An Integrated Strategic-Tactical Approach to Managing Traffic Flows to the Northeast During Severe Convective Weather

En route congestion caused by severe convective weather is a major problem in the US national aviation system (NAS). In 2007, the FAA commenced the use of wide area traffic flow constraints in the form of Airspace Flow Programs (AFPs) to strategically mitigate the impact of en route convective weather. The most commonly used AFPs were used to control the arrivals into the northeast quadrant of the US. Analysis of severe convective events in 2007 and 2008 found that ground stop and ground delay programs were often needed in addition to these AFPs and, that frequently the east- or north-bound traffic controlled by the AFPs deviated into airspace reserved for departures from northeast airports.

In this paper, we look at improving severe weather decision support for these most commonly used AFPs through an integrated strategic-tactical decision support system.

A route blockage based quantitative model for the achievable throughput in an AFP has been developed and validated using archived weather and flight track data. This model shows that the fractional capacity loss in convective weather can differ greatly for different route flows within an AFP. These significant differences in storm impacts together with operational inflexibilities that prevents the use of adjacent arrival routes to handle flows for blocked routes necessitates a tactical decision support system to facilitate rerouting of individual airport flows to feasible alternative routes. The possible need for such tactical rerouting (including the location of the decision points for traffic reroutes) would be determined on the basis of the CoSPA 2-8 hour convective weather forecasts.

The route blockage quantitative models have been interfaced to the CIWS 0-2 hour forecasts and the ability to tactically forecast overall throughput for an AFP (and, split AFPs) as well as blockage of individual flows demonstrated.

The paper will present results of the AFP throughput model validation, the ability to forecast AFP throughput using the CIWS 0-2 hour forecasts, alternative routes and the associated decision points for major flows to the northeast, and a candidate operational concept (including operational decision maker displays) for the integrated strategic-tactical decision support system.