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Status and next steps in the PS752 safety investigation

Gatineau, Quebec, 23 January 2020  — The Transportation Safety Board of Canada (TSB) is committed to keeping Canadians, particularly the families and loved ones of those killed in the downing of  Ukrainian International Airlines flight PS752, informed of its activities in support of the Iranian-led safety investigation as soon as, and to the greatest extent, it can.

The TSB’s two investigators have completed their work in Tehran and Kyiv and will soon be heading home to Canada.

Investigation activities to date

As previously indicated, two TSB air accident investigators spent 6 days in Tehran, where they had several meetings with officials from the Aircraft Accident Investigation Bureau of the Islamic Republic of Iran (AAIB), visited the accident site, and examined the wreckage, which is secured in a separate location. The AAIB was cooperative and helpful in its interactions with the TSB investigators.

This week, the TSB investigators spent two days in Kyiv for joint meetings with the AAIB of Iran and the National Bureau of Air Accidents Investigation of Ukraine NBAAI, during which they continued to share information regarding the investigation. In particular, an assessment is underway regarding the feasibility of downloading the aircraft flight data and cockpit voice recorders in Ukraine.

Next steps: Flight data and cockpit voice recorders

The TSB understands that the aircraft’s flight data and cockpit voice recorders—the “black boxes”—are still in Iran, and that Iran is assessing options for their download and analysis, including doing it in Iran. The TSB has been invited to participate in the download and analysis of the recorders and will deploy a second team of investigators who specialize in aircraft recorder download and analysis wherever and whenever that activity takes place.

This safety investigation doesn’t end with the downloading of these recorders. While this activity may provide additional critical data, there is much more analysis required of all the information gathered in order to determine the many factors that caused or contributed to this accident.  

Other information

Annex 13 safety investigations, and investigations by other organizations

The purpose of a safety investigation conducted under Annex 13 to the Convention on International Civil Aviation, governed by the International Civil Aviation Organization (ICAO), is to find all causal and contributing factors to an accident, without attributing blame or civil or criminal liability. This allows the focus to be placed on addressing safety deficiencies, and on preventing similar accidents from happening again. Experience has shown that a thorough safety-focused independent investigation offers the best chance of confirming what really happened and providing the answers that everyone is asking for, particularly for the families who lost so much.

The TSB is pleased that ICAO has accepted an invitation from the government of the Islamic Republic of Iran to provide expert advice in support of the safety investigation of the aircraft accident involving PS752. 

Other organizations may also be conducting their own investigations into this accident, and for different purposes—including, for instance, judicial proceedings. To be clear, that kind of investigation is outside the TSB’s mandate, and Annex 13 expressly provides for the separation of these investigations.

Canada’s status under Annex 13 to the Convention on International Civil Aviation

In accordance with Annex 13, Iran is the State of Occurrence, and consequently the AAIB of Iran is leading the investigation into the accident. The role of other involved States is similarly prescribed by Annex 13.

Because so many Canadians died in this accident, Annex 13 entitles the TSB to appoint an Expert. In this role, we are entitled only to visit the accident site, have access to the relevant factual information approved for public release by the AAIB, monitor the progress of the investigation, and receive a copy of the final report (see the Backgrounder).

The AAIB has permitted the TSB to participate in the investigation to a greater extent than this by inviting TSB investigators not only to view the scene of the accident but also to examine the wreckage and participate in the download and analysis of the recorders, whenever and wherever that will occur.

The TSB continues to pursue increased involvement in the safety investigation by seeking status as an Accredited Representative (section 5.25 of Annex 13; see the Backgrounder). Accredited Representative status would entitle the TSB to participate in all aspects of the investigation, under the control of the AAIB’s investigator-in-charge. This would mean, among other things, that the TSB could suggest areas of enquiry and have full access to relevant data.

Adding Canada’s world-class expertise in independent air transportation safety investigation to this international effort would mean a lot to those affected by this tragedy, whether in Canada, in Iran, in Ukraine, and around the world. It could become a significant example of cooperation in the aviation industry on the world stage.

Limitations on information-sharing during the safety investigation

Regardless of TSB’s status in the investigation, we must emphasize that, under Annex 13 of the Convention on International Civil Aviation, the TSB is not allowed to release any information regarding the progress or results of the investigation without the permission of the AAIB of Iran.

The TSB must, and will, respect the limitations on its role in this foreign investigation.

We will therefore continue to make public only the information that we can validate and that we are allowed to release. Doing otherwise would undermine our relationships with our international partners.


The TSB has not released the identities of its investigators in order to protect their and their families’ privacy, as well as to facilitate security arrangements while they were overseas. The TSB will continue to maintain the confidentiality of its investigation team until further notice.

Possible delays in other TSB investigations

Given the significant resources that the TSB is dedicating to this investigation, there have been questions about its effect on our other investigations. The TSB will carry out its mandate, responding to transportation occurrences as it always does, but we will have to adjust resources and timelines for some ongoing investigations.

Next update

At this time, there is no new factual information to report with respect to the TSB’s deployment to Tehran and Kyiv. We will provide further updates as and when we can. Specifically, we will notify the public of any change in our status under Annex 13, or when there is news regarding the deployment of our specialists to participate in the download and analysis of the recorders.

In the meantime, any further questions about the progress of this safety investigation, or the TSB’s role, should be directed to the TSB.

The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.

For more information, contact:
Transportation Safety Board of Canada
Media Relations
Telephone: 819-360-4376