Weather Forecast Requirements to Facilitate Fix-based Airport Ground Delay Programs

A Ground Delay Program (GDP) in Air Traffic Management (ATM) is a control mechanism that determines the optimal take off time for a set of aircraft such that a desired Airport Arrival Rate (AAR) is achieved. When forecasted convective weather events are expected to occur at or near airports, the airports will often lower their expected (forecasted) AARs to safeguard their ability to safely land and taxi aircraft. GDPs are used today to control the take off time of aircraft such that the amount of aircraft arriving at the GDP airport matches the (estimated) reduced AAR. In the future, we expect that a new type of GDP - a fix-based GDP - can be used when more precise weather forecast information is achieved. A fix-based GDP analyzes how the convective weather is expected to affect each metering fix arrival rate around an airport (typically, there will be 4 metering fixes), not just the airport arrival rate in general. The question is: what weather forecast accuracies are required to perform this new ATM control strategy? In order to perform this analysis, we must be able to accurately evaluate how the forecasted weather is going to affect not only the metering fix locations, but also the jet routes leading to these airport metering fixes. This analysis evaluates the performance of fix-based GDP procedures relative to current airport-based GDPs under a range of weather forecasting capabilities. We compare current airport-based GDPs to future airport fix-based GDPs, with weather forecasting requirements expressed in terms of various temporal and spatial forecast errors relative to a baseline perfect forecast. A general modeling framework is developed for studying weather impacts on airport GDPs and is applied as a single-day case study of Chicago O'Hare International Airport (ORD). The analysis demonstrates the payoff for using more precise fix-based GDP flow control mechanisms to exploit improved weather forecasting capabilities expected in the future. The results indicate the weather forecast requirements to achieve a particular airport GDP performance level.