Air Traffic Management Research Research Articles

Introduction to the Virtual Collection of Best Papers from Air Traffic Management Research and Development Seminar 2021

Introduction to the Virtual Collection of Best Papers from Air Traffic Management Research and Development Seminar 2021

Harmonization and Verification of Three National European Icing Forecast Models Using Pilot Reports

The Single European Sky Air Traffic Management Research (SESAR) program aims at modernizing and harmonizing the European airspace, which currently has a strongly fragmented character. Besides turbulence and convection, in-flight icing is part of SESAR and can be seen as one of the most important meteorological phenomena, which may lead to hazardous flight conditions for aircraft. In this study, several methods with varying complexities are analyzed for combining three individual in-flight icing forecasts based on numerical weather prediction models from Deutscher Wetterdienst, Météo-France, and Met Office. The optimal method will then be used to operate one single harmonized in-flight icing forecast over Europe. As verification data, pilot reports (PIREPs) are used, which provide information about hazardous weather and are currently the only direct regular measure of in-flight icing events available. In order to assess the individual icing forecasts and the resulting combinations, the probability of detection skill score is calculated based on multicategory contingency tables for the forecast icing intensities. The scores are merged into a single skill score to give an overview of the quality of the icing forecast and enable comparison of the different model combination approaches. The concluding results show that the most complex combination approach, which uses iteratively optimized weighting factors for each model, provides the best forecast quality according to the PIREPs. The combination of the three icing forecasts results in a harmonized icing forecast that exceeds the skill of each individual icing forecast, thus providing an improvement to in-flight icing forecasts over Europe.

An evaluation of practitioners’ perceptions of a security risk assessment methodology in air traffic management projects

Cyber security is a key enabler for safe Air Traffic Management (ATM). This paper presents results from an empirical study, in which we have investigated and evaluated the use of the Security Risk Assessment Methodology for SESAR (SecRAM) in European ATM research and development projects. The study was performed with the intention to find and document common issues and aspects that could be improved in the methodology. The results from the study reveal that while most of the practitioners had a positive perception of the methodology itself, they were less satisfied with the process of applying it in their projects. Based on the results, we provide a number of recommendations, which aim to improve the security risk assessment process in the ATM domain.

Aircraft-Type-Specific Impact of Speed Brakes on Lift and Drag

The increasing influence of current research in air traffic management on daily flight operations leads to a stronger consideration of individually optimized aircraft trajectories. However, in the dichotomy between ecological, economic, and safety-based optimization goals, four-dimensionally optimized trajectories are subject to severe constraints in terms of position and speed. To fully assess the performance envelope of these trajectories, precise modelling of the influence of secondary control surfaces on flight performance is necessary. In particular, the use of speed brakes can significantly influence the descent and speed profile and allows the implementation of different cost indices. In this study, we present a modelling approach of the influence of extended speed brakes on flight performance and apply this method in a simulation environment for trajectory modelling of twelve different aircraft types. In doing so, we can determine an almost linear influence of the additional fuel requirement from the effective area of the speed brakes. The results can be implemented in any flight performance model and enable more precise modelling of future aircraft trajectories. Specifically, optimization targets regarding the required time of arrival, or the cost index and the consideration of the dynamic impact of atmospheric conditions in the trajectory optimization, only becomes possible through the calculation of the influence of the speed brake on lift and drag.

Importance of Weather Conditions in a Flight Corridor

Current research initiatives, such as the Single European Sky Air Traffic Management Research Program, call for an air traffic system with improved safety and efficiency records and environmental compatibility. The resulting multi-criteria system optimization and individual flight trajectories require, in particular, reliable three-dimensional meteorological information. The Global (Weather) Forecast System only provides data at a resolution of around 100 km. We postulate a reliable interpolation at high resolution to compute these trajectories accurately and in due time to comply with operational requirements. We investigate different interpolation methods for aerodynamic crucial weather variables such as temperature, wind speed, and wind direction. These methods, including Ordinary Kriging, the radial basis function method, neural networks, and decision trees, are compared concerning cross-validation interpolation errors. We show that using the interpolated data in a flight performance model emphasizes the effect of weather data accuracy on trajectory optimization. Considering a trajectory from Prague to Tunis, a Monte Carlo simulation is applied to examine the effect of errors on input (GFS data) and output (i.e., Ordinary Kriging) on the optimized trajectory.

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.

