VS 48 then AA 39 at Heathrow
New York JFK → London → Miami
Timetable, London time
08:35VS 48 from New York JFK at the gate
12:10AA 39 to Miami leaves the gate
3 h 35 apart on the timetable
The last days
VS 48 and AA 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.