E
R&T Challenges for Intelligent and Autonomous Systems, Operations and Decision Making, Human Integrated Systems, and Networking and Communications

A total of 20 R&T Challenges were prioritized in the Area of intelligent and autonomous systems, operations and decision making, human integrated systems, and networking and communications. Table E-1 shows the results. The R&T Challenges are listed in order of NASA priority. National priority scores are also shown.1 This appendix contains a description of each R&T Challenge, including milestones and an item-by-item justification for each score that appears in Table E-1.2

E1 Methodologies, tools, and simulation and modeling capabilities to design and evaluate complex interactive systems

The U.S. air transportation system is a complex interactive system whose behavior is difficult to simulate with currently available models. Methodologies, tools, and simulation and modeling capabilities suited for the design and integration of complex interactive systems are needed to understand the air transportation system as an integrated, adaptive, distributed system that includes aircraft, ATM facilities, and airports, each with its own complex systems, all of which interact with one another, the environment, and human operators. Simulations and models for complex interactive systems are needed to accurately estimate system performance, to properly allocate resources, and to select appropriate design parameters. Additionally, the large number of possible future system designs requires models that can be reconfigured to model a wide range of design parameters.

One key barrier to developing integrated aviation systems is the lack of basic research that regulators can use to develop new certification standards and testing methodologies. Tools and methodologies that can assess the reliability and effectiveness of complex, nondeterministic, software-intensive future systems need to be developed. In some cases, this will also require changes to FAA regulations and certification standards (Aerospace Commission, 2002, pp. 2-9). This Challenge will help ensure that the right architecture and design decisions can be made in developing the air transportation system of the future. Key milestones include

  • Demonstrate methodologies and tools for the design, test, and certification of a flexible, robust, safe air transportation system that is readily adaptable to changing operational paradigms suited to new and different vehicles, including unmanned air vehicles (UAVs), very light jets (VLJs), and spacecraft operating in civil airspace; communications, navigation, and surveillance capabilities; and optimization techniques.

  • Demonstrate a flexible ATM model that incorporates the performance characteristics and limitations of the wide mix of present and future aircraft arriving, departing, and operating within airspace surrounding major hub airports. This model should be capable of analyzing the impacts of (1) aircraft mix and (2) operator and controller decision making and actions on system efficiency and capacity.

  • Demonstrate the ability of an enhanced version of the model to assess the impact of regional weather phenomena, such as convective activity, snow, and high winds.

  • Demonstrate the capability to test and certify nondeterministic systems.

  • Demonstrate the ability of an enhanced version of the ATM model to assess impacts of aircraft mix and operator and controller decision making.

Relevance to Strategic Objectives

Capacity (9): The capacity of the air transportation system must double or triple over the next 20 years to keep up

1

The prioritization process is described in Chapter 2.

2

The technical descriptions for the first 10 Challenges listed below are the same as the technical descriptions for these Challenges as they appear in Chapter 3.



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Decadal Survey of Civil Aeronautics: Foundation for the Future E R&T Challenges for Intelligent and Autonomous Systems, Operations and Decision Making, Human Integrated Systems, and Networking and Communications A total of 20 R&T Challenges were prioritized in the Area of intelligent and autonomous systems, operations and decision making, human integrated systems, and networking and communications. Table E-1 shows the results. The R&T Challenges are listed in order of NASA priority. National priority scores are also shown.1 This appendix contains a description of each R&T Challenge, including milestones and an item-by-item justification for each score that appears in Table E-1.2 E1 Methodologies, tools, and simulation and modeling capabilities to design and evaluate complex interactive systems The U.S. air transportation system is a complex interactive system whose behavior is difficult to simulate with currently available models. Methodologies, tools, and simulation and modeling capabilities suited for the design and integration of complex interactive systems are needed to understand the air transportation system as an integrated, adaptive, distributed system that includes aircraft, ATM facilities, and airports, each with its own complex systems, all of which interact with one another, the environment, and human operators. Simulations and models for complex interactive systems are needed to accurately estimate system performance, to properly allocate resources, and to select appropriate design parameters. Additionally, the large number of possible future system designs requires models that can be reconfigured to model a wide range of design parameters. One key barrier to developing integrated aviation systems is the lack of basic research that regulators can use to develop new certification standards and testing methodologies. Tools and methodologies that can assess the reliability and effectiveness of complex, nondeterministic, software-intensive future systems need to be developed. In some cases, this will also require changes to FAA regulations and certification standards (Aerospace Commission, 2002, pp. 2-9). This Challenge will help ensure that the right architecture and design decisions can be made in developing the air transportation system of the future. Key milestones include Demonstrate methodologies and tools for the design, test, and certification of a flexible, robust, safe air transportation system that is readily adaptable to changing operational paradigms suited to new and different vehicles, including unmanned air vehicles (UAVs), very light jets (VLJs), and spacecraft operating in civil airspace; communications, navigation, and surveillance capabilities; and optimization techniques. Demonstrate a flexible ATM model that incorporates the performance characteristics and limitations of the wide mix of present and future aircraft arriving, departing, and operating within airspace surrounding major hub airports. This model should be capable of analyzing the impacts of (1) aircraft mix and (2) operator and controller decision making and actions on system efficiency and capacity. Demonstrate the ability of an enhanced version of the model to assess the impact of regional weather phenomena, such as convective activity, snow, and high winds. Demonstrate the capability to test and certify nondeterministic systems. Demonstrate the ability of an enhanced version of the ATM model to assess impacts of aircraft mix and operator and controller decision making. Relevance to Strategic Objectives Capacity (9): The capacity of the air transportation system must double or triple over the next 20 years to keep up 1 The prioritization process is described in Chapter 2. 2 The technical descriptions for the first 10 Challenges listed below are the same as the technical descriptions for these Challenges as they appear in Chapter 3.

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Decadal Survey of Civil Aeronautics: Foundation for the Future TABLE E-1 Prioritization of R&T Challenges for Area E: Intelligent and Autonomous Systems, Operations and Decision Making, Human Integrated Systems, and Networking and Communications       Strategic Objective National Priority Why NASA? NASA Priority Score       Capacity Safety and Reliability Efficiency and Performance Energy and the Environment Synergies with Security Support to Space Supporting Infrastructure Mission Alignment Lack of Alternative Sponsors Appropriate Level of Risk Why NASA Composite Score R&T Challenge Weight 5 3 1 1/4 each E1 Methodologies, tools, and simulation and modeling capabilities to design and evaluate complex interactive systems 9 9 9 9 9 3 156 3 9 3 9 6.0 936 E2 New concepts and methods of separating, spacing, and sequencing aircraft 9 9 9 3 3 1 130 3 9 3 9 6.0 780 E3 Appropriate roles of humans and automated systems for separation assurance, including the feasibility and merits of highly automated separation assurance systems 9 9 9 1 3 1 124 3 9 3 9 6.0 744 E4 Affordable new sensors, system technologies, and procedures to improve the prediction and measurement of wake turbulence 9 9 3 1 1 1 104 3 9 3 9 6.0 624 E5 Interfaces that ensure effective information sharing and coordination among ground-based and airborne human and machine agents 3 9 9 1 9 3 102 3 9 3 9 6.0 612 E6 Vulnerability analysis as an integral element in the architecture design and simulations of the air transportation system 3 9 9 1 9 1 100 3 9 3 9 6.0 600 E7 Adaptive ATM techniques to minimize the impact of weather by taking better advantage of improved probabilistic forecasts 9 3 9 3 1 1 98 3 9 3 9 6.0 588 E8a Transparent and collaborative decision support systems 3 9 9 1 3 3 96 3 9 3 9 6.0 576 E8b Using operational and maintenance data to assess leading indicators of safety 3 9 9 1 3 3 96 3 9 3 9 6.0 576 E8c Interfaces and procedures that support human operators in effective task and attention management 3 9 9 1 3 3 96 3 9 3 9 6.0 576 E11 Automated systems and dynamic strategies to facilitate allocation of airspace and airport resources 9 3 9 3 3 1 100 3 9 1 9 5.5 550 E12 Autonomous flight monitoring of manned and unmanned aircraft 3 9 3 1 9 1 82 3 9 3 9 6.0 492 E13 Feasibility of deploying an affordable broad-area, precision-navigation capability compatible with international standards 9 9 3 1 3 1 106 3 3 3 9 4.5 477 E14 Advanced spacecraft weather imagery and aircraft data for more accurate forecasts 3 3 9 3 1 1 68 3 9 3 9 6.0 408 E15 Technologies to enable refuse-to-crash and emergency autoland systems 1 9 1 1 3 1 60 3 9 3 9 6.0 360 E16 Appropriate metrics to facilitate analysis and design of the current and future air transportation system and operating concepts 3 3 9 3 3 1 70 3 9 3 3 4.5 315 E17 Change management techniques applicable to the U.S. air transportation system 9 9 9 1 3 1 124 1 3 3 3 2.5 310 E18 Certifiable information-sharing protocols that enable exchange of contextual information and coordination of intent and activity among automated systems 3 1 9 1 9 1 60 3 9 3 3 4.5 270 E19 Provably correct protocols for fault-tolerant aviation communications systems 3 9 3 1 3 1 76 3 3 1 1 2.0 152 E20 Comprehensive models and standards for designing and certifying aviation networking and communications systems 3 9 3 1 1 1 74 3 3 1 1 2.0 148