High Performance Implementation of Next Generation Aeronautical Communication Systems

Current air traffic communication systems are mainly based on voice communication, with a newer digital communication technology called L-Band Digital Aeronautical Communication System (LDACS) being investigated in the Single European Sky Air Traffic Management Research (SESAR) project. An essential feature of this communication infrastructure is the encoding of data that guarantees reliable transport. While the encoding in the transmission path is straightforward, the decoding is computationally expensive due to the peculiarities of the convolutional codes used. As the target platform for the communication equipment is an embedded system, a proper system design is essential for the receiving path to ensure real-time processing. This paper therefore focuses on the hardware/software co-design of the functional system parts needed for decoding in the LDACS radio receiver. We describe the fundamental design considerations, followed by the actual implementation in form of software and FPGA-based hardware modules. Subsequently, the decoding solution was verified to prove a standard-compliant system. In an experimental validation, the actual system was fed with test data from a reference system. This allows conclusions to be drawn about system characteristics like data throughput, latency, and error correction. The resulting system demonstrates high-performance decoding that can exceed the desired requirements for quality and speed for use in the LDACS communication system.

The effect of the Croatian Free Route Airspace implementation on the Air Traffic Complexity

It is well known that the increase in air traffic brings some negative connotations regarding delays, airspace capacity, air traffic controller workload, etc. To mitigate those problems, the European Commission has issued a development plan through the Single European Sky initiative, which yields a dozen solutions through the Single European Sky Air Traffic Management Research Joint Undertaking. Some of which is Free Route Airspace which enables aircraft operators to fly and plan direct routes through the airspace. Since this solution changes the way that the aircraft flies through airspace, different and new airspace routes have emerged. In this paper, the authors used fast time simulations with the PRU complexity model to observe how air traffic complexity was affected through Free Route Airspace implementation. It was observed that the increase in occupancy followed the increase in air traffic complexity, but not all results could be explained through the increase in the occupancy count. Also, to verify suspected claims the pre-FRA traffic from the 2016 was run on the FRA airspace and the reduction of complexity was observed. The authors concluded that the Free Route Airspace helped reduce the overall air traffic complexity, but further research and validation are still needed to concisely confirm those claims.

Calculation of AeroMACS Spectrum Requirements Based on Traffic Simulator.

In this paper, we propose a methodology for calculating the necessary spectrum requirements of aeronautical mobile airport communication system (AeroMACS) to provide various airport communication services. To accurately calculate the spectrum requirement, it is necessary to evaluate the AeroMACS traffic demand of the peak time and statistical data on the packet traffic generated at the airport. Because there is no AeroMACS traffic model and real trace data, we have developed the AeroMACS traffic simulator based on the report of Single European Sky Air Traffic Management Research (SESAR). To calculate the spectrum requirements, the AeroMACS traffic simulator is combined with the methodology of ITU-R M.1768-1. The developed traffic simulator reflects AeroMACS traffic priorities and can generate the required traffic according to its location in the airport. We observed the spectrum requirement by changing the number of sectors and the spectral efficiency. To show the feasibility of our methodology, we applied it to the case of Incheon International Airport in Korea. The simulation results show that the average bandwidth of 0.94 MHz is required in the ground area and 8.59 MHz is required in the entire airport.

SESAR: The Past, Present, and Future of European Air Traffic Management Research

The Single European Sky Air Traffic management (ATM) Research (SESAR) project is the technological pillar of the European Commission’s Single European Sky Initiative to modernize ATM. Here, we describe the process of establishing SESAR and the main parts of the project: the research and development (R&D) part, which is led by the SESAR Joint Undertaking; the deployment part, which is managed by the SESAR Deployment Manager; and the European ATM Master Plan, which collects and lays out both the R&D and deployment needs. The latest European ATM Master Plan was adopted just prior to the current pandemic. The huge loss in air traffic due to the pandemic, and the speed of the recovery of the aviation industry will require reprioritization, but the main elements that have been established—particularly those in support of the environment—remain valid.

