A3 600 then BA 742 at Heathrow
Athens → London → Geneva
Timetable, London time
11:10A3 600 from Athens at the gate
15:05BA 742 to Geneva leaves the gate
3 h 55 apart on the timetable
The last days
A3 600 and BA 742 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.