Air Traffic Management Operations Research Articles

Constraint reconciliation optimization to minimize primary and reactionary delay in a research network strategic tool

AbstractWhen regulated network capacities are violated, flights may be delayed to meet time-based slot restrictions. In addition, reactionary delays occur when time buffers to subsequent flight legs are exceeded. This work aims to minimize both—primary and reactionary delays in a dynamic simulation of the European Air Transportation System. The slot allocation process is solved by minimizing network delay with a binary optimization approach instead of using the current first-planned–first-served principle. The new module presented in this study, called constraint reconciliation and optimization (CRO), is applied within EUROCONTROL’s Research Network Strategic Tool (R-NEST). The results are compared to delays generated by R-NEST’s computer-aided slot allocation (ISA–CASA). In simulations of tactical air traffic flow management (ATFM) operations, time is iterated over the day and flight plans are updated with random and propagated delays. The computational complexity of all possible delay- and slot-entry-permutations is reduced by the method of column generation for solving large linear problems. Three validation scenarios that contain flight plans, rotation margins, sector configurations, regulations, and deterministic or stochastic delays are evaluated. In the most realistic scenario, compared to ISA–CASA, CRO reduces primary and reactionary delays by up to 16% while achieving low levels of airspace sector and airport overloads and fast computation times.

Tangible digital twin with shared visualization for collaborative air traffic management operations

In recent years, digital twin technology has become increasingly popular and been widely applied across different industries including air traffic management (ATM). While previous studies on digital twin in ATM focused on factors such as system architecture, synthetic data generation and transfer, and real-time simulation, there is currently a lack of research on visualization and interaction design of digital twin from human factors’ perspective. Moreover, recent advances in virtual and mixed reality (VR/MR) technology give potential for designing interactive digital twin in 3D space that can assist human operators in performing their duties. Therefore, this research aims to explore visualization and interaction design of an MR-based digital twin prototype that can assist air traffic controllers (ATCOs) in carrying out ground control tasks. Specifically, MR headsets (Microsoft HoloLens 2) are leveraged to project out-of-tower view of airport traffic onto a 3D printed airport model at a 1:1 scale. The spatially aligned tangible system enables ATCOs to perform typical ATM operations by directly touching the 3D printed airport model. In addition, collaborative features are implemented into the system, which enable multiple ATCOs to have a shared view of the airport traffic and collaboratively perform ATM operations when wearing the MR headsets. Finally, a user study was conducted with the recruitment of ten licensed ATCOs to investigate usability of the system and ATCOs’ workload, situational awareness and trust when using the system. The feedback from the ATCOs in the user study suggested that: (1) The visual and interactive design were acceptable; (2) The ATCOs indicated varied workload under different scenarios; (3) The ATCOs developed a high level of shared situational awareness with shared view of the system; and (4) The ATCOs were open and confident to use the system in its’ mature form. The findings show that the MR-based tangible airport digital tower system has high potential in collaborative ATM operations by improving user performance and user experience.

New Generation Space Vehicle Operations in the United Arab Emirates – An Airspace and Risk Assessment

Air Transport is a highly technocentric and rapidly evolving industry. While certain legacy systems persist, more advanced technological concepts for carrying payloads and passengers further, faster, and more efficiently place this particular industry at the forefront of the most cutting-edge research and development initiatives in the fields of autonomous systems, artificial intelligence, cybersecurity, and advanced communication, navigation, surveillance applications. While drone technologies and applications have been widely and comprehensively addressed in recent years, the incipient hypersonic and suborbital commercial transport sector has received disproportionately less academic attention. Although certain suborbital passenger transport concepts such as the German Aerospace Center’s SpaceLiner are proposed for the more distant future, other concepts have reached operational status. A recent addition into the foray has been Blue Origin and its vertically launched New Shepherd autonomous vehicle. The United Arab Emirates, an increasingly active spacefaring nation, has signaled its interest. Among the nation’s highly ambitious short and long-term initiatives is the idea of launching space tourism flights from its own soil. Blue Origin, along with other candidates, has emerged as a contender to operate its New Shepard vehicle from a UAE-based spaceport. This paper explores how Next Generation Space Vehicle Operations (NGSVO) could impact a highly dense and compact airspace when operating from and to a UAE spaceport. Preliminary results suggest that under certain circumstances, NGSVOs may indeed affect existing Air Traffic Management (ATM) operations and pose increased safety risks while leading to higher fuel consumption and larger carbon dioxide footprints of regular air traffic. To establish a benchmark for future comparisons, the current study applies traditional airspace segregation methods to the UAE airspace to accommodate a specific type of NGSVO. Operational gains may be deduced by comparing the results of future studies applying more advanced ATM concepts to those reported in the current study.