Advanced Flight Planning and the Benefit of In-Flight Aircraft Trajectory Optimization

The implementation of Trajectory-Based Operations, invented by the Single European Sky Air Traffic Management Research program SESAR, enables airlines to fly along optimized waypoint-less trajectories and accordingly to significantly increase the sustainability of the air transport system in a business with increasing environmental awareness. However, unsteady weather conditions and uncertain weather forecasts might induce the necessity to re-optimize the trajectory during the flight. By considering a re-optimization of the trajectory during the flight they further support air traffic control towards achieving precise air traffic flow management and, in consequence, an increase in airspace and airport capacity. However, the re-optimization leads to an increase in the operator and controller’s task loads which must be balanced with the benefit of the re-optimization. From this follows that operators need a decision support under which circumstances and how often a trajectory re-optimization should be carried out. Local numerical weather service providers issue hourly weather forecasts for the coming hour. Such weather data sets covering three months were used to re-optimize a daily A320 flight from Seattle to New York every hour and to calculate the effects of this re-optimization on fuel consumption and deviation from the filed path. Therefore, a simulation-based trajectory optimization tool was used. Fuel savings between 0.5% and 7% per flight were achieved despite minor differences in wind speed between two consecutive weather forecasts in the order of 0.5 m s−1. The calculated lateral deviations from the filed path within 1 nautical mile were always very small. Thus, the method could be easily implemented in current flight operations. The developed performance indicators could help operators to evaluate the re-optimization and to initiate its activation as a new flight plan accordingly.

Flight Evaluation of Helicopter Curved Point-in-Space Approach Procedures

Helicopter point-in-space instrument procedures are key to enabling simultaneous noninterfering procedures and enhancing all-weather access in dense airspace and remote locations. This paper describes the flight evaluation of navigation and human performance in helicopter curved point-in-space procedures as part of Single European Sky Air Traffic Management Research. An experimental procedure was designed at Donauwörth heliport including radius-to-fix legs with descent gradients and airspeed variations in the terminal segments, followed by a steep, straight-in final approach segment. Two strategies were evaluated for vertical descent profiles: fixed flight path angle, and fixed vertical speed. Three test pilots were instructed to execute the entire approach until the missed approach point in simulated instrument meteorological conditions using advanced autopilot modes and head-down flight and navigation displays. Navigation performance was measured using cross-track and vertical-track deviations. Pilot workload and situational awareness were measured using the task load index and the situational awareness rating technique, respectively. The results showed that flight paths were maintained within the required navigation performance limits despite strong crosswinds, and the final approach glidepath was successfully captured in all cases. All pilots reported low workload, adequate spare capacity, and high situational awareness in all cases. Furthermore, the fixed flight path angle descent was found to induce lower workload and required fewer crew actions compared with the fixed vertical speed descent. Owing to the small sample size, conclusions with statistical significance cannot be established.

Aircraft trajectory prediction and synchronization for air traffic management applications

Commercial aircraft operating today are faced with an air traffic management (ATM) system operating with methods that have been developed for a paper- and voice-based system. Important information can be both different and unavailable to the various automation systems supporting decision makers. The consequence of such an environment is that automation systems suffer from inconsistency and inaccuracy. Faced with such a basis for decision making, the ATM environment is highly tactical by necessity. Aircraft operators may plan to optimize their operations in the face of uncertain or unknown information, but these plans are superseded as the tactical situation evolves. In response to these limitations, ATM research and modernization programs are underway across multiple regions of the world. While differences exist between these programs, these align with a single global vision as articulated by the International Civil Aviation Organization's Global Air Traffic Management Operational Concept. One key aspect is the migration to Trajectory-Based Operations (TBO) under which each flight is represented with a trajectory that is shared, managed, and used as a common plan for the flight. Decision-support automation for both the aircraft operator and air navigation service providers can use the same trajectory information for planning and tactical decision making, leveraging System Wide Information Management (SWIM). Achieving TBO requires more accurate trajectory prediction and synchronization across participants. This paper reviews research applicable to trajectory prediction throughout the trajectory prediction process, addresses differences in decision-making structures, and considers trajectory synchronization research applicable to TBO. Where possible, operational realities are identified concluding with future research and validation needs for TBO across the entire process from inputs to a synchronized trajectory.

Collaborative Solutions for Interference Management in GNSS-Based Aircraft Navigation.

Nowadays, the Global Navigation Satellite Systems (GNSS) technology is not the primary means of navigation for civil aviation and Air Traffic Control, but its role is increasing. Consequently, the vulnerabilities of GNSSs to Radio Frequency Interference, including the dangerous intentional sources of interference (i.e., jamming and spoofing), raise concerns and special attention also in the aviation field. This panorama urges for figuring out effective solutions able to cope with GNSS interference and preserve safety of operations. In the frame of a Single European Sky Air traffic management Research (SESAR) Exploratory Research initiative, a novel, effective, and affordable concept of GNSS interference management for civil aviation has been developed. This new interference management concept is able to raise early warnings to the on-board navigation system about the detection of interfering signals and their classification, and then to estimate the Direction of Arrival (DoA) of the source of interference allowing the adoption of appropriate countermeasures against the individuated source. This paper describes the interference management concept and presents the on-field tests which allowed for assessing the reached level of performance and confirmed the applicability of this approach to the aviation applications.

