AA 1997 then KD 218 at O'Hare
St Louis → Chicago → Anchorage
Timetable, Chicago time
09:00AA 1997 from St Louis at the gate
12:00KD 218 to Anchorage leaves the gate
3 h apart on the timetable
The last days
AA 1997 and KD 218 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.