Anthony D. Andre

THE FUTURE NATIONAL AIRSPACE SYSTEM: DESIGN REQUIREMENTS IMPOSED BY WEATHER CONSTRAINTS

In this paper, we present design requirements for the future National Airspace System (NAS) focusing on the most fundamental constraint imposed on this system – namely, the effects of weather. We begin by performing a problem-space analysis in order to classify weather related problems across NAS domains: surface, terminal, and en route. We then identify a set of core ideas that address many of the weather constraints in these domains. The core ideas include flexible traffic management, coupled traffic and weather prediction, and human factors issues that relate to establishing and maintaining common situation awareness between the various decision makers in the NAS. From these core ideas, we discuss a set of functional requirements for the future NAS to enable it to be more robust to the impact of weather and its uncertainty on capacity.

Future Air Traffic Management Requirements for Dynamic Weather Avoidance Routing

We present information requirements for a future air traffic management (ATM) system focusing on dynamic weather avoidance maneuvering. Assuming a net-centric operation (NCO) that provides a mechanism to inform all users of weather forecast information, hazardous weather constraints, and weather avoidance routing requirements, the future ATM system can move away from static jet route routing toward a system where routes are defined dynamically, adjusted during the course of the day as required by traffic demand and the geometry of severe weather constraints. Such an operational concept will be particularly useful for time periods where weather is a major constraint to operating the national airspace system (NAS), and traffic delays or reductions in safety are often the result

Designing On-Demand Coded Departure Routes

Coded Departure Routes (CDRs) help coordinate traffic flows around weather constraints between airports in the National Airspace System (NAS). Today, CDRs are generated far in advance of the day that they are implemented. The routes are maintained in a database and distributed between the Air Traffic Service Provider (ATSP) and the users (airlines). If the weather forecast is highly predictable, the ATSP selects the CDR that best solves a weather avoidance problem, given other traffic flow management constraints. For less predictable weather, the ATSP identifies CDRs that could be used to avoid multiple weather constraint scenarios, asks the NAS users to prepare for this full set of contingencies (alternative CDRs), and then assigns the actual route to the flight as it departs. This paper investigates a method of dynamically generating CDRs based on the latest weather forecast. The benefit of generating CDRs as needed to meet the constraints imposed by the weather forecast is that the routing solution adapts and best fits both the emergent weather pattern and traffic flow requirements. We demonstrate how such weather avoidance routes can be generated with an algorithm that takes into consideration the weather forecast and discuss relevant human factors and domain knowledge requirements.

Requirements for Super Dense Operations for the NGATS Terminal Airspace

We present requirements for super dense operations (SDO) in a future next generation air transportation system (NGATS), targeted at a 2025 timeframe. The requirements emphasize the needs for dynamic weather avoidance maneuvering and performance-based services (PBS) based on required navigation performance (RNP). A net-centric operation (NCO) will provide a mechanism to inform all users of weather forecast information, hazardous weather constraints, and weather avoidance routing requirements. The future air traffic management (ATM) system will move away from static jet route navigation toward a system where routes are defined more dynamically, adjusted during the course of the day as required by traffic demand and the geometry of severe weather constraints. Such a concept of operation (ConOps) will be particularly useful for time periods where weather is a major terminal area constraint in the national airspace system (NAS), making it possible to achieve SDO, reduce traffic delays, and ensure safe operations that would otherwise not be feasible in current day operations.

Traffic flow management strategies to support super-dense operations in the terminal area

In order to achieve the goals associated with the NextGen concept of Super-Dense Operations (SDO) in the terminal area, it is necessary to integrate more tightly strategic and tactical operations. New tactical capabilities offer the potential to increase throughput by enabling reduced separation, more effective sequencing, parallel approaches and flexible arrival and departure routes. The foundation for these tactical capabilities include advanced communication, navigation and surveillance (CNS) functions that enable control based on more closely spaced 4D trajectories enabled by aircraft with tighter Required Navigational Performance (RNP) and RNAV capabilities. Especially in weather scenarios, however, use of these tactical capabilities must be embedded in an integrated approach to managing the traffic flows providing arrivals and departures through SDO airspace. This paper focuses on the development of Collaborative Traffic Flow Management (CTFM) strategies to deliver aircraft to airports and metroplexes (groups of geographically close airports) in a manner that enables effective use of advanced tactical operations making use of Trajectory-Based Operations (TBO) -using 4D Trajectories as a basis to support closely spaced, parallel approaches and departures and the optimization of trajectories to reduce fuel consumption and minimize environmental impacts.

