Guidance

The AAIB’s role in aircraft accident and serious incident investigations overseas

Published 17 June 2025

1. International protocols

The responsibility for conducting an investigation into an aircraft accident or serious incident is laid down in international protocols, specifically the standards and recommended practices defined in Annex 13 to the Convention on International Civil Aviation, Aircraft Accident and Incident Investigation, and published by the International Civil Aviation Organization (ICAO).

This provides that the State of Occurrence is responsible for instituting an investigation.  Where the accident occurs in international waters and therefore outside a contracting State the responsibility then lies with the State of Registry of the aircraft.

If the accident or serious incident occurs in the United Kingdom or one of its overseas territories or crown dependencies, the investigation is conducted by the UK Air Accidents Investigation Branch (AAIB).

For those that occur in other States, the relevant Accident Investigation Authority in that State will conduct the investigation.

2. Accredited Representatives and Advisers

The State of Occurrence is then obliged to notify other States who have rights of participation.  They are:

• State of Registry
• State of the Operator
• State of Design of the aircraft or powerplant
• State of Manufacture of the aircraft or powerplant

These States can then each assign an Accredited Representative who has the right to:

a) visit the scene of the accident;

b) examine the wreckage;

c) obtain witness information and suggest areas of questioning;

d) have full access to all relevant evidence as soon as possible;

e) receive copies of all pertinent documents;

f) participate in read-outs of recorded media;

g) participate in off-scene investigative activities such as component examinations, technical briefings, tests and simulations;

h) participate in investigation progress meetings including deliberations related to analysis, findings, causes, contributing factors and safety recommendations; and

i) make submissions in respect of the various elements of the investigation.

Other States can become involved.  These are:

• State providing, on request, information, facilities or expertise to an investigation
• State providing an operational base for field investigations or involved in search and rescue or wreckage recovery operations (by invitation)
• State of a code-share or alliance partner of the operator (by invitation)

These States can also assign an Accredited Representative, but their participation may be limited to those aspects for which they were invited to participate.

An Accredited Representative is usually from the State’s accident investigation authority. 

The UK Accredited Representative will be an AAIB Inspector of Air Accidents.

The Accredited Representative can then be assisted by Advisers.  These are entitled to participate to the extent necessary for the Accredited Representative to make their participation effective.

Advisers to the UK Accredited Representative will normally include other AAIB Inspectors of Air Accidents but may also include advisers from the regulator (usually the CAA), the operator, the manufacturer, the design organisation and other organisations that may have useful information or expertise.

The Accredited Representative and Advisers are required to provide to the State conducting the investigation all relevant information available to them.

Importantly, they are not to divulge any information on the progress and findings of the investigation without the consent of the State conducting the investigation.

At the conclusion of an investigation the Accredited Representative is entitled to receive and comment on the draft final report through a consultation.  They can use their Advisers as necessary to formulate their comments.  They can also ask for these comments to be appended to the published final report.

3. Experts

Annex 13 includes a standard that for States which have suffered fatalities or serious injuries to their citizens they have certain rights and entitlements and can appoint an Expert.  The function of the Expert is different to that of an Accredited Representative as they would not normally have information available that may directly assist in the investigation.  Their role is however important in providing information to those directly affected by an accident and, as such, an Expert has the following rights:

• visit the scene of the accident;
• have access to the relevant factual information which is approved for public release by the State conducting the investigation, and information on the progress of the investigation; and
• receive a copy of the Final Report.

Despite the term used, this doesn’t give any rights for the “Expert” to participate in the investigation directly nor to receive factual information that is sensitive and not publicly released.  Also, the Expert is not entitled to receive copies of draft reports nor provide any commentary. 

The onus for providing information on the progress of the investigation and release of information lies with the State conducting the investigation. 

However, this does not preclude the Expert from assisting the families of the victims and meeting with them to explain the process and explaining or clarifying what can be quite technically complex information when it is released.

In the UK, irrespective of whether the AAIB has been granted Accredited Representative or Expert status, the AAIB will provide information to UK victims and their families within the limitations of the rights of participation and the availability of information from the investigating State.  This includes supporting any related UK Coroner’s Inquests or Fatal Accident Inquiries. 

The AAIB typically provides Accredited Representatives or Experts to about 50 – 100 overseas investigations a year.