AI 131 then BA 11 at Heathrow
Mumbai → London → Singapore
Timetable, London time
18:55AI 131 from Mumbai at the gate
18:45BA 11 to Singapore leaves the gate
23 h 50 apart on the timetable, overnight
BA 11 leaves 23 h 50 after AI 131 arrives on the timetable: more than half a day, so not a connection we count.