BA 1391 then VS 47 at Heathrow
Belfast City → London → New York JFK
Timetable, London time
10:00BA 1391 from Belfast City at the gate
13:05VS 47 to New York JFK leaves the gate
3 h 05 apart on the timetable
The last days
BA 1391 and VS 47 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.