BR 642 then UA 3758 at O'Hare
Anchorage → Chicago → Des Moines
Timetable, Chicago time
11:55BR 642 from Anchorage at the gate
20:10UA 3758 to Des Moines leaves the gate
8 h 15 apart on the timetable
The last days
BR 642 and UA 3758 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.