UA 3902 then NH 8421 at O'Hare
Rio De Janeiro → Chicago → Tokyo Narita
Timetable, Chicago time
17:01UA 3902 from Rio De Janeiro at the gate
09:15NH 8421 to Tokyo Narita leaves the gate
16 h 14 apart on the timetable, overnight
NH 8421 leaves 16 h 14 after UA 3902 arrives on the timetable: more than half a day, so not a connection we count.