AA 9604 then BA 744 at Heathrow
Charlotte → London → Geneva
Timetable, London time
09:40AA 9604 from Charlotte at the gate
16:20BA 744 to Geneva leaves the gate
6 h 40 apart on the timetable
The last days
AA 9604 and BA 744 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.