Single European Sky ATM Research Research Articles

Optimal Contract for Reducing Flight Delays in EU: In the Context of SESAR

In the context of the SESAR (Single European Sky Air traffic management Research) Joint Undertaking, the role that the air navigation service provider (ANSP) could play has been reconsidered. ANSP manages traffic and deals with potential conflict situations and external events, which have led to the reorganization of the air traffic. The modification of traffic inevitably leads to delays for airlines, which is costly. In this study, we suggest that ANSP could provide a costly delay reduction service to airlines. Indeed, if ANSP has several solutions for traffic conflict resolution or reorganization, there is room for a choice between these solutions using additional criteria. Our study thus proposes an original model in which we determine the optimal design of a delay reduction contract signed between welfare- or profit-maximizing ANSPs and a monopoly airline. We give some comparative statics, in particular, the evaluation of the impact of a modification in safety standards on the contract.

IMPROVING THE GEVGELIJA AERODROME PROJECT METHODOLOGY THROUGH THE EYE OF LOGIC OPTIMIZATION

The term equilibrium and the emergence of new technologies intended for aerodrome infrastructure development puts increasing pressure on the field of optimized traffic networks as crucial criteria for location selection. There is a constant need to improve optimization processes as one of the needed solutions for an equalized system. However, finding and implementing an optimization model is a potential requirement for traffic capacity for planned aerodromes where the intended capacity has the decision rule. In this paper, the authors show how the optimization model may be recast as a decision factor. We then take advantage of the recent advantage of recent advantages in Single European Sky ATM Research- SESAR reinforcement learning to build a project methodology that learns how the new aerodrome infrastructure can be born. Our design for the Gevgelija aerodrome has a number of desirable locations and it is decisional for one that generalizes many decision factors. Additionally, this methodology natively supports problems like this one, without the need to handle special cases. Finally, it is the same methodology that can be used to achieve different optimization objectives, e.g. aerodrome category and aerodrome development.

Performance-Based Navigation Flight Path Analysis Using Fast-Time Simulation

The growing demand for air transportation has led to an increase in worldwide air traffic inefficiency due to capacity constraints. The impacts associated with this situation can be reduced through operational changes. To better handle the problem, the Single European Sky ATM Research (SESAR) and the Next Generation Air Transportation System (NextGen) program suggest Performance-Based Navigation (PBN) as a solution. The Area Navigation (RNAV) and Required Navigation Performance (RNP) approaches belong to the group of PBN procedures. These procedures allow for a more efficient use of airspace by reducing route distances, fuel consumption and perceived aircraft noise. This article quantifies the benefits of PBN systems for two indicator parameters—fuel burn and flight time—and compares PBN systems to conventional instrument navigation procedures. The case studies use five airports in Brazil. The results of this analysis show that the benefits of the PBN approach vary with aircraft type and individual route characteristics.

Air traffic flow management with layered workload constraints

Many regions of the world are currently struggling with congested airspace, and Europe is no exception. Motivated by our collaboration with relevant European authorities and companies in the Single European Sky ATM Research (SESAR) initiative, we investigate novel mathematical models and algorithms for supporting the Air Traffic Flow Management in Europe. In particular, we consider the problem of optimally choosing new (delayed) departure times for a set of scheduled flights to prevent en-route congestion and high workload for air traffic controllers while minimizing the total delay. This congestion is a function of the number of flights in a certain sector of the airspace, which in turn determines the workload of the air traffic controller(s) assigned to that sector. We present a MIP model that accurately captures the current definition of workload, and extend it to overcome some of the drawbacks of the current definition. The resulting scheduling problem makes use of a novel formulation, Path&Cycle, which is alternative to the classic big-M or time-indexed formulations. We describe a solution algorithm based on delayed variable and constraint generation to substantially speed up the computation. We conclude by showing the great potential of this approach on randomly generated, realistic instances.

