Modeling time and space metering of flights in the national airspace system

Metering flights at key points such as sector crossings is an important operational procedure in mitigating National Airspace System (NAS) traffic congestion due to high demand or changing weather conditions. The authors combine a mathematical model for minutes-in-trail or miles-in-trail (MIT) metering with discrete event simulation in a newly developed tool that can be used by analysts to examine or predict existing or developing bottlenecks within NAS. We define a penalty function recursively in terms of MIT delays between leading and following flights. With discrete event simulations, it is possible to examine the anticipated MIT delays for all the flights scheduled to arrive at any crossing point. Impacts of flight cancellations, route changes, and additional enroute delays as results of airport or sector congestion can all be evaluated during each simulation by updating the scheduled flight crossing times and the expected MIT delay penalties for all the trailing flights.