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Decadal Survey of Civil Aeronautics: Foundation for the Future with demand. The capacity of the air transportation system is not the sum of the capacities of system components, because interactions among components are complex and interactions among system components may not be synergistic. The most effective way to estimate the capacity of the many options for the future U.S. air transportation system, and thereby identify the option that best meets future capacity needs, is to use system-of-system models that capture the functional relationships within the air transportation system. Safety and Reliability (9): Models suited to complex interactive systems are needed to understand the complex behavior of the air transportation system and to quantify safety for the current system and proposed changes to the system. These models would provide a unique and vital capability to identify safety issues, including unintended consequences, especially for radically different system configurations. Efficiency and Performance (9): Significant increases in efficiency will also be required to satisfy projected increases in demand. Models suited to complex interactive systems are needed to understand the behavior of the air transportation system and to quantify levels of efficiency and performance for the current system and proposed changes to the system. Energy and the Environment (9): Environment considerations (noise and emissions) are limiting the growth in air transportation. Thus, increased demand will be satisfied only if there is a good understanding of the magnitude and location of environmental impacts. Models suited to complex interactive systems would help design an air transportation system with improved performance in terms of energy and the environment. Synergies with National and Homeland Security (9): The DoD uses simulations of complex interactive systems to evaluate battlefield strategy and tactics. Thus, there are potential synergies in terms of using the simulation techniques that the DoD has developed to help evaluate commercial and private operations in the air transportation system. Additionally, the DoD and DHS would be interested in this Challenge because safety is also important for their operations, and the ability to distinguish between a component failure and an attack is predicated on the ability to predict and model failure modes. Support to Space (3): This Challenge would facilitate space launch operations through civil airspace. Why NASA? Supporting Infrastructure (3): NASA has highly capable facilities (such as the Future Flight Central simulator and easily configurable full-motion cockpit simulators that can be integrated with other simulation facilities) that contribute to meeting this Challenge. The DoD, FAA, academia, and industry also have facilities and expertise that would help meet this Challenge. Mission Alignment (9): This Challenge would directly contribute to the usefulness, performance, speed, safety, and efficiency of aircraft and the air transportation system, and it encompasses the type of long-term research that must occur before industry and operational agencies begin to develop specific components or synthesize components into system prototypes. Thus, this Challenge is well aligned with the NASA mission. Lack of Alternative Sponsors (3): The capabilities that this Challenge would provide are essential. The DoD is sponsoring related research, but it is not focused on civil aviation applications. Appropriate Level of Risk (9): This Challenge involves moderate risk. E2 New concepts and methods of separating, spacing, and sequencing aircraft Expected growth in the demand for air transportation will require efficient, denser en route and terminal area operations. This necessitates procedures that reduce minimum spacing requirements during all phases of flight and in all weather conditions, through an integrated approach that leverages a suite of emerging technologies such as required navigation performance and automatic dependent surveillance broadcast (ADS-B). The objective of this Challenge is to efficiently accommodate a large number and wide range of aircraft, including UAVs, through spacing and sequencing based on aircraft type and equipment rather than a common worst-case standard. Several concepts of operation should be systematically compared in terms of their technological, business, and human factors issues as well as their impact on capacity, safety, and the environment. This Challenge will study reduced separation operations within the context of existing ATM protocols and revolutionary paradigms that could significantly increase capacity, although the latter would involve a much more complicated transition process. Integration of UAVs into the air transportation system will require procedures that can safely manage aircraft with diverse performance characteristics and highly automated onboard flight management systems (Sabatini, 2006). Safe, high-capacity operations in a complex future airspace environment will require fundamental research into alternative ATM paradigms such as simultaneous noninterfering operations (Xue and Atkins, 2006) in which general aviation, rotorcraft, and UAV traffic are threaded through airspace unused by commercial air traffic. As onboard automation and cooperative control algorithms are matured (McLain and Beard, 2005), UAV traffic might also be efficiently managed using formations of UAVs that are coordinated locally but treated as a single entity by air traffic controllers and pilots of nearby aircraft. Key milestones include Demonstrate high-efficiency airspace and airway structures that can be effectively managed and understood.

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Decadal Survey of Civil Aeronautics: Foundation for the Future Design and evaluate separation, spacing, and sequencing procedures for UAVs operating in civilian airspace and assess their impact on commercial aircraft capacity and safety. Extend models and simulation tools to enable accurate evaluation of emerging technologies (e.g., ADS-B) in all weather conditions and during all phases of flight. Complete an in-depth examination of the ability of concepts such as runway-independent aircraft and UAV formations or swarms to safely increase capacity and accommodate nontraditional aircraft operations. Demonstrate advanced, autonomous collision avoidance technologies and protocols. Relevance to Strategic Objectives Capacity (9): New methods for managing separation, spacing, and sequencing are key enablers to increase capacity in both en route and terminal area airspace. Safety and Reliability (9): The air transportation system can safely manage growth only through a fundamental understanding of system behaviors and associated constraints. To be certified, new separation, spacing, and sequencing methods and associated procedures must prove they provide levels of safety that are comparable to or better than current operational procedures, even with much higher traffic density. Efficiency and Performance (9): The current air transportation system operates near saturation, resulting in significant travel delays during periods of increased demand or adverse weather conditions. Alternative spacing and sequencing methods are of paramount importance to alleviate these delays, resulting in more efficient travel despite system growth. Energy and the Environment (3): New methods to more efficiently space and sequence traffic will have a modest impact on energy use and the environment through reduced holding times and less circuitous flight paths. Synergies with National and Homeland Security (3): Although primarily directed toward transport operations, new methods for traffic separation, spacing, and sequencing must also take into account surveillance and UAV traffic. Support to Space (1): Given the relative infrequency of space launches, traffic density is not a factor. Therefore, this Challenge would have little or no relevance to the space program. Why NASA? Supporting Infrastructure (3): NASA has established and maintained a research group that studies alternative traffic management concepts in en route and terminal airspace. The FAA and industry also possess relevant expertise and facilities. Mission Alignment (9): Research associated with this Challenge will greatly benefit the aeronautics community and broaden our fundamental understanding of highly dense flight operations. This Challenge would benefit the air transportation system in general and general aviation in particular. Lack of Alternative Sponsors (3): NASA has a respected ATM research program capable of pursuing this Challenge. The FAA and private industry also are capable of performing related research—and leveraging work being done in Europe—but it is unclear that sufficient resources will be available from non-NASA sources, especially with regard to the development of revolutionary concepts with long-term application. Appropriate Level of Risk (9): The development and validation of new methods capable of having a significant impact on capacity will require substantial research, but the goal can be attained with reasonable effort. E3 Appropriate roles of humans and automated systems for separation assurance, including the feasibility and merits of highly automated separation assurance systems Air traffic control is currently a labor-intensive process. FAA controllers—aided by radar, weather displays, and procedures—maintain traffic flow and assure separation by communicating instructions to aircraft in their sector of responsibility. Limitations to this traditional paradigm are, in some areas, constraining the capacity of the air transportation system. For example, the FAA required airlines serving the Chicago O’Hare airport to reduce some of their flights during 2005 because of congestion-related delays. A recent study of en route sector congestion suggested that capacity could be increased by a factor of two or more while maintaining existing spacing, by developing new systems that merge human and computer decision making and automate time-critical separation assurance tasks (Andrews et al., 2005). Initiatives to reduce aircraft separation by providing automated advisories to air traffic controllers and flight crews have not lived up to expectations, because of controller workload concerns, institutional resistance, and other factors. The advent of UAVs has caused additional concern because it may not be feasible for UAVs with human-in-the-loop collision avoidance schemes to act in time to prevent midair collisions. This has led to interest in determining whether automating aircraft separation, whereby the controller is neither in the loop nor responsible for separation, is feasible and desirable. However, changing the role of the controller from tactical separation to traffic flow management and trusting automated systems to manage the tactical separation of aircraft would require resolution of major human factors, safety, and institutional issues (Wickens et al., 1998; Woods and Hollnagel, 2006). Collisions could occur if a UAV fails to respond or the automated traffic separation system fails and if human intervention is not effective. This Challenge would determine the appropriate roles of humans and automated systems to assure separation in high-density