Enabling real-time collaborative decision-making between airport and surface transport operations

Current developments in collaborative decision-making in the air transport context are restricted to airport and air traffic management operations and stakeholders, disregarding the relevance of airport access and egress in the door-to-door journey for passengers. This paper summarises the IMHOTEP (Integrated Multimodal Airport Operations for Efficient Passenger Flow Management) concept of operations, which extends Airport Collaborative Decision-Making implementations by incorporating surface access. Enhanced situational awareness achieved by extending the monitoring of passenger flows beyond the airport boundaries improve resource allocation and last-minute capacity utilization. It also facilitates the identification of passenger connectivity requirements in terms of links to ground services.

Level-offs in terminal areas and path stretches: Empirically estimating extra fuel burn rates in commercial aviation

Improvements in air traffic management (ATM) and aircraft operations can have significant impacts on reducing jet fuel consumption. Although there are studies concerned with estimating this potential benefit, isolating the impacts of ATM inefficiencies on a certain air network is yet a complex task that relies on privately-owned data on aircraft performances and operational parameters, and assumptions regarding ideal and feasible flight paths, which may hamper proper monitoring by all stakeholders involved. To tackle those limitations, we propose a statistical approach based on public data of actual flights. Using econometric techniques, we estimated extra fuel burn rates due to path stretch and level segments inside origin and destination terminal areas. We applied the proposed methodology to the 20 most flown routes of the Brazilian domestic market in two different periods, covering 44 days in 2017 and 60 days in 2019. The results indicate that the model is capable of isolating the impacts of path stretch and level segments inside origin and destination terminal areas on the fuel consumption of the air network analyzed. Considering the 2019 sample as a reference, our estimates indicate that if all flights analyzed could fly great circle paths with continuous climbs and descents with the same operational parameters as those flights that could do so, the average potential savings would be between 189-231 L, mainly driven by horizontal inefficiency of descents. For vertical inefficiencies in terminal airspace, results indicate average potential savings per flight of about 4 L with continuous climbs and 20 L with continuous descents, if trajectories could reach the sample best performers, and considering the upper limit of the estimates. This study may help air navigation service providers, aviation authorities, airlines, and airports in monitoring ATM inefficiencies to prioritize operational improvement efforts, air traffic flow management (ATFM) measures, and technology investments.

The omnidirectional runway with infinite heading as a futuristic runway concept for future free route airspace operations

PurposeThe purpose of this paper is to create and analyze the effectiveness of a new runway system, which is totally created for the future free route operations.Design/methodology/approachThis paper researches and analyses the new generated runway concept with the fast time simulation method. Fuel consumption and environmental effect of the new runway system are calculated based on simulation results.FindingsAccording to different traffic density analyses the Omnidirectional Runway with Infinite Heading (ORIH) reduced fuel consumption and CO2 emissions up to 46.97%. Also the total emissions of the ORIH concept, for the hydro carbon (HC), carbon monoxide (CO) and nitrogen oxides (NOx) pollutants were lower than the total emissions with the conventional runway up to 83.13, 74.36 and 51.49%, respectively.Practical implicationsFree route airspaces bring many advantages to air traffic management and airline operations. Direct routes become available from airport to airport thanks to free route airspace concept. However, conventional single runway structure does not allow aircraft operations for every direction. The landing and take-off operations of a conventional airport with a single runway must be executed with only two heading direction. This limitation brings a bottleneck direct approach and departure route usage as convenient with free route airspace concept. This paper suggests and analyzes the omnidirectional runway with infinite heading (ORIH) as a solution for free route airspace.Originality/valueThis paper suggests a new and futuristic runway design and operation for the free route operations. This paper has its originality from the suggested and newly created runway system.

