Design, evaluation and acceptance of a visual support tool for air traffic control (CDI thesis version)

Abstract

This study has researched what are defining factors on the attitude toward a new technology within the group of Area Control (ACC) at Luchtverkeersleiding Nederland (LVNL) and how these factors shape an Air Traffic Controller’s (ATCo) attitude toward the technology in an exploratory way. The outcomes of the research suggest that dominant factors are result demonstrability, output quality, job relevance, subjective norm and (timeliness of) involvement in the development process. First, the work domain of air traffic control and the functioning of holding patterns were researched and a description of these things was given, based on interviews with air traffic controllers and on literature. It was found that the largest challenge when holding at LVNL is adherence to Expected Approach Time (EAT), and that this is caused by two things: the first is a lack of accurate and integrated information on the impact of a control decision on EAT adherence, the second is that current practice of ATCos is to aim for a 2:00 minute deviation from the EAT, which is the current error margin they are allowed to operate on. It was found, based on interviews with two professional area controllers and one other expert from LVNL, that in current practice an ATCo makes estimations of when to give a turn-to-IAF command based on a rule of thumb with a holding loop timing of four minutes and by extrapolating the history dots of the aircraft. However, analysis of historical holding pattern data shows that lap times often take six or seven minutes and that wind severely influences the in- and outbound ground speeds, making both the four-minute loop time and history dot extrapolation unreliable estimators. A support tool was designed that gives a prediction of the time it takes to reach the IAF from different locations, taking into account aircraft characteristics and wind. The new tool was designed such that it is in accordance with the layout and style of present LVNL systems. It involves two things. First, a prediction of the EAT adherence error upon giving an immediate turn-to-IAF command in the form of a delta-T in the aircraft label. Second, and a prediction of the turn-to-IAF locations at which an EAT adherence error of +120s, +110s, ..., 0s, 10s, ...-120s will be achieved, in the form of colored dots (ECOL dots) on the vertical view and the top view radar screen. The social situation at LVNL was described based on interviews with two professional area controllers and one other expert from LVNL. Indications were found for two opposite things. On the one hand, that (some) ATCos are willing to innovate and actually take initiative in innovation processes, and on the other hand, that (some) ATCos have a strong resistance toward technological system innovation. Regarding collaboration between groups, itwas found that the relation between ACC and Approach Control (APP) that is characterized by skepticism on the skills of the other party. Finally, it was found that ATCos take pride in the way they execute their job and are willing to work hard to achieve the goals they believe match their job description. In doing this, ATCos have indicated to value their autonomy and the idea that the effort they put in actually adds value for the full Air Traffic Control (ATC) process. Besides interviews to describe the situation at LVNL, case studies were done to research innovation in other organizations that showed similarities to the context of LVNL. Three things were found. First, ensuring people can contribute and influence the innovation from early stages of the innovation process is a promising factor that seems to influence a person’s attitude toward using the innovation in a positive way. Second, the lack of implementation of innovations has caused skepticism under ATCos. Third, the TAM is a suitable framework to further explore how area controllers at LVNL’s attitude toward innovations manifests itself. To be able to use the TAM in the framework, first, literature on the TAM has been reviewed. It has been found that there are different versions of the TAM that include or exclude several variables. For the present research, the most suitable version of the TAM was determined to be the TAM2, using the following external variables: result demonstrability, output quality, job relevance, image, subjective norm, experience, voluntariness, age. Next to the TAM in the framework, literature was reviewed on several factors surrounding the interaction with support systems, where autonomy and trust were found to be of a valuable contribution to the framework in the present research. The operationalization of the framework was done using survey questions, a semi-structured interview, and results from letting ATCos interact with the system innovation concept (the tool). It was found that some factors of the TAM could be questioned straightforward in either the survey or the interview, while for other factors it was necessary do design multiple questions and depend on the type of answers given by the participants. Since the research is exploratory, it was decided to keep the interview setup semi-structured to ensure participants would be able to outline defining factors for their attitude toward innovation relatively freely, instead of needing to keep them within a predefined set of factors. From the performed case study, where 10 ATCos participated in an experiment in which they had to manage two holding scenarios, with and without the tool, the following things were learned. First, three of the external variables defined in the framework played the largest role for participants’ perceived usefulness of the tool were result demonstrability, output quality and job relevance. Second, it was found that subjective norm impacts the attitude towards use for the participant group. A mismatch was found between the participants’ attitude toward innovation in general and the way the participants thought their colleagues viewed system innovations. Subjective norm was also found to be of influence on the participants personal objective in the level of EAT adherence they aim to obtain in their day-to-day work. Third, participants linked the external variables not only toward perceived ease of use and perceived usefulness, as is the case in the TAM, but also to attitude towards use. Finally, it was found that participants appreciated being part of an innovation process rather than being presented with the final solution, which was further improved by the fact that the concept was visibly not perfected yet (even though it was functioning, it was clear it was still under development and showed some minor issues in e.g., the stability of the computer program).