top of page



Air Accident and Incident Investigation Group of Experts (ACC)

The involvement of the ECAC Group of experts on air accident and incident investigation (ACC) in the international development of the organisation of accident and incident investigations dates back to ICAO's Accident Investigation Divisional meeting in 1992, and has continued ever since. It serves as a think-tank for European Safety Investigation Authorities (SIAs) and contributes to the thinking behind some initiatives planned at the European level.

A key focus of ACC activities is the exchange of experience in methods of investigation, the evolution of investigation techniques and tools and the challenges encountered during investigations. These exchanges happen formally through meeting presentations and discussions, and can include a host country's briefing on its organisation, reports on recent investigations and updates on latest experiences or developments. The development of cooperation in Europe was a natural extension of these contacts.

ACC Code of Conduct on Cooperation in the Field of Accident/Incident Investigation

In December 2016, ACC released an updated version of its Code of Conduct on Cooperation in the Field of Accident/Incident Investigation, originally opened for signature by heads of the accident investigation bodies in April 2006. As of 15 December 2022, 38 out of 44 ECAC Member States signed the Code of Conduct.

ACC guidance documents

In November 2012, ECAC published Guidance on the Underwater Location and Recovery of Aircraft Wreckage and Flight Recorders. Reflecting on the learning gained from the two workshops mentioned above, this guidance addresses the issues peculiar to underwater location and recovery operations, including the expertise, procedures and equipment needed to mount an effective response to an accident of this kind.

A major outcome of the May 2014 Workshop on the Investigations in Extreme and Challenging Environments was the publication in October 2015 of ECAC Guidance for Investigations in Extreme and Challenging Environments, now available for free on this website.

In 2020, ACC developed the ECAC ACC Guidance Note on Conducting Investigations during a Pandemic, due to the challenges faced for air accident investigations during the COVID-19 pandemic, as well as the General Aviation Accident Investigation: Summary paper and best practices, developed following the ACC workshop on general aviation incident investigation held in Valletta (Malta) on 13 November 2018. These proposals was approved by the ACC group in December 2020 and endorsed by Directors General in January 2021, both through a written consultation.

ACC workshops

ACC also organises workshops on issues of common interest to Europe's accident investigators.

These have included a seminar in Tallinn (Estonia) in 2000 on the needs of victims and their families, a workshop in Nicosia (Cyprus) in 2002 on the organisation of investigation bodies, one in Bucharest (Romania) in 2005 on communication following an accident, and one on the drafting and issuing of safety recommendations, in Athens (Greece).

In 2009, in close cooperation with the Croatian authorities, ECAC and the French Bureau d'Enquêtes et d'Analyses (BEA) organised a three-day workshop in Dubrovnik on the underwater recovery of aircraft wreckage and flight recorders, which included a day at sea practising location and recovery techniques. Given the interest triggered by this workshop, it was followed up the next year with a second one in Larnaca (Cyprus) focusing on underwater recovery operations.

Accident and incident investigation was also on the agenda of a joint ECAC/FAA workshop held in Istanbul (Türkiye) in 2013. Focusing on best practices in three key areas of aviation safety, the workshop discussed, inter alia, developments in new oversight systems such as continuous monitoring and regional oversight, collaboration in identifying safety risks and solving them, and the role of incident investigation in aviation safety. 

A workshop was held in May 2014 in Lucerne (Switzerland) on the subject of investigations in extreme and challenging environments. This workshop attracted the support of speakers from several parts of the world, involving experts who had conducted investigations in conditions of snow and ice, jungle, mountains and deserts as well as politically and culturally challenging circumstances. It also led to the issuance of Guidance on the Underwater Location and Recovery of Aircraft Wreckage and Flight Recorders (2015).

In 10 May 2016 in The Hague (Netherlands), ACC organised a workshop on social communication associated with the air accident investigation process. Participants examined issues including the impact of social media on the investigation, best practices for developing communication plans, finding the balance between the need to inform and the need to maintain the integrity of an investigation, communication with the families of the victims and managing media expectations. 

The ACC workshop held in Valletta (Malta) on 13 November 2018  looked at the investigation of general aviation accidents within the ECAC Member States and observer States. In particular, it focused on the potential for increased cooperation or technical assistance among safety investigation authorities.

An ACC workshop dedicated to unmanned aircraft systems (UAS) investigations was organised by videoconference on 13-14 October 2021. The workshop covered the main topics of UAS investigations, including the applicable regulatory framework, the investigation process (e.g. when should a SIA investigate a UAS accident or incident) and related challenges, the development of UAS investigation capability (including training requirements for investigators), the improvement of safety in the UAS sector, and the use of drones to support investigations.

The latest ACC workshop focused on the treatment of serious investigations and was held in Bratislava on 25 April 2023. Participants benefited from informative presentations, engaging case studies, and fruitful discussions on the importance of improving communication between various stakeholders involved in safety investigations, as well as the need for facilitating data sharing and analysis to enhance the effectiveness of safety investigations. The meeting served as a platform for participants to share their experiences and perspectives and develop best practices on the classification of serious incidents and make informed decisions on safety investigations.

bottom of page