The equation above is a highly unscientific observation based on the U.S. Department of Transportation's monthly report. Apparently, 25 of the 50 most frequently delayed flights involved JFK and Comair in September. The AP says Comair Flight 5283, between JFK and Washington DC's Reagan National is the worst:

The evening rush hour jet from JFK to Washington Reagan National Airport landed late 100 percent of the time in September.
Planes flying the route arrived an average of 79 minutes behind schedule, on a trip that involves less than an hour of flying time. Three of the 30 scheduled flights were canceled altogether.
The delays are blamed on several factors, including chronic congestion at New York's airports. And the Comair delays have only worsened as its parent, Delta Air Lines, has descended deeper into financial turmoil.

Ugh. Five other flights in the top 10 most delayed flights were Comair + JFK in some form. Comair says they have worked on improvements and points out that it has many flights in the Northeast.

And some sobering words from the Port Authority's Pasquale DiFulco: "Understand that this is the most congested airspace in the world. We know growth is coming, and we only have so much airspace, and you can only fit so many planes in the sky."