AA 3521 then AA 3546 at O'Hare
Bloomington-Normal → Chicago → Detroit
Timetable, Chicago time
06:14AA 3521 from Bloomington-Normal at the gate
06:59AA 3546 to Detroit leaves the gate
45 min apart on the timetable
The last days
AA 3521 and AA 3546 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.