AA 386 then UA 391 at O'Hare
New York LaGuardia → Chicago → Detroit
Timetable, Chicago time
10:00AA 386 from New York LaGuardia at the gate
14:30UA 391 to Detroit leaves the gate
4 h 30 apart on the timetable
The last days
AA 386 and UA 391 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.