An initial report into the shooting down of a Ukraine International Airlines Boeing 737 soon after takeoff from Tehran on January 8 has implicated incorrect changes to the alignment of Iranian air defense systems and a failure by military personnel to follow correct procedures. The factual report, issued by the Civil Aviation Organization of the Islamic Republic of Iran (CAO-IRI) on July 11, confirmed that two surface-to-air missiles destroyed the aircraft just over two hours after military officials instructed civilian air traffic controllers that airline departures would require clearance from military authorities.
All 176 people on board flight PS752 were killed when the aircraft was shot down around five minutes after takeoff, despite the fact that its departure from Imam Khomeini International Airport had been cleared by the Air Defense Coordination Center. According to the report, a sequence of errors was triggered by a failure to take account of the recent relocation of one of the air defense units near the Iranian capital, which resulted in a 107-degree discrepancy in how military radar tracked the aircraft. That resulted in military personnel mistaking the departing airliner for what they assumed to be a hostile military aircraft or missile heading towards Tehran.
The CAO-IRI’s initial investigation also found that the person operating the air defense unit fired the first missile despite not having received confirmation from the military coordination unit that the target should be engaged. This was a breach of Iran’s military procedures for its air defense system.
Investigators have yet to determine definitively which of the two missiles caused the aircraft to crash. They did confirm that the 737’s transponder was functioning correctly and that ADS-B signals were received by the air traffic control system.
CAO-IRI indicated that further investigations will continue, with the report mentioning the possibility of criminal prosecutions resulting from the incident. According to Iranian state news agency IRNA, the aircraft’s flight and voice data recorders are due to be sent to be examined by France’s BEA accident investigation team, which has been leading the international cooperation with CAO-IRI due to the lack of diplomatic relations between Iran and the U.S.