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Control forgetting accounts for most of the current unsafe incidents. In the research field of radar surveillance control, how to avoid control forgetting to ensure the safety of flights is becoming a hot issue which attracts more and more attention. Meanwhile, aviation safety is substantially influenced by the way of eye movement. The exact relation of control forgetting with eye movement, however, still remains puzzling. Motivated by this, a control forgetting prediction method is proposed based on the combination of Convolutional Neural Networks and Long-Short Term Memory (CNN-LSTM). In this model, the eye movement characteristics are classified in terms of whether they are time-related, and then regulatory forgetting can be predicted by virtue of CNN-LSTM. The effectiveness of the method is verified by carrying out simulation experiments of eye movement during flight control. Results show that the prediction accuracy of this method is up to 79.2%, which is substantially higher than that of Binary Logistic Regression, CNN and LSTM (71.3%, 74.6%, and 75.1% respectively). This work tries to explore an innovative way to associate control forgetting with eye movement, so as to guarantee the safety of civil aviation. [ABSTRACT FROM AUTHOR]

With the rapid expansion of transportation demand, the number of global flights has rapidly increased, which also poses challenges to air traffic management (ATM). Considering that the radar system in ATM can no longer meet the requirements of flight safety, a very promising next-generation air traffic control technology—Automatic Dependent Surveillance Broadcast (ADS-B) technology has been introduced. However, in the event of on-board equipment failure and local area signal interference, the ADS-B's signal will disappear or be interrupted. This sudden situation can pose a danger to aviation safety. To solve this problem, this article proposes a bidirectional long short-term memory (Bi-LSTM) network prediction method combining historical ADS-B data to short-term predict the trajectory of aircraft, which can improve aviation safety in busy airspace. Firstly, the problem of frequent dynamic modeling of different types of aircraft was solved by utilizing historical ADS-B data as the data source. Secondly, the data cleansing method is proposed for ADS-B raw data. Furthermore, considering that the spatial trajectory of the aircraft is a complex time series with continuity and interactivity, a bidirectional LSTM based aircraft trajectory prediction framework is proposed to further improve prediction accuracy. Finally, a trajectory with frequent changes was selected for prediction, and compared with 7 prediction methods. The results showed that the proposed method had high prediction accuracy, thus also improving the aviation safety of the aircraft. [ABSTRACT FROM AUTHOR]

GPS-dependent localization, tracking and navigation applications have a significant impact on the modern aviation industry. However, the lack of encryption and authentication makes GPS vulnerable for spoofing attacks with the purpose of hijacking aircrafts or threatening air safety. In this paper, we propose GPS-Probe, a GPS spoofing detection algorithm which leverages the air traffic control (ATC) messages periodically broadcasted by aircrafts. By exploiting the received signal strength indicator (RSSI) and the timestamps at server (TSS) of the ATC messages monitored by multiple ground sensors, GPS-Probe constructs a machine learning enabled framework which can estimate the real position of the target aircraft and then detect whether GPS is spoofed or not. Unlike existing techniques, GPS-Probe neither requires any updates of the GPS infrastructure nor of the GPS receivers. It also releases the requirement on the time synchronization of the ground sensors distributed around the world. We further present GPS-Probe-Plus by incorporating a flight height estimation module and a calibration method for RSSI and TSS values, which performs better on both target localization and spoofing detection than GPS-Probe. Using the real-world ATC data crowdsourced by OpenSky Network, our experiment results show that GPS-Probe (resp. GPS-Probe-Plus) can achieve an average detection accuracy and precision, of 81.7% (resp. 86.8%) and 85.3% (resp. 91.2%), respectively, significantly outperforming the state-of-the-arts. [ABSTRACT FROM AUTHOR]

The next generation Air Transport Management (ATM) requires performance-based safety management that is fully integrated into seamless operational management. To realize this objective, a framework is proposed in this article that structures risk information on ATM consoles in terms of four design principles: (i) integrating operational and safety-related data, (ii) managing interactions and minimizing transfer of risks to other sectors, (iii) generating risk patterns from accumulated experience and (iv) managing resources and safety barriers. The framework is applied to an approach control unit of a regional airport for the design of a performance dashboard that is linked to a safety module for managing hazards and safety barriers. In this sense, safety management is not an additional task to normal operations since risk information is integrated with operational data on a daily basis. Furthermore, the safety module combines traditional elements of bow-ties with new safety indices such as complexity metrics and risk patterns. [ABSTRACT FROM AUTHOR]