Analysis of vulnerability of ATM to weather phenomena

Weather conditions and Air Traffic Management (ATM) operations are strongly related, due to the relevant influence that the observed and forecasted weather conditions into assigned airspace have on the operational conditions that are therefore possible for such airspace. In the framework of the SESAR JU funded project CREATE (Innovative operations and climate and weather models to improve ATM resilience and reduce impacts), therefore, a dedicated study has been carried out in order to investigate the relation between weather and ATM. Such study both investigated the consequences that adverse weather conditions can have on ATM and, on the other side, addressed the currently and future available tools that can support ATM in the prediction and management of weather conditions from the aeronautical operations point of view. In this paper, the results of such literature study are outlined. More in details, in the paper first the main outcomes of the study are summarized, in terms of identification of the most relevant weather phenomena that affect the ATM operations, indication of their main impacts on them in terms of operational disruptions and, finally, identification of the associated level of severity. In particular, the above indicated aspects are addressed by taking into specific consideration the enroute and the TMA (Terminal Manoeuvring Area) flight phases and, for each of them, the main affecting weather phenomena and the main affected operations are identified. Then, in the paper the results of the study are summarized about the identification of the most relevant meteo tools that are expressed by state-of-the-art technologies to support the ATM operations in order to properly take into account the weather conditions in a precise and timely manner. This study addresses both the review of available and perspective tools for weather reporting and of the available and perspective numerical models supporting ATM in terms of weather models and air quality models.

LDACS Flight Trials: Demonstration and Performance Analysis of the Future Aeronautical Communications System

The L-band digital aeronautical communications system (LDACS) is a key enabler of the new air traffic services and operational concepts necessary for the modernization of the air traffic management (ATM). After its initial design, compatibility tests with legacy L-band systems, and functional demonstrations in the laboratory, the system is currently undergoing the standardization process of the International Civil Aviation Organization (ICAO). However, LDACS has not been demonstrated in flight yet. In this article, we present the first in-flight demonstration of LDACS, which took place in March and April 2019 in southern Germany and included four LDACS ground stations and one LDACS airborne station. We detail the experimental setup of the implemented LDACS ground and airborne stations together with the flight routes, the conducted experiments, and the frequency planning to ensure compatibility with legacy systems. In addition, we describe the demonstrated ATM applications and the security measures used to protect them. Based on the obtained measurement results, we evaluate the LDACS in-flight communication performance for the first time, including the achieved communication range, the measured end-to-end message latency, and the LDACS capability to provide quality of service by effectively prioritizing safety-relevant data traffic. Furthermore, we use the in-flight received signal power to assess the applicability of a theoretical path loss model. These flight trials contribute to the final steps in the development of LDACS by providing its in-flight communication performance and by demonstrating: first, its correct functionality in a realistic environment; second, its capability of supporting ATM applications and the advanced security measures that can be used to protect them; and third, its spectrum compatibility with legacy systems. We conclude that LDACS is ready to support ATM operations and that LDACS frequency planning can safeguard legacy systems successfully.

