UA 3876 then AA 843 at O'Hare
Miami → Chicago → Washington National
Timetable, Chicago time
14:49UA 3876 from Miami at the gate
14:55AA 843 to Washington National leaves the gate
6 min apart on the timetable
The last days
UA 3876 and AA 843 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.