UA 3377 then AA 1051 at O'Hare
Pittsburgh → Chicago → Charlotte
Timetable, Chicago time
08:30UA 3377 from Pittsburgh at the gate
21:06AA 1051 to Charlotte leaves the gate
12 h 36 apart on the timetable
AA 1051 leaves 12 h 36 after UA 3377 arrives on the timetable: more than half a day, so not a connection we count.