AA 3664 then AA 2009 at O'Hare
Buffalo → Chicago → Nashville
Timetable, Chicago time
12:29AA 3664 from Buffalo at the gate
13:24AA 2009 to Nashville leaves the gate
55 min apart on the timetable
The last days
AA 3664 and AA 2009 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.