Professional Air Traffic Controllers Research Articles

Visual Interface for Time-Based Separation in Approach Air Traffic Control

On final approach, an approach controller is responsible for separating aircraft lining up on the instrument landing system. In an attempt to increase traffic throughput, especially in strong headwind conditions, European regulation advises all European airports to move from distance-based to time-based separation. This effectively changes the controller’s task from a distance-based to a time-based problem. Further complications arise because of the European recategorization of aircraft types initiative, and experts fear that the gains foreseen with time-based separation will not be realized. This paper presents a visual tool integrated into the radar screen to assist controllers in performing time-based separation, the ideal turn-in point (ITIP) display. To assist controllers in selecting optimal approach strategies, starting from the moment aircraft enter the terminal control area, the display shows the possibilities and restrictions in the system rather than giving (restricting) advisories. A proof-of-concept experiment was performed with people knowledgeable in air traffic control (N=8) and compared the ITIP to a current industry state-of-the-art display designed by U.K.’s National Air Traffic Services in scenarios of varying difficulty. Results show that with the ITIP tool, efficiency improved with similar or higher levels of safety and similar or lower workload. These promising results justify testing the interface with professional air traffic controllers. Future work aims at reducing clutter, increasing simulation fidelity, and increasing the level of support in complex traffic situations.

Fuzzy decision-making model for solving the ISAO “risk triangle” in conditions of violation of air-craft separation norms.

Taking into account the prevailing influence of the human factor on the occurrence of the vast majority of aviation events and serious incidents, the leading role of such a component of the current ISAO flight safety concept as “the attitude of aviation personnel towards dangerous actions or conditions” has been determined, which well explains the mutual influence of other components of this paradigm. In turn, the components of this relationship are determined through indicators of the influence of the human factor on decision-making by frontline aviation operators, in particular air traffic controllers. This approach is logical, since, firstly, the professional activity of an air traffic controller is easy to imagine as a continu-ous chain of decisions; secondly, according to statistics, unwanted aviation events are the result of false decisions; thirdly, the vast majority of aviation security experts believe that the point is not that “front line” aviation operators do not make decisions at all, but that these decisions are untimely, incor-rect, ineffective, etc. In the context of this publication, such a component of decision making is considered as fuzzy risk as-sessment models, in particular violations of standard operating procedures, namely aircraft separation standards. Using the modifier “very” and the methodology of fuzzy mathematics, a scale (term set) of the linguistic variable “danger level” was formed. The dimension of the scale is larger than that recommended by ISAO, which allows for a more detailed analysis of the dangers of violations of separation standards. On the other hand, scale reduction does not cause difficulties in the conditions of using fuzzy operations of “concentration”, “stretching”, “merging”. Having adapted the well-known “Cooper-Harper scale” for research needs, a survey was conducted of professional air traffic controllers m = 70, employees of the Unified Air Traffic Control System of the Republic of Azerbaijan, who expressed their attitude to the dangers of violations of the separation norms of ACC, ARR aircraft S = 20 km in the form of a “point on the parameter scale”, which contributed to the use of the so-called “hint matrix” for constructing membership functions of the linguistic variable “hazard level” with smooth falling fronts. It has been established that all points of intersection of the membership functions of neighboring terms of the linguistic variable “hazard level” are greater than the “transition point” of L. Zadeh, therefore the distances between them, established on the continuum of the studied separation norm, “rather belong” to the corresponding linguistic assessment of the established scale. The reduction of this scale to the ISAO dimension contributed to the solution of the corresponding “risk triangle”.

Professionalism of Soekarno Hatta Air Traffic Controllers in Islamic Perspective

This study aims to explore the meaning of the professionalism of Air Traffic Controller at Soekarno Hatta Airport from Islamic perspective. Air Traffic Control is a profession whose goal is to provide air traffic control services, especially for aircraft flight traffic, such as airplanes, helicopters and others. As a service provider who has a big responsibility for safety, it is only natural for Air Traffic Controls to work professionally. The research method used is qualitative research with a concept analysis approach. The results of the study shows that to ensure aviation safety as the main goal of service, an air traffic controller is required to work professionally in accordance with expertise, regulations and work discipline. The professionalism of air traffic controllers in Islam is that an air traffic controller must have the right intentions and have the spirit to perform services based on his knowledge expertise and its application in daily work. The results of this study are expected to serve as a reference for air traffic controllers in improving their ability to become a professional air traffic controllers referring to the teachings of the Islamic religion so that they have implications for service quality and achievement of service objectives.

