BA 355 then BA 748 at Heathrow
Lyon → London → Geneva
Timetable, London time
13:50BA 355 from Lyon at the gate
17:55BA 748 to Geneva leaves the gate
4 h 05 apart on the timetable
The last days
BA 355 and BA 748 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.