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Decadal Survey of Civil Aeronautics: Foundation for the Future airspace during nominal and off-nominal operations. As part of this challenge, NASA should assess the feasibility and merits of highly automated separation assurance systems. Key milestones include Complete basic research necessary to determine the most appropriate separation assurance roles for humans and automation, for ground-centered and aircraft-centered designs. Complete the development of the NASA Ames Advanced Airspace Concept, an automated ground-based separation assurance system, for the en route domain. Determine how humans interact with the Advanced Airspace Concept and other automation designs. Determine how the Advanced Airspace Concept and other designs respond to air and/or ground automation failures, or when the flight crew fails to respond to automated directives. Develop an adaptation of the Advanced Airspace Concept or other designs for UAVs, and determine its performance. Determine through analysis and simulation the safety of the Advanced Airspace Concept and other designs. Relevance to Strategic Objectives Capacity (9): Recent research indicates that automated separation methods could enable significant en route and terminal capacity growth. Safety and Reliability (9): The safe use of automated separation must be assured through independent monitoring. Automated separation will reduce traffic delays if it can better adapt to disruptions caused by adverse weather and congestion. Efficiency and Performance (9): Automated separation could improve system efficiency and performance by reducing spacing requirements. Energy and the Environment (1): Automation may reduce unnecessary variations in flight times due to holding and thus reduce fuel consumption. Synergies with National and Homeland Security (3): The advent of automated separation may improve the ability to detect aircraft that deviate from approved flight paths because of terrorist activity or pilot error. Support to Space (1): This Challenge is likely to have little relevance to the space program. Why NASA? Supporting Infrastructure (3): NASA, the FAA, and industry have the facilities and expertise to conduct research on automated separation. Mission Alignment (9): This Challenge would have a broad benefit for aeronautics in general and civil aviation in particular. Lack of Alternative Sponsors (3): Research related to this Challenge (by the FAA and foreign research agencies) would likely proceed even without NASA support, though it would be significantly diminished. Appropriate Level of Risk (9): Developing fully automated separation systems would be very challenging, but a concerted effort is likely to produce worthwhile results and facilitate increases in system capacity and safety. E4 Affordable new sensors, system technologies, and procedures to improve the prediction and measurement of wake turbulence Existing wake vortex separation standards reduce system capacity during takeoff and landing operations and instrument approaches. Encounters with a wake vortex are also a growing concern in en route Reduced Vertical Separation Minima (RVSM) airspace (Reynolds and Hansman, 2001).3 Current research by the FAA and NASA is focused on procedural enhancements that take advantage of wake transport by winds (Mundra, 2001). For example, the capacity of San Francisco International Airport is expected to improve by using this approach to enable arrivals on both closely spaced parallel runways during low visibility weather. However, the relaxation of in-trail wake separation standards awaits improved measurement and prediction of wake behavior. Existing sensors and models do not adequately characterize wake decay phenomena, especially at typical final approach altitudes. Improved sensors, including coherent pulsed lidars, capable of directly measuring wake rotational momentum, are needed to support phenomenological studies and enable more accurate predictions of wake magnitude and decay in various atmospheric conditions. Those predictions, combined with models of aircraft upset risk, should allow reduced wake separation standards without degrading safety. R&T Challenge A10 will conduct research to improve techniques for predicting and measuring the formation, trajectory, and decay of vortices, including methods to accurately predict wingtip vortex formation and define changes in aircraft design to mitigate the strength of the vortices. This Challenge would complement that work by developing affordable new sensors, system technologies, and procedures to improve prediction and measurement of wake strength, location, motion, and aircraft upset risk in terminal and en route airspace. Together, Challenges A10 and E4 will enable safe flight with reduced in-trail wake separation. Key milestones include 3 Reduced Vertical Separation Minima apply to the airspace from flight levels 290 to 410 (which is equivalent to altitudes of approximately 29,000 feet to 41,000 feet) and create twice as many usable flight levels, decreasing the vertical separation between aircraft from 2,000 to 1,000 feet. While increasing capacity, this also could exacerbate the effects of wake turbulence.

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Decadal Survey of Civil Aeronautics: Foundation for the Future Demonstrate new sensors, including a scientific, coherent lidar capable of accurate wake velocity strength measurements. Conduct phenomenological studies of wake behavior supported by field experiments using ground-based sensor(s) that measure wake decay and atmospheric conditions at altitudes up to 8,000 feet above the ground. Determine aircraft upset risks from wake vortices encounters, taking advantage of existing models and enhancing them where needed with field data. Demonstrate procedures, monitoring equipment, and other systems to safely reduce wake separation. Demonstrate an airborne means to sense and quantify the intensity of hazardous wakes en route in time for aircraft to evade them. Relevance to Strategic Objectives Capacity (9): Reduced wake vortex spacing requirements near airports would typically decrease arrival and departure aircraft spacing. Safety and Reliability (9): Improved wake detection and avoidance systems and procedures will improve the ability to avoid accidents associated with wake vortices, even with higher traffic density. Efficiency and Performance (3): Aircraft arrival and departure rates will be improved if wake vortex spacing can be safely reduced. Energy and the Environment (1): Reductions in arrival and departure spacing may reduce airport and airborne congestion and could provide some reduction in fuel burn; however, the amount is difficult to calculate due to the lack of empirical data. Synergies with National and Homeland Security (1): This Challenge would have little relevance to national and homeland security. Support to Space (1): This Challenge would have little relevance to the space program. Why NASA? Supporting Infrastructure (3): NASA is currently leading a joint program with the FAA in wake vortex procedures and technologies. NASA has also sponsored research in wake upset risks. Mission Alignment (9): This Challenge would have a broad benefit for aeronautics in general. Lack of Alternative Sponsors (3): Industry is not supporting wake vortex research because it lacks facilities, and past efforts made little progress. Universities are not engaged due to the high costs of experimentation. Long-term research by NASA is needed to supplement near-term developments being made by the FAA. Appropriate Level of Risk (9): This Challenge has moderate to high risks. Development of sensors and systems is challenging but doable. E5 Interfaces that ensure effective information sharing and coordination among ground-based and airborne human and machine agents The potential for sharing a wide range of information within the air transportation system raises additional questions about how multiple agents (pilots, controllers, other system users, and automated system elements) can coordinate and share information given their disparate viewpoints and contexts. For information sharing to be effective, information must be provided to the right agents, at the right time, and in a fashion that facilitates accurate interpretation regardless of the source of the information. Some of the shared information may be factual (e.g., aircraft position, speed, heading, altitude, and flight plan), while some of it may be less tangible (e.g., potential responses to disruptions). The information elements will also likely vary in their timeliness and accuracy, and access to some information will be restricted for security and business reasons. Developing appropriate interfaces (in terms of information-sharing protocols, as well as display and visualization technology) is a nontrivial challenge, because agents can be easily overwhelmed by too much information or by the need to translate and analyze the information relative to their own situation and goals (Woods et al., 2002). Interfaces for human agents, in particular, will need to include methods for visualizing and interpreting operational situations to facilitate effective judgments and decisions. In addition, information-sharing and decision-making processes will often be conducted collaboratively by multiple agents. Therefore, they will require knowledge of both individual human cognition and of collaborative work among agents with potentially conflicting goals and different representations of the immediate situation (Brennan, 1998; Olson et al., 2001). Information-sharing protocols become exceptionally critical during crises, such as 9/11, when control of the national airspace was transferred to the military. Communications and decision-making protocols were fragmented. Research related to this Challenge must be coordinated with DoD and DHS to avoid a recurrence of such problems. The Challenge should also capitalize on technologies pioneered in the telecommunications industry that would facilitate the transfer of diverse information through dynamically reconfigured networks using thousands of disparate nodes. Key milestones include Document improved understanding of human cognitive control, judgment, and decision making in a variety of contexts and under a variety of stressors. Document improved understanding of organizational dynamics and business concerns associated with information sharing.

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Decadal Survey of Civil Aeronautics: Foundation for the Future Relevance to Strategic Objectives Capacity (3): Making it possible for systems agents to share more information and make better use of it will enable the air transportation system to safely handle the expected growth in demand. Safety and Reliability (9): Effective information sharing is vital, especially during emergencies, when operations are disturbed from established structures and real-time information is central to fluidly developing a course of action involving multiple agents. Efficiency and Performance (9): Taking better advantage of information sharing will reduce unnecessary flight delays due to uninformed management of system resources and will also allow local entities (e.g., aircraft operators) to make better decisions relative to their individual goals. Energy and the Environment (1): New methods of information sharing may be required to achieve reduced fuel consumption and more efficient ascent and descent profiles, but overall this Challenge would have only a small impact on energy and the environment. Synergies with National and Homeland Security (9): This Challenge will facilitate the information sharing in situations involving national and homeland security, and will help manage disparate concerns (e.g., closing airspace for security versus maintaining capacity). Support to Space (3): This Challenge would facilitate space launch applications through civil airspace and could be of value in the future as the number of U.S. space launches—and U.S. space launch facilities—increases. Why NASA? Supporting Infrastructure (3): NASA’s Ames and Langley Research Centers have expertise in several human factors areas, although additional insight may be required for the organizational, security, and business aspects of information sharing. Mission Alignment (9): This Challenge will benefit all segments of the civil aviation community and is consistent with ongoing research at several NASA research centers. Lack of Alternative Sponsors (3): Industry is not motivated to produce methods and protocols for information sharing beyond some limited applications benefiting themselves (e.g., the Collaborative Decision-Making Program). Some work exists at federally funded research and develop centers (FFRDCs) and the FAA Air Traffic Control System Command Center. The large-scale and interdisciplinary aspects of the research are beyond the scope of most individual university research programs. Appropriate Level of Risk (9): There is moderate risk due to the scale of the problem and the Challenge of responding to different users with different resources and needs. E6 Vulnerability analysis as an integral element in the architecture design and simulations of the air transportation system More than three-fourths of air transportation system delays are weather related (Meyer, 2005). Snow or thunder-storms at major hub airports often significantly reduce overall system capacity and efficiency. Abnormal en route winds cause unexpected peaking and depeaking at arrival gateways. En route convective weather causes disruptive and unpredictable rerouting, precipitating en route delays and reducing capacity and efficiency. Disruptions can also be caused by natural disasters (such as volcanoes, hurricanes, tornadoes, and wildfires), electronic attacks (such as power out-ages, hurricanes, GPS spoofing, spurious communication messages, and hacking into navigation aids), and physical attacks (such as destruction of control facilities and radars). The effects of these disruptions may be local, regional, or national. In all cases, system capacity and efficiency are directly affected, and, more important, the safety of the air transportation system may be compromised by an inadequate response. Airlines use a variety of techniques to respond to such disruptions. Some reduce schedule to preposition aircraft for the recovery, when the weather abates; others try to fly their full schedule, hoping that the recovery will take care of itself. System safety impacts of unplanned service disruptions should be evaluated early in the development cycle of new ATM system architectures, operating concepts, and system components. An agile ATM design should include provisions to counter or recover from system disruptions, and the design of the overall air transportation system should be evaluated by research and simulation to develop both system design concepts and/or operational procedures. In addition, quantitative analyses should be used to assess the safety impact of system architecture options. This Challenge would introduce vulnerability analyses as an integral element in the architecture design and simulations of the air transportation system to reduce the likelihood that the system will experience major system disruptions, to mitigate the severity of specific system disruptions, and to facilitate recovery from system disruptions. The result would be an air transportation system that is self-diagnosing and self-healing. Key milestones include Complete end-to-end vulnerability analysis of system architecture and signal flow. Demonstrate the ability of a more capable model to simulate critical element disruptions as defined by vulnerability analyses. Document safety and capacity impacts using modified system simulations. Develop changes in system architecture and operational procedures and demonstrate that they can mitigate the effects of specific system disruptions.

