UA 5407 then B6 8412 at O'Hare
Kansas City → Chicago → Boston
Timetable, Chicago time
13:15UA 5407 from Kansas City at the gate
16:00B6 8412 to Boston leaves the gate
2 h 45 apart on the timetable
The last days
UA 5407 and B6 8412 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.