AA 4599 then AA 901 at Boston
Philadelphia → Boston → Charlotte
Timetable, Boston time
15:43AA 4599 from Philadelphia at the gate
18:50AA 901 to Charlotte leaves the gate
3 h 07 apart on the timetable
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 4599 and AA 901 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.