An observation tool to study air traffic control and flightdeck collaboration

The complex systems of the flightdeck (FD) and the Air Traffic Control Centre (ATC) are characterised by numerous concurrently operating and interacting communication channels between people and between people and machines/computer systems. This paper describes work in support of investigating the impact of changes to technologies and responsibilities within this system with respect to human factors. It focuses primarily on the introduction of datalink (text-based communication rather than traditional radio communication) and the move towards freeflight (pilot-mediated air traffic control). Air traffic management investigations have outlined these specific changes as strategies to enable further increases in the volume of air traffic. A systems approach was taken and field studies were conducted. Small numbers of domain experts such as air traffic controllers (ATCOs) were involved in the field-based observations of how people interact with systems and each other. This paper summarises the overall research approach taken and then specifically reports on the field-based observations including the justification, development, and findings of the observation tool used. The observation tool examined information propagation through the air traffic control-flightdeck (ATC-FD) system, and resulted in models of possible information trajectories through the system.     

Exploring team sensemaking in air traffic control (ATC): insights from a field study in low visibility operations

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, 2007) 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.     

Managing emergencies and abnormal situations in air traffic control (part II): Teamwork strategies

Team performance has been studied in many safety-critical organizations including aviation, nuclear power plant, offshore oil platforms and health organizations. This study looks into teamwork strategies that air traffic controllers employ to manage emergencies and abnormal situations. Two field studies were carried out in the form of observations of simulator training in emergency and unusual scenarios of novices and experienced controllers. Teamwork strategies covered aspects of team orientation and coordination, information exchange, change management and error handling. Several performance metrics were used to rate the efficiency of teamwork and test the construct validity of a prototype model of teamwork. This is a companion study to an earlier investigation of taskwork strategies in the same field (part I) and contributes to the development of a generic model for Taskwork and Teamwork strategies in Emergencies in Air traffic Management (T²EAM). Suggestions are made on how to use T²EAM to develop training programs, assess team performance and improve mishap investigations.     

Managing emergencies and abnormal situations in air traffic control (part I): Taskwork strategies

A lot of research in Air Traffic Control (ATC) has focused on human errors in decision making whilst little attention has been paid to the cognitive strategies employed by controllers in managing abnormal situations. This study looks into cognitive strategies in taskwork that enable controllers to become resilient decision-makers. Two field studies were carried out where novice and experienced controllers were observed in simulator training in emergency and unusual scenarios. A prototype model of taskwork strategies in air traffic management was developed and its construct validity was tested in the context of the field studies. A companion study (part II), follows that investigates aspects of teamwork in the same field and contributes to the development of a generic model of Taskwork & Teamwork strategies in Emergencies in Air traffic Management (T²EAM). The final section addresses the difficulties experienced by novice controllers and explains taskwork strategies employed by experts to manage uncertainty and balance workload in simulator emergencies.     

Dynamics and control technologies in air traffic management

Dynamics and Control technologies play a central role in the development and operation of decision support systems of modern air traffic management systems. Recent emergence of Global Navigation Satellite Systems and satellite-based augmentation systems have enabled higher precision execution of aircraft trajectories, opening-up the potential for the implementing more quantitative air traffic management approaches. Already, this navigation capability is enabling higher traffic through puts, and safer operation of aircraft in the proximity of the terrain at several major airports in the US. This paper discusses the aircraft trajectory optimization, conflict resolution algorithms, and traffic flow management problems which form the essential components of the evolving air traffic management system. It will be shown that Optimal Control Theory, Model Predictive Control and the Discrete Event Systems theory form the underlying analytical machinery in this domain. Finally, the paper will outline some of the algorithms for realizing the Trajectory Based Operations concept, currently being developed for future air traffic management.     

Uncertainty management in enroute air traffic control: a field study exploring controller strategies and requirements for automation

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.     