Innovative time-based separation procedures for civil RPAS integration

Purpose This paper aims to suggest feasible solutions to overcome the problem of unmanned aerial vehicles integration within the existing airspace. Design/methodology/approach It envisages innovative time-based separation procedures that will enhance the integration in the future air traffic management (ATM) system of next generation of large remotely piloted aircraft system (RPAS). 4D navigation and dynamic mobile area concepts, both proposed in the framework of Single European Sky ATM Research program, are brought together to hypothesize innovative time-based separation procedures aiming at promoting integration of RPAS in the future ATM system. Findings Benefits of proposed procedures, mainly evaluated in terms of volume reduction of segregated airspace, are quantitatively analyzed on the basis of realistic operational scenarios focusing on monitoring activities in both nominal and emergency conditions. Eventually, the major limits of time-based separation for RPAS are investigated. Practical implications The implementation of the envisaged procedures will be a key enabler in RPAS integration in future ATM integration. Originality/value In the current ATM scenario, separation of RPAS from air traffic is ensured by segregating a large amount of airspace areas with fixed dimensions, dramatically limiting the activities of these vehicles.

Bayesian Network Modelling of ATC Complexity Metrics for Future SESAR Demand and Capacity Balance Solutions.

Demand & Capacity Management solutions are key SESAR (Single European Sky ATM Research) research projects to adapt future airspace to the expected high air traffic growth in a Trajectory Based Operations (TBO) environment. These solutions rely on processes, methods and metrics regarding the complexity assessment of traffic flows. However, current complexity methodologies and metrics do not properly take into account the impact of trajectories’ uncertainty to the quality of complexity predictions of air traffic demand. This paper proposes the development of several Bayesian network (BN) models to identify the impacts of TBO uncertainties to the quality of the predictions of complexity of air traffic demand for two particular Demand Capacity Balance (DCB) solutions developed by SESAR 2020, i.e., Dynamic Airspace Configuration (DAC) and Flight Centric Air Traffic Control (FCA). In total, seven BN models are elicited covering each concept at different time horizons. The models allow evaluating the influence of the “complexity generators” in the “complexity metrics”. Moreover, when the required level for the uncertainty of complexity is set, the networks allow identifying by how much uncertainty of the input variables should improve.

Impact of multi-criteria optimized trajectories on European airline efficiency, safety and airspace demand

Today the European airspace is facing multiple capacity constraints which are regulating demand during busy traffic periods of the day. These capacity limits cause inefficiencies in flight and airport ground handling. Current market forecasts predict an annual growth in passenger air traffic demand between 4.5 percent and 4.8 percent. This growth will be realized by an increasing number of aircraft movements reflected in an expected annual growth of jet airplanes by 3.3 percent with a negative impact on airspace capacity. To better manage the rare airspace capacity, the Single European Sky ATM Research (SESAR) and the Next Generation Air Transportation System (NextGen) program suggest free route airspaces, a Performance Based Navigation (PBN) and harmonized airspace structures as efficient concepts of improvement in air traffic efficiency. Beside today's minimum fuel and time objectives, a growing public awareness of the anthropogenic environmental impact necessitates further functions for flight planning and execution. Additionally, today's high safety standards must not be negatively influenced by the introduction of free route airspaces. In this paper, we present a trajectory calculation model capable of exploiting a 4D free route optimization potential while considering the divergent targets of safety, efficiency and environmental compatibility. In particular, the environmental effects of condensation trails depending on the time of the day are carefully considered. To further estimate the impact of free routes on airspace demand and on safety issues, the model is implemented in the simulation environment TOMATO, and the European flight intentions have been optimized for an entire day based on departure airports, arrival airports and original departure times July 2016. The resulting trajectories are evaluated against the number, location and duration of separation infringements. Despite constantly changing air speeds and cruising altitudes induced by the optimization target functions, the number and duration of separation infringements could be reduced by 30% due to optimized lateral and vertical trajectories. The results of this case study show a high potential for an increased airspace capacity under free routing conditions. Furthermore, fuel burn (20%) and airline direct operational costs (40%) could be significantly reduced.