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Decadal Survey of Civil Aeronautics: Foundation for the Future Relevance to Strategic Objectives Capacity (3): This Challenge would minimize the magnitude, geographic extent, and duration of reductions in system capacity during air transportation system disruptions. Safety and Reliability (9): Both safety and reliability would be significantly and directly impacted if vulnerability analysis is not included as a basic consideration in system design. Efficiency and Performance (9): Because of the complex nature of the air transportation system, if sufficient attention is not paid to vulnerability analysis, the overall performance of the system could be excessively degraded in response to weather, major system malfunctions, terrorist actions, etc. Energy and the Environment (1): Delays and diversions caused by disruptions in the air transportation system would likely have only a short-term effect on energy utilization or the environment. Synergies with National and Homeland Security (9): Vulnerability analysis would improve the ability of the DoD and DHS to prevent disruptions to the air transportation system and to prepare themselves to respond as effectively and quickly as possible when they do occur. Support to Space (1): This Challenge would have little relevance to the space program. Why NASA? Supporting Infrastructure (3): The NASA Ames air traffic simulation facilities would be an excellent evaluation tool in support of this Challenge. The FAA, DoD, and industry also have relevant facilities and capabilities. Mission Alignment (9): This Challenge is directly tied to NASA’s aeronautics role. Lack of Alternative Sponsors (3): The FAA, DoD, and DHS also have an interest in vulnerability analysis. Appropriate Level of Risk (9): Conducting comprehensive vulnerability analyses of the air transportation system would be challenging, but it can be accomplished if adequately supported. E7 Adaptive ATM techniques to minimize the impact of weather by taking better advantage of improved probabilistic forecasts Adaptive traffic flow management methods are needed to take advantage of recent improvements in automated aviation weather forecasts. About 70 percent of aviation delay is due to operationally significant weather, including thunder-storms, low ceilings and visibilities, high winds, and turbulence. Exploitation of weather data collected from ground sensors and satellites using advanced image processing and machine intelligence has enabled significant improvements in aviation weather forecasts. One- to two-hour storm motion products are now being routinely displayed in key airport and en route air traffic facilities and in airline dispatch centers. Included are automatically updated estimates of the forecast accuracy, expressed as a probability (Robinson et al., 2004). This information is beginning to be used by air traffic managers and dispatchers, but only manually (Wolfson et al., 2004). Algorithms are needed that automatically translate the weather forecasts into actionable traffic flow recommendations, with the goal of fully incorporating the weather data into air traffic automation designs. A few examples of automation that translate probabilistic weather forecasts into traffic flow recommendations have been developed, and FAA air traffic managers have shown they can reduce delays. For example, the LaGuardia Airport traffic flow managers are using storm motion forecast tools, such as the Route Advisory Planning Tool, to automatically identify safe departure routes (Evans, 2006). However, many automation systems are not incorporating the new weather information into their designs. This Challenge would demonstrate the use of automated weather forecasts in making traffic flow decisions and determine where this capability is cost beneficial. Key milestones include Identify potential reductions in weather-induced delays. Demonstrate use of automated weather forecasts in making traffic flow decisions. Quantify the benefit of using automated weather forecasts in making traffic flow decisions. Determine where this capability is cost beneficial. Relevance to Strategic Objectives Capacity (9): Significant benefits from the manual use of new aviation weather forecasts have been realized in isolated cases. ATM operations could make use of advanced weather data to significantly reduce delays. Safety and Reliability (3): Better integration of improved weather forecasts with air traffic control will reduce flight risks and improve traffic reliability (i.e., on-time performance). Efficiency and Performance (9): Taking better advantage of improved weather forecasts will reduce unnecessary flight delays due to unnecessary holds on the ground or in the air. Energy and the Environment (3): With improved weather data, fuel consumption could be reduced through better routing and more efficient climb and descent profiles. Synergies with National and Homeland Security (1): Improved weather forecasts contribute to enhanced situational awareness and the navigation of intercept aircraft, but overall this Challenge would have a small impact on national and homeland security. Support to Space (1): This Challenge would have little relevance to the space program; advanced weather forecasts are already providing launch-critical information.

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Decadal Survey of Civil Aeronautics: Foundation for the Future Why NASA? Supporting Infrastructure (3): NASA has several ATM research programs, but NASA’s capabilities are not unique. Mission Alignment (9): This Challenge would benefit all segments of the civil aviation community and is consistent with ongoing research at several NASA research centers. Lack of Alternative Sponsors (3): Industry is not developing methods to integrate weather with traffic flow management. Some work exists at FAA-sponsored FFRDCs. Little work is being done at universities, because the necessary test facilities are cost-prohibitive. Appropriate Level of Risk (9): There is moderate risk due to the scale of the problem and the Challenge of responding to many aviation users with different equipment capabilities and levels of pilot expertise and who respond differently to various kinds of adverse weather. E8a Transparent and collaborative decision support systems Air traffic operations are enhanced by effective decision support systems that assist pilots, controllers, traffic flow managers, and airline personnel in tasks such as routing, flight planning, scheduling, and traffic separation. These decision support systems contribute to safe and efficient operations by using technology to enhance human capabilities and collaborate with the operator, as opposed to fully automated systems, which use technology rather than an operator to perform tasks. Collaborative decision support systems are most effective when the operators understand the basis for and limitations in the system’s reasoning process and can judge the appropriateness of system-generated recommendations. Similarly, the system’s recommendations should take into account operators’ knowledge and intentions as well as the context in which they operate. Support for reciprocal information sharing and mutual understanding of intentions and actions—a process called grounding—is critical to avoid breakdowns in human– machine collaboration and overall system performance (Sorkin et al., 1988; Lee and Moray, 1994; Smith et al., 2001; McGuirl and Sarter, 2006). This Challenge will identify the type of information to be shared between human operators and automated decision support systems and develop candidate designs for these systems. Key milestones include Identify the type of information to be shared between human operators and automated decision support systems and the most appropriate form of information representation and exchange. Develop, demonstrate, evaluate, and iteratively refine candidate designs in collaboration with operators. Relevance to Strategic Objectives Capacity (3): Collaborative decision support systems will help the air transportation system safely handle the expected growth in demand. Safety and Reliability (9): Past experience with decision support systems has shown that a lack of transparency can cause users to rely on information provided by decision aids too much or too little, because they do not understand how the decision aids work and what their limitations are. Also, stand-alone systems that perform tasks for, rather than with, human operators have been shown to make it very difficult for operators to monitor their performance and intervene when necessary. Both of these problems can affect safety and can be addressed through improved design of collaborative decision support systems. Efficiency and Performance (9): Improved system efficiency and performance is a prerequisite for meeting future demands on the air transportation system. Collaborative decision support systems will contribute to this goal by leading to more effective communications, fewer misunderstandings, and more effective operations. Energy and the Environment (1): More effective and collaborative decision support systems would have only a small impact on energy and the environment. Synergies with National and Homeland Security (3): National and homeland security would be enhanced by more effective and collaborative decision support systems. Support to Space (3): This Challenge would facilitate planning and execution of space missions. Why NASA? Supporting Infrastructure (3): NASA, especially the Ames and Langley Research Centers, has the resources and expertise to develop improved decision support system designs. NASA is well connected to other organizations conducting research in this field. Mission Alignment (9): The design of safe and efficient human–machine systems and interfaces is an important part of NASA’s aeronautics mission. Lack of Alternative Sponsors (3): Research associated with this Challenge will likely find a sponsor if NASA does not perform the work. It is not clear, however, that other sponsors are as well qualified. Appropriate Level of Risk (9): Developing improved collaborative decision support systems is difficult, but NASA has the capability to make substantial progress over current systems. E8b Using operational and maintenance data to assess leading indicators of safety Safety analysis is often a reactive, ad hoc process made difficult, in part, by the very high level of safety required of air transportation in the United States. Few unambiguous data points (accidents) are available for analysis, the number of data points continues to decrease because of the success of ongoing safety efforts, and accidents that do occur are increasingly the result of a complex chain of unlikely cir-

