The organization said in a statement issued late Saturday that a failure in the mobile air defense system occurred due to a human error in following the procedure for aligning the radar.
The statement noted that this error "initiated a chain of hazards," adding that due to radar misalignment, the air defense unit's operator misidentified the passenger plane as a military target approaching Tehran from Southwest.
Elsewhere in the CAOI's statement, the body said the first of the two missiles launched at the aircraft was fired by an air defense unit operator who had acted "without receiving any response from the Coordination Center" from which he was commanded.
The report continued that the second missile was fired 30 seconds later when the operator "observed that the detected target was continuing on its flight trajectory."
In relevant remarks, Iranian Deputy Foreign Minister Mohsen Baharvand announced on June 28 that his country will lead the specialized team of aviation investigators tasked with decrypting and analyzing the black box data of the Ukrainian plane which was downed due to a human error early in 2020.
"The Islamic Republic of Iran's team of experts and specialists will lead the investigations and the data will be analyzed under the guidance and monitoring of the Iranian team," Baharvand said.
He noted that if everything goes well and nothing unprecedented happens, the black boxes of the Ukrainian plane will be transferred to France by the Iranian team to start analyzing the data on July 20.
Baharvand said that other countries which are in some way related to the regrettable incident can also send a representative to France as an observer.
On June 23, Baharvand had announced that his country had decided to send the black box of the downed Ukrainian plane to France after Kiev procrastinated sending a delegation for talks to Iran.
"We have raised the issue of compensation with the Ukrainian officials once or twice, but we don't know yet why they first said they were ready but then procrastinated when it came to exercising their decision," Baharvand said.
He added that the Ukrainians have decided to form a new delegation in the past one or two days, but have not yet stated anything to Iran, noting, "We are waiting to see if they declare anything to us officially, then we will negotiate with them step by step."
Baharvand said that Iran and Ukraine enjoy good ties and Iran wanted to meet their demand to send the black box to the country, but Kiev's procrastination and delay made Tehran decide to dispatch it to France.
Iranian Foreign Minister Mohammad Javad Zarif said on June 22 that the black box of the Ukrainian downed plane would be sent to France, adding that Tehran is ready to compensate for the losses.
Iran has decided to send the plane's black box to have its data analyzed and "this decision will be implemented soon," Zarif said in a phone call with Canada’s Minister of Foreign Affairs François-Philippe Champagne.
He said that Iran has already informed Ukraine of its preparedness to settle all legal issues related to the sad incident, establish a procedure to pay compensation to the families of victims and repay the Ukrainian jetliner for the accident.
Zarif stressed that Kiev has not yet sent its delegation to hold talks while Tehran continues the follow-up measures.
Earlier in June, Spokesman of Iran Civil Aviation Organization Reza Jafarzadeh said that Iran may send the Ukrainian plane’s black box to another country for decryption in the presence of Iranian experts.
"We have already said that if it is possible to decrypt the Ukrainian plane’s black box in Iran, we will decrypt it in the presence of the representatives of the countries involved," Jafarzadeh said on June 11, adding, "otherwise, the black box will be decrypted in a third country in the presence of representatives of these countries."
Iranian experts were assigned to examine the crash of the Ukrainian plane in the presence of French, Ukrainian and Canadian representatives and representatives of other countries involved in the incident but the probe was suspended since the onset of coronavirus epidemic and the cancellation of the flights, he said.
Jafarzadeh stressed, "There is no problem to decrypt the black box in another country."
As soon as the grounds are provided for the probe, the black box will be decrypted in the presence of experts of Iran Civil Aviation Organization, or else it will be decrypted in France or Ukraine, he noted.
In relevant remarks on June 9, Baharvand said that Iran is prepared to talk with Ukraine to resolve issues pertaining to the black box of