Flights are delayed, however since planes are choreographed by airlines for maximum utilization, long enough delays and you will see mass cancellations, potentially across large swaths of the country.
i.e. a plane for one route might go between various different cities in 24 hours, with different crew each time of course before it gets back to the first route.
Any flights that are to depart for JFK but are still on the ground must stay put until the expiration or cancellation of the stop. No, it doesn’t impact other airports.
Any disruption at one major airport affects pretty much all the airports, if it lasts long enough. Those grounded planes will soon be expected elsewhere.