Designing 4-D trajectories for super-dense operations given weather constraints

For the Next Generation Air Transportation System (NGATS), we present trajectory design guidelines focusing on dynamic weather avoidance routing in transition airspaces -within 200 nmi of an airport or a set of metroplex airports. Assuming a Net-Centric Operation (NCO) that provides a mechanism to inform all users of hazardous weather constraints and weather avoidance routing requirements, the NGATS can move away from static jet route routing toward a system in which routes are defined dynamically in four dimensions (4D), and adjusted during the course of the day as required by traffic demand and the geometry of severe weather constraints. Such an operational concept will be particularly useful for time periods for which weather is a major constraint to terminal area operations, and when Super-Dense Operations (SDO) are thus required to maintain a high throughput. This paper describes both a Concept of Operations (ConOps) for using 4D trajectories to establish SDO in NGATS and an approach to designing 4D trajectories.

A critique of an operational concept for managing traffic in super dense operations airspace

In a previous paper we outlined an operational concept for managing traffic in Super Dense Operations (SDO) airspace based on a knowledge elicitation effort involving traffic managers and pilots. In this paper we extend this effort, soliciting feedback from a new set of 10 experienced controllers, asking them to evaluate the assumptions and design recommendations making up this operational concept. In the previous paper at this conference, we presented an operational concept for the functioning of airspace operating under Super Density Operations (SDO) that assumes that, in the mid-term (2018) the controllers for SDO for Next Generation Air Transportation System (NextGen) airspace are still responsible for separation assurance and for the merging and spacing of arrivals, departures and overflights. The concept further proposes extensive use of procedural separation based on a predefined “plays” based on a set of alternative advanced Area Navigation (RNAV) arrival and departure routes and based on a set of alternatives for using airspace for arrivals and departures. Assuming datalink capabilities to communicate a new route to the flight deck, the concept further allows for dynamically generated advanced RNAV arrival and departure routes [1–3] when the set of predefined “plays” is insufficient to deal with weather or traffic constraints. In general, the participants were strongly in favor of having predefined route and airspace structures in SDO airspace, with the ability to deal with weather and traffic constraints using predefined alternatives or “plays” whenever possible, but considering dynamically generated route and airspace structures when the predefined “plays” are inadequate. Additional details are provided below.

Future Concepts for Collaborative Traffic Flow Management in the National Airspace System

Because of its cognitive complexity, the responsibility for operating the National Airspace System (NAS) is distributed among many organizations and individuals. An understanding of how this distributed work system functions requires consideration not only of the allocation of control and responsibility, but also of the distribution of data, knowledge, processing capacities and characteristics, goals and priorities. It further requires consideration of how alternative architectures for distributing work (as defined by these different dimensions) impact performance on different types of tasks. Given such a distributed system, one of the most significant challenges is how to plan at a system level, in the face of uncertainty about critical NAS conditions, where the level of uncertainty changes over time. In this paper, a number of concepts for distributing responsibility in the NAS in order to better deal with uncertainty will be discussed, focusing on the need to allocate responsibility so that it better matches access to the knowledge and data necessary to make effective decisions to maintain capacity, safety and equality

Managing arrivals in super-dense operations: Guidance based on a cognitive walkthrough

This paper describes the results of a cognitive walkthrough which was used to structure a knowledge elicitation effort. The goal of this task was to further define and evaluate alternative operational concepts to support evolution toward a Next Generation Air Transportation System (NextGen) in which it is possible to dynamically design the flows for arrivals through super-dense operations (SDO) airspace for an airportal in order to safely maximize throughput given different levels and patterns of traffic demand and given convective weather constraints.

Human Factors Issues in the Design of Super-Dense Operations Airspace

A knowledge acquisition study was completed focusing on two questions: 1. What is a concept of operation for the design and use of Super-Dense Operations (SDO) airspace within the next 10 years? 2. What are the human factors issues that need to be addressed in order to enable this concept of operation? To address these questions, a series of structured interviews were conducted with four FAA specialists with significant experience as controllers, traffic managers and airspace designers and with one experienced commercial pilot. The operational concept developed based on the expertise of these individuals has similarities to proposals under the FAAs “Big Airspace” project, making heavy use of advanced Area navigation (RNAV) routes, but goes beyond the current state of that concept by making explicit a number of foundational assumptions, and by proposing a system design to deal with convective weather.