EK 9987 then UA 391 at O'Hare
Liege → Chicago → Detroit
Timetable, Chicago time
10:50EK 9987 from Liege at the gate
14:30UA 391 to Detroit leaves the gate
3 h 40 apart on the timetable
The last days
EK 9987 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.