AA 3124 then WN 3373 at Philadelphia
St Louis → Philadelphia → Chicago Midway
Timetable, Philadelphia time
09:19AA 3124 from St Louis at the gate
13:50WN 3373 to Chicago Midway leaves the gate
4 h 31 apart on the timetable
The last days
AA 3124 and WN 3373 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.