Remembering Herbert Gutman's Work, Culture, and Society Fifty Years On

Remembering Herbert Gutman's <i>Work, Culture, and Society</i> Fifty Years On

Structure and Solidarity

Two strikes serve as bookends for the heyday of the twentieth-century American labor movement: the 1936–37 sit-down strike of the fledgling United Auto Workers (UAW) against what was then the nation’s largest corporation, General Motors, and the 1981 strike of the Professional Air Traffic Controllers Organization (PATCO) against the Federal Aviation Administration, a government agency. The successful UAW strike led not only to the unionization of General Motors; it opened the door to the unionization of basic industry across the U.S. economy, from auto, steel, and textiles to important components of transportation, food production, and communications. The PATCO strike, broken by President Ronald Reagan, led not only to the demise of that union; it marked the start of a period during which industrial unions were decimated and strikes in the United States dwindled to a mere handful.

Ecological Collaborative Interface for Unmanned Aerial Vehicle Traffic Management and Tower Control

The forecasted increase in unmanned aerial vehicle (UAV) traffic in lower airspace raises concerns for maintaining the safety and efficiency of flight operations near towered airports. Regulatory bodies envision a collaborative interface between UAV traffic management and air traffic management to allow for coordinated operations of both systems. This study identifies the main challenges that such an environment poses for tower control. To address these challenges, an initial design for a collaborative tower control display is introduced. Remote human-in-the-loop simulations with professional air traffic controllers confirmed the usefulness of several interface elements (in particular, UAV priority and routing indications), as well as the utilization of a grid of geofences to dynamically segregate UAVs from manned aircraft. Surprisingly, the control strategy for geofence activation was similar to that of managing manned aircraft from a tower control perspective. Participants also mentioned that they would like more control over UAV traffic than initially expected. Performance could be improved by increasing predictability of UAV routing, adding conflict detection support as well as providing more authority over individual UAV locomotion supported by a tailored geofence structure. Further work is needed to investigate controller behavior in an environment that also requires control over manned traffic.

Cognitive performance and electroencephalographic variations in air traffic controllers under various mental workload and time of day

The aim of this study was to investigate the effects of mental workload (MWL) and time of day on cognitive performance and electroencephalographic (EEG) parameters of air traffic controllers. EEG signals recorded while 20 professional air traffic controllers performed cognitive tasks [A-X Continuous Performance Test (AX-CPT) and 3-back working memory task] after they were exposed to two levels of task difficulty (high and low MWL) in the morning and afternoon. Significant decreases in cognitive performance were found when the levels of task difficulty increased in both tasks. The results confirmed the sensitivity of the theta and beta activities to levels of task difficulty in the 3-back task, while they were not affected in the AX-CPT. Theta and beta activities were influenced by time of day in the AX-CPT. The findings provide guidance for application of changes in EEG parameters when MWL level is manipulated during the day that could be implemented in future for the development of real-time monitoring systems to improve aviation safety.

Impact of Spatial Orientation Ability on Air Traffic Conflict Detection in a Simulated Free Route Airspace Environment.

