F9 1327 then DL 5639 at Charlotte
Philadelphia → Charlotte → Boston
Timetable, Charlotte time
10:40F9 1327 from Philadelphia at the gate
14:30DL 5639 to Boston leaves the gate
3 h 50 apart on the timetable
The last days
F9 1327 and DL 5639 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.