BA 963 then BA 700 at Heathrow
Hamburg → London → Vienna
Timetable, London time
11:30BA 963 from Hamburg at the gate
17:05BA 700 to Vienna leaves the gate
5 h 35 apart on the timetable
The last days
BA 963 and BA 700 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.