VN 98 then UA 3900 at San Francisco
Ho Chi Minh City → San Francisco → Rio De Janeiro
Timetable, San Francisco time
17:00VN 98 from Ho Chi Minh City at the gate
16:00UA 3900 to Rio De Janeiro leaves the gate
23 h apart on the timetable, overnight
UA 3900 leaves 23 h after VN 98 arrives on the timetable: more than half a day, so not a connection we count.