AA 2411 then SQ 1550 at San Francisco
Charlotte → San Francisco → Boston
Timetable, San Francisco time
09:51AA 2411 from Charlotte at the gate
10:44SQ 1550 to Boston leaves the gate
53 min apart on the timetable
The last days
AA 2411 and SQ 1550 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.