Conduct of a safety investigation


Every investigation conducted by the AAUI(Be) goes through a number of steps or phases: 

  • notification 
  • data collection and evaluation 
  • further investigation and analysis 
  • producing of report 
  • publication and follow-up of safety recommendations 

However, these are not always delineated and may well be intertwined. 


The start of an investigation begins with reporting the incident to the AAIU(Be). The sooner the AAIU(Be) is notified, the sooner we can begin collecting data and evidence. 

Data collection and evaluation. 

An evaluation then follows based on the initial data. This way we decide whether to actually launch an investigation. If necessary, a team goes immediately to the scene to make initial determinations. This phase is then sometimes called the field phase. The most important activities immediately after an accident are recording the situation at the scene and taking statements from those involved and witnesses. 

At the accident site, investigators have broad powers. Among other things, they are authorized to inspect records and documents and may make copies of them. Investigators can also retain custody of audio and visual material, data files, (parts of) equipment, wreckage, etc., at the scene. 

Further investigation and analysis 

The data collection phase is followed by a phase of further investigation and analysis: analysis of materials, flight data, video images, model calculations, reconstruction and simulation ... Depending on the specifics, parts of this are outsourced to specialized labs or research bodies of other countries. 

Drawing up the report 

In the next phase of an investigation, the AAIU(Be) prepares a draft final report. This draft report contains a description of the event, an analysis of the causes, a listing of the main conclusions and any safety recommendations. 

A safety recommendation is a proposal made by a safety investigation authority, based on information from an investigation or study. Its sole purpose is to prevent accidents or incidents and reduce the consequences of such occurrences. The recommendation is independent of any judicial investigation and does not include any judgment of blame or liability. Nor does it reflect the degree of contribution to a specific accident or incident. 

The draft report is submitted to key stakeholders for review for factual inaccuracies or ambiguities. 

Publication and follow-up of safety recommendations 

In the final stage of the investigation process, the AAIU(Be) adopts the final report for publication. The final reports do not include the names of the individuals involved to ensure their anonymity and to comply with regulations on the non-disclosure of certain information. All reports are available on the website.


The purpose of a safety investigation authority is to improve aviation safety worldwide. We do this by identifying the causes of accidents and serious incidents in civil aviation and making safety recommendations to prevent recurrences. Safety recommendations are the means by which a safety investigation authority shares its concerns about safety deficiencies identified during an investigation or analysis of aviation safety information. 


Recommendations are addressed to the agencies responsible for the domain within which the safety issue was identified by the investigators. The addressees are not legally required to follow these recommendations and decide what actions to take. However, they are required to respond within 90 days to indicate whether and in what way they follow the recommendation. Even if they take no actions, they must notify the safety investigation authority, along with the reasons for doing so. 

Within 60 days of receiving the response, the AAIU(Be) will inform the addressee whether or not it is satisfied with the response and why, if they differ on the decision not to take action. 


Follow-up is maintained in the Safety Recommendations Information System (SRIS), the European central database for safety recommendations in civil aviation. With this, the AAIU(Be) tracks the progress of their recommendations and publishes their status, including whether their implementation is considered closed and acceptable. 

Recommendations at any stage 

By the way, the AAIU(Be) does not have to wait to make recommendations until the report is published. If it already becomes clear during the investigation that something needs to be done quickly, the AAIU(Be) can issue a recommendation so that preventive measures are already taken.