AA 2129 then AA 5456 at Philadelphia
Miami → Philadelphia → Atlanta
Timetable, Philadelphia time
09:45AA 2129 from Miami at the gate
10:35AA 5456 to Atlanta leaves the gate
50 min apart on the timetable
The last days
AA 2129 and AA 5456 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.