Hwasoo Lee

A Human-in-the Loop Exploration of the Dynamic Airspace Configuration Concept

An exploratory human-in-the-loop study was conducted to better understand the impact of Dynamic Airspace Configuration (DAC) on air traffic controllers. To do so, a range of three progressively more aggressive algorithmic approaches to sectorizations were chosen. Sectorizations from these algorithms were used to test and quantify the range of impact on the controller and traffic. Results show that traffic count was more equitably distributed between the four test sectors and duration of counts over MAP were progressively lower as the magnitude of boundary change increased. However, taskload and workload were also shown to increase with the increase in aggressiveness and acceptability of the boundary changes decreased. Overall, simulated operations of the DAC concept did not appear to compromise safety. Feedback from the participants highlighted the importance of limiting some aspects of boundary changes such as amount of volume gained or lost and the extent of change relative to the initial airspace design.

Sector Design and Boundary Change Considerations for Flexible Airspace Management

In Next Generation Air Transportation System (NextGen) operations, we expect that the demand-capacity balance can be achieved by selectively managing the airspace capacity in conjunction with managing the traffic demand. In Flexible Airspace Management (FAM), the airspace complexity can be assessed a few hours ahead in order to identify sectors that could exceed their defined traffic threshold as well as sectors that are under-utilized. Using various airspace optimization algorithms, airspace can be reconfigured to manage the existing traffic demand without moving aircraft away from their original user-preferred routes. A human-in-the-loop simulation study was conducted in 2009 to assess the impact of airspace reconfiguration on the controllers. The results from the objective data found that the acceptability of the boundary change and the associated workload were mainly affected by airspace volume change and aircraft that changed ownership. However, observations and subjective feedback have suggested that other cognitively-driven factors, such as spatial relationships between upstream/downstream sectors, may also play a role, especially in traffic situations where the airspace has only a few aircraft that change ownership but still has a high degree of airspace complexity associated with the reconfiguration. In this paper, we identify these factors and discuss the human factors issues that should be considered in designing the airspace and airspace transitions.

A Human-in-the-Loop Investigation of Multi-Sector Planning Operations for the NextGen Mid-Term

A human-in-the-loop simulation was conducted to evaluate a concept for introducing multi-sector trajectory planning operations into en route air traffic facilities in the NextGen Mid-Term timeframe. Multi-sector planning tools and procedures for local area traffic flow management were developed, and then tested using two different service provider team configurations. In one condition, local area flow planning was performed by the traffic management coordinator and area supervisor. A second condition added a new, dedicated multi-sector planner position to the planning team. A set of eight convective weather and traffic load scenarios was used to evaluate the operational feasibility, potential benefits, and tool performance requirements of each condition. Significant improvements in weather avoidance and controller workload were observed in the multi-sector planner condition but no significant improvement was observed in user efficiency. Results indicate that multisector planning operations are effective and feasible in either team configuration.

An Evaluation of Operational Airspace Sectorization Integrated System (OASIS) Advisory Tool

In January 2013, a human-in-the-loop evaluation of the Operational Airspace Sectorization Integrated System (OASIS) was conducted in the Airspace Operations Laboratory of the Human Systems Integration Division (Code TH) in conjunction with the Aviation Systems Division (Code AF). The development of OASIS is a major activity of the Dynamic Airspace Configuration (DAC) research focus area within the Aeronautics Research Mission Directorate (ARMD) Airspace Systems Program. OASIS is an advisory tool to assist Federal Aviation Administration (FAA) En Route Area Supervisors in their planning of sector combinedecombine operations as well as opening closing of Data-side (D-side) control positions. These advisory solutions are tailored to the predicted traffic demand over the next few hours. During the experiment, eight retired FAA personnel served as participants for a part-task evaluation of OASIS functionality, covering the user interface as well as the underlying algorithm. Participants gave positive feedback on both the user interface and the algorithm solutions for airspace configuration, including an excellent average rating of 94 on the tool usability scales. They also suggested various enhancements to the OASIS tool, which will be incorporated into the next tool development cycle for the full-scale human-in-the-loop evaluation to be conducted later this year.

Human-in-the-Loop Investigation of Airspace Design

A part-task, human-in-the-loop study on Flexible Airspace Management (FAM) was conducted to explore the role of algorithm-generated airspace designs, human-centered design practices, and the potential benefits of FAM within these contexts. Participants were independently exposed to 4and 7-sector traffic scenarios that involved sector load imbalances due to reroutes around convective weather. Peak sector loads were well above the imposed threshold of 22 aircraft and required active management in each of the following conditions: No Boundary Change (No BC) in which traffic load imbalances were addressed through reroutes alone, Manual BC in which participants modified the existing airspace boundaries to reduce and redistribute load imbalances followed by reroutes for the remaining excess, and Algorithm + Manual BC in which sets of algorithm-generated boundary configurations were available for selection and further modification followed by reroutes to reduce remaining excess traffic load. Overall, results showed that FAM operations in the Manual and Algorithm + Manual BC conditions required fewer reroutes and managed peak sector loads better than the No BC condition. Furthermore, algorithmgenerated airspace designs and the support they provided in the Algorithm + Manual BC condition resulted in consistent benefits in terms of fewer reroutes and better peak management than in the Manual BC condition. Feedback from participants also highlighted the beneficial role of airspace optimization algorithms in FAM by providing a means of developing more acceptable and effective airspace designs and overall solutions to the problems presented.