Formal Guarantees of Timely Progress for Distributed Knowledge Propagation

Autonomous air traffic management (ATM) operations for urban air mobility (UAM) will necessitate the use of distributed protocols for decentralized coordination between aircraft. As UAM operations are time-critical, it will be imperative to have formal guarantees of progress for the distributed protocols used in ATM. Under asynchronous settings, message transmission and processing delays are unbounded, making it impossible to provide deterministic bounds on the time required to make progress. We present an approach for formally guaranteeing timely progress in a Two-Phase Acknowledge distributed knowledge propagation protocol by probabilistically modeling the delays using theories of the Multicopy Two-Hop Relay protocol and the M/M/1 queue system. The guarantee states a probabilistic upper bound to the time for progress as a function of the probabilities of the total transmission and processing delays being less than two given values. We also showcase the development of a library of formal theories, that is tailored towards reasoning about timely progress in distributed protocols deployed in airborne networks, in the Athena proof assistant.

Convection indicator for pre-tactical air traffic flow management using neural networks

Convective weather is a large source of disruption for air traffic management operations. Being able to predict thunderstorms the day before operations can help traffic managers plan around weather and improve air traffic flow management operations. In this paper, machine learning is applied on data from satellite storm observations and ensemble numerical weather prediction products to detect convective weather 36 h in advance. The learning task is formulated as a binary classification problem and a neural network is trained to predict the occurrence of storms. The neural network results are used to develop a probabilistic based convection indicator capable of outperforming existing convection indicators found in the literature. Lastly, applications of the neural network based indicator in an air traffic management setting are presented.

Feasibility study on fixed flight-path angle descent for wide-body passenger aircraft

This study proposes the use of fixed flight-path angle (FPA) descent as a potential alternative for eco-friendly air traffic operations. Additionally, given that the proposed descent procedure follows a fixed, assigned flight-path angle, with the aircraft continuously descending toward the runway threshold with near-idle thrust, the trajectory should be more predictable for air-traffic controllers. As such, the proposed approach is expected to contribute significantly toward decreasing the air traffic fuel consumption, while simultaneously facilitating the air traffic controllers’ task of maintaining the required time spacing between concurrent traffic. Furthermore, FPA descent does not require any retrofits in the fundamental components of current ground systems and/or onboard avionics. This paper clarifies the feasibility of fixed flight-path angle descent for B777-200 and B787-8 wide-body jet passenger aircraft, envisaging its implementation in near-term operations. A total of 30 trials were carried out in a series of experiments designed to evaluate the proposed descent method, considering arrivals at two major international airports in Japan—the Tokyo and Kansai International Airports—using B777-200 and B787-800 full flight simulators of a national airline. The pilots’ procedures, cockpit operability, assigned vertical path tracking performance, and fuel efficiency associated with the proposed FPA descent are discussed and compared with those of conventional arrival operations. The analysis results indicate that the fixed flight-path angle descent is feasible for large-sized jet aircraft within the assumed operational environment, and that its combined use with speed control has the potential to result in even better energy-saving performance in future air traffic management operations.

Demonstration of the “Work Models that Compute” Simulation Framework for Objective Function Allocation

This document describes a demonstration of the computational simulation framework Work Models that Compute (WMC). WMC is a framework for the objective evaluation of function allocation between humans and robots. The WMC framework has been used to study the impact of function allocation on both the air traffic management and spacecraft operations work domains. Recent advances include modeling of human-robot control modes, locomotion, failures and physical resources. We propose a demonstration of WMC showcasing how WMC can provide useful, objective and quantitative insight in the trade-offs asso-ciated with function allocation. In the demonstration, we will analyze function allocation for an on-orbit maintenance scenario. We will first show how minor changes to a function allocations can have major ef-fects on the emergent work patterns that result from the simulation framework. Second, we will demon-strate an analysis of 10-15 possible function allocations (defined in advance) and cross-compare their char-acteristics based on measures such as the idle time, taskload for each agent, information transfer require-ments, physical resources exchanges and others. This will show the framework’s capability to rapidly ex-plore the function allocation trade-space and allow the designer to make more informed trade-offs.