Safety assessment of ‘RNP parallel approach transitions’: a new air traffic management operational concept. Part 2 – safety design and implementation

This article describes a safety assessment of a new Air Traffic Management (ATM) operational concept—RNP Parallel Approach Transitions (RPAT)—at a hypothetical major international-hub airport. The methodology employed is that developed initially for the innovative and highly complex Single European Sky ATM Research programme but further refined by the authors and applied to a wide range of safety-related projects. Though the described application of the methodology is based on experience gained from a specific ATM project, this article does not take the form of a case study. Rather, the operational environment has been generalised and the article explains how the safety of RPAT operations would be assessed for this generalised application. Part 1 described how the required safety properties of the RPAT concept are derived at the ATM-service level—this is the highest level of abstraction, and addresses what the ATM service needs to achieve for the safe movement of aircraft in the airspace (and on the airport surface), without any reference to the underlying end-to-end ATM system. Part 2 describes how those safety properties are then allocated to the ATM system architectural elements and how they are shown to have been met in the implemented system.

Safety assessment of ‘RNP parallel approach transitions’: a new air traffic management operational concept. Part 1 – safety specification

This article describes a safety assessment of a new Air Traffic Management (ATM) operational concept—RNP Parallel Approach Transitions (RPAT)—at a hypothetical major international-hub airport. The methodology employed is that developed initially for the innovative and highly complex Single European Sky ATM Research programme but further refined by the authors and applied to a wide range of safety-related projects. Though the described application of the methodology is based on experience gained from a specific ATM project, this article does not take the form of a case study. Rather, the operational environment (OE) has been generalised and the article explains how the safety of RPAT operations would be assessed for this generalised application. Part 1 describes how the required safety properties of the RPAT concept are derived at the ATM-service level—this is the highest level of abstraction, and addresses what the ATM service needs to achieve for the safe movement of aircraft in the airspace (and on the airport surface), without any reference to the underlying end-to-end ATM system. Part 2 describes how those safety properties are then allocated to the ATM system architectural elements and how they are shown to have been met in the implemented system.

Certification challenges for next-generation avionics and air traffic management systems

Air traffic is doubling every 15 years, and aviation systems must modernize to address sustainability challenges. The need to balance capacity, efficiency, safety, and environmental requirements is reflected by the several air traffic management (ATM) and avionics modernization initiatives under way. The major collaborative research programs today are the European Union's Single European Sky ATM Research (SESAR) project and the United States' Next-Generation Air Transportation System (NextGen) led by the Federal Aviation Administration (FAA). Other modernization initiatives include the Collaborative Action for Renovation of Air Traffic Systems in Japan, SIRIUS in Brazil, OneSky in Australia, and similar programs in Canada, China, India, and Russia [1]. The International Civil Aviation Organization (ICAO) has authorized a globally coordinated plan, published as the Global Air Navigation Plan (GANP) [1], to guide the harmonized implementation of communication, navigation, surveillance, and avionics (CNS+A) enhancements across regions and states. In the CNS+A context, aircraft safety is a shared responsibility between airborne and ground-based resources [1]. Hence, this is a safety challenge requiring changes to the current regulatory framework to properly capture the nature of this shared responsibility and the concept of integrated CNS+A systems. Certification of aircraft and ground equipment (hardware and software) and organizational approvals are essential elements to ensure continued and enhanced safety.

Multiple remote tower for Single European Sky: The evolution from initial operational concept to regulatory approved implementation

The European Union project of Single European Sky initiated a reorganization of European airspace and proposed additional measures for air traffic management to achieve the key objectives of improving efficiency and capacity while at the same time enhancing safety. The concept of multiple remote tower operation is that air traffic controllers (ATCOs) can control several airfields from a distant virtual control centre. The control of multiple airfields can be centralised to a virtual centre permitting the more efficient use of ATCO resources. This research was sponsored by the Single European Sky ATM Research Program and the ATM Operations Division of the Irish Aviation Authority. A safety case was developed for migration of multiple remote tower services to live operations. This research conducted 50 large scale demonstration trials of remote tower operations from single tower operations to multiple tower operations for safety assessment by air navigation safety regulators in 2016. A dedicated team of air traffic controllers and technology experts successfully completed the safety assessment of multiple remote tower operations in real time. The implementation of this innovative technology requires a careful balance between cost-efficiency and the safety of the air traffic control in terms of capacity and human performance. The live trial exercises demonstrated that the air traffic services provided by the remote tower for a single airport and two medium airports by a single ATCO with ‘in sequence’ and ‘simultaneous’ aircraft operation was at least as safe as provided by the local towers at Cork and Shannon aerodromes. No safety occurrence was reported nor did any operational safety issue arise during the conduct of the fifty live trial exercises.

