DL 3990 then DL 5531 at Detroit
Louisville → Detroit → Washington
Timetable, Detroit time
12:04DL 3990 from Louisville at the gate
21:46DL 5531 to Washington leaves the gate
9 h 42 apart on the timetable
The last days
DL 3990 and DL 5531 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.
Later flights to Washington
DL 470421:509 h 46 after DL 3990 on the timetable