In the selection of job candidates who have the mental ability to become professional ATCOs, psychometric testing has been a ubiquitous activity in the ATM domain. To contribute to psychometric research in the ATM domain, we investigated the extent to which spatial orientation ability (SOA), as conceptualized in the spatial cognition and navigation literature, predicted air traffic conflict detection performance in a simulated free route airspace (FRA) environment. The implementation of free route airspace (FRA) over the past few years, notably in Europe, have facilitated air traffic services by giving greater flexibility to aviation operators in planning and choosing preferred air routes that can lead to quicker arrivals. FRA offers enhanced system safety and efficiency, but these benefits can be outweighed by the introduction of air traffic conflicts that are geometrically more complex. Such conflicts can arise from increased number and distribution of conflict points, as well as from elevated uncertainty in aircraft maneuvering (for instance, during heading changes). Overall, these issues will make conflict detection more challenging for air traffic controllers (ATCOs). Consequently, there is a need to select ATCOs with suitably high levels of spatial orientation ability (SOA) to ensure flight safety under FRA implementation. In this study, we tested 20 participants who are eligible for ATCO job application, and found that response time-based performance on a newly developed, open access, computerized spatial orientation test (SOT) predicted time to loss of minimum separation (tLMS) performance on an air traffic conflict detection task (AT-CDT) we designed. We found this predictive relationship to be significant to a moderately large extent under scenarios with high air traffic density (raw regression coefficient = 0.58). Moreover, we demonstrated our AT-CDT as a valid test in terms of eliciting well-known mental workload and spatial learning effects. We explained these findings in light of similar or overlapping mental processes that were most likely activated optimally under task conditions featuring approximately equal numbers of outcome-relevant stimuli. We conclude by discussing the further application of the SOT to the selection of prospective ATCOs who can demonstrate high levels of conflict detection performance in FRA during training simulations.

Undelivered: From the Great Postal Strike of 1970 to the Manufactured Crisis of the U.S. Postal Service

Undelivered: From the Great Postal Strike of 1970 to the Manufactured Crisis of the U.S. Postal Service

Exploring the Peak-End Effects in Air Traffic Controllers' Mental Workload Ratings.

This study examined whether professional air traffic controllers (ATCos) were subject to peak-end effects in reporting their mental workload after performing an air traffic control task, and in predicting their mental workload in future scenarios. In affective experience studies, people's evaluation of a period of experience is strongly influenced by the most intense (peak) point and the endpoint. However, whether the effects exist in mental workload evaluations made by professional operators is still not known. In Study 1, 20 ATCos performed air traffic control scenarios on high-fidelity radar simulators and reported their mental workload. We used a 2 (high peak, low peak) × 2 (high end, low end) within-subject design. In Study 2, another group of 43 ATCos completed a survey asking them to predict their mental workload given the same air traffic control scenarios. In Study 1, ATCos reported higher mental workload after completing the high-peak and the high-end scenarios. In contrast, in Study 2, ATCos predicted the peak workload effect but not the end workload effect when asked to predict their experience in dealing with the same scenarios. Peak and end effects exist in subjective mental workload evaluation, but experts only had meta-cognitive awareness of the peak effect, and not the end effect. Researchers and practitioners that use subjective workload estimates for work design decisions need to be aware of the potential impact of peak and end task demand effects on subjective mental workload ratings provided by expert operators.

Neurophysiological Vigilance Characterisation and Assessment: Laboratory and Realistic Validations Involving Professional Air Traffic Controllers.

Vigilance degradation usually causes significant performance decrement. It is also considered the major factor causing the out-of-the-loop phenomenon (OOTL) occurrence. OOTL is strongly related to a high level of automation in operative contexts such as the Air Traffic Management (ATM), and it could lead to a negative impact on the Air Traffic Controllers’ (ATCOs) engagement. As a consequence, being able to monitor the ATCOs’ vigilance would be very important to prevent risky situations. In this context, the present study aimed to characterise and assess the vigilance level by using electroencephalographic (EEG) measures. The first study, involving 13 participants in laboratory settings allowed to find out the neurophysiological features mostly related to vigilance decrements. Those results were also confirmed under realistic ATM settings recruiting 10 professional ATCOs. The results demonstrated that (i) there was a significant performance decrement related to vigilance reduction; (ii) there were no substantial differences between the identified neurophysiological features in controlled and ecological settings, and the EEG-channel configuration defined in laboratory was able to discriminate and classify vigilance changes in ATCOs’ vigilance with high accuracy (up to 84%); (iii) the derived two EEG-channel configuration was able to assess vigilance variations reporting only slight accuracy reduction.