SAFETY ANALYSIS OF GOODS TRANSPORTATION BY UNMANNED AERIAL VEHICLES

Modern transport companies around the world actively study the possibility of intra-urban transportation of goods using unmanned aerial vehicles (UAV).The objective of the study is to reveal the existing problems preventing full-scale introducing of UAVs into the operations of logistics centers that accomplish cargo delivery in modern megacities as well as to propose a possible option for their solution.The study conducted applying the methods of comparative analysis and generalization showed that the main obstacle to the use of unmanned aerial vehicles for cargo delivery is currently unsettled problem of safety when UAVs operate in the urban environment.The study has analyzed the worldwide UAV traffic safety management programs. Among the programs reviewed were U-Space (the program is implemented by the European Commission and other participants); NASA Unmanned Aircraft System Traffic Management (the program is implemented by NASA and the US Federal Aviation Administration); European Aviation Safety Agency drone categories (the program is implemented by European Aviation Safety Agency (EASA)); Urban Traffic Management of Unmanned Aircraft System (the program is implemented by Air Traffic Management Research Institute (ATMRI) and other participants). The analysis showed that these programs paid a lot of attention to preventing the UAVs collisions with other air vehicles. But almost no attention was paid to the fact that the flight routes of unmanned aerial vehicles would intersect with the ground highways.The analysis carried out in the article allows us to conclude that one of the solutions to the problem of UAV implementation in the field of cargo delivery is the development of a new concept of UAV traffic safety in the urban conditions, which will take into account the threat of collision of cargo UAV not only with air vehicles but also with ground ones. The concept should determine the requirements for thetechnology for safe traffic of drones over the main surface transport routes including highways, highspeed railways, etc. The development of such a concept will be a turning point for starting the fullscale use of UAVs as a new and effective means of cargo delivery in the city, which, in its turn, willcreate the next-generation transport infrastructure in the cities.

IMPLEMENTATION PROSPECTS OF THE REMOTE TOWER CONCEPT IN UKRAINE

The real cost of the air travel and air transportation has been decreasing over the past years making air transportation more accessible and thus leading to an increase in the demand for it. This allowed to expand the air connectivity network and provide more destinations for the air travel, including smaller regional airports. One of the components of the cost of the air travel is air navigation service costs for the provision of services by air navigation service providers and these costs are flat-rate costs. For small regional airports with low and/or irregular traffic these costs might be a burden limiting their development. Remote tower concept developed as part of the Single European Sky air traffic management Research program aims at optimising and reducing costs for the provision of air navigation services at small airports allowing them to better utilise resources and improve their profitability. Most of the air traffic in Ukraine is handled by a few strategic airports while small regional airports handle only a few flights a day and in order to provide air traffic services for those flights the regional airports are equipped with local aerodrome control service facilities. Due to the low traffic at the regional airports, resources and facilities aren’t used in the most efficient way. The purpose of this work is to investigate the feasibility of implementation of the remote tower concept at Ukrainian airports to improve the cost efficiency of the provision of air traffic services at the airports and correspondingly decrease the cost of the air travel to the regional airports in Ukraine.

A Variation of the ATC Work Shift Scheduling Problem to Deal with Incidents at Airport Control Centers

