LF 8443 then UA 4447 at O'Hare
MQY → Chicago → Sioux Falls
Timetable, Chicago time
09:24LF 8443 from MQY at the gate
21:30UA 4447 to Sioux Falls leaves the gate
12 h 06 apart on the timetable
UA 4447 leaves 12 h 06 after LF 8443 arrives on the timetable: more than half a day, so not a connection we count.