Using Modeling & Simulation Tools to Analyze National Airspace System PerformanceMarch 2014
Topics: Modeling and Simulation, Airspace
These modeling and simulation, or M&S, tools help show how new systems, policies, and regulations will affect National Airspace System (NAS) operations.
One of these simulation tools, called the systemwideModeler, can model the gate-to-gate plans and progress of an entire day's worth of flights in the NAS, ranging from 50,000 to 100,000 flights across the country. Using this tool, analysts can model numerous circumstances that could affect NAS performance. These factors include airport congestion and weather, arrival merging and spacing, delay propagation from late arriving aircraft, and limited gate availability, to name a few.
A benefit of systemwideModeler is that it can represent dozens of airports and hundreds of air traffic control sectors. MITRE staff use the tool to test how the NAS responds to changes—such as an increase in traffic volume, the construction of new runways, or the implementation of new technologies, policies, and procedures. For example, analysts have used systemwideModeler to understand the impact and benefits of introducing new data communications, or "DataComm," capabilities into the NAS, rather than depending solely on voice communications. Our work helps answer questions such as: How much will delays decrease because of reductions in controller workload due to this new capability?
Some distinctive features of systemwideModeler make it a unique tool in NAS-wide analyses. Unlike traditional queuing models, systemwideModeler consists of a number of component models that use flight plans to anticipate congestion and strategically impede traffic. This is a more realistic way of spreading delays and rerouting flights upstream of the congestion.
One such model represents en route sector capacity. Aviation professionals often define en route sector capacity as the maximum number of aircraft that can safely be in a sector at one time. However, this definition fails to take into account the impact of traffic characteristics that change dynamically over the course of the day. In systemwideModeler studies, en route sector capacity can be defined as a limit to the workload that sector controllers can handle. This capability allows us to better understand how operational changes affecting air traffic controllers will impact the performance of the NAS.
As researchers develop NextGen Traffic Flow Management tools, we can use our M&S capabilities to better understand how traffic flow tools can facilitate more efficient air travel. For example, MITRE is using the systemwideModeler to represent the impact preemptive rerouting of flights around en route weather has on reducing air traffic controller workload.
The Whole Is Greater than Its Parts
The value of the systemwideModeler is enhanced by its being part of a sophisticated infrastructure of MITRE-developed M&S capabilities that support and leverage each other. The overall package includes scenario generation, simulation execution, and analysis and visualization tools that we have created over time to support NAS-wide analyses.
For example, MITRE has developed processes for creating various demand scenarios, using a range of tools and datasets. Analysts can use these processes to develop schedules for future years. The scenarios allow them to add flights to an existing schedule based on projected traffic growth rates, airline scheduling practices, aircraft routings, and limited airport capacity. These processes have also helped the Federal Aviation Administration develop demand scenarios for other analyses.
Many of our research teams also use another important capability to enhance their simulations—the MITRE Elastic Goal-Directed (MEG) Simulation Framework. MEG provides high-performance computing and automated design-of-experiments support to simulation programs, enabling the execution of hundreds of simulations simultaneously. Using MEG to perform systemwideModeler simulations allows our teams to conduct improved analyses with large and complex experimental designs and to better understand the sensitivity of analysis results.
MITRE continually looks for ways to improve our broad-ranging suite of analysis capabilities. For example, our researchers recently developed a capability to modify flight paths to represent maneuvers needed to absorb delays. This capability facilitated the integrated use of systemwideModeler, which simulated flight delays, and the FAA's Aviation Environmental Design Tool, which estimates fuel burn, emissions, and noise resulting from modeled flight paths. This combination assists analysis of both the operational and environmental performance of the NAS on a common scenario.
MITRE's sponsors are using the analytical data produced by systemwideModeler and supporting capabilities to make informed decisions about the development of new applications and their effect on NAS-wide operational performance. For example, a 2012 systemwideModeler analysis of the aforementioned DataComm capability contributed to the FAA's decision to approve deployment. Our researchers are now conducting another analysis to help the FAA identify those airports expecting the most capacity growth in the future so the agency can decide where to apply resources.
—by Billy Baden