How Delays Propagate Across US Airports

"How Delays Propagate Across the US Airport Network".  One key observation:

[T]hree main mechanisms lie behind this spread.

The first is through each plane’s flight schedule from one destination to the next–a delay in one leg naturally propagates to the next.

The second comes from passenger and crew connections. Clearly, an aircraft cannot take off if the crew are delayed on another flight.

Finally, there is airport congestion. A given airport can handle only a certain rate of take offs and landings and becomes congested when numbers rise beyond these levels. 

However, Fleurquin and co conclude one of these factors is far more damaging than the others. “Our simulations evidence that passenger and crew connections is the most effective single mechanism to induce network congestion,” they say.

(Via Ryan Sager.)