Canada's Transport Safety Board responded to Iran's final report on the downing of Ukraine International Airlines flight 752.
The board's chair, Kathy Fox, said the report explains how Iran accidentally downed the flight on January 8, 2020, killing all 176 people on board – including 55 Canadians and 30 permanent residents – but not why it happened.
"The report says what happened, but doesn’t address the why," Ms Fox said in a report on Iran’s findings.
Iran's final report blamed the downing of the plane on an air defence unit mistaking the flight as a threat because of a misalignment of the missile launcher’s radar.
“Iran has provided no evidence to support this scenario,” Ms Fox said. “The report does not provide detailed information regarding how the misalignment occurred, nor what steps were taken to ensure it was properly calibrated, the missile operator’s training, experience, or proficiency, nor about how or why the required communications with central command were either not followed or were unsuccessful,” she said.
The board, Canada's air safety investigator, also questioned why commercial airspace was kept open when Iran knew it was on heightened military alert.
The board said the report failed to address adequate safety measures and improvements that could be put in place to ensure such a tragedy does not happen again.
"The report indicates that some unspecified safety actions have since been taken to reduce the risk of this happening again. However, the lack of detail means we can't confirm that these actions will actually reduce the risks to civil aviation operations within Iran's airspace," Ms Fox said.