The management of uncertainty is a critical aspect of current as well as future air traffic control operations. This study investigated: (1) sources of uncertainty in enroute air traffic control, (2) strategies that air traffic controllers adopt to cope with uncertainty, (3) the trade-offs and contingencies that influences the adoption of these uncertainties, and (4) the requirements for system design that support controllers in following these strategies. The data were collected using a field study in two enroute air traffic control centres, involving 'over the shoulder' observation sessions, discussions with air traffic controllers, and document analysis. Three types of uncertainty coping strategies were identified: reducing uncertainty, acknowledging uncertainty, and increasing uncertainty. The RAWFS heuristic (Lipshitz and Strauss in Organ Behav Hum Decis Process 69:149-163, 1997) and anticipatory thinking (Klein et al. in Anticipatory thinking, Proceedings of the eighth international NDM conference, Pacific Grove, CA, 2007) were used to identify reduction and acknowledgement strategies. Recent suggestions by Grote (Saf Sci 71:71-79, 2015) were used to further explore strategies that increase uncertainty. The study presents a new framework for the classification of uncertainties in enroute air traffic control and identified the uncertainty management strategies and underlying tactics, in context of contingencies and trade-offs between operational goals. The results showed that controllers, in addition to reducing and acknowledging uncertainty, may deliberately increase uncertainty in order to increase flexibility for other actors in the system to meet their operational goals. The study describes new tactics for acknowledging and increasing uncertainty. The findings were summarized in the air traffic controller complexity and uncertainty management model. Additionally, the results bring to light system design recommendations that allow controllers to follow these different coping strategies, including (1) the design of alerts, (2) the transparency of prediction tools, and (3) system flexibility as a requirement for acknowledging and increasing uncertainty. The results are particularly important as uncertainty is likely to increase in future operations of enroute air traffic control, requiring automation support for controllers. Implications for future air traffic management scenarios as envisioned within the SESAR Joint Undertaking (SESAR JU in European ATM Master Plan, 2 eds, 2012) and NextGen (FAA in FAA's NextGen implementation plan, 2014) operational concepts are discussed. [ABSTRACT FROM AUTHOR]

This paper brings a social science perspective (from the ethnicity and diversity literature) to bear on a process that is regarded by many as essentially a technical one: the safe insertion of military unmanned aircraft systems (UAS) in the (inter)national European airspace. The aim of this qualitative study was to gain a more adequate scientific socio-technological understanding of the topic, so as to strengthen issue dialogue and discussion. Indeed, studying the 'integration' of these UASs (as this process is often referred to) through the lens of acculturation literature revealed some socio-technological processes that have been little noticed but which seem to underlie and inform this debate. For example, some voices seem to be favoured over others, a well-known phenomenon in the ethnicity and diversity literature. Safety, it could even be argued, is in this debate the pivot point around which social and other dynamics revolve. Belief and power may thus be more important factors here-'masked' of course-than technical aspects of safety. The results of this study are important not only for the military since the incorporation of military UAS occurs, partially at least, in civilian airspace. Civil actors thus formed a substantial subset of those interviewed here. [ABSTRACT FROM AUTHOR]

Departure routine is essential part in the air traffic control and must be formally designed to avoid potential hazards and to verify proper functioning of the underlying processes. This paper addresses the Petri net approach to formally model the departure routine of the aircraft which ensures the organized flow of air traffic during departure. First, the high-level design of the system is presented by identifying key objects involved in departure routine, and then, its detailed model is presented. Moreover, the verification of the underlying methodology has been made using coverability tree. The proposed model is verified to be safe (bounded), potentially reversible and deadlock free which ensures reliability of the system and guarantees the efficient and controlled communication between the aircraft and local and ground controllers. [ABSTRACT FROM AUTHOR]

