Iranian authorities say a misaligned missile battery and miscommunication between soldiers and superior officers were to blame for the January downing of a Ukrainian jetliner that killed 176 people.
The conclusions by Iran's Civil Aviation Organization were detailed in a new report released late on July 11.
Ukrainian International Airlines Flight 752 was struck by two missiles and crashed shortly after taking off from Tehran's main airport on January 8.
The disaster happened the same night that Iran launched a ballistic-missile attack that targeted U.S. soldiers in Iraq.
That attack was in response to an American drone strike that had killed the powerful commander of Iran's Revolutionary Guards Corps, Major General Qassem Soleimani, in Baghdad five days earlier.
"A failure occurred due to a human error in following the procedure" for aligning the radar, causing a "107-degree error" in the system, the Civil Aviation Authority said in its report.
The authority said the document was a "factual report" and not the final report for the accident.