AA 4721 then AS 39 at JFK
Boston → New York → San Francisco
Timetable, New York time
19:03AA 4721 from Boston at the gate
20:20AS 39 to San Francisco leaves the gate
1 h 17 apart on the timetable
The last days
AA 4721 and AS 39 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.