Joey Mercer

Human-In-the-Loop Evaluation of NextGen Concepts in the Airspace Operations Laboratory

The Airspace Operations Laboratory (AOL) at the NASA Ames Research Center hosts a powerful simulation environment for human-in-the-loop studies of air traffic operations. The primary real-time simulation capabilities are developed by the AOL development team as part of the Multi Aircraft Control System (MACS) and cover a wide range of operational environments from current day operations to future operational concepts like those envisioned for the Next Generation Air Transportation System (NextGen). The research focus in the AOL is on examining air traffic control and traffic management operations across multiple air traffic control sectors and Centers in rich air/ground environments that can include oceanic, enroute and terminal airspace. The basic simulation capabilities and earlier research was presented at the AIAA Modeling and Simulation Technologies conference in 2006. Since then, the AOL capabilities have been continuously improved and expanded. Over the past four years the AOL has been extensively utilized to investigate a variety of NextGen concepts for NASA’s NextGen Airspace Program and the FAA’s Air Traffic Organization for Planning, Research and Technology. The primary focus areas under investigation in the AOL are Separation Assurance and the associated Functional Allocation for NextGen, Controller Managed Spacing for nearto mid-term Terminal area operations, flow-based trajectory management and multi-sector planning and dynamic airspace configuration and flexible airspace management. This paper first gives an overview over the most significant capabilities that were added since 2006 and then reviews at a high level the main activities and findings in the different research focus areas.

Human-in-the-Loop Evaluation of Ground-Based Automated Separation Assurance for NextGen

This paper describes human-in-the-loop research at NASA Ames Research Center on service provider-based automated separation assurance for the Next Generation Air Transportation System (NextGen). Key human/automation integration aspects such as levels of automation and roles and responsibilities of automated separation management are investigated in the Airspace Operations Laboratory. A trilogy of part-task studies was designed to examine efficiency, safety, workload impact and acceptability of central aspects of the concept. Findings from a 2007 study on strategic trajectory-based automated separation assurance with data link-equipped aircraft are discussed in detail. Preliminary results on mixed operations with data link and conventional aircraft gathered in spring 2008 are included. The experiment design for investigating tactical safety assurance and off-nominal situations in summer 2008 is outlined. This research was funded by the Separation Assurance element of NASA’s Next Generation Air Transportation System – Airspace Project.

The Airspace Operations Laboratory (AOL) at NASA Ames Research Center

The Airspace Operations Laboratory (AOL) at NASA Ames Research Center hosts a powerful simulation environment for human-in-the-loop studies of air traffic operations. The capabilities have been developed at NASA Ames and cover a wide range of operational environments from current day operations to future operational concepts like those envisioned for the Next Generation Air Transportation System (NGATS). The research focus in the AOL is on examining air traffic control and management operations across multiple air traffic control sectors in rich air/ground environments that can include oceanic, enroute and terminal airspace. Past research involving the AOL includes distributed air/ground traffic management studies on trajectory negotiation, airborne self-separation and airborne spacing. Ongoing research with various government and industry partners include trajectory-oriented operations with limited delegation; multi sector planning; the US tailored arrivals initiative; airline-based sequencing and spacing, and airborne merging and spacing. In the future we expect using the AOL extensively for early exploration of operational questions crucial to the NGATS, like human-automation interaction, roles and responsibilities in distributed environments and required automation capabilities. This paper first gives an overview over philosophy, physical layout, software and connectivity of the AOL. Next, the available real-time capabilities are described in detail followed by a description of some important offline capabilities. The paper concludes with a summary of past and present research in the AOL and concluding remarks.

MACS: A Simulation Platform for Today's and Tomorrow's Air Traffic Operations

This paper describes the Multi Aircraft Control System (MACS) simulation platform developed in the Airspace Operations Laboratory (AOL) at NASA Ames Research Center. MACS is a comprehensive research tool that has been developed to increase the overall realism and flexibility of controller- and pilot-in-the loop air traffic simulations. The research focus in the AOL is on examining air traffic operations in rich air/ground environments that can include multiple oceanic, en route, and terminal airspace sectors. The AOL research and development team maintains and continuously expands the capabilities of MACS to rapidly prototype new interfaces, displays, tools and operational concepts for addressing the complex controller/pilot/automation integration crucial to the implementation of the Next Generation Air Transportation System (NextGen). Sample applications of the MACS software are presented to show the range of air traffic environments that can be investigated. Funding for this work was provided by NASA’s Aeronautics Research Mission Directorate (ARMD) and NGATS Airspace Systems research program.

