Regulation (EU) 2015/340 already required the provision of training on the effects and prevention of fatigue as part of the ATCOs’ licensing scheme.

In 2017, mandatory provisions applicable to Air Traffic Service Providers (ATSPs) concerning the prevention and mitigation of ATCO fatigue and stress were introduced with Regulation (EU) 2017/373 and associated Acceptable Means of Compliance (AMC) and Guidance Material (GM).

Five years later, the European Union Aviation Safety Agency (EASA) wished to comprehensively assess how Member States and their ATSPs had implemented these provisions and take stock of the current EU landscape in this field. In this context, it was opportune to collect scientific data and undertake dedicated research to support decision-making on a possible further development of the existing EU regulatory framework on this matter.

The potential impact of new innovative technologies on ATCOs’ occupational health and working conditions also needed to be assessed in the context of the rapid development of automation in ATM/ANS.

In 2022, EASA under tender EASA.2022.HVP.19, commissioned a consortium of researchers and fatigue risk management specialists to complete a first-of-its-kind, independent scientific study into ATCO fatigue in Europe.

Led by the Netherlands Aerospace Centre (NLR) and Welbees with support from CAAi as a consortium sub-contractor, the objective of the research was “to perform a study on the assessment, prevention and management of occupational fatigue risks, as well as related work environment and operational factors, of ATCOs in the EU, in order to support future decision-making of the EU regulator”.

The study set out three objectives:

1. Evaluate how the current EU regulations (EU) 2017/373 and (EU) 2015/340 on ATCO fatigue have been implemented since 2017.
2. Collect scientific data on the prevalence, causes and effects of ATCO fatigue.
3. Assess the potential impacts of future technologies on the ATCO’s workload and fatigue.

The UK CAA, through CAAi, offered advice on ATS and fatigue risk management as well as support in communications and stakeholder management.

Led by NLR and Welbees with technical input from CAAi, a survey on the implementation of EU fatigue regulatory requirements was distributed to 46 ATSPs in EASA Member States, achieving a 78% response rate. With support from UK CAA ATS experts, follow-up interviews were conducted with 22 ATSPs, and additional input was gathered from EU ATCO associations and National Aviation Authorities, alongside extensive desk-based research.

A comprehensive data collection campaign analysed ATCO fatigue, its causes, prevalence, and effects in actual operations:

• 24 rosters from 16 ATSPs were examined, with interviews to gather insights on rostering systems and fatigue management practices.
• Subjective data was collected from 216 volunteer ATCOs at six ATSPs for at least 10 consecutive days using a smartphone app developed by Welbees. Participating ATCOs were asked to record their daily events, including sleep, working sessions, stand-by duties, and non-operational duties.
• Objective data was collected from five ATSPs involving 20 volunteer ATCOs during their actual operational duties in the operations room and control tower. Continuous eye-tracking technology and wearable devices were used to validate subjective data and assess pre- and post-duty performance.

Alongside scientific research, CAAi led the project’s Communications and Stakeholder Management workstream to ensure transparent and effective collaboration with stakeholders throughout the study process. A detailed plan was implemented throughout the project, involving stakeholder webinars, a final dissemination event, and tailored communication materials such as infographics, social media content, and a video to share the findings with the European aviation community.

Evaluation of the implementation of the 2017 Regulations
The study concluded that generally, by 2023, the regulatory requirements have all been implemented in the 46 EU ATSPs, with a low social and economic impact.

Prevalence, causes and effects of ATCO fatigue
The study concluded the prevalence of ATCO fatigue in the EU is low to moderate compared to other relevant sectors, with 5.6% of ATCO duties associated with a critical level of fatigue.

The study identified the main sources of fatigue and provided a ‘fatigue risk index’ attached to each of these main factors.

• Night duties (increases the risk of critical levels of fatigue by 253%)
• Difficult weather conditions (increases the risk of critical levels of fatigue by 192%)
• Monotonous traffic situations (increases the risk of critical levels of fatigue by 120%)
• Sleep debt (increases the risk critical levels of fatigue by 80% for each 10% of sleep debt)
• Maximum time providing services without breaks (each hour increases the risk of critical levels of fatigue by 33%)
• Maximum consecutive days with duties (each additional day increases the risk of critical levels of fatigue by 27%)
• Minimum number of rest periods within a roster (each additional rest period reduces the risk of critical fatigue by 43%)

The study recommended that risks be mitigated in a proportionate and commensurate manner through the implementation of progressive/incremental Fatigue Risk Management measures. It also formulated recommendations and good practices with a set of practical reactive, proactive, and predictive measures to manage ATCO fatigue in the operational environment.

Impact of technology on ATCO’s workload and fatigue
The study identified opportunities as well as risks linked to the introduction of technologies supporting ATCOs in their tasks.

For the full results and recommendations, please visit the EASA study webpage or download the study’s final report. The study results were used by EASA to develop an Action Plan on ATCO Fatigue, which was validated by its Member States.