All occurrence investigations progress through a series of phases in accordance with the ATSB’s investigation methodology to ensure a rigorous and comprehensive investigation report with evidence-based findings that lead to improvements in transport safety. 

Evidence collection  

During the evidence collection phase investigators build a detailed picture of the occurrence or safety issue being investigated. Evidence gathered may include: 

  • site observations and mapping, including recording wreckage distribution and witness marks 

  • relevant components and wreckage, materials and recorded data (including on-board flight, voyage and event recorders, GPS, images, video, system equipment data, and voice recorders) for subsequent analysis 

  • human performance information such as work and rest patterns and time awake, workload, perceptual limitations, communications, and social norms 

  • testing or procuring test and examination reports such as fuel quality-tests, toxicology, functional tests, manufacturer’s test procedures, simulation studies, meteorological analyses 

  • interviews with involved parties, witnesses and subject matter experts 

  • operational records such as logbooks, technical logs, maps or charts, trip reports, weather observations, job sheets, repair records, training records and performance checks, and audit reports 

  • technical documentation such as procedures and manuals, training manuals, maintenance manuals, troubleshooting guides, design drawings and system safety assessments, and 

  • data on similar occurrences in Australia and overseas and other occurrence data. 

Examination and analysis 

ATSB investigators aim to use the collected evidence to build a detailed understanding of the circumstances surrounding a transport safety occurrence or issue. 

During this phase, evidence is reviewed and evaluated to determine its relevance, validity, credibility and relationship to other evidence and to the occurrence. ATSB investigators may: 

  • undertake detailed data analysis 

  • create simulations and reconstruct events 

  • examine company, vehicle, regulator and other records 

  • examine wreckage and test components and system in the ATSB’s technical facilities  

  • research scientific literature related to human factors associated with the evidence 

  • review specialist reports (such as meteorology, component examination, post-mortem report and toxicology reports) 

  • conduct further interviews, and 

  • determine the sequence of events. 

Examination and analysis requires reviewing complex sets of data, and available evidence can be vague, incomplete and or contradictory. This may prompt the collection of more evidence, which in turn needs to be analysed and examined, potentially adding to the length of an investigation. 

Once the examination of the evidence is complete, the investigation team will test a series of hypotheses to arrive at a number of safety factors that could have contributed to the transport safety occurrence or issue, or otherwise increased safety risk.   

The investigation team then convenes a Safety Factor Review with ATSB management. This is a rigorous internal review of the progress of the investigation, its preliminary findings and focus. The Safety Factor Review involves the investigation team presenting their evidence and analysis to reach consensus on the investigation findings. Once consensus is achieved, the report drafting phase of the investigation can begin. 

Final report: Drafting

Most ATSB reports contain the following sections: 

  • Executive summary—a one-page summary of the transport safety occurrence, the findings and any safety action taken as a result, as well as any broader safety messages.   

  • The occurrence—a description of the sequence of events related to the occurrence and, if relevant, the consequences in terms of injuries and damage. 

  • Context—of evidence collected as part of the investigation that is necessary to help the reader understand the occurrence and safety analyses, or the broader safety issues for research purposes. 

  • Safety analysis—a demonstration of how the evidence justifies the investigation findings 

  • Findings—a list of contributing factors and other safety factors identified during the safety analysis. 

  • Safety issues and actions—a summary of safety issues that were identified during the investigation and details of what safety action has been taken, or is planned to be taken by relevant parties to address those issues. 

During the drafting of the report it may be necessary to return to the evidence collection or examination and analysis phases of an investigation. There will often be significant overlap in time between the evidence collection, examination and analysis and final report drafting phases. 

Final report: Internal review 

Final ATSB investigation reports undergo a rigorous internal review process to ensure the report adequately and accurately reflects the evidence collected, analysis, and agreed findings of the Safety Factor Review. Final investigation reports also undergo other technical and administrative reviews to ensure the reports meet national and international standards for transport safety investigations. 

If a review identifies any issues with a report, such as information that needs to be expanded or findings that need to be modified, investigators will look to collect new evidence or conduct additional examination and analysis of existing evidence. 

Final report: External review

To check factual accuracy and ensure natural justice, Directly Involved Parties (DIPs) are given the opportunity to comment on the final report before it is approved to ensure their input to the investigation has been accurately reflected. 

DIPs are individuals or organisations outside the ATSB who possess direct knowledge of the circumstances surrounding the incident or accident.   

Draft reports are provided to DIPs under Section 26(1)(a) of the Transport Safety Investigation Act 2003. Under Section 26, the report may only be copied and disclosed for the purpose of taking safety action or providing comment to the ATSB. Anyone who receives a copy for these purposes is also bound by the confidentiality requirements. 

Disclosure of the draft report in any other circumstance may constitute a criminal offence. 

ATSB draft reports may contain information that is subject to change as a result of internal and external review and consideration of further evidence. In its draft form, copying or disclosing the report may unjustly affect reputations. This in turn could potentially impede and discourage the crucial, future free flow of safety information to the ATSB. 

The external review process is consistent with international transport safety investigation conventions, including those published by the International Civil Aviation Organization, International Maritime Organization as well as the Transport Safety Investigation Act 2003. DIPs are provided from five to 28 working days to provide their comment and present evidence in support of their comments. This timeframe can be extended to allow DIPs based overseas to provide comment. 

Final report: Approval

Following the external review process, the report is approved by management before being sent to the ATSB Commission for final approval. Once approved, the final report is prepared for publication and dissemination and released to DIPs prior to its public release. 

Final report: Dissemination

Once an ATSB report is approved, it is prepared for public release and approved safety issues and recommendations are formally communicated to the relevant parties. The report is then released publicly on the ATSB website and shared on social media, to ATSB subscribers via email and with the media. The progress of safety action to address ATSB recommendations is tracked and communicated, on an ongoing basis, via the ATSB website.