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Decadal Survey of Civil Aeronautics: Foundation for the Future cumstances, each of them benign (Leiden et al., 2001). While human error is often cited as a major safety concern, successful human performance is also a major (and under-reported) contributor to system safety. Thus, a particular concern for safety analysis is the human contribution to safety, especially when predicting the safety impact of dramatic changes to the role of human operators and increased reliance on automation. Likewise, safety analysis must consider individual aircraft as well as systemwide safety, which involves complex interactions among many agents. Using a common set of safety metrics (see R&T Challenge E16), this Challenge would develop methods both for monitoring the current system through ongoing analysis of operational and maintenance data and for predicting potential safety problems associated with proposed changes to the air transportation system. Key milestones include Produce a common taxonomy for all safety information acceptable to all stakeholders. Demonstrate methodologies to discover and analyze anomalous system, components, and human behavior in nominal and off-nominal conditions. Demonstrate methods to integrate system models into analytical processes. Demonstrate advanced, affordable methods to analyze anecdotal written reports of safety problems and cross-reference them to operational data from aircraft, ATM, and weather systems. Demonstrate methods to cross-reference operational data to certification and training simulator data to determine if aircraft are performing as designers intended and if pilots and controllers are performing as trained. Relevance to Strategic Objectives Capacity (3): Safety concerns can pose limits on operating concepts and criteria such as separation standards; however, more effective safety analysis might show that these limits are overly conservative and could be relaxed. Safety and Reliability (9): Established metrics and methods of assessing and predicting safety issues are fundamental to developing and maintaining safe operations. Efficiency and Performance (9): Without these developments, efficiency and performance will likely be constrained by overly conservative standards and operational procedures. Energy and the Environment (1): Methods of ensuring safety should be careful to not conflict with methods of conserving energy and protecting the environment, and vice versa, but overall this Challenge would have only a small impact on energy and the environment. Synergies with National and Homeland Security (3): Safety concerns can impose limits on unusual types of operations (e.g., UAV operations) within general-use airspace; likewise, in extreme circumstances (e.g., closing the national airspace and grounding all aircraft in an emergency), safe methods are needed to transition between normal and emergency modes of operations, including transfer of operational authority. Support to Space (3): This Challenge would help improve the safety of the space program. Why NASA? Supporting Infrastructure (3): NASA Ames Research Center has expertise in relevant system-safety analysis and monitoring, although additional insight may be required for the organizational, security, and business considerations in safety analysis. Mission Alignment (9): This Challenge would benefit all segments of the civil aviation community and is consistent with ongoing research at several NASA research centers. Lack of Alternative Sponsors (3): Industry is not motivated to perform systemwide safety analysis or to share some sensitive data and analyses, which impedes systemwide analyses and the easy sharing of safety-critical information. FAA-sponsored FFRDCs are conducting some related research, but NASA has a unique and objective third-party role given the regulatory function of the FAA. The large-scale and interdisciplinary aspect of the research is beyond the scope of most individual university research programs. Appropriate Level of Risk (9): There is moderate risk due to the scale of the problem and the difficulty of analyzing many types of operations with different characteristics and technologies. E8c Interfaces and procedures that support human operators in effective task and attention management The expected growth in air transportation demand will likely require operators to perform a wider range of tasks and to collaborate more closely with one another and with modern technologies. Pilots may begin to play a more active role in traffic separation or spacing and will need to coordinate their activities and intentions with other pilots and controllers. They will need to interact and exchange information, often interrupting each other and creating new tasks for one another. In general, more information will need to be distributed in a timely manner, task sets will increase, interruptions will become more likely, and the tolerance for delayed action or intervention will probably be reduced. It will be critical to ensure that operators are supported in properly scheduling and prioritizing their tasks, to improve attention management and avoid errors caused by unnecessary task switching, unnecessary interruptions, or inappropriate dismissals of demands (i.e., the failure to switch attention when appropriate and necessary) (Woods, 1995; McFarlane and Latorella, 2002; Ho et al., 2004). Major milestones include Complete basic research to document how operators absorb information, process information, and prioritize tasks.

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Decadal Survey of Civil Aeronautics: Foundation for the Future Demonstrate tools to efficiently evaluate operational data and reports of nominal and off-nominal decision making by operators. Demonstrate and evaluate candidate designs and procedures in support of preattentive reference, timesharing among different tasks, and task switching.4 Relevance to Strategic Objectives Capacity (3): In order to handle the expected growth in demand on the future air transportation system, timely interactions among operators and proper task prioritization will be important Safety and Reliability (9): Increased task and attention demands on pilots and controllers lead to unwarranted interruptions of ongoing tasks and lines of reasoning. Interruptions are known to increase the risk of errors involving both the interrupted and the interrupting task and should therefore be minimized. At the same time, inappropriate dismissals of demands can similarly affect the safety of operations, especially in congested airspace with reduced separation. Efficiency and Performance (9): Making sure that operators optimally direct their attention will help avoid errors and breakdowns in coordination that reduce system efficiency and performance. Energy and the Environment (1): This Challenge has little or no relevance to energy or the environment. Synergies with National and Homeland Security (3): Attention management challenges faced by DoD and DHS are similar to this Challenge faced by civil aviation. All are engaged in operations that require fast and efficient information exchange and interactions among many stakeholders, and research that will reduce unnecessary disruptions and improve attention management in the civil air transportation system will be of some assistance in addressing these challenges in the DoD and DHS. Support to Space (3): Some space operations require operators to cope with competing demands for their attention, especially in case of system failures. Thus, this Challenge is relevant to the space program. Why NASA? Supporting Infrastructure (3): NASA (especially the Ames and Langley Research Centers) has the resources and expertise to conduct research on improved systems and procedures in support of task and attention management. In fact, limited efforts are already under way to address this growing Challenge. Mission Alignment (9): Human-centered design and the development of safe and efficient human–machine systems for aviation and space operations are an important part of NASA’s mission. Lack of Alternative Sponsors (3): Research on task and attention management may be conducted by other sponsors if NASA does not address this Challenge. It is not clear, however, that research by others would have a sufficient aeronautical focus. Appropriate Level of Risk (9): This Challenge faces moderate risk but is likely to lead to significant improvements. E11 Automated systems and dynamic strategies to facilitate allocation of airspace and airport resources Many major airports have little or no excess capacity. The competition for airspace and airport resources (e.g., airport departure and arrival slots) at major airports will be exacerbated by growth in commercial and private air travel (including, for example, the introduction of VLJs). Automated systems and dynamic strategies driven by economic reasoning would facilitate quick and effective decision making when the transportation system encounters disruptions. They could also be used during normal operations to quickly negotiate and make decisions regarding, for example, real-time allocation of airspace and landing slots among aircraft with diverse size and performance characteristics, while considering the needs of all stakeholders, air transportation system efficiency, and energy conservation (Cramton et al., 2002). Key milestones include Modify available models to create dynamic tools for assessing the current and future state of the air transportation system. Document decision-making drivers of all users of the air transportation system. Create and demonstrate an architecture to allocate landing slots. Create and demonstrate an architecture to allocate airspace dynamically. Relevance to Strategic Objectives Capacity (9): Fast-response negotiation, quick decision making, and dynamic strategies that adapt themselves to changing conditions could substantially increase capacity at times and places where air transportation resources are constrained, especially during disruptions. Safety and Reliability (3): Fast-response decision making will increase safety and reliability during system disruptions. 4 Preattentive reference is supported by presenting partial information about a potentially interrupting task or event to help the operator decide whether a shift in attention is warranted. The information needs to be presented in such a way that it is quickly noticed and easily processed and understood without requiring an interruption of the ongoing task or line of reasoning (Woods, 1995). Operational systems that provide preattentive reference reduce the risk of task-switching errors and improve operator efficiency and performance.

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Decadal Survey of Civil Aeronautics: Foundation for the Future Efficiency and Performance (9): More effective allocation of access to air transportation resources, including quick response to disruptions in the air transportation resources, will greatly improve system efficiency and performance. Energy and the Environment (3): Dynamic strategies that lead to more effective allocation of airspace and landing slots would have a positive impact on energy conservation and the environment. Synergies with National and Homeland Security (3): Quick, highly effective decision-making systems suitable for emergency situations would enhance national and homeland security. Support to Space (1): This Challenge is not directly relevant to the space program. Why NASA? Supporting Infrastructure (3): NASA has the resources to develop decision-making tools, methodologies, and systems based on software agents, and it is well connected to other relevant research communities with relevant skills. Mission Alignment (9): Improving the performance of the air transportation system is part of NASA’s mission. Lack of Alternative Sponsors (1): The FAA is already supporting research related to traffic flow management and collaborative decision making that would contribute to this Challenge. Current funding is probably not at a high enough level to address all of the complexities of this issue, but in any case, solutions to this Challenge are highly dependent on specific FAA implementation plans and architectures (e.g., the Enhanced Traffic Management System). Appropriate Level of Risk (9): The technology goals are realistic, and the technical risk is moderate. E12 Autonomous flight monitoring of manned and unmanned aircraft Safe, high-capacity operations can only be achieved if pilots (and ground-based operators of UAVs) reliably comply with their communicated intentions. This means that each UAV must have numerous fail-safes in case of system failure or loss of the communications link between a UAV and its operator (Sabatini, 2006). The effects of unexpected deviations can ripple throughout the system, increasing delays and the risk of collision. An autonomous flight monitoring system would identify unanticipated and unauthorized deviations from flight plans, as well as their likely cause (e.g., degraded equipment performance, adverse weather, or unexpected actions by the pilot or autopilot). The system would also disseminate relevant information to agents in the air transportation system that might be affected, with the goal of rapidly initiating analysis and intervention systems to identify and resolve near- and long-term conflicts or hazards. To be useful, flight monitoring technologies will need to avoid false alarms associated with routine deviations to adjust spacing between aircraft or in response to local weather conditions. Technologies developed in response to this Challenge could also be used to better predict the near-term consequences of flight plan deviations. Data generated by onboard systems could be combined with data provided by ground systems to extend the time horizon of the predictive capabilities to more than just a few minutes. Key milestones include Produce a detailed set of requirements and design specification for flight monitoring systems deployed on manned and unmanned aircraft. Demonstrate algorithms and knowledge to enable a flight monitoring system that accurately anticipates, detects, and diagnoses flight plan deviations. Demonstrate the ability to more accurately project the near-term results of manipulating aircraft controls and inform pilots of likely consequences in terms of aircraft motion, potential collisions, airspace violations, etc. Design protocols for disseminating information from flight monitoring systems locally and throughout the air transportation system. Specify corrective actions appropriate for manned and unmanned aircraft in response to unplanned deviations detected by a flight monitoring system. Relevance to Strategic Objectives Capacity (3): The ability of an autonomous flight monitoring system to provide early warning of unplanned flight deviations could have a modest impact on capacity by enabling reduced separation standards as a result of increased trust that each aircraft will accurately follow its flight plan. Safety and Reliability (9): An autonomous flight monitoring system would increase safety by providing information on localized and systemwide deviations and their potential to create hazards or conflicts. Efficiency and Performance (3): An autonomous flight monitoring system would help assess systemwide performance and delays as well as provide warnings of flight plan deviations, which would allow operators to make changes to improve system performance. Energy and the Environment (1): An autonomous flight monitoring system would have minimal impact on energy and the environment. Synergies with National and Homeland Security (9): Early warning of flight plan deviation could help identify potentially hostile action. Autonomous flight monitoring could also provide early indication of tampering with air transportation system equipment (e.g., navigation signals and communication channels). Support to Space (1): Future space vehicles will have extensive onboard monitoring capabilities, but this Chal-