Air Traffic Management based on 4D Trajectories: A Reliability Analysis using Multi-State Systems Theory

Abstract The current Air Traffic Management (ATM) functional approach is changing. Both SESAR (Single European Sky ATM Research) and NEXTGEN (Next Generation Air Transportation System) support the four-dimension (4D) trajectory implementation within their operational concepts. Apart from the three classical spatial dimensions, ‘time’ is now integrated as an additional fourth dimension, which will restrict aircraft flights over indicated waypoints along the trajectory. 4D trajectories can be understood as complex Multi-State Systems (MSS) that rely on environmental, internal and usage conditions. A reliability analysis of the waypoints and time windows that describe the 4D trajectory may allow airline operators and air traffic service providers to establish performance indicators and compliance metrics. This paper develops a model to evaluate potential ‘malfunctions’ of a 4D trajectory, based on the MSS reliability theory. This is a natural extension of classical binary-state evaluation: trajectories present different performance levels and several failure modes (a degradation range). The operational reliability assessment, which is achieved with Monte Carlo simulation and random processes (Markov) methods, offers a framework to predict how probable is for the trajectory to enter a degraded state. We use this analysis to quantify the 4D trajectory level of variability and to propose corrective measures to solve potential trajectory degradations or unplanned situations. The methodology is validated through a practical case study. The main contribution of this paper is to provide a methodology to evaluate the robustness of 4D trajectories and to deal with their perturbation, which is a cornerstone in traffic synchronization and conflict resolution.

Analysing and modelling some effects of solutions for matching the airport runway system capacity to demand

The paper deals with analysing and modelling some effects of three solutions for matching the airport runway system (landing) capacity to corresponding demand. These are: i) charging congestion applied to the NY LaGuardia airport (New York, USA); ii) deployment of the innovative operational procedures supported by the new technologies developing in the scope of European SESAR (Single European Sky ATM Research) and U.S. NextGen (Next Generation) program applied to the system of two closely-spaced parallel runways at Dubai International airport (Dubai, UAE (United Arab Emirates)); and iii) building the new additional runway(s) applied to the runway system of three London airports - Heathrow, Gatwick, and Stansted (London, UK).The results have shown that each of the considered solutions can contribute to more efficient and effective matching of the airport runway (landing) capacity to the current and expected (prospectively growing) airside demand under given (specified) conditions.

A safety assessment framework for the Automatic Dependent Surveillance Broadcast (ADS-B) system

The ATM system is currently undergoing various fundamental changes to improve air travel performance. A key change is the transition from a mainly reactive and tactical system to a significantly more predictive and strategic system. This is encapsulated in the concept of 4D trajectory based operations, currently being developed in Europe and the USA through the Single European Sky (SES)/Single European Sky ATM Research (SESAR) and the Next Generation Air Transportation System (NextGEN) respectively. At the core of this transition, is the need for improved situational awareness, shared between relevant stakeholders. The Automatic Dependent Surveillance Broadcast (ADS-B) system is a key enabler of this concept, targeted at distributing real-time positioning and navigation information to stakeholders. Therefore, the safety and credibility of the ADS-B system to support various ground and airborne applications are key, and need to be assessed and validated. This paper reviews existing safety assessment methods, identifies key limitations and proposes a novel, comprehensive and rigorous safety assessment framework for the ADS-B system.

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.

Trajectory prediction for future air traffic management – complex manoeuvres and taxiing

AbstractThe future air traffic management (ATM) concept envisaged by the Single European Sky ATM Research – SESAR – and the USA equivalent NextGen, mark a paradigm shift from the current reactive approach of ATM towards holistic strategic collaborative decision making. The core of the future ATM concept relies on common situational awareness over potentially large time-horizons, based upon the user operational intent. This is beyond human capabilities and requires the support of automation tools to predict aircraft state throughout the operation and provide support to optimal decision making long before any potential conflict may arise. This is achieved with trajectory predictors and conflict detectors and resolvers respectively. Numerous tools have been developed, typically geared towards addressing specific airborne applications. However, a comprehensive literature search suggests that none of the tools was designed to predict trajectories throughout the entire operation of an aircraft, i.e. gate-to-gate. Yet, such functionality is relevant in the holistic optimisation of aircraft operations. To address this gap, this paper builds on an existing en route trajectory prediction (TP) model and develops novel techniques to predict aircraft trajectories for the transitions between the ground- and enroute-phases of operation and for the ground-phase, thereby enabling gate-to-gate (or enroute -to-enroute) TP. The model is developed on the basis of Newtonian physics and operational procedures. Real recorded data obtained from a flight data record (FDR) were used to estimate some of the input parameters required by the model. The remaining parameters were taken from the BADA 3.7 model. Performance results using these flight data demonstrate that the proposed TP model has the potential to accurately predict gate-to-gate trajectories and to support future ATM applications such as gate-to-gate synchronisation.

