The Ukrainian Boeing 737 that crashed in Tehran on Jan. 7 was accidentally downed by missile-defense interceptor, according to Hassan Rouhani, Iran’s president. He called it a “disastrous mistake.”
US and Canadian governments had already said their intelligence agencies and space missile detection systems pointed to a Russian-made air defense missile operated by the Iranian military as the cause of Flight 752’s destruction. Media outlets had published videos taken in Tehran that night which appear to show a flying object colliding with the aircraft.
The accidental destruction of the aircraft and the deaths of the 176 people onboard highlight the challenges of managing an undeclared conflict fought with high-tech weapons, and the increasing danger presented to civilians by the spread of missile technology. That terrorist groups have obtained man-operated air defense missiles like the Stinger has worried national security analysts for years, but comparatively less attention has been paid to the spread of more elaborate air defense systems with longer ranges and complex sensor packages.
While airliners rarely fly over explicit war zones, the rise of “gray zone” conflicts like the Middle East proxy war between the United States and Iran lead to scenarios where civilian jets pass near territories where unreliable air defense systems are on high alert. In this case, Iran had just launched a barrage of ballistic missiles against US forces in Iraq, and its defenses were likely on high alert for a potential response. US intelligence sources have claimed that Iran also fired on civilian airliners by mistake, luckily missing, during another period of high tension in 2007 and 2008.
Still, American military officials were surprised that Iranian forces mistook a civilian airliner departing from Tehran for an inbound enemy aircraft or missile, given its speed, heading and the fact that civilian airliners operate on schedules and broadcast their identities on public radio channels.
But such mistakes are hardly unknown in busy airspace where the military relies on remote sensors to identify targets. This week, many recalled the 1988 incident when a US Navy destroyer shot down Iran Air Flight 655 using a surface to air missile after sailors mistook it for a jet fighter. The United States ultimately apologized for the incident and paid the families of the victims a $62 million settlement.
In 2001, Siberia Airlines Flight 1812 strayed too close to Ukrainian-Russian air defense exercises and was shot down by an S-200 long-range anti-aircraft missile launched by the Ukrainian Air Force, killing all 78 people onboard.
More recently, in 2014, Malaysia Airlines Flight 17 was shot down while flying over Ukraine. Independent analysts assembled evidence that it was destroyed by a Russian-built air defense missile, supporting a Russian-backed insurgency against the central government in Kiev. To this day, it’s not clear if the aircraft was downed by mistake or as an act of terror.
Sophisticated air defense systems are getting cheaper and more powerful, and smaller countries purchasing them from manufacturers like Russia or the United States may not have the level of training needed to operate them effectively. Air defense analysts wonder if automated systems in the Iranian air defense systems may have triggered the missile that brought down Flight 752.
Iran says it was at least in part, human. “Human error at time of crisis,” Iran’s Foreign Minister wrote on Twitter “led to disaster.”
Even highly-trained operators of air defense systems make mistakes. During the 2003 invasion of Iraq, US air defenses destroyed two coalition planes with friendly fire, a British Tornado fighter-bomber and an American F-18. In a third incident, a US Patriot missile battery locked onto an American F-16, causing the fighter’s pilot to launch a radar-seeking missile of his own that destroyed the battery.
Update: This item has been updated to reflect Iran’s determination that it shot down Flight 752.