Comparison of Ground-Based and Airborne Function Allocation Concepts for NextGen Using Human-In-The-Loop Simulations

Investigation of function allocation for the Next Generation Air Transportation System is being conducted by the National Aeronautics and Space Administration (NASA). To provide insight on comparability of different function allocations for separation assurance, two human-in-the-loop simulation experiments were conducted on homogeneous airborne and ground-based approaches to four-dimensional trajectory-based operations, one referred to as ground-based automated separation assurance (groundbased) and the other as airborne trajectory management with self-separation (airborne). In the coordinated simulations at NASA s Ames and Langley Research Centers, controllers for the ground-based concept at Ames and pilots for the airborne concept at Langley managed the same traffic scenarios using the two different concepts. The common scenarios represented a significant increase in airspace demand over current operations. Using common independent variables, the simulations varied traffic density, scheduling constraints, and the timing of trajectory change events. Common metrics were collected to enable a comparison of relevant results. Where comparisons were possible, no substantial differences in performance or operator acceptability were observed. Mean schedule conformance and flight path deviation were considered adequate for both approaches. Conflict detection warning times and resolution times were mostly adequate, but certain conflict situations were detected too late to be resolved in a timely manner. This led to some situations in which safety was compromised and/or workload was rated as being unacceptable in both experiments. Operators acknowledged these issues in their responses and ratings but gave generally positive assessments of the respective concept and operations they experienced. Future studies will evaluate technical improvements and procedural enhancements to achieve the required level of safety and acceptability and will investigate the integration of airborne and ground-based capabilities within the same airspace to leverage the benefits of each concept.

DISTRIBUTED AIR/GROUND TRAFFIC MANAGEMENT SIMULATION: RESULTS, PROGRESS AND PLANS

A mixed-fidelity simulation environment for humanin-the-loop study of Distributed Air / Ground – Traffic Management (DAG-TM) concepts has been developed at NASA’s Ames Research Center. The simulation environment facilitates large-scale experiments supporting high numbers of pilot, air traffic controller, and air traffic manager participants. Decision Support Tools (DST) for flight crews and air traffic service providers are accessible at the respective operator stations. Many operator positions can be augmented or autonomously run with agent support. We present samplings of results from studies conducted using this environment, and outline our goals in terms of improving and refining the simulation. We review the overall simulation architecture, and the key upgrades, including:

Examining Airspace Structural Components and Configuration Practices for Dynamic Airspace Configuration

Dynamic Airspace Configuration (DAC) is a new operational paradigm that proposes to migrate from the current structured, static airspace to a dynamic airspace capable of adapting to user demand while meeting changing constraints of weather, traffic congestion and complexity, as well as a highly diverse aircraft fleet (Kopardekar et al., 2007). To understand how the air traffic system can transform from current airspace structures and operational practices to what is envisioned in the NextGen operations, current airspace structures and configuration practices are cataloged in this paper. The purpose of this paper is twofold. The first purpose is to introduce and summarize current airspace structures to researchers who may not be familiar with them and describe specific examples on how these structures are currently used in the operational contexts at different facilities. The second purpose is to describe the near to mid-term operational implementations planned by the Federal Aviation Administration (FAA) to researchers whose focus is on far-term concepts but may not be aware of the transition pathway to the far-term concepts. These near to midterm implementations modify and/or extend the current airspace structures to provide greater flexibility and efficiency in air travel. The paper explores how the proposed airspace structures may be extended further to the NextGen timeframe with fully dynamic airspace and a mixture of highly equipped aircraft fleet.

Terminal-Area Traffic Management with Airborne Spacing

A Distributed Air Ground Traffic Management (DAG-TM) simulation of terminal-area arrival operations conducted at NASA Ames Research Center evaluated the feasibility and potential benefits of using pilot and controller decision support tools to support time-based airborne spacing and merging. Simulated aircraft were equipped with Flight Management Systems (FMSs) and ADS-B and entered the terminal area on charted FMS routes. Traffic scenarios began with a traffic flow that was well coordinated for merging and spacing and ended with an uncoordinated flow. In airborne spacing conditions, seventy-five percent of aircraft assigned to the primary landing runway were equipped to self-space. The results indicate that airborne spacing improves spacing accuracy and is feasible for FMS operations and mixed spacing equipage. Airborne spacing capabilities and flow coordination affect clearance selection. Controllers and pilots can manage spacing clearances that contain two callsigns without difficulty. For best effect, both decision support tools and spacing guidance should exhibit consistently predictable performance. This paper compares the experimental conditions and results with those from related airborne spacing research.

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.

The Impact of Trajectory Prediction Uncertainty on Air Traffic Controller Performance and Acceptability

A Human-In-The-Loop air traffic control simulation investigated the impact of uncertainties in trajectory predictions on NextGen Trajectory-Based Operations concepts, seeking to understand when the automation would become unacceptable to controllers or when performance targets could no longer be met. Retired air traffic controllers staffed two en route transition sectors, delivering arrival traffic to the northwest corner-post of Atlanta approach control under time-based metering operations. Using trajectory-based decision-support tools, the participants worked the traffic under varying levels of wind forecast error and aircraft performance model error, impacting the ground automations ability to make accurate predictions. Results suggest that the controllers were able to maintain high levels of performance, despite even the highest levels of trajectory prediction errors.