I have an app in the Apple App Store called Fly Or Delay.  It shows airport delays based on the FAA's data.  It doesn't show individual flight delays, but you can generally get a sense of what is going to happen to your flight if you see there is a ground stop at your departing airport, for example.  I admit that I spend a fair amount of time looking at the app, not just because I wrote it, but because it is interesting.

Look at the three screen shots above.  I'll wait...

The left-hand one is a typical weekday:  There are general delays at O'Hare and Newark, but nothing too bad is happening.  

The middle one is a bad day during a hurricane or a snowstorm:  Lots of airports are closed and you'd need to scroll to see the rest of the bad things happening.  

The right-hand one is the typical one I have seen in the last month:  There are no delays.  Period.

It turns out that if you operate an airport at one-half capacity, the airport runs smoothly.  Individual flights may be delayed for weather or by waiting on flight crews or for mechanical reasons, but, generally, things run smoothly.

I am sure the airlines would all trade some airport delays for paying passengers.  I'm just noodling on the next updates to the app and wondering when I'll get my live test data back again.