AA 5021 then UA 3305 at Charlotte
St Louis → Charlotte → Pittsburgh
Timetable, Charlotte time
19:29AA 5021 from St Louis at the gate
15:00UA 3305 to Pittsburgh leaves the gate
19 h 31 apart on the timetable, overnight
UA 3305 leaves 19 h 31 after AA 5021 arrives on the timetable: more than half a day, so not a connection we count.