F9 2021 then DL 1371 at Detroit
Philadelphia → Detroit → St Louis
Timetable, Detroit time
00:05F9 2021 from Philadelphia at the gate
15:04DL 1371 to St Louis leaves the gate
14 h 59 apart on the timetable
DL 1371 leaves 14 h 59 after F9 2021 arrives on the timetable: more than half a day, so not a connection we count.