BA 1365 then BA 836 at Heathrow
Manchester → London → Dublin
Timetable, London time
13:10BA 1365 from Manchester at the gate
17:20BA 836 to Dublin leaves the gate
4 h 10 apart on the timetable
The last days
BA 1365 and BA 836 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.