Air traffic control (ATC) system is a safety critical system because its failure may result into loss of life, considerable financial and environmental damages. Modelling safe and efficient ATC system is an open research problem and has become a challenging task due to its complexity and ever increasing traffic at airports. It is reported in the literature that a number of collisions occurred at airports surface are three time larger than the collisions in the airspace. The delays at airport surface require effective safety and guidance protocols to control traffic at the airport. In this paper, formal procedure of managing air traffic from taxiing to take-off is provided using graph theory and Z notation. After definition of airport surface by the graph structure in terms of nodes and edges, formal specification of taxiways, aircrafts and runways is provided in static part of the model. The state space analysis is provided by describing optimal paths in dynamic model expediting the departure procedure. The safety properties are described in terms of invariants over the data types carrying critical information. Further, the safety is insured by defining pre- and post-conditions in description of operations for changing state space of the system. The proposed study is focussed more on the safety component; however, the efficiency of the system is not ignored. For example, the model is based on the next generation ATC systems that use new technologies expediting the procedures. Graph theory is used in our model under the Z specification that is a foundation for automating the procedure in our future work. Formal specification is analysed and validated using Z/Eves tool. It is observed that weaknesses of testing and simulation can be overcome by applications of formal techniques avoiding state space explosions problems in complex systems. [ABSTRACT FROM AUTHOR]

Sensemaking helps teams coordinate their efforts to understand and anticipate events in uncertain situations. While it is recognized that breakdowns in team sensemaking can lead to incidents, next generation air traffic management (ATM) projects have not paid serious attention to this research topic. This article presents findings from an exploratory field study of team sensemaking in air traffic control for low visibility operations. The study uses the critical decision method and the data/frame model of sensemaking (Klein et al. in Expertise out of context: proceedings of the 6th international conference on naturalistic decision making. Erlbaum, Mahwah, ) as a theoretical basis for examining Tower and Approach operations that will be transformed by next generation ATM projects. The findings concern the elicitation of explanatory frameworks for making sense of low visibility operations, the identification of domain-specific strategies that shape sensemaking and the presentation of emergent requirements for team sensemaking. Implications are made for embedding operational experience into future ATM systems to improve collaborative decision making. [ABSTRACT FROM AUTHOR]

Improvements of aviation systems are now in progress to ensure the safety and efficiency of air transport in response to the rapid growth of air traffic. For providing theoretical and empirical basis for design and evaluation of aviation systems, researches focusing on cognitive aspects of air traffic controllers are definitely important. Whereas various researches from cognitive perspective have been performed in the Air Traffic Control (ATC) domain, there are few researches trying to illustrate ATCO's control strategies and their effects on task demands in real work situations. The authors believe that findings from these researches can contribute to reveal why ATCOs are capable of handling air traffic safely and efficiently even in the high-density traffic condition. It can be core knowledge for tackling human factors issues in the ATC domain such as development of further effective education and training program of ATCO trainees. However, it is difficult to perform such kinds of researches because identification of ATC task from a given traffic situation and specification of effects of ATCO's control strategies on task demands requires expert knowledge of ATCOs. The present research therefore aims at developing an automated identification and visualization tool of en route ATC tasks based on a cognitive system simulation of an en route controller called COMPAS (COgnitive system Model for simulating Projection-based behaviors of Air traffic controller in dynamic Situations), developed by the authors. The developed visualization tool named COMPAS (COMPAS in interactive mode) equips a projection process model that can simulate realistic features of ATCO's projection involving setting extra margins for errors of projection. The model enables COMPAS to detect ATC tasks in a given traffic situation automatically and to identify Task Demand Level (TDL), that is, an ATC task index. The basic validity of COMPAS has been confirmed through detailed comparison between TDLs given by a training instructor and ones by COMPAS in a simulation-based experiment. Since TDL corresponds to demands of ATC tasks, temporal sequences of TDLs can reflect effectiveness of ATCO's control strategies in terms of regulating task demands. By accumulation and analysis of such kind of data, it may be expected to reveal important aspect of ATCO's skill for achieving the safety and efficiency of air traffic. [ABSTRACT FROM AUTHOR]

Public awareness of airplane safety is very high due to the spectacular nature of airplane accidents. Partly as a result, civil airplane operations are tightly regulated at all levels from design to operation and maintenance. Scheduled airline operations have thus been able achieve a very high level of safety. In this article we quantify the safety of flight operations and indicate the design concepts like fail safety and safe life used in achieving a high level of safety. As an illustration, we consider the safety of a flight of a twin engine airplane in the event of one engine failure. [ABSTRACT FROM AUTHOR]

