BA 52 then TK 6903 at Heathrow
Seattle → London → Istanbul
Timetable, London time
07:10BA 52 from Seattle at the gate
15:30TK 6903 to Istanbul leaves the gate
8 h 20 apart on the timetable
The last days
BA 52 and TK 6903 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.