Comparison of alternative route selection strategies based on simulation optimization

Air traffic flow management (ATFM) is a collaborative process between the airspace provider and the airspace users. The result of the collaboration should be an outcome that maximizes the utility of the system without excessively penalizing any of the agents. This paper develops a discrete-event simulation model which consists of aggregate departure/arrival airports, flight routes, and sectors for evaluating the alternative collaborative route selection strategy. Given the different perspectives from air traffic control center (ACC) and airlines, eight performance-metrics and five alternative route selection strategies represent the past, current and proposed air traffic flow management operations that were evaluated. The Monte Carlo method combined with the Optimal Computing Budget Allocation (OCBA) simulation optimization technique is employed to assess the performance of different strategies. A case study of the upper air routes in central and southern China shows that the proposed model can be readily implemented to simulate different kinds of air traffic flow management strategies and predict the effect of changes on the airspace system. It also shows that the proposed alternative collaborative route selection strategy is an effective way in alleviating the en-route traffic congestion.

Satisficing Game Approach to Collaborative Decision Making Including Airport Management

Collaborative decision making (CDM) has been used as an essential paradigm to increase the efficiency of air traffic flow management (ATFM), including takeoff or landing operations at airports. Air traffic control (ATC) services and airlines have been involved in the current CDM, but airport management service, an important stakeholder, has not been involved yet, generally. This paper proposes a new CDM model, which is named satisficing CDM, that is based on the satisficing game theory. This model includes three main entities (ATC, airlines, and airport management) in ATFM. The complete set of functions (preference, rejectability, and selectability) is established for each of the entities. Because the delay due to ground or air holding potentially alters the takeoff or the landing order of a flight, the sequence of takeoff and landing is determined through the satisficing negotiation process. To demonstrate the utility of the developed intelligent system, experiments are run with real air traffic in the terminal area of Sao Paulo. The experimental results show the importance and effectiveness of including airport management services in CDM. The sequences of takeoff and landing determined by the proposed model mostly meet the preferences of the three stakeholders in the given real traffic scenarios.

Predicting Air Traffic Controller Workload: Trajectory Uncertainty as the Moderator of the Indirect Effect of Traffic Density on Controller Workload Through Traffic Conflict.

Our study investigates whether trajectory uncertainty moderates the relationship between traffic conflict and workload. Furthermore, we examine if the indirect effect of traffic density on workload through traffic conflict is conditional on the presence of trajectory uncertainty. Although it is widely accepted that uncertainty related to the future trajectory of an aircraft impacts air traffic controller decision making, little is known about how the presence of trajectory uncertainty impacts controller workload. A better understanding of the impact on controller workload can improve workload prediction models for en route air traffic control. We collected data in a live operation environment, including workload ratings based on over-the-shoulder observations and real-time sector data. Hierarchical linear modeling was used to analyze the data. Trajectory uncertainty interacts with traffic conflict in such a way that the positive relationship between traffic conflict and workload is strongest in the presence of trajectory uncertainty. Furthermore, we found that the mediating effect of traffic density through traffic conflict is conditional on the presence of trajectory uncertainty. Our results indicate that workload prediction tools that do not incorporate trajectory uncertainty may underestimate workload under conditions of trajectory uncertainty, leading to possible overload situations of air traffic controllers. Sources that generate trajectory uncertainty, as well as their interaction effects with dynamic complexity metrics, should be acknowledged in workload prediction models to increase the predictive power of these models. Implications for future air traffic management operations as envisioned by SESAR and NextGen are discussed.

New air traffic management approach based on expert system and using real-time scheduling algorithms

The air traffic management operations are considered as complex problems. In practice, they can formulate as a constrained optimisation problem that needs to be solved in a real-time environment, also they are non-regular problems, so we can use the expert system to schedule the air traffic management operations. Expert systems using extracted cognitive data, inspiring from the human expertise and its best practices. They are based on the machine performance and its ability to carry out a very large number of complex iterations. Almost all air traffic management operations are classified as scheduling operations. The goal of this paper is to present a new intelligent system with an evolving knowledge base and a creative inference engine. This system allows choosing the optimal way based on real time algorithms to schedule all air traffic management operations such as aircrafts' landing scheduling.

