AA 1716 then UA 1043 at Miami
St Louis → Miami → Newark
Timetable, Miami time
08:49AA 1716 from St Louis at the gate
15:10UA 1043 to Newark leaves the gate
6 h 21 apart on the timetable
The last days
AA 1716 and UA 1043 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.