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Decadal Survey of Civil Aeronautics: Foundation for the Future lenge focuses on monitoring of the air transportation system and thus would have minimal direct relevance to the space program. Why NASA? Supporting Infrastructure (3): NASA has placed significant emphasis on aircraft and spacecraft diagnostics and monitoring, but it has limited expertise in the systemwide monitoring capabilities associated with this Challenge. Mission Alignment (9): Autonomous flight monitoring has the potential to significantly enhance aviation safety through improved compliance with flight plans and improved situational awareness. Lack of Alternative Sponsors (3): Development of a systemwide autonomous flight monitoring capability may also be supported by the FAA, and some capabilities would be supported by commercially developed flight management systems that currently monitor and store statistics onboard each aircraft. Appropriate Level of Risk (9): Systemwide flight monitoring is feasible, but significant challenges remain to reliably detect, diagnose, and project the impact of flight plan deviations. E13 Feasibility of deploying an affordable broad-area, precision-navigation capability compatible with international standards Current Global Positioning System (GPS) satellites do not provide navigation data that are precise enough (particularly with regard to altitude) or reliable enough to support precision approach and landing in low visibility conditions (Shively and Hsaio, 2005). In addition, GPS signals are vulnerable to jamming (Volpe, 2001). Installation of ground-based augmentation systems, such as pseudolites, at each landing area would address these shortcomings. However, ground augmentation, as currently envisioned, is not an affordable solution for many small airports. In cooperation with the Russian and European sponsors of the Global Navigation Satellite System (GLONASS) and Galileo satellite navigation systems, this Challenge would investigate the feasibility of improving existing systems so that measurement geometry, terrestrial coverage, integration of inertial sources, etc. would provide navigation signals with enough integrity and redundancy to enable a broad-area precision navigation capability without the need for ground-based augmentation or independent backup. Key milestones include Demonstrate appropriate concepts of operations. Review currently planned enhancements to the GPS, Galileo, and GLONASS systems to assess the degree to which performance improvements and/or design modifications of one or more systems would be required. Assess the cost, affordability, and technical feasibility of developing and deploying a fully compliant broadarea precision navigation system, including quality assurance methodologies, based on one or more operational concepts. Relevance to Strategic Objectives Capacity (9): A broad-area precision navigation capability (including vertical guidance) would open up any site as a potential landing area and facilitate greater reliance on runway-independent operations. This would increase air transportation system capacity, especially at small airports that currently lack precision approaches. Safety and Reliability (9): Safety is enhanced with the addition of precision landing guidance in all weather conditions. Efficiency and Performance (3): Efficiency and performance would be enhanced by the availability of Category III landing at any site. Energy and the Environment (1): The Challenge would have no significant impact on this Objective. Synergies with National and Homeland Security (3): A broad-area precision navigation capability would facilitate response to natural disasters or terrorist attacks because it would not depend on preexisting ground infrastructure and it would provide coverage to disaster sites wherever they might be. Support to Space (1): A broad-area precision navigation capability would be of minimal use to space operations. Why NASA? Supporting Infrastructure (3): NASA’s space program already has a role in GPS spacecraft design and could help develop requirements and design specifications. The DoD, however, has deployment and operational control of the GPS satellite constellation and the FAA is responsible for certification. Assessing the feasibility of a broad-area precision navigation capability for civil aviation is closely tied to regulatory and economic issues that fall outside NASA’s area of expertise. Mission Alignment (3): The technical feasibility issues are well aligned with NASA’s aeronautics mission, but economic feasibility issues are better handled by industry, and regulatory feasibility issues are better handled by the FAA. Lack of Alternative Sponsors (3): DoD has no requirement to provide a GPS system with these capabilities. Industry is in a good position to assess cost, affordability, and economic feasibility. Appropriate Level of Risk (9): This Challenge has moderate to high risk. E14 Advanced spacecraft weather imagery and aircraft data for more accurate forecasts FAA-sponsored weather research has been successfully exploiting data from the National Weather Service and FAA

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Decadal Survey of Civil Aeronautics: Foundation for the Future weather radars, as well as space imagery from Geostationary Operational Environmental Satellites (GOES), to enable accurate 1- to 2-hour forecasts of convective storm motion and other weather hazardous to aviation. These forecasts are beginning to provide significant benefits to civil aviation, especially by reducing delays. More forecast improvements are needed but await better understandings of storm growth and decay phenomena (Wolfson et al., 2004). That, in turn, requires improved space imagery with finer resolution and higher update rates than existing Next Generation Weather Radar (NEXRAD) radars. There is also significant interest in using satellite-based multi- and hyperspectral images to better understand cloud formations and develop precursors to storm growth and decay. New imagery that is expected to provide these data will come with the 2012 launches of the GOES-R satellite and the first satellite for the National Polar-Orbiting Operational Environmental Satellite System (NPOESS). Even so, research is needed to understand how to use these data and combine the knowledge they provide with existing terrestrial sensor data. Key milestones include Demonstrate the ability to use existing multi- and hyperspectral space imagery for tactical aviation forecasts using data from the following sources: Hyperion imager on the Earth Observing-1 Satellite. Atmospheric Infrared Sounder. the Infrared Atmospheric Sounding Interferometeron on the Meteorological Operational Satellite (METOP). Geosynchronous Imaging Fourier Transform Spectrometer developed by Langley Research Center, an on-the-shelf GOES-R prototype sensor that tracks the three-dimensional movement of water vapor and winds, to accelerate the exploitation of GOES-R imagery. Demonstrate methods of predicting the growth and decay of convective systems using space imagery and terrestrial data sources on timescales consistent with aviation needs. Relevance to Strategic Objectives Capacity (3): Extending the forecast horizon to beyond 2 hours would increase the capacity of the air transportation system during adverse weather. Safety and Reliability (3): Improvements in the accuracy and reliability of weather forecasts directly impact both safety and dispatch reliability of flight. Efficiency and Performance (9): Improved weather forecasts will reduce unnecessary flight delays due to excessive ground holds, reroutes, and airborne holding. Energy and the Environment (3): With improved weather data, reduced fuel consumption and more efficient climb and descent profiles may be achieved. Synergies with National and Homeland Security (1): Improved weather forecasts contribute to enhanced situational awareness and the navigation of intercept aircraft, but this would be only a small contribution to the overall state of national and homeland security. Support to Space (1): Advanced weather forecasts are already providing launch-critical information, and improved forecasts would have only a small impact on the space program. Why NASA? Supporting Infrastructure (3): NASA is already supporting research in hyperspectral imagery as well as launch and support systems. Mission Alignment (9): This Challenge would directly benefit the air transportation system, and it would complement ATM research already under way. Lack of Alternative Sponsors (3): NASA support will ensure that space imagery research already under way includes a component that is specifically focused on tactical forecasts for civil aviation. Appropriate Level of Risk (9): This Challenge has moderate to high risk. E15 Technologies to enable refuse-to-crash and emergency autoland systems Flight management systems can safely execute flight plans from takeoff through landing under nominal conditions, and UAV autopilots are approaching this level of capability. Less well understood is the response of flight management systems to abnormal operating conditions that may occur on the aircraft or in the portion of the air transportation system in which the aircraft is operating. Emergencies may be caused by miscommunications; errors involving onboard or remote pilots, air traffic controllers, or automated systems; and other irregularities (e.g., airframe damage) that significantly impact aircraft performance. Refuse-to-crash systems are intended to prevent both controlled and uncontrolled flight into terrain and collisions with other aircraft (Croft, 2003). Emergency autoland systems would be activated to safely land an aircraft when a failed system makes the aircraft difficult or impossible to continue powered flight safely. Such systems are likely to be most successful if implemented both onboard and on the ground. Key milestones include Demonstrate fundamental flight planning and control algorithms for refuse-to-crash and emergency autoland systems applicable to manned and unmanned aircraft. Demonstrate robust integration of algorithms within a distributed air transportation system that enables both onboard and remotely controlled recovery from system failures or hostile activities.

