Forensic's Factual Analysis of the Downing of Flight PS752

Iran’s Accident Investigation Pursuant to the Chicago Convention As the State in which the downing occurred, Iran’s Civil Aviation Organization Aircraft and Accident Investigation Board (AAIB) led the Flight PS752 investigation in accordance with Article 26 of the Convention on International Civil Aviation (Chicago Convention) and its Annex 13. The investigation was to be conducted according to the standards and recommended practices of the International Civil Aviation Organization (ICAO) to identify all relevant causes and contributing factors, and to make safety recommendations in order to prevent similar events in the future. Annex 13 investigations are not conducted with the intent to apportion blame or liability.

The AAIB released five accident investigation reports including the most recent Final Report, which was issued on March 15, 2021 and released publicly on March 17, 2021. Despite its many flaws, from an aviation safety perspective, the Final Report represents Iran’s latest and most comprehensive account of the sequence of events and causal factors that resulted in the downing of Flight PS752.

In Iran’s Final Report, the AAIB acknowledged that the crash was caused by damage to the aircraft from the detonation of the first of two surface-to-air missiles launched from the SAM unit.80 The report also concluded that mitigation measures (intended to protect civilian flights from potential threats from Iranian defence forces) failed to prevent the downing due to the occurrence of “unanticipated errors in threat identification” by the SAM unit.81 Iran’s Final Report suggested that the misidentification of Flight PS752 as a perceived hostile target, and the subsequent launch of missiles at the flight, resulted from the following sequence of events:82 1. The SAM unit was misaligned 105 degrees off north83 due to “human error,” which resulted in the operator observing the detected target direction inaccurately, 2. Defective communication occurred between the SAM unit and the Coordination Center, 3. The SAM operator misidentified Flight PS752 as a hostile target, 4. The SAM operator failed to follow military command procedure for missile launch and fired upon Flight PS752 without approval.

While the airline operator has a role to play in conducting its own risk assessment, Iran’s Final Report placed excessive blame on UIA, suggesting that the airline should have been tracking emerging events from the region through social media and subsequently applying mitigation measures to the flight. Their Final Report later acknowledged that no other airlines with departing flights from IKA on the day of the downing imposed restrictions on their own flights on the basis of a risk assessment.84 Iran’s Final Report also presented an incomplete account of the military sector’s role in events, despite the fact that actions by IRGC personnel were central to the downing and military safeguards were most relevant to protecting civilian aircraft against the risk of misidentification and targeting. Disappointingly, the AAIB states that, in its view, the military’s actions were outside the scope of its investigation.85 The report claims that the investigation of military matters were instead within the purview of the Armed Forces of the Islamic Republic of Iran only.86 The Transportation Safety Board of Canada has stated that it did not agree with Iran’s exclusion of the military’s role in the shoot-down from its Annex 13 investigation.87 30