AA 2663 then S9 999 at Philadelphia
San Francisco → Philadelphia → Washington
Timetable, Philadelphia time
08:24AA 2663 from San Francisco at the gate
12:00S9 999 to Washington leaves the gate
3 h 36 apart on the timetable
The last days
AA 2663 and S9 999 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.