AA 9780 then DL 1818 at O'Hare
London → Chicago → Seattle (SEA)
Timetable, Chicago time
13:35AA 9780 from London at the gate
17:30DL 1818 to Seattle (SEA) leaves the gate
3 h 55 apart on the timetable
The last days
AA 9780 and DL 1818 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.