Chapter 15 - Monitoring performance of professional and occupational operators

The human capacity to simultaneously perform several tasks depends on the quantity and the mode of mentally processing the information imposed by the tasks. Since operational environments are highly dynamic, priorities across tasks will be expected to change as the mission evolves, thus the capability to reallocate the mental resources dynamically depending on such changes is very important. The resources required in very complex situations, such as air traffic management (ATM), can exceed the user's available resources leading to increased workload and performance impairments. In this regard, the availability of information concerning the workload experienced by the operators while dealing with tasks will be fundamental for both warning them when overload conditions are approaching and improving interactions with the system. The idea of our work was to use neurophysiologic data collected from professional air traffic controllers (ATCOs) to provide additional information to standard measures with which to assess the ATCOs' expertise and a machine learning electroencephalography-based index to evaluate their mental workload during the execution of ATC tasks. The results showed that the proposed method was able to track the workload alongside the execution of the realistic ATM scenario, and provide added values to objectively assess the expertise of the ATCOs.

Quantitative indicators of air traffic controllers’ attitude to the danger of errors

The negative and persistent impact of the human factor on the statistics of aviation accidents and serious incidents makes proactive studies of the attitude of “front line” aviation operators (air traffic controllers, flight crewmembers) to dangerous actions or professional conditions as a key component of the current paradigm of ICAO safety concept. This “attitude” is determined through the indicators of the influence of the human factor on decision-making, which also include the systems of preferences of air traffic controllers on the indicators and characteristics of professional activity, illustrating both the individual perception of potential risks and dangers, and the peculiarities of generalized group thinking that have developed in a particular society. Preference systems are an ordered (ranked) series of n = 21 errors: from the most dangerous to the least dangerous and characterize only the danger preference of one error over another. The degree of this preference is determined only by the difference in the ranks of the errors and does not answer the question of how much time one error is more dangerous in relation to another. The differential method for identifying the comparative danger of errors, as well as the multistep technology for identifying and filtering out marginal opinions were applied. From the initial sample of m = 37 professional air traffic controllers, two subgroups mB=20 and mG=7 people were identified with statisti-cally significant at a high level of significance within the group consistency of opinions a = 1%. Nonpara-metric optimization of the corresponding group preference systems resulted in Kemeny’s medians, in which the related (middle) ranks were missing. Based on these medians, weighted coefficients of error hazards were determined by the mathematical prioritization method. It is substantiated that with the ac-cepted accuracy of calculations, the results obtained at the second iteration of this method are more ac-ceptable. The values of the error hazard coefficients, together with their ranks established in the preference systems, allow a more complete quantitative and qualitative analysis of the attitude of both individual air traffic controllers and their professional groups to hazardous actions or conditions.

ПРЕВЕНТИВНЕ ОЦІНЮВАННЯ КОМПЛЕКСНОЇ ЗНАЧУЩОСТІ ХАРАКТЕРНИХ ПОМИЛОК АВІАДИСПЕЧЕРІВ

It is substantiated that the main factor explaining the impact of "front-line" aviation operators on the interaction of ICAO flight safety concept components is their "attitude to dangerous activities or conditions". To this “attitude” is assigned a preference system based on indicators and characteristics of professional activity. Based on ICAO recommendations and statistics on accidents and serious incidents during the organization of air traffic, a spectrum of n = 21 characteristic errors of air traffic controllers was formed, which most fully and comprehensively illustrates their erroneous decisions. Focusing on the linguistic indicators of ICAO to determine the levels of frequency and danger of adverse events, it is reasonable to carry out their defuzzification by using weighted error significance factors to determine individual and group preference systems. The coefficients are determined at the fifth iteration of the application of the mathematical method of prioritization. m=37 of professional air traffic controllers were involved in the experiment. To summarize their opinions regarding the frequency and danger of errors, a multiplicative approach was implemented, in contrast to the additive approach, more accurate results are obtained. The group systems of preferences of the tested air traffic controllers were constructed in terms of the frequency and dangers of characteristic errors that do not coincide. Indistinguishability indicator was introduced. It is found that its value for the study of the frequency of errors in the group system of advantages is equal to the value R*LF= 1,23·10-2, and for the analysis of the risks of errors - three times worse and equalR*LD= 3,77·10-2. An integrative (holistic) indicator of the significance of each error summarizes its coefficients of significance for the frequency and hazard indicators and is multiplicative. Which made it possible to build the ultimate group benefits system. The degree of indistinction of the significance of errors in it is equalR*g = 0,91·10-2, which testifies to the effectiveness of the proposed approach to the implementation of the recommendations of ICAO on the consideration in the processes of safety management of the frequency of flights and from the top of adverse events. It is proposed to use the obtained results to create a methodology for analyzing the “event tree” in flight safety management systems.

