Airline Percolation (image) Indiana University Share Print E-Mail Caption A "percolation diagram" of the flight patterns of several major US carriers. Airports in red and their connections indicate a "structural core" that protects against abrupt breakdowns in the system. Credit Filippo Radicchi Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.