JL 717 then AA 9921 at Phoenix
Rapid City → Phoenix → Chicago O'Hare
Timetable, Phoenix time
09:23JL 717 from Rapid City at the gate
12:00AA 9921 to Chicago O'Hare leaves the gate
2 h 37 apart on the timetable
The last days
JL 717 and AA 9921 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.