UA 3912 then BA 296 at O'Hare
Orlando → Chicago → London
Timetable, Chicago time
09:36UA 3912 from Orlando at the gate
21:50BA 296 to London leaves the gate
12 h 14 apart on the timetable
BA 296 leaves 12 h 14 after UA 3912 arrives on the timetable: more than half a day, so not a connection we count.