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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.

An Overview of Current Capabilities and Research Activities in the Airspace Operations Laboratory at NASA Ames Research Center

The Airspace Operations Laboratory at NASA Ames conducts research to provide a better understanding of roles, responsibilities, and requirements for human operators and automation in future air traffic management (ATM) systems. The research encompasses developing, evaluating, and integrating operational concepts and technologies for near-, mid-, and far-term air traffic operations. Current research threads include efficient arrival operations, function allocation in separation assurance and efficient airspace and trajectory management. The AOL has developed powerful air traffic simulation capabilities, most notably the Multi Aircraft Control System (MACS) that is used for many air traffic control simulations at NASA and its partners in government, academia and industry. Several additional NASA technologies have been integrated with the AOLs primary simulation capabilities where appropriate. Using this environment, large and small-scale system-level evaluations can be conducted to help make near-term improvements and transition NASA technologies to the FAA, such as the technologies developed under NASA’s Air Traffic Management Demonstration-1 (ATD-1). The AOL’s rapid prototyping and flexible simulation capabilities have proven a highly effective environment to progress the initiation of trajectory-based operations and support the mid-term implementation of NextGen. Fundamental questions about accuracy requirements have been investigated as well as realworld problems on how to improve operations in some of the most complex airspaces in the US. This includes using advanced trajectory-based operations and prototype tools for coordinating arrivals to converging runways at Newark airport and coordinating departures and arrivals in the San Francisco and the New York metro areas. Looking beyond NextGen, the AOL has started exploring hybrid human/automation control strategies as well as highly autonomous operations in the air traffic control domain. Initial results indicate improved capacity, low operator workload, good situation awareness and acceptability for controllers teaming with autonomous air traffic systems. While much research and development needs to be conducted to make such concepts a reality, these approaches have the potential to truly transform the airspace system towards increased mobility, safe and efficient growth in global operations and enabling many of the new vehicles and operations that are expected over the next decades. This paper describes how the AOL currently contributes to the ongoing air transportation transformation.

Multi Sector Planning Tools for Trajectory-Based Operations

This paper discusses a suite of multi sector planning tools for trajectory-based operations that were developed and evaluated in the Airspace Operations Laboratory (AOL) at the NASA Ames Research Center. The toolset included tools for traffic load and complexity assessment as well as trajectory planning and coordination. The situation assessment tools included an integrated suite of interactive traffic displays, load tables, load graphs, and dynamic aircraft filters. The planning toolset allowed for single and multi aircraft trajectory planning and data communication-based coordination of trajectories between operators. Also newly introduced was a real-time computation of sector complexity into the toolset that operators could use in lieu of aircraft count to better estimate and manage sector workload, especially in situations with convective weather. The tools were used during a joint NASA/FAA multi sector planner simulation in the AOL in 2009 that had multiple objectives with the assessment of the effectiveness of the tools being one of them. Current air traffic control operators who were experienced as area supervisors and traffic management coordinators used the tools throughout the simulation and provided their usefulness and usability ratings in post simulation questionnaires. This paper presents these subjective assessments as well as the actual usage data that was collected during the simulation. The toolset was rated very useful and usable overall. Many elements received high scores by the operators and were used frequently and successfully. Other functions were not used at all, but various requests for new functions and capabilities were received that could be added to the toolset.

Integrated Demand Management: Coordinating Strategic and Tactical Flow Scheduling Operations

NASA Ames researchers are developing a nearto mid-term concept called Integrated Demand Management (IDM). The objective of IDM is to improve National Airspace System (NAS) performance when the capacity of major high-volume resources is insufficient for the expected demand, using procedural coordination of different NextGen traffic management capabilities. An arrival capacity problem involving Newark Liberty International Airport (EWR) served as a use case for concept development. Under IDM, Traffic Flow Management System (TFMS) tools are used to pre-condition traffic into the Time-Based Flow Management (TBFM) system, enabling TBFM to better manage delivery to the capacity-constrained destination. The proposed solution leverages three capabilities: (1) the Collaborative Trajectory Options Program (CTOP) tools within TFMS to condition arrival demand into TBFM, (2) required-time-of-arrival (RTA) flight deck capabilities to support conformance to CTOP-planned TBFM entry times, and (3) TBFM metering to manage delivery to the capacity-constrained airport. The solution was refined through a series of human-in-the-loop (HITL) simulation studies and demonstrations with input from the FAA, airline stakeholders and subject matter experts. This paper describes the concept and results from an early proof-of-concept HITL experiment that focused on the EWR traffic problem.

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.

