AA 2129 then DL 506 at Miami
Los Angeles → Miami → Seattle
Timetable, Miami time
14:33AA 2129 from Los Angeles at the gate
18:15DL 506 to Seattle leaves the gate
3 h 42 apart on the timetable
The last days
AA 2129 and DL 506 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.