How Neurophysiological Measures Can be Used to Enhance the Evaluation of Remote Tower Solutions.

New solutions in operational environments are often, among objective measurements, evaluated by using subjective assessment and judgment from experts. Anyhow, it has been demonstrated that subjective measures suffer from poor resolution due to a high intra and inter-operator variability. Also, performance measures, if available, could provide just partial information, since an operator could achieve the same performance but experiencing a different workload. In this study, we aimed to demonstrate: (i) the higher resolution of neurophysiological measures in comparison to subjective ones; and (ii) how the simultaneous employment of neurophysiological measures and behavioral ones could allow a holistic assessment of operational tools. In this regard, we tested the effectiveness of an electroencephalography (EEG)-based neurophysiological index (WEEG index) in comparing two different solutions (i.e., Normal and Augmented) in terms of experienced workload. In this regard, 16 professional air traffic controllers (ATCOs) have been asked to perform two operational scenarios. Galvanic Skin Response (GSR) has also been recorded to evaluate the level of arousal (i.e., operator involvement) during the two scenarios execution. NASA-TLX questionnaire has been used to evaluate the perceived workload, and an expert was asked to assess performance achieved by the ATCOs. Finally, reaction times on specific operational events relevant for the assessment of the two solutions, have also been collected. Results highlighted that the Augmented solution induced a local increase in subjects performance (Reaction times). At the same time, this solution induced an increase in the workload experienced by the participants (WEEG). Anyhow, this increase is still acceptable, since it did not negatively impact the performance and has to be intended only as a consequence of the higher engagement of the ATCOs. This behavioral effect is totally in line with physiological results obtained in terms of arousal (GSR), that increased during the scenario with augmentation. Subjective measures (NASA-TLX) did not highlight any significant variation in perceived workload. These results suggest that neurophysiological measure provide additional information than behavioral and subjective ones, even at a level of few seconds, and its employment during the pre-operational activities (e.g., design process) could allow a more holistic and accurate evaluation of new solutions.