Abstract The increasing level of automation in critical infrastructures requires development of effective ways for finding faults in safety critical software components. Synchronization in concurrent components is especially prone to errors and, due to difficulty of exploring all thread interleavings, it is difficult to find synchronization faults. In this paper we present an experimental study demonstrating the effectiveness of model checking techniques in finding synchronization faults in safety critical software when they are combined with a design for verification approach. We based our experiments on an automated air traffic control software component called the Tactical Separation Assisted Flight Environment (TSAFE). We first reengineered TSAFE using the concurrency controller design pattern. The concurrency controller design pattern enables a modular verification strategy by decoupling the behaviors of the concurrency controllers from the behaviors of the threads that use them using interfaces specified as finite state machines. The behavior of a concurrency controller is verified with respect to arbitrary numbers of threads using the infinite state model checking techniques implemented in the Action Language Verifier (ALV). The threads which use the controller classes are checked for interface violations using the finite state model checking techniques implemented in the Java Path Finder (JPF). We present techniques for thread isolation which enables us to analyze each thread in the program separately during interface verification. We conducted two sets of experiments using these verification techniques. First, we created 40 faulty versions of TSAFE using manual fault seeding. During this exercise we also developed a classification of faults that can be found using the presented design for verification approach. Next, we generated another 100 faulty versions of TSAFE using randomly seeded faults that were created automatically based on this fault classification. We used both infinite and finite state verification techniques for finding the seeded faults. The results of our experiments demonstrate the effectiveness of the presented design for verification approach in eliminating synchronization faults. [ABSTRACT FROM AUTHOR]

This paper reports a field study of work in a complex setting:an airport. The study was largely focused on the Air Traffic Control activities carried out in the airport control tower, but also investigated other work sites around the airport. An important feature of the successful operation of the airport., then, is the way that the activities occurring in these different sites become articulated through explicit communicative acts and through common understandings of the work of the airport. The airport is viewed as a common information space, a perspective that emphasises meaning and interpretation and the processes by which meanings become common across a heterogeneous work system. A characteristic of the environment studied here is that white meanings may not be common across the different communities of practice working at the airport, interpretations appear to be sufficiently common as to pose few problems in most circumstances. [ABSTRACT FROM AUTHOR]

The object is to identify characteristics of feasible systems for UK — and European — Air Traffic Management (ATM) in the coming decades. ATM here covers Air Traffic Control (ATC) provision plus wider issues, such as airspace design. The analytical focus is on the financial decision-making processes and constraints that will act to shape this future system. R&D work into control workload and planning based on an "ATM core concept" are proposed as likely to offer the best way forward. [ABSTRACT FROM AUTHOR]

Hub-and-spoke has become the predominant configuration of airline routes, with individual hubs typically dominated by single carriers. These operations have characteristics of natural monopoly; but dominance is a consequence also of advantages that cannot be subsumed under the rubric of superior efficiency. The carrier with the strongest presence attracts a grossly disproportionate amount of traffic and, secondarily, of the high fare-paying traffic originating at the hub. While the welfare consequences of the consequent price discrimination are ambiguous, United's acquisition of 50 additional slots at the slot-constrained O'Hare airport raised a legitimate Clayton Act Section 7 issue. [ABSTRACT FROM AUTHOR]

Recent work performed for the Federal Aviation Administration to support the development of future concepts of air traffic management has involved simulation modeling of patterns of airspace usage by commercial and business air traffic. The objective of these efforts has been to investigate the impacts of a pattern of airspace usage known as ‘free flight’, whereby pilots and flight dispatchers have much more freedom to choose, say, direct or wind-optimal routing through airspace. One of the figures of merit investigated is a count of ‘convergence pairs’ as a measure of the complexity of various traffic patterns. These are cases when aircraft in the simulation model fly close to each other. Interestingly, geographic plots of convergence pairs accumulated over time bring out certain features or patterns of congested air traffic flows or flight alignments. However, these plots are also thick with ‘noise’ or extraneous convergence pairs, whose presence detracts from the ability to perceive congested air traffic flows. Cluster analysis has been found to be an effective method of filtering these displays so that the congested flow features are discernible. The process developed for this purpose is based on a two-pass clustering approach. The process has worked well for the simulation modeling performed to date. Classification of the locations of convergence pairs into congested flow corridors is visually appealing, and has helped distinguish differences in contrasting scenarios of airspace usage. The paper presents graphical results and describes the clustering algorithms employed. [ABSTRACT FROM AUTHOR]