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Decadal Survey of Civil Aeronautics: Foundation for the Future Specify data requirements and protocols that will enable unambiguous local or remote detection of situations that require response by a refuse-to-crash or emergency autoland agent. Relevance to Strategic Objectives Capacity (1): This Challenge focuses on safety and has no direct impact on capacity. Safety and Reliability (9): Successful development of refuse-to-crash and emergency autoland capabilities would provide another layer of safety. Efficiency and Performance (1): The responsive algorithms developed by this Challenge apply to important but improbable events, so this Challenge would not significantly affect the overall efficiency or performance of the air transportation system. Energy and the Environment (1): This Challenge has little impact on this Objective. Synergies with National and Homeland Security (3): An emergency autoland system can enable a damaged or otherwise compromised aircraft to safely land despite reduced performance capabilities. Support to Space (1): This Challenge would have little impact on the space program. Why NASA? Supporting Infrastructure (3): NASA has an active research program on emergency autoland systems but has placed less emphasis on refuse-to-crash systems. This Challenge requires systemwide implementation of these capabilities, which has not been a major focus of NASA or others. Mission Alignment (9): This Challenge could broadly benefit commercial and general aviation. Lack of Alternative Sponsors (3): Although other government and industrial organizations would perform some research related to this Challenge, NASA support will be important for the fundamental research required by this Challenge. Appropriate Level of Risk (9): This Challenge is feasible, but it has a moderate to high risk. E16 Appropriate metrics to facilitate analysis and design of the current and future air transportation system and operating concepts As advanced technologies and procedures are developed to address air transportation needs, it is important that their performance be understood and compared to existing capabilities. Metrics are important because the metrics that are used to measure the performance of a system have a direct impact on the design of the system; parameters that are not measured—or are measured incorrectly or incompletely— will not be fully considered or accounted for in the final design. Hence the importance of identifying appropriate metrics and incorporating them into system analysis and design tools and processes. However, there is no comprehensive, widely held set of metrics to analyze and design the current and future air transportation system, assess related operating concepts, and define bounds on system performance. Key milestones include Identify and document objective measures of current capacity, safety, and efficiency. Conduct sensitivity analyses of the above factors to determine causality. Relevance to Strategic Objectives Capacity (3): Additional capacity is a key requirement that any future air transportation system must meet. However, there are many ways to measure capacity, and many places where capacity could be measured. Thus, it is important to develop composite metrics that capture the overall ability of the system to handle traffic. Safety and Reliability (3): More effective safety and reliability metrics would help guide system changes to improve performance in these areas. Efficiency and Performance (9): High efficiency is the basis for cost effectiveness. Thus, it is important that the efficiency of a system be known before and during development. Energy and the Environment (3): Environmental considerations are often considered only at the end of the design process. However, they will impact the acceptance of any proposed changes as evidenced by the litigation surrounding the expansion of airports and changes to terminal area trajectories in the United States. Therefore, such considerations must be measured directly or by proxy (with appropriate metrics) throughout the design process to ensure that the resulting solution is at the very least environmentally feasible. Synergies with National and Homeland Security (3): The DoD and DHS use many metrics related to security. Metrics that are developed to evaluate the civil air transportation system would be of some interest to the DoD and DHS, in that they would facilitate military operations in civil airspace and improve the ability of the air transportation system to respond to emergencies. Support to Space (1): This Challenge is not relevant to this Objective. Why NASA? Supporting Infrastructure (3): NASA has some researchers who could address this Challenge, but outside expertise would also be needed. Mission Alignment (9): This Challenge involves long-term research that should occur before others begin to develop specific components or synthesize components into

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Decadal Survey of Civil Aeronautics: Foundation for the Future system prototypes. Thus, it is well aligned with NASA’s mission. Lack of Alternative Sponsors (3): This Challenge might be addressed by the FAA if NASA is not able to perform it. Appropriate Level of Risk (3): This Challenge involves low risk. E17 Change management techniques applicable to the U.S. air transportation system The air transportation system comprises technology as well as large organizations with long-standing institutional cultures and business concerns, which must be motivated to participate in new operating concepts. Changing such a complex interactive system is difficult both in terms of the immensity of changing its individual elements (new technologies, personnel training, etc.) and in terms of motivating the institutional and business changes. Additionally, the end state of the future air transportation system remains undefined, so R&T should create and maintain the flexibility to change the system in any of several different directions. This requires the interdisciplinary application of large-scale system engineering, organization design, economics, and financial analysis, which in some ways is beyond the current state of knowledge. Even so, improved change management techniques are vital to a cost-effective, noncontentious, and safe transition to the air transportation system of the future. Key milestones include Demonstrate methods to identify key obstacles to change in large-scale sociotechnical systems. Demonstrate methods to describe and predict the impacts of proposed changes on personnel roles, skills, and training; staffing levels; organizational structures; operating procedures, policies, and regulations; and economic and financial concerns, including funding sources for government agencies. Create an architecture to apply change management methods to interagency work that is developing the Next Generation Air Transportation System. Relevance to Strategic Objectives Capacity (9): Many elements of and organizations involved in the air transportation system must collectively and simultaneously transition to new operating concepts to satisfy future demand for air transportation. Safety and Reliability (9): Poorly executed transitions to new operating concepts may degrade safety due to unclear responsibility and authority, dissonant work practices between and within organizations, and poor use of resources, including newly available information. Efficiency and Performance (9): Coordinated, simultaneous shifts to new operating concepts will facilitate multiple agents working together to improve the overall performance of the air transportation system. It will also allow individual entities to use their individual resources effectively and efficiently. Energy and the Environment (1): Improved change management techniques will not have a substantial impact on energy consumption or the environment. Synergies with National and Homeland Security (3): Poorly executed transitions to new operating concepts may degrade security due to unclear responsibility and authority, dissonant work practices between and within organizations, and poor use of resources. Support to Space (1): Improved change management techniques developed for the civil air transportation system are unlikely to be of substantial value to the space program. Why NASA? Supporting Infrastructure (1): This Challenge would require NASA to acquire additional expertise in large-scale system engineering, organization design, economics, and financial analysis. Mission Alignment (3): This Challenge would benefit all aeronautics domains, but many aspects of this Challenge involve organizational and economic issues that fall outside the normal scope of NASA’s aeronautics research. Lack of Alternative Sponsors (3): Many other organizations are already involved in transformation of the air transportation system. Appropriate Level of Risk (3): The risk associated with this Challenge is low if it is properly incorporated into the overall effort to develop the NGATS. E18 Certifiable information-sharing protocols that enable exchange of contextual information and coordination of intent and activity among automated systems Situational awareness is required for safe and efficient operation of individual aircraft and the air transportation system as a whole. Numeric data from radar or onboard instruments is routinely processed by onboard flight management systems for navigation and local deconfliction. ATM tools predict conflicts given information on the current status of aircraft and their flight plans. However, these systems are somewhat rigid and do not always adapt well to contingency system disruptions and frequent flight plan alterations. The air transportation system of the future may use dynamic routing capabilities to increase capacity and efficiency. This would require the system to understand at a more fundamental level aircraft objectives and the protocols by which flight plans will be changed, rather than rely on static flight plans that will likely become obsolete. Objectives of this Challenge are to (1) model the information that must be shared in a dynamic air transportation system and the criteria under which data must be explicitly

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Decadal Survey of Civil Aeronautics: Foundation for the Future communicated rather than inferred and (2) interact with certification authorities to ensure that it will be feasible to transfer research results to operational systems. Research associated with this Challenge should also take into account limitations on the ability to reconfigure aircraft and the time required for each manned or unmanned aircraft to dynamically alter its flight plan, in response to, for example, changes in the environment and the flight plans of other aircraft. Key milestones include Quantify communication bottlenecks in the air transportation system during nominal operation and off-nominal operating conditions. Define information-sharing protocols that could enable dynamic routing of all classes of manned and unmanned traffic, considering the performance of different aircraft and their ability to respond to flight plan changes. Demonstrate the application of strategies to infer the intent of aircraft locally, to minimize the need for high-bandwidth communication across the air transportation communications networks. Relevance to Strategic Objectives Capacity (3): Efficient information sharing is a key component of distributed, dynamic routing, but it does not directly increase capacity. Safety and Reliability (1): This Challenge is explicitly focused on improving the efficiency of the air transportation system. Efficiency and Performance (9): Information sharing will become a key enabler in a distributed, dynamic air transportation system. This Challenge would directly increase efficiency and performance of the system through minimal and expressive information exchange. Energy and the Environment (1): Information sharing has no direct impact on energy or the environment. Synergies with National and Homeland Security (9): Aircraft coordination and interpretation of intent through information sharing have significant overlap with homeland security. Intent inference could enable early detection of compromised aircraft, and managing such deviations will require elements of the air transportation system to be efficiently coordinated. Support to Space (1): This Challenge is not relevant to this Objective. Why NASA? Supporting Infrastructure (3): NASA has participated in the development of information-sharing protocols present in current and emerging ATM systems. Mission Alignment (9): This Challenge would improve the safety and (indirectly) the capacity of the air transportation system. Effective information-sharing protocols applicable to all aircraft types (e.g., transport, UAV, and general aviation) will help ensure that all aircraft types will be able to function efficiently within the congested airspace of the future. Lack of Alternative Sponsors (3): Other government and industrial organizations will likely sponsor related work as it applies to transport operations. Appropriate Level of Risk (3): The technology risk for this Challenge is low. E19 Provably correct protocols for fault-tolerant aviation communications systems The future air transportation system will increasingly rely on information exchange and automation. Thus, the ability to communicate among systems (ground- and airborne-based) must be ensured through the application of fault-tolerant system design. Key milestones include Demonstrate new communication protocols and design standards that are widely accepted within the aviation community. Demonstrate methods for certifying systems that incorporate the new protocols and standards. Relevance to Strategic Objectives Capacity (3): Air-to-ground information sharing and new decision support technologies, which will improve capacity, would benefit from reliable communications systems. Safety and Reliability (9): Fault-tolerant aviation communications systems will enhance the safety and reliability of the air transportation system. Efficiency and Performance (3): Fault-tolerant aviation communications systems will be more reliable and thus enhance efficiency. Energy and the Environment (1): This Challenge is not relevant to this Objective. Synergies with National and Homeland Security (3): Fault-tolerant networks would be better able to withstand equipment failures and deliberate attacks. Support to Space (1): This Challenge is not relevant to this Objective. Why NASA? Supporting Infrastructure (3): NASA has experience designing fault-tolerant systems. Mission Alignment (3): NASA does not have an explicit mission to develop communication protocols. Lack of Alternative Sponsors (1): The FAA and industry organizations are able to take on this Challenge. Appropriate Level of Risk (1): The risk associated with this Challenge is so low that industry or the FAA will likely achieve success even without NASA’s involvement.

