To be sure, the Iranian air defenses were on high alert fearing an American attack in the wake of the U.S. government’s assassination of Soleimani on January 3rd followed by a missile strike from Iran directed against two U.S. bases in Iraq. In spite of the tension and the escalation, the Iranian government did not shut down the country’s airspace. Civilian passenger flights were still departing and arriving in Tehran, almost certainly an error in judgment on the part of the airport authorities. Inexplicably, civilian aircraft continued to take off and land even after Flight 752 was shot down.
What seems to have been a case of bad judgements and human error does, however, include some elements that have yet to be explained. The Iranian missile operator reportedly experienced considerable “jamming” and the planes transponder switched off and stopped transmitting several minutes before the missiles were launched. There were also problems with the communication network of the air defense command, which may have been related.