Perhaps, is the age old terrain memory leakage problem so, depending on what areas you pass over (=landclasses, different terrain), you might arrive at JFK in different memory situation and that, since New York is a big scenery, not just the airport, but the whole area, it just crashed because it exhausted all the memory available.
It might be worth to check by keeping an eye with Task Manager on the memory usage.
Also, the memory might not be exhausted, but it might just be fragmented, meaning there is memory, but not a big enough contiguous chunk, when requested. There are utilities around that allows to defrag RAM in real-time, without interrupting your flight (they do it automatically or after pressing a key), it might be worth trying one of those, when making a long flight, perhaps before landing in a big airport.