Visualizing complexities: the human limits of air traffic control

Air traffic management is organized into filters in order to prevent tactical controllers from dealing with complex conflicting situations. In this article, we describe an experiment showing that a dynamic conflict display could improve human performance on complex conflict situations. Specifically, we designed a display tool that represents the conflicting portions of aircraft trajectories and the evolution of the conflict zone when the user adds a maneuver to an aircraft. The tool allows the user to dynamically check the potential conflicting zones with the computer mouse before making a maneuver decision. We tested its utility on a population of forty students: twenty air traffic controller (ATC) students at the end of their initial training and twenty engineering students with the same background but no ATC training. They had to solve conflicts involving 2–5 aircraft with a basic display and with the dynamic visualization tool. Results show that in easy situations (2 aircraft), performance is similar with both displays. However, as the complexity of the situations grows (from 3 to 5 aircraft), the dynamic visualization tool enables users to solve the conflicts more efficiently. Using the tool leads to fewer unsolved conflicts and shorter delays. No significant differences are found between the two test groups except for delays: ATC students give maneuvers that generate less delays than engineering students. These results suggest that humans are better able to manage complex situations with the help of our conflict visualization tool.     

Human centered design in the air traffic control system

A review of the current air traffic control system is undertaken from the perspective of human centered design, focusing on the development of today’s system, the problems in today’s system, and the challenges going forward. Today’s system evolved around the operators in the system (mainly air traffic controllers and pilots), rather than being designed based on specific engineering analyses. This human centered focus has helped make air transportation remarkably safe, but has also made the air traffic control system somewhat inscrutable. This opaqueness of how the system operates poses significant problems for current attempts to transform the system into its “next generation” with significantly improved capacity. Research advances in human centered computing research required in order for this transformation work to proceed are discussed, specifically advances in computing the safety of complex human-integrated systems, understanding and measuring situation awareness, and visualizations of complex data.     

Managing safety in the air traffic control terminal airspace

Cognition, Technology & Work - The air traffic control system is designed so that controllers are able to accept aircraft into their airspace and handoff aircraft exiting their airspace with...     

Redesigning air traffic control: an exercise in software design

This case study demonstrates how basic software engineering techniques can make a complex system dramatically simpler. The authors describe lessons learned from reverse engineering an air traffic control system with a variety of tools and redesigning it to be smaller, simpler and more flexible     

Attentional costs and failures in air traffic control notifications

Large display screens are common in supervisory tasks, meaning that alerts are often perceived in peripheral vision. Five air traffic control notification designs were evaluated in their ability to capture attention during an ongoing supervisory task, as well as their impact on the primary task. A range of performance measures, eye-tracking and subjective reports showed that colour, even animated, was less effective than movement, and notifications sometimes went unnoticed. Designs that drew attention to the notified aircraft by a pulsating box, concentric circles or the opacity of the background resulted in faster perception and no missed notifications. However, the latter two designs were intrusive and impaired primary task performance, while the simpler animated box captured attention without an overhead cognitive cost. These results highlight the need for a holistic approach to evaluation, achieving a balance between the benefits for one aspect of performance against the potential costs for another.

Practitioner summary: We performed a holistic examination of air traffic control notification designs regarding their ability to capture attention during an ongoing supervisory task. The combination of performance, eye-tracking and subjective measurements demonstrated that the best design achieved a balance between attentional power and the overhead cognitive cost to primary task performance.     

基于卡尔曼滤波和AHP的航空管制航空器应急指挥效能评估

近年来,航空安全问题引人关注。传统航空应急指挥系统模型建立存在线性信号分析失常、应急指挥模型时效性滞后、空中管制系统信号算法穿透力差等问题,无法满足现代航空安全应急指挥的要求。针对传统航空应急指挥系统存在的问题,提出基于卡尔曼滤波和AHP的航空管制航空器应急指挥系统设计。利用卡尔曼滤波良好的线性分析能力与抗干扰性,结合AHP航空数据分析式,设计出针对性强的航空管制航空器应急指挥系统,并对设计系统进行指挥应用模型的效能评估。评估数据表明,提出的基于卡尔曼滤波和AHP的航空管制航空器应急指挥系统设计满足航空管制应急的使用要求。     

The role of the air traffic controller in future air traffic management: an empirical study of active control versus passive monitoring

