AA 540 then AS 1478 at O'Hare
Nashville → Chicago → San Diego
Timetable, Chicago time
11:05AA 540 from Nashville at the gate
19:49AS 1478 to San Diego leaves the gate
8 h 44 apart on the timetable
The last days
AA 540 and AS 1478 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.