A Comparison of Methods for Assessing Situation Awareness in Current Day and Future Air Traffic Management Operations: Graphics-Based vs Text-Based Online Probe Systems

Abstract: Operator situation awareness can be measured by examining operator response time and accuracy to online queries or probes. We compared an existing, text-based query method with a new graphics-based method. The text-based method presented multiple-choice queries to air traffic controllers (ATCos) on a display next to the DSR. Responses were entered by selecting one of the response alternatives presented with the query. The graphics-based method presented the query along with a screen shot of ATCo’s current traffic on the DSR. The ATCo responded by touching the symbol of the aircraft that was the subject of the question. These methods were compared in a simulation involving student ATCos currently enrolled in an Aviation Sciences program.

Towards understanding work-as-done in air traffic management safety assessment and design

This paper describes the approach taken and the results to develop guidance, to include Resilience Engineering principles in methodology for safety assessment of functional changes, in Air Traffic Management (ATM). It summarizes the process of deriving resilience principles for ATM, originating from Resilience Engineering concepts and transposed into ATM operations. These principles are the foundation for guidance material incorporating Resilience Engineering (RE) concepts into safety assessment methodology. The guidance material provides a method using workshops generating qualitative descriptions of RE principles applied to ATM services of everyday work, as done currently and as envisioned after introduction of a new technology or way of working. The guidance material has been proposed as part of the safety assessment methodology of SESAR (Single European Sky ATM Research), and as stand-alone guidance for ATM design processes. The methodology was validated via a test case on the i4D/CTA (Controlled Time of Arrival) concept. Operational examples from the application of the developed guidance to the i4D/CTA concept are provided. Initial evaluation of the guidance suggests that the methodology (1) provides a narrative, vocabulary and documentation means of project discussions on resilience; (2) brings the discussions of safety and resilience closer to operational practice; (3) facilitates a broader systemic and integrative perspective on operational, management, business, safety, environmental, and human performance aspects; and (4) can extend the vocabulary of safety assessment to include the description of emergent properties, to better support functional changes in ATM.

Critical Incident Stress Management (CISM) in complex systems: Cultural adaptation and safety impacts in healthcare

In complex systems, such as hospitals or air traffic control operations, critical incidents (CIs) are unavoidable. These incidents can not only become critical for victims but also for professionals working at the “sharp end” who may have to deal with critical incident stress (CIS) reactions that may be severe and impede emotional, physical, cognitive and social functioning. These CIS reactions may occur not only under exceptional conditions but also during every-day work and become an important safety issue. In contrast to air traffic management (ATM) operations in Europe, which have readily adopted critical incident stress management (CISM), most hospitals have not yet implemented comprehensive peer support programs. This survey was conducted in 2010 at the only European general hospital setting which implemented CISM program since 2004. The aim of the article is to describe possible contribution of CISM in hospital settings framed from the perspective of organizational safety and individual health for healthcare professionals. Findings affirm that daily work related incidents also can become critical for healthcare professionals. Program efficiency appears to be influenced by the professional culture, as well as organizational structure and policies. Overall, findings demonstrate that the adaptation of the CISM program in general hospitals takes time but, once established, it may serve as a mechanism for changing professional culture, thereby permitting the framing of even small incidents or near misses as an opportunity to provide valuable feedback to the system.

Air traffic complexity in future Air Traffic Management systems

In this paper we study the issue of characterizing the complexity of air traffic to support Air Traffic Management (ATM) operations. We discuss, in particular, the features of a complexity metric that are relevant for application to future ATM systems where part of the responsibility for separation assurance and trajectory management operations is distributed on board of the aircraft. We then describe a probabilistic complexity metric that meets all those features and is amenable for supporting onboard conflict detection and resolution and trajectory management operations. A numerical example illustrates its possible use in a fully automated self-separation context.