DL 278 then DL 1922 at Atlanta
Buenos Aires → Atlanta → Washington
Timetable, Atlanta time
07:44DL 278 from Buenos Aires at the gate
12:25DL 1922 to Washington leaves the gate
4 h 41 apart on the timetable
The last days
DL 278 and DL 1922 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.