Nextgen operations in a simulated NY area airspace

A human-in-the-loop simulation conducted in the Airspace Operations Laboratory (AOL) at NASA Ames Research Center explored the feasibility of a Next Generation Air Transportation System (NextGen) solution to address airspace and airport capacity limitations in and around the New York metropolitan area. A week-long study explored the feasibility of a new Optimal Profile Descent (OPD) arrival into the airspace as well as a novel application of a Terminal Area Precision Scheduling and Spacing (TAPSS) enhancement to the Traffic Management Advisor (TMA) arrival scheduling tool to coordinate high volume arrival traffic to intersecting runways. In the simulation, four en route sector controllers and four terminal radar approach control (TRACON) controllers managed traffic inbound to Newark International Airports primary runway, 22L, and its intersecting overflow runway, 11. TAPSS was used to generate independent arrival schedules for each runway and a traffic management coordinator participant adjusted the arrival schedule for each runway 11 aircraft to follow one of the 22L aircraft. TAPSS also provided controller-managed spacing tools (slot markers with speed advisories and timelines) to assist the TRACON controllers in managing the arrivals that were descending on OPDs. Results showed that the tools significantly decreased the occurrence of runway violations (potential go-arounds) when compared with a Baseline condition with no tools. Further, the combined use of the tools with the new OPDs produced a peak arrival rate of over 65 aircraft per hour using instrument flight rules (IFR), exceeding the current maximum arrival rate at Newark Liberty International Airport (EWR) of 52 per hour under visual flight rules (VFR). Although the participants rated the workload as relatively low and acceptable both with and without the tools, they rated the tools as reducing their workload further. Safety and coordination were rated by most participants as acceptable in both conditions, although the TRACON Runway Coordinator (TRC) rated neither as acceptable in the Baseline condition. Regarding the role of the TRC, the two TRACON controllers handling the 11 arrivals indicated that the TRC was very much needed in the Baseline condition without tools, but not needed in the condition with tools. This indicates that the tools were providing much of the sequencing and spacing information that the TRC had supplied in the Baseline condition.

Evaluation of High Density Air Traffic Operations with Automation for Separation Assurance, Weather Avoidance and Schedule Conformance

In this paper we discuss the development and evaluation of our prototype technologies and procedures for far-term air traffic control operations with automation for separation assurance, weather avoidance and schedule conformance. Controller-in-the-loop simulations in the Airspace Operations Laboratory at the NASA Ames Research Center in 2010 have shown very promising results. We found the operations to provide high airspace throughput, excellent efficiency and schedule conformance. The simulation also highlighted areas for improvements: Short-term conflict situations sometimes resulted in separation violations, particularly for transitioning aircraft in complex traffic flows. The combination of heavy metering and growing weather resulted in an increased number of aircraft penetrating convective weather cells. To address these shortcomings technologies and procedures have been improved and the operations are being re-evaluated with the same scenarios. In this paper we will first describe the concept and technologies for automating separation assurance, weather avoidance, and schedule conformance. Second, the results from the 2010 simulation will be reviewed. We report human-systems integration aspects, safety and efficiency results as well as airspace throughput, workload, and operational acceptability. Next, improvements will be discussed that were made to address identified shortcomings. We conclude that, with further refinements, air traffic control operations with ground-based automated separation assurance can routinely provide currently unachievable levels of traffic throughput in the en route airspace.

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.

Integrated Demand Management (IDM) - Minimizing Unanticipated Excessive Departure Delay while Ensuring Fairness from a Traffic Management Initiative

This paper introduces NASA’s Integrated Demand Management (IDM) concept and presents the results from an early proof-of-concept evaluation and an exploratory experiment. The initial development of the IDM concept was focused on integrating two systems—i.e. the FAA’s newly deployed Traffic Flow Management System (TFMS) tool called the Collaborative Trajectory Options Program (CTOP) and the Time-Based Flow Management (TBFM) system with Extended Metering (XM) capabilities—to manage projected heavy traffic demand into a capacity-constrained airport. A human-in-the-loop (HITL) simulation experiment was conducted to demonstrate the feasibility of the initial IDM concept by adapting it to an arrival traffic problem at Newark Liberty International Airport (EWR) during clear weather conditions. In this study, the CTOP was utilized to strategically plan the arrival traffic demand by controlling take-off times of both shortand long-haul flights (long-hauls specify aircraft outside TBFM regions and short-hauls specify aircraft within TBFM regions) in a way that results in equitable delays among the groups. Such strategic planning decreases airborne and ground delay within TBFM by delivering manageable long-haul traffic demand while reserving sufficient slots in the overhead streams for the short-haul departures. A manageable traffic demand ensures the TBFM scheduler does not assign more airborne delay than a particular airspace is capable of absorbing. TBFM uses its time-based metering capabilities to deliver the desirable throughput by tactically coordinating and scheduling the long-haul flights and short-haul departures. Additional research was performed to explore the use of Required Time of Arrival (RTA) capabilities as a potential control mechanism to improve the arrival time accuracy of scheduled long-haul traffic. Results indicated that both shortand long-haul flights received similar ground delays. In addition, there was a noticeable reduction in the total amount of excessive, unanticipated ground delays, i.e. delays that are frequently imposed on the shorthaul flight in current day operations due to saturation in the overhead stream, commonly referred to as ‘double penalty.’ Furthermore, the concept achieved the target throughput while minimizing the expected cost associated with overall delays in arrival traffic. Assessment of the RTA capabilities showed that there was indeed improvement of the scheduled entry times into TBFM regions by using RTA capabilities. However, with respect to reduction in delays incurred within TBFM, there was no observable benefit of improving the precision of entry times for long-haul flights.