Iranian Report Details Chain Of Mistakes In Shooting Down Ukrainian Passenger Plane

Human error, a misaligned missile guidance system and a decision to fire without authorization contributed to Iran's downing of a civilian passenger plane in January, according to a new report from Iran's Civil Aviation Organization.

Ukraine International Airlines Flight 752 was shot down shortly after takeoff from the Iranian capital, Tehran, killing all 176 people on board. For several days, no one took responsibility, but signs pointed toward it being struck by a missile. Eventually, Iran admitted it had targeted the plane after mistakenly believing it was a U.S. missile.

"PS 752 was identified by one of the air defense units as a threat and targeted consequently," Iran's accident investigation report says in its introduction, before laying out the pertinent facts. The Kyiv-bound plane received permission from air traffic control to take off from Tehran's Imam Khomeini International Airport. The flight plan was relayed to Iran's air defense coordination center, and the military granted clearance for the plane to depart.

That's when everything went awry. Mistake No. 1: One of Iran's air defense units had been moved — but because of human error, its radar system was never realigned. So when the unit spotted an object traveling on an unknown flight path, the unit didn't realize that it was the Boeing 737-800 that had already gotten clearance.