Labor Under Fire: A History of the AFL-CIO since 1979 by Timothy J. Minchin

Reviewed by: Labor Under Fire: A History of the AFL-CIO since 1979 by Timothy J. Minchin Elizabeth Fones-Wolf (bio) Labor Under Fire: A History of the AFL-CIO since 1979. By Timothy J. Minchin (Chapel Hill: University of North Carolina Press, 2017. Pp. xii, 414. $39.95 cloth) In 1955, when the American Federation of Labor and the Congress of Industrial Organizations merged, one-third of American workers belonged to unions. Twenty-four years later, when George Meany stepped down as the first president of the AFL-CIO, the ranks of organized labor had declined by a third. Today just one in ten workers are members of unions. It is not surprising, then, that the theme that dominates Timothy Minchin's deeply researched and engagingly written account of the recent history of the AFL-CIO [End Page 144] is the labor movement's decline, and the efforts of the Federation's leaders to combat it. Drawing on the archival records of the AFL-CIO and extensive oral-histories, Minchin focuses on the post-Meany presidential administrations of Lane Kirkland (1979–1995) and John Sweeney (1995–2009). He examines how each leader dealt with the challenges of relentless de-industrialization and globalization, intensifying employer opposition, and an often-hostile political climate. Minchin concludes that critics have not given the AFL-CIO a fair shake. They have condemned the Federation's failure to address labor union racism and its Cold War foreign policy and have argued that the AFL-CIO's conservative philosophy was a critical factor in its decline. While acknowledging the truthfulness of these criticisms, Minchin "recognizes its achievements and its limitations" (p. 6). Minchin begins with a brief review of the AFL-CIO's first two decades under George Meany's leadership, a period when it wielded significant economic and political power. The Federation played a critical role in the passage of an array of progressive legislation that benefitted all workers, such as Medicare, the Civil Rights Act of 1964, and the landmark Occupational Safety and Health Act. However, as Minchin notes, the roots of the Federation's and the labor movement's decline can also be traced to this period. Although the seventies saw the beginnings of the decline in union density with massive factory closures, Meany was complacent about the decline and showed little concern with organizing or addressing union racism and sexism. In the early eighties, the AFL-CIO faced a pivotal turning point. Minchin finds that the 1980 election of Ronald Reagan and his breaking of the 1981 Professional Air Traffic Controllers Organization strike as well as a depressed economy put labor on the defensive and hastened the AFL-CIO's deterioration. Union-busting intensified and takeback bargaining, lockouts, and decertification campaigns became common. These factors combined with the impact of deindustrialization caused industrial union membership to drop precipitously. Moreover, Reagan's tax cuts and new harsh policies undercut critical [End Page 145] social welfare programs. Under Kirkland's leadership, the Federation fought back, organizing public protests and making stabs at expanding organizing, supporting strikes, and reaching out to minorities and women, as well defending Social Security and workplace safety. Moreover, in the nineties the AFL-CIO was critical to pushing through the Family and Medical Leave Act and a higher minimum wage. But, as Minchin acknowledges, under Kirkland, the Federation was unable to block the North American Free Trade Agreement and there was no fundamental turnaround in its fortunes. In 1995, frustrated at the AFL-CIO's emphasis on political activity instead of organizing and grassroots mobilization, insurgents from the most dynamic unions in the service and public sectors challenged Kirkland's leadership and elected John Sweeney president. Emphasizing change and militancy, the Federation quickly diversified the AFL-CIO's leadership and coordinated major organizing campaigns, as well as emphasizing environmentalism and connecting with progressive community groups. However, Sweeney's reforms were undermined by the election of George Bush in 2000, the terrorist attacks of 9/11, which created a more conservative political climate, and by internal dissension within the Federation. Minchin has written a more balanced history of the AFL-CIO, although at times he struggles to find a silver-lining...

Differential method for establishing a comparative danger of air traffic controllers errors in professional activity

The advantage systems of air traffic controllers as operators of the “front line”, which are directly responsible for ensuring the appropriate level of flight safety, are considered as a component of their decision making, determines, on the one hand, the influence of the human factor on the choice they make, and on the other hand, makes this choice much easier. The use of paired comparisons and determination of part of the total comparative danger as a way of establishing the systems of benefits of professional air traffic controllers on the spectrum of the characteristic errors that they make in the process of professional activity are substantiated. For the first time, the total risk of a pair of errors is determined in an absolute and unique by quasi metric features 100-point scale, and their separate contribution to this danger covers the entire continuum of the scale. In contrast to the traditional practice, which regulates part of the total danger, it allowed for a more differentiated assessment of the comparative dangers of errors. Using the traditional and the proposed method, group systems of advantages of air traffic controllers on the studied range of errors, which are almost identical, are constructed: Spearman’s rank correlation coefficient is equal to the value. The Kendall concordance coefficient calculated for the group preference system constructed in the traditional way is equal to and statistically reliable, and therefore the corresponding preference system is consistent. The coefficient of concordance calculated for the group system of benefits based on the application of the proposed differential approach to the pairwise comparison of the dangers of errors is almost twice greater, equal to the value and statistically reliable at a high level of significance. This indicates both the consistency of the opinions of the subjects and the high efficiency of the proposed differential approach.

Human-Machine Interaction Assessment by Neurophysiological Measures: A Study on Professional Air Traffic Controllers.

