AA 1252 then MQ 3926 at Miami
Philadelphia → Miami → Jacksonville
Timetable, Miami time
08:59AA 1252 from Philadelphia at the gate
09:50MQ 3926 to Jacksonville leaves the gate
51 min apart on the timetable
The last days
AA 1252 and MQ 3926 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.