UA 949 then UA 3900 at San Francisco
London → San Francisco → Rio De Janeiro
Timetable, San Francisco time
16:55UA 949 from London at the gatealso LX 3048, AC 5082, OS 7855, SN 9101, LH 9378, NZ 9855
16:00UA 3900 to Rio De Janeiro leaves the gate
23 h 05 apart on the timetable, overnight
UA 3900 leaves 23 h 05 after UA 949 arrives on the timetable: more than half a day, so not a connection we count.