AA 4669 then UA 3907 at O'Hare
Madison → Chicago → Washington
Timetable, Chicago time
08:00AA 4669 from Madison at the gate
12:00UA 3907 to Washington leaves the gate
4 h apart on the timetable
The last days
AA 4669 and UA 3907 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.