Design and Evaluation of a Corridors-in-the-sky Concept: The Benefits and Feasibility of Adding Highly Structured Routes to a Mixed Equipage Environment

A human-in-the-loop simulation of a Corridors-in-the-sky concept was conducted that focused on investigating the potential benefits and feasibility of the concept with human operators in a realistic environment. In this simulation, the definition of “corridors” was changed from meaning separate corridor airspace with dedicated corridor controllers to highly structured routes with potentially common speeds and avionics equipage. The change in definition allowed the concept to be realizable within the mid-term Next Generation Air Transportation System (NextGen) timeframe and mitigated many of the feasibility issues that were identified in earlier research. Feasibility and benefits were tested through the variance of traffic levels within the test airspace (High and Max). In the High Traffic condition, the radar (R-side) and supporting data (D-side) controllers managed a high level of traffic without aircraft being rerouted out of the congested sectors. In the Max Traffic condition, a traffic flow manager and area supervisors worked together to reroute aircraft out of the congested sectors. Four different procedures were tested with different corridor structures: (1) no specific corridors (No Corridors), (2) only equipped aircraft within corridors (Equipped in Corridors), (3) only unequipped aircraft within corridors (Unequipped in Corridors), and (4) a mix of both equipped and unequipped aircraft within corridors (Mixed in Corridors). Surrounding non-corridor traffic consisted of a 50/50 mix of Data Comm and non-Data Comm equipped aircraft in all conditions. The results of the study indicate that the Equipped in Corridors condition showed the greatest benefits with the highest levels of throughput and the lowest reported workload relative to the other conditions. In contrast, the Unequipped in Corridors condition showed little throughput or workload benefits relative to the No Corridors condition. The results for the Mixed in Corridors condition fell in between the values observed for Equipped in Corridors and No Corridors. Feedback from the participants revealed that the observed reduction in benefits when unequipped aircraft were in the corridors was a result of the workload associated with the communications and monitoring required for the unequipped corridor aircraft as well as the display clutter of their data blocks. In addition, the study showed that the concept was feasible and was well received by the participants. Service for equipage was also shown to be feasible with fewer Data Comm equipped aircraft rerouted than non-Data Comm equipped aircraft.

Flexible Airspace Management Operator Roles, Task Distribution, and Coordination Mechanisms

A human-in-the-loop study was conducted to further test the potential benefits of the Flexible Airspace Management concept and to begin exploring the required coordination aspects of the concept. The air navigation service providers were able to dynamically alter sector boundaries to reduce traffic overload, thereby potentially increasing airspace utilization, increasing route efficiency, and minimizing excessive delays. Although prior studies have shown benefits of the concept, the operational procedures have yet to be sufficiently prototyped. To address this issue, the current study investigated the roles, task distribution, and coordination mechanisms involved in Flexible Airspace Management operations, specifically in regard to the Area Supervisor and the Traffic Management Coordinator positions. Results suggest that sharing the airspace management function between the Area Supervisors and Traffic Management Coordinators was appropriate and worked well when their roles were clearly defined and the Traffic Management Coordinators had the final authority for implementing the airspace configuration change. New data communication functions were prototyped to share airspace configuration proposals among the team members and the new functions were considered highly useful and usable. Coordination mechanisms that combined voice and data communication worked well and posed little difficulty to the operators.

Trajectory assessment and modification tools

• NextGen solutions have to be integrated • Move from controlled airspace to managed airspace • Leverage and expand on current technologies • Implement new automated DSTs • Ground systems that can work with advanced aircraft technologies • ADS-B • Performance-based trajectory navigation • Data Comm • Support a more advanced, efficient, safe and flexible air traffic control system

Trajectory assessment and modification tools for next generation air traffic management operations

This paper reviews three Next Generation Air Transportation System (NextGen) based high fidelity air traffic control human-in-the-loop (HITL) simulations, with a focus on the expected requirement of enhanced automated trajectory assessment and modification tools to support future air traffic flow management (ATFM) planning positions. The simulations were conducted at the National Aeronautics and Space Administration (NASA) Ames Research Centers Airspace Operations Laboratory (AOL) in 2009 and 2010. The test airspace for all three simulations assumed the mid-term NextGen En-Route high altitude environment utilizing high altitude sectors from the Kansas City and Memphis Air Route Traffic Control Centers. Trajectory assessment, modification and coordination decision support tools were developed at the AOL in order to perform future ATFM tasks. Overall tool usage results and user acceptability ratings were collected across three areas of NextGen operations to evaluate the tools. In addition to the usefulness and usability feedback, feasibility issues, benefits, and future requirements were also addressed. Overall, the tool sets were rated very useful and usable, and many elements of the tools received high scores and were used frequently and successfully. Tool utilization results in all three HITLs showed both user and system benefits including better airspace throughput, reduced controller workload, and highly effective communication protocols in both full Data Comm and mixed-equipage environments.