JFK is mostly and O&D market for United. They have transcon flights from LAX and SFO and a few other feeds, both mainline and on Atlantic Coast Airlines. But then there are 7 million people in New York, plus who knows how many more in the surrounding area. i am sure there is a decent enough load factor to fill up a 767-300, and maybe at some point a 777.
Stop drop and roll will not save you in hell. --- seen on a church marque in rural Virginia