This study aims at investigating the possibility to employ neurophysiological measures to assess the humanmachine interaction effectiveness. Such a measure can be used to compare new technologies or solutions, with the final purpose to enhance operator's experience and increase safety. In the present work, two different interaction modalities (Normal and Augmented) related to Air Traffic Management field have been compared, by involving 10 professional air traffic controllers in a control tower simulated environment. Experimental task consisted in locating aircrafts in different airspace positions by using the sense of hearing. In one modality (i.e. "Normal"), all the sound sources (aircrafts) had the same amplification factor. In the "Augmented" modality, the amplification factor of the sound sources located along the participant head sagittal axis was increased, while the intensity of sound sources located outside this axis decreased. In other words, when the user oriented his head toward the aircraft position, the related sound was amplified. Performance data, subjective questionnaires (i.e. NASA-TLX) and neurophysiological measures (i.e. EEG-based) related to the experienced workload have been collected. Results showed higher significant performance achieved by the users during the "Augmented" modality with respect to the "Normal" one, supported by a significant decreasing in experienced workload, evaluated by using EEG-based index. In addition, Performance and EEG-based workload index showed a significant negative correlation. On the contrary, subjective workload analysis did not show any significant trend. This result is a demonstration of the higher effectiveness of neurophysiological measures with respect to subjective ones for Human-Computer Interaction assessment.

EEG-Based Cognitive Control Behaviour Assessment: an Ecological study with Professional Air Traffic Controllers

Several models defining different types of cognitive human behaviour are available. For this work, we have selected the Skill, Rule and Knowledge (SRK) model proposed by Rasmussen in 1983. This model is currently broadly used in safety critical domains, such as the aviation. Nowadays, there are no tools able to assess at which level of cognitive control the operator is dealing with the considered task, that is if he/she is performing the task as an automated routine (skill level), as procedures-based activity (rule level), or as a problem-solving process (knowledge level). Several studies tried to model the SRK behaviours from a Human Factor perspective. Despite such studies, there are no evidences in which such behaviours have been evaluated from a neurophysiological point of view, for example, by considering brain activity variations across the different SRK levels. Therefore, the proposed study aimed to investigate the use of neurophysiological signals to assess the cognitive control behaviours accordingly to the SRK taxonomy. The results of the study, performed on 37 professional Air Traffic Controllers, demonstrated that specific brain features could characterize and discriminate the different SRK levels, therefore enabling an objective assessment of the degree of cognitive control behaviours in realistic settings.

A passive brain-computer interface application for the mental workload assessment on professional air traffic controllers during realistic air traffic control tasks.

In the last decades, it has been a fast-growing concept in the neuroscience field. The passive brain-computer interface (p-BCI) systems allow to improve the human-machine interaction (HMI) in operational environments, by using the covert brain activity (eg, mental workload) of the operator. However, p-BCI technology could suffer from some practical issues when used outside the laboratories. In particular, one of the most important limitations is the necessity to recalibrate the p-BCI system each time before its use, to avoid a significant reduction of its reliability in the detection of the considered mental states. The objective of the proposed study was to provide an example of p-BCIs used to evaluate the users' mental workload in a real operational environment. For this purpose, through the facilities provided by the École Nationale de l'Aviation Civile of Toulouse (France), the cerebral activity of 12 professional air traffic control officers (ATCOs) has been recorded while performing high realistic air traffic management scenarios. By the analysis of the ATCOs' brain activity (electroencephalographic signal-EEG) and the subjective workload perception (instantaneous self-assessment) provided by both the examined ATCOs and external air traffic control experts, it has been possible to estimate and evaluate the variation of the mental workload under which the controllers were operating. The results showed (i) a high significant correlation between the neurophysiological and the subjective workload assessment, and (ii) a high reliability over time (up to a month) of the proposed algorithm that was also able to maintain high discrimination accuracies by using a low number of EEG electrodes (~3 EEG channels). In conclusion, the proposed methodology demonstrated the suitability of p-BCI systems in operational environments and the advantages of the neurophysiological measures with respect to the subjective ones.