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Decadal Survey of Civil Aeronautics: Foundation for the Future E20 Comprehensive models and standards for designing and certifying aviation networking and communications systems The communications technologies being incorporated into new aircraft and integrated airborne and ground systems constitute a major shift from federated systems connected with dedicated wiring to a network-centered approach, where most data are shared on a common data network. A set of overarching models would facilitate the design and certification of network-based air-ground communications systems. These models should be able to accommodate the increasing number of ATM, dispatch, and other functions that are participating in networked communication, as well as increasingly complex protocols. Key milestones include Demonstrate independent models of the safety of networked systems. Define and document criteria that could be incorporated into standards used for certification of systems. Relevance to Strategic Objectives Capacity (3): A defined and consistent approach to certification of aviation networking and communications systems will facilitate development and deployment of aircraft-to-ground ATM communication systems, which will provide more communication channels, improve the ability of the air transportation system to handle large numbers of aircraft in congested areas, and contribute to increased capacity. Safety and Reliability (9): Comprehensive models and standards for designing and certifying aviation networking and communications systems could make a significant contribution to safety, because future systems that rely heavily on networking and deterministic means of assuring the safety of these systems might not be available. Single failures of a network could affect the performance of multiple aircraft systems. Improved methods may be required to assure that the ad hoc methods currently used will not result in crucial errors going undetected. A side benefit would be improving the consistency and efficiency of certifying network-based systems. Efficiency and Performance (3): The efficiency and performance of the air transportation system would be improved by communications and networking systems that reduce the need for voice communications between pilots and controllers. However, lack of certifiable approaches may prevent these systems from being implemented. For example, the FAA Aircraft Certification Service originally prohibited the operational use of these systems because there was no assurance that pilots would receive critical information. Energy and the Environment (1): This Challenge is not relevant to this Objective. Synergies with National and Homeland Security (1): This Challenge is not relevant to this Objective. Support to Space (1): This Challenge is not relevant to this Objective. Why NASA? Supporting Infrastructure (3): NASA has communications technology experts, it has conducted research in aviation safety, and it has a background in formal methods that might apply to this Challenge. However, communications networking has not been a focus of NASA research. Mission Alignment (3): This Challenge is not explicitly within the existing NASA mission. Lack of Alternative Sponsors (1): The FAA and industry organizations could address this Challenge. Appropriate Level of Risk (1): There is low risk associated with this Challenge. REFERENCES Aerospace Commission. 2002. Final Report of the Commission on the Future of the U.S. Aerospace Industry. Washington, D.C.: U.S. Department of Commerce, International Trade Administration, Office of Aerospace. Available online at <www.faa.gov/programs/oep/v7/library/AeroCommissionFinalReport.pdf>. Andrews, J., H. Erzberger, and J. Welch. 2005. Safety Analysis for Advanced Separation Concepts, 6th USA/Europe Seminar on Air Traffic Management Research and Development, Baltimore, Md., June 27-30. Available online at <www.eurocontrol.int/eec/public/standard_page/EEC_News_2005_2_Seminar_Best.html>. Brennan, S.E. 1998. The grounding problem in conversations with and through computers. In S.R. Fussel and R.J. Kreuz (eds.), Social and Cognitive Psychological Approaches to Interpersonal Communication. Hillsdale, N.J.: Lawrence Erlbaum. Cramton, P., L.M. Ausubel, and P. Milgrom. 2002. Comments on Alternative Policy Options for Managing Capacity and Mitigating Congestion and Delay at LaGuardia Airport before the U.S. Department of Transportation, Washington, D.C., Dockets FAA-2001-9852 and FAA-2001-9854, June 20. Bethesda, Md.: Market Design, Inc. Available online at <www.cramton.umd.edu/papers2000-2004/mdi-comment-to-faa-on-managing-capacity-at-lga.pdf>. Croft, J.W. 2003. Refuse-to-crash: NASA tackles loss of control. Aerospace America 41(3): 42-45. Evans, J.E. 2006. Implications of a Successful Benefits Demonstration for Integrated Weather/Air Traffic Management (WX/ATM) System Development and Testing. 12th American Meteorological Society Conference on Aviation, Range and Aerospace Meteorology, Atlanta, Ga., January 29-February 2. Ho, C.-Y., M. Nikolic, M. Waters, and N.B. Sarter. 2004. Not now: Supporting interruption management by indicating the modality and urgency of pending tasks. Human Factors 46(3): 399-409. Lee, J., and N. Moray. 1994. Trust, self-confidence, and operators’ adaptation to automation. International Journal of Human-Computer Studies, 40: 153-184. Leiden, K., J. Keller, and J. French. 2001. Context of Human Error in Commercial Aviation. Boulder, Colo.: Micro Analysis and Design, Inc. Available online at <http://human-factors.arc.nasa.gov/ihi/hcsl/HPM_pubs/AvHumanError.pdf>. Maier, M. 2006. Architecting Principles for Systems-of-Systems. The Information Architects Cooperative (TiAC) White Paper Repository. Available online at <www.infoed.com/Open/PAPERS/systems.htm>.

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Decadal Survey of Civil Aeronautics: Foundation for the Future McFarlane, D.C., and K.A. Latorella. 2002. The scope and importance of human interruption in human-computer interaction design. Human-Computer Interaction 17(1): 1-61. McGuirl, J., and N.B. Sarter. 2006. Supporting Trust Calibration and the Effective Use of Decision Aids by Presenting Dynamic System Confidence Information. In press. McLain, T., and R. Beard. 2005. Coordination variables, coordination functions, and cooperative timing missions. AIAA Journal of Guidance, Control, and Dynamics 28(1): 150-161. Meyer, D. 2005. Corridor Integrated Weather System. Presentation to the National Business Aviation Association Friends/Partners in Aviation Weather Forum, Orlando, Fla., November 11. Available online at <www.ral.ucar.edu/general/fpaw2005/4%20_Segment/meyer.pdf>. Mundra, A.D. 2001. An Assessment of the Potential for Wake Vortex-Related Enhancements in NAS [national airspace system]. McLean, Va.: MITRE Center for Advanced Aviation System Development. Olson, G.M., T.W. Malone, and J.B. Smith. 2001. Coordination Theory and Collaboration Technology. Hillsdale, N.J.: Lawrence Erlbaum. Reynolds, T.G., and R.J. Hansman. 2001. Analysis of Aircraft Separation Minima Using a Surveillance State Vector Approach. Updated version of paper from 3rd International Air Traffic Management R&D Seminar (ATM2000), Naples, Italy, June 13-16, 2000. Available online at <http://icat-server.mit.edu/library/fullRecord.cgi?idDoc=183>. Robinson, M., J. Evans, B. Crowe, D. Klingle-Wilson, and S. Allan. 2004. Corridor Integrated Weather System Operational Benefits 2002-2003: Initial Estimates of Convective Weather Delay Reduction. Project Report ATC-313. Lexington, Mass.: MIT Lincoln Laboratory. Sabatini, N.A. 2006. Testimony of the FAA Associate Administrator for Aviation Safety before the House Committee on Transportation and Infrastructure, Subcommittee on Aviation on Unmanned Aircraft Activities, March 29, 2006. Available online at <www.faa.gov/news/news_story.cfm?contentKey=4029>. Shively, C.A., and T.T. Hsaio. 2005. Error and availability analysis of category IIIb LAAS augmented by radar altimeter. Navigation 52(3). Smith, P.J., E. McCoy, and J. Orasanu. 2001. Distributed cooperative problem-solving in the air traffic management system. In G. Klein and E. Salas (eds.), Naturalistic Decision Making. Hillsdale, N.J.: Lawrence Erlbaum. Sorkin, R.D., B.H. Kantowitz, and S.C. Kantowitz. 1988. Likelihood alarm displays. Human Factors 30(4): 445-459. Volpe National Transportation Systems Center. 2001. Vulnerability Assessment of the Transportation Infrastructure Relying on the Global Positioning System. Cambridge, Mass.: Volpe National Transportation Systems Center. Available online at <http://gps.gov/archive/2001/Oct/FinalReport-v4.6.pdf>. Wickens, C.D., A.S. Mavor, R. Parasuraman, and J.P. McGee, eds. 1998. The Future of Air Traffic Control: Human Operators and Automation. Washington, D.C.: National Academy Press. Available online at <http://fermat.nap.edu/catalog/6018.html>. Wolfson, M.M., B.E. Forman, K.T. Calden, W.J. Dupree, R.J. Johnson, R.A. Boldi, C.A. Wilson, P.E. Bieringer, E.B. Mann, and J.P. Morgan. 2004. Tactical 0-2 Hour Convective Weather Forecasts for the FAA. Proceedings of the 11th Conference on Aviation, Range and Aerospace Meteorology, Hyannis, Mass., October 4-8. Woods, D.D. 1995. The alarm problem and directed attention in dynamic fault management. Ergonomics 38(11): 2371-2393. Woods, D.D., and E. Hollnagel. 2006. Joint Cognitive Systems: Patterns in Cognitive Systems Engineering. New York, N.Y.: Taylor and Francis. Woods, D.D., E.S. Patterson, and E.M. Roth. 2002. Can we ever escape from data overload? A cognitive systems diagnosis. Cognition, Technology, and Work 4(1): 22-36. Xue, M., and E. Atkins. 2006. Noise-minimum runway-independent aircraft approach design for Baltimore-Washington International Airport. AIAA Journal of Aircraft 43(1): 39-51.