JL 6740 then CZ 8310 at Narita
Hanoi → Tokyo → Shanghai
Timetable, Tokyo time
09:42JL 6740 from Hanoi at the gate
14:20CZ 8310 to Shanghai leaves the gate
4 h 38 apart on the timetable
The last days
JL 6740 and CZ 8310 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.