Proposals for air traffic management such as Free Flight call for a transfer of responsibility for separation between aircraft from air traffic controllers (ATCos) to pilots. Under many proposals, the role of the ATCo will change from one of active control to passive monitoring. The present study directly compared these types of control with respect to ATCo mental workload, conflict detection, and memory. Eighteen ATCos participated in an air traffic control simulation of Free Flight procedures under moderate and high traffic load. Dependent variables included accuracy and timeliness in detecting potential conflicts, accepting and handing off aircraft, mental workload (as assessed by a secondary task, heart rate variability, and subjective ratings), and memory for aircraft location. High traffic density and passive control both degraded conflict detection performance. Actual or potential applications of this research include the recommendation that designs for future air traffic management keep authority for separation of aircraft with the controller.     

Classification of air traffic control scenarios using decision trees: insights from a field study in terminal approach radar environment

Air traffic controllers are responsible for the safe, expeditious and orderly flow of the air traffic. Their training relies heavily on the use of simulators that can represent various normal and emergency situations. Accurate classification of air traffic scenarios can provide assistance towards a better understanding of how controllers respond to the complexity of a traffic scenario. To this end, we conducted a field study using qualified air traffic controllers, who participated in simulator sessions of terminal radar approach control in a variety of scenarios. The aim of the study was twofold, firstly to explore how decision trees and classification rules can be used for realistic classification of air traffic scenarios and secondly to explore which factors reflect better operational complexity. We applied machine learning methods to the data and developed decision trees and classification rules for these scenarios. Results indicated that decision trees and classification rules are useful tools in accurately categorizing scenarios and that complexity requires a larger set of predictors beyond simple aircraft counts. The derived decision trees and classification rules performed well in prediction, stability and interpretability. Practical benefits can be derived in the areas of operations and system design in the context of air traffic flow and capacity management systems.     

Creative practices in the design studio culture: collaboration and communication

For the purpose of developing collaborative support in design studio environments, we have carried out ethnographic fieldwork in professional and academic product design studios. Our intention was to understand design practices beyond the productivity point of view and take into account the experiential, inspirational and aesthetical aspects of design practices. Using examples from our fieldwork, we develop our results around three broad themes by which design professionals support communication and collaboration: (1) use of artefacts, (2) use of space and (3) designerly practices. We use the results of our fieldwork for drawing implications for designing technologies for the design studio culture.     

An examination of distributed planning in the world of air traffic control

A Distributed Planning System is a network whose nodes represent distinct processors, each cooperating with a selected set of others to achieve a common set of goals. We address two important issues in this paper: (i) How individual processors should be interconnected so that their capacities are fully utilized and their goals can be accomplished effectively and efficiently. (ii) What kind of planning activity the individual processors should engage in. We have chosen the Air Traffic Control (ATC) environment, an intellectually challenging domain of much practical importance, to study different ideas in distributed planning systems. Here we show the results obtained with one type of possible organizational architecture, Location-Centered Cooperative mode of operation. We describe and demonstrate algorithmically a simulation-based planning process based on this architecture. The work described in this paper is part of our continuing effort in examining ways in which greater responsibilities can be delegated to computers in ATC.     

航管仿真训练系统运行控制的设计与实现

描述了对航管仿真系统运行控制机制的设计和实现。先对系统功能做了简要介绍,再从进程组的监控、基于多个队列的进程调度设计等方面介绍了系统的实现过程和处理细节,最后采用负载均衡算法针对系统进行了优化设计。本系统最终实现了对进程实施定位和运行监视,对控制指令采用命令优先级处理机制,使用多个队列调度进程,从而完成训练计划,较好地控制了航管仿真训练系统的运行。     

空中交通管理系统中航迹发散判据及抑制处理

描述了对机动目标跟踪的Kalman滤波方程和空管系统中易于计算的各参数矩阵理论依据及相应的初值,论述了航迹发散的判断依据及抑制算法．结合应用仿真的具体处理算法及步骤,将发散判据和抑制算法应用于空中交通管理系统进行航迹处理．通过项目验证和仿真结果表明,该算法能进行准确的发靓判断和有效的抑制处理．