadelphia → Boston
Timetable, Philadelphia time
13:28AA 9953 from Atlanta at the gate
17:31AA 2404 to Boston leaves the gate
4 h 03 apart on the timetable
The last days
AA 9953 and AA 2404 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.