This paper deals with a variation of the air traffic controller (ATC) work shift scheduling problem focusing on the tactical phase, in which the plan for the day of operations can be modified according to real-time traffic demand or other possible incidents (one or more ATCs become sick and/or there is an increase in unplanned air traffic), which may lead to a new sectorization and a lower number of available ATCs. To deal with these issues, we must reassign the available ATCs to the new sectorization established at the time the incident happens, but also taking into account the work done by the ATCs up to that point. We propose a new methodology consisting of two phases. The goal of the first phase is to build an initial possibly infeasible solution, taking into account the sectors that have been closed or opened in the new sectorization, together with the ATCs available after the incident. In the second phase, we use simulated annealing (SA) and variable neighborhood search (VNS) metaheuristics to derive a feasible solution in which the available ATCs are used and all the ATC labor conditions are met. A weighted additive objective function is used in this phase to account for the feasibility of the solution but also for the number of changes in the control center at the time the incident happens and the similarity of the derived solution with templates usually used by the network manager operations center, a center managing the air traffic flows of an entire network of control centers. The methodology is illustrated by means of seven real instances provided by the Air Traffic Management Research, Development and Innovation Reference Center (CRIDA) experts representing possible incidents that may arise. The solutions derived by SA outperform those reached by VNS in terms of both the number of violated constraints in all seven instances, and solution compactability in six out the seven instances, and both are very similar with regard to the number of control center changes at the time of the incident. Although computation times for VNS are clearly better than for SA, CRIDA experts were satisfied with SA computation times. The solutions reached by SA were preferred.

Estimating aircraft drag polar using open flight surveillance data and a stochastic total energy model

In air traffic management research, aircraft performance models are often used to generate and analyze aircraft trajectories. Although a crucial part of the aircraft performance model, the aerodynamic property of aircraft is rarely available for public research purposes, as it is protected by aircraft manufacturers for commercial reasons. In many studies, a simplified quadratic drag polar model is assumed to compute the drag of an aircraft based on the required lift. In this paper, using surveillance data, we take on the challenge of estimating the drag polar coefficients based on a novel stochastic total energy model that employs Bayesian computing. The method is based on a stochastic hierarchical modeling approach, which is made possible given accurate open aircraft surveillance data and additional analytical models from the literature. Using this proposed method, the drag polar models for 20 of the most common aircraft types are estimated and summarized. By combining additional data from the literature, we propose additional methods allowing aircraft total drag to be calculated under other configurations, such as when flaps and landing gears are deployed. We also include additional models allowing the calculation of wave drag caused by compressibility at high Mach number. Though uncertainties exist, it has been found that the estimated drag polars agree with existing models, as well as CFD simulation results. The trajectory data, performance models, and results related to this study are shared publicly.

Assessing the Contribution of Data Mining Methods to Avoid Aircraft Run-Off from the Runway to Increase the Safety and Reduce the Negative Environmental Impacts.

The Single Europe Sky Air Traffic Management Research (SESAR) program develops and implements innovative technological and operational solutions to modernize European air traffic management and to eliminate the negative environmental impacts of aviation activity. This article presents our developments within the SESAR Solution “Safety Support Tools for Avoiding Runway Excursions”. This SESAR Solution aims to mitigate the risk of runway excursion, to optimize airport operation management by decreasing the number of runway inspections, to make chemical treatment effective with respect to the environment, and to increase resilience, efficiency and safety in adverse weather situations. The proposed approach is based on the enhancement of runway surface condition awareness by integrating data from various sources. Dangerous windy conditions based on Lidar measurements are also discussed as another relevant factor in relation to runway excursions. The paper aims to explore four different data mining methods to obtain runway conditions from the available input data sources, examines their performance and discusses their pros and cons in comparison with a rule-based algorithm approach. The output of the SESAR Solution is developed in compliance with the new Global Reporting Format of the International Civil Aviation Organization for runway condition description to be valid from 2020. This standard is expected to provide concerned stakeholders with more precise information to enhance flight safety and environmental protection.

Human performance assessment of a single air traffic controller conducting multiple remote tower operations

AbstractThe innovative concept of multiple remote tower operations (MRTO) can maximize cost savings by applying video panorama‐based remote tower working positions, which can facilitate fewer air traffic controllers (ATCO) to provide the air traffic services (ATS) function for more airports. Five subject‐matter experts, qualified remote tower ATCOs, participated in this research work by applying the human error template (HET) and comparing workload between physical tower operations and MRTO using NASA‐TLX (Task Load Index). The results demonstrate that augmented visualization provided sufficient technical support for a single ATCO to perform tasks originally designed to be performed by four ATCOs, however, the demands of the associated multiple tasks induced significant workload. There were significant differences in ATCOs’ mental demand, temporal demand, effort, and frustration between MRTO and physical tower operations. This innovative technology may induce human–computer interaction (HCI) issues that impact ATCO's perceived workload. This creates a need for further research on how to manage ATCO's workload in a multiple remote tower environment. This research work provided scientific evidence that MRTO can achieve the objectives of Single European Sky Air Traffic Management Research program. The findings can be applied to both ATCO training design and remote tower system design.