Aviation System Performance During the Summer Convective Weather Season

This paper analyzes recent trends related to delays, airborne holding and diversions in the National Airspace System (NAS) during the summer convective weather season. A weather variable is introduced to help analyze these performance metrics in a way that factors out differences in the location and intensity of thunderstorms. Regression analysis indicates a nearly 50% increase in flights delayed more than an hour from summer 2003 to 2005. The increase in delay is associated with a growing concentration of flights at busy hub airports over the past five years.