Wreckage from the Boeing 737-800 flying Ukraine International Airlines Flight 752 is clearly visible on the ground on outskirts of Tehran after being hit by two surface-to-air missiles.

Iran provides more details on the shootdown of Ukraine International Airlines flight 752 on 8th January, but questions remain unanswered.

Serious lapses in radar and communications protocols are blamed by the Iranians. Nonetheless it is unclear why measures such as correct Identification Friend or Foe (IFF) measures and Automatic Dependent Surveillance-Broadcast data do not appear to have been used to confirm whether or not the aircraft was hostile.

CAO Report

Iran’s Civil Aviation Organisation (CAO) has made public some of the findings of its inquiry into the destruction of a Ukraine International Airlines 737-800 bound for Boryspil International Airport in Kiev. The aircraft was shot down by an Almaz-Antey 9K330 Tor (NATO reporting name SA-15 Gauntlet) short/medium range air defence system belonging to Iran’s Islamic Revolutionary Guard Corps (IRGC) shortly after its departure from Tehran’s Imam Khomeini International Airport causing the loss of all 208 onboard.

The CAO’s report published on 10 July blamed the accident on a misaligned radar system, presumably referring to the ‘Scrum Half’ C-band (5.25 gigahertz/GHz to 5.925GHz) and Ku-band (13.4GHz to 14GHz/15.7GHz to 17.7GHz) fire control radar? Alongside the radar, the report blamed a lack of communication between the 9K330 battery and higher echelons of command citing “a mistake in aligning the radar system.” It continued that “an operator had forgotten to re-adjust the direction on the radar system after moving to a new position, an error that contributed to misreading the radar’s data.” It seems that the radar operator had failed to calibrate their system correctly as the battery was being activated which sounds like a serious training error.

Armada published an analysis of possible explanations for the jet’s destruction. We blamed a lack of training as one potential factor, along with a lack of communication, not only with higher echelons of command, but also with local Iranian Air Traffic Control (ATC) authorities, and the aircraft itself; all of which could have established that the target was an airliner. Tellingly, the report states that missiles were fired without authorisation from higher levels of command. This indicates both lackadaisical command and control structures and the dangers of keeping ground-based air defence systems on a hair trigger.

As mentioned in our original article, tensions were running high in Iran. On 3rd January the US had killed General Qassem Soleimani, commander of the IRGC’s Quds Force, an insurgent organisation. Gen Soleimani met his end following an attack by a US unmanned combat aerial vehicle which bombed his vehicle convoy as he left Baghdad International Airport. The Iranian government retaliated earlier the same day the 737-800 was lost with Fateh-313 and Qiam short-range ballistic missiles hitting the US military presence at Al Assad airbase in western Iraq and at an airbase near Erbil in northern Iraq, although with no US casualties. Iranian air defenders would have been on high alert for possible US retaliation in the aftermath of the missile attack. However, we also emphasised that those same air defenders should have been sufficiently trained to perform their craft under high stress conditions where normal air traffic is present. Clearly, they were not.


Despite the welcome move of Iran’s CAO shedding some light on what went wrong that fateful morning, several questions remain unanswered: As we asked in our earlier article, why had the target not been flagged as friendly by the IFF (Identification Friend or Foe) interrogator equipping the 9K330’s radar? IFF data would have acted as a useful ‘second pair of eyes’ potentially resolving anomalies or uncertainties depicted by the 9K330’s radars. The IFF should have been capable of receiving the standard civilian transponder squawks transmitted by the airliner to ATC Secondary Surveillance Radars (SSRs) within range which the ill-fated airliner would have been transmitting. Anecdotal evidence shared with Armada noted that the 9K330’s IFF interrogator maybe basic at best, and only tuned to receive IFF transmissions from friendly aircraft. Such a process potentially depicts all aircraft not squawking those IFF codes as hostile. The potentially devastating consequences of such IFF protocols are clear. Moreover if the IFF had been unserviceable or switched off yet the battery still online, this would have been a serious dereliction of duty by the battery personnel, particularly when operating in an environment where civil aircraft were continuing to fly as normal. A battery with an unserviceable IFF should have been taken offline immediately until this was repaired.


Finally, it is known that the airliner was transmitting its identity and flight information using its internationally-mandated Automatic Dependent Surveillance-Broadcasting (ADS-B) transponder. This uses frequencies of 1.090GHz and 978 megahertz to carry this information across standard SSR frequencies and via satellite communications. The very fact that the jet’s flight could be followed using ADS-B shows that the air defenders perhaps had no access to ADS-B tracking software. Why they had no access to ADS-B information is unclear. Such data are easily available even via standard websites such as Flightradar24 which routinely presents ADS-B information for flights around the world. Not having the ability to easily see ADS-B data, even on a standard laptop connected to the internet, correlating that with radar data at the 9K330 command post, or having such data available to a higher echelon to warn the battery of a potential target’s identity before the trigger is pulled was another glaring failure.

Unanswered questions

The admission of training and communications errors by the CAO goes some way to explaining why things went wrong on the outskirts of Tehran early in the morning on 8th January. Yet correct IFF protocols and supplementing radar data with ADS-B information may have helped to avoid this tragedy. Why these measures do not seem to have been used remains unknown.

by Dr. Thomas Withington