A teaching experience using a flight simulator: Educational Simulation in practice

The use of appropriate Educational Simulation systems (software and hardware for learning purposes) may contribute to the application of the “Learning by Doing” (LbD) paradigm in classroom, thus helping the students to assimilate the theoretical concepts of a subject and acquire certain pre-defined competencies in a more didactical way. The main objective of this work is to conduct a teaching experience using a flight simulation environment so that the students of Aeronautical Management degree can assume the role of an aircraft pilot, in order to allow the students understanding the basic processes of the air navigation and observe how the new technologies can transform and improve these processes. This is especially helpful in classroom to teach the contents of the Single European Sky ATM Research (SESAR) programme, an European project that introduces a new Air Traffic Management (ATM) paradigm based on several relevant technological and procedural changes that will affect the entire air transportation system in the short and medium term. After the execution of several activities with a flight simulator in the classroom a short test and a satisfaction survey have been requested to the students in order to assess the teaching experience.

A causal model to explore the ACAS induced collisions

Current Air Traffic Management research programs (i.e. Single European Sky ATM (air traffic management) Research (SESAR), next generation air transportation system (NextGen)), try to overcome airside capacity shortages while improving cost-efficient operations and safety. An increment in the airspace traffic density can lead to congested traffic scenarios for which it becomes necessary to develop new safety procedures that address multithread threats. This paper considers some of the difficulties in establishing validation of the airborne collision avoidance system (ACAS), which constitutes the last-resort for reducing the risk of near mid-air collision between aircraft in a multithread scenario. A causal model that is specified in Colored Petri Net (CPN) formalism is presented as a key approach to analyze the state space of a congested traffic scenario in which the events that could transform a conflict into a collision are identified, providing a challenging tool not only for validation but also for the implementation of a new ACAS logic. The InCAS EuroControl simulator has been used to illustrate the importance of cause–effect analysis for the relationships between various encounters that arise in a multithread scenario, in which TCAS II v. 7.1 fails to avoid a collision when two Resolution Advisories are issued without consideration of the downstream effects.

Strategic de-confliction in the presence of a large number of 4D trajectories using a causal modeling approach

This paper presents a strategic de-confliction algorithm based on causal modeling developed under the STREAM project and launched under the umbrella of the Single European Sky ATM Research (SESAR) Program. The basic underlying concept makes use of the enriched information included in the Shared Business Trajectories (SBTs) of the flights prior to takeoff (or in the Reference Business Trajectories (RBTs) if the flight is airborne) to allocate conflict-free trajectories in a traffic planning phase that should lead to an actual conflict-free scenario in the flight execution phase in the absence of flight and/or network uncertainties. The proposed approach could decrease the workload of the air traffic controllers, thus improving the Air Traffic Management (ATM) capacity while meeting the maximum possible expectations of the Airspace Users’ requirements in terms of horizontal flight efficiency. The main modules of the implemented system are also presented in this paper; these modules are designed to enable the processing of thousands of trajectories within a few seconds or minutes and encompass a global network scope with a planning horizon of approximately 2–3h. The causal model applied for network conflict resolution and flight routing allocation is analyzed to demonstrate how the emergent dynamics (i.e., domino effects) of local trajectory amendments can be efficiently explored to identify conflict-free Pareto-efficient network scenarios. Various performance indicators can be taken into account in the multi-criteria optimization process, thus offering to the network manager a flexible tool for fostering a collaborative planning process.

Developments in aviation meteorology

Developments in aviation meteorology