Introduction to Accident Investigation

Introduction to Accident Investigation


The sole objective of the investigation of an accident or incident shall be the prevention of accidents and incidents. It is not the purpose of this activity to apportion blame or liability. (ICAO Annex 13, Aircraft Accident and Incident Investigation)


International Civil Aviation Organisation (ICAO) Annex 13, Aircraft Accident and Incident Investigation, details the international Standards and Recommended Practices (SAPRS) for the investigation of accidents and incidents, including which States may participate, and the rights and responsibilities of those States.

The States that generally are entitled to participate in an investigation include the State of the aircraft operator, the State where the accident aircraft is registered, the State of aircraft design and aircraft manufacture, and a State that has a special interest in the accident, such as because of fatalities or serious injuries to its citizens.

Aircraft accident investigations generally, but not always, are conducted by the State in the which the accident occurs (the State of occurrence), regardless of whether the accident aircraft is registered in that State or was operated by an airline registered in that State. This requirement is stipulated in Article 26 of the Convention on International Civil Aviation (the Chicago Convention), which says that “in the event of an accident to an aircraft of a Contracting State occurring in another Contracting State, and involving either death, serious injury, or serious technical defect in the aircraft or air navigation facilities, the State in which the accident occurs will institute an inquiry into the circumstances of the accident.”

The State of occurrence may delegate all or part of the investigation to another State or a regional accident and incident investigation organization and may also call on technical expertise from any source to assist with the investigation.

Accident investigations are carried out in accordance with national regulations, which are governed by Annex 13, if the country is a signatory to the Chicago Convention.

Annex 13 contains numerous definitions, including exactly what is considered an Accident, Serious Incident, and Serious Injury.

Under terms of Annex 13, the accident investigation authority “shall have independence in the conduct of the investigation and have unrestricted authority over its conduct, consistent with the provisions of this Annex.”

The investigation should include the gathering, recording and analysis of all available information; the issuance of safety recommendations, if appropriate; the determination of the causes, if possible; and the completion of a final report.

Further Reading

  • ICAO Annex 13, Aircraft Accident and Incident Investigation
  • ICAO Doc 9756, Manual of Aircraft Accident and Incident Investigation
  • ICAO Doc 9946, Manual on Regional Accident and Incident Investigation Organization
  • ICAO Doc 9962, Manual on Accident and Incident Investigation Policies and Procedures
  • ICAO Doc 9973, Manual on Assistance to Aircraft Accident Victims and their Families

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