UAS Loss of Link Procedure Evaluation Methodology The MITRE Corporation
George Mason University

The developed methodology includes a predictability model that uses a Monte Carlo simulation to estimate the probability that a controller can adequately predict the first maneuver of a UA's contingency procedure. For the purpose of this analysis, the team used a multi-agency propose procedure that allocated UA maneuver timing.

The team found that the model can provide the user with the determination of whether or not the controller was able to identify the UA as lost link before the UA performed the first maneuver of its contingency procedure. This model is repeatable and utilizes adjustable parameters so that different procedures can be analyzed. The user can determine whether the results (probability of when a loss of link situation was not identified in time) are appropriate based on his or her set thresholds and then further compare the results to other modeled procedures.

The methodology also includes a controller workload simulation using a MITRE-developed tool called airspaceAnalyzer. Although the tool was not created as a workload model, the team's sponsor recommended this tool to the team for the analysis. Three scenarios involving loss of link situations were designed to explore the functionality of the tool and to determine whether it could be used to evaluate a loss of link situation's impact on controller workload.

The team determined that there are some potential limitations in using airspaceAnalyzer as a model of controller workload. The largest limitation is that the software attempts to solve separation issues by maximizing forward progress of aircraft, and therefore may maneuver more aircraft than is necessary in order to avoid a major disruption to one aircraft's intended route. Because of this, a more thorough evaluation of airspaceAnalyzer should be performed in order to ensure that appropriate and interpretable controller workload metrics are capable of being produced by the tool.

Read the UL2 Team's Final Paper for more detail on the Deliverables page


The MITRE Corporation is a not-for-profit organization that manages Federally Funded Research and Development Centers (FFRDCs), one of which is the Center for Advanced Aviation System Development, which supported this project. The sponsor for the project was Andrew Lacher, the UAS Cross-Center Coordinator and Research Strategist at The MITRE Corporation.

This work was done as a graduate project for the Volgenau School of Engineering at George Mason University.

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