AA 2907 then UA 5210 at O'Hare
New York JFK → Chicago → Detroit
Timetable, Chicago time
09:05AA 2907 from New York JFK at the gate
13:00UA 5210 to Detroit leaves the gate
3 h 55 apart on the timetable
The last days
AA 2907 and UA 5210 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.