TS 573 then DL 8838 at Montréal
Lyon → Montréal → Boston
Timetable, Montréal time
12:15TS 573 from Lyon at the gate
16:10DL 8838 to Boston leaves the gate
3 h 55 apart on the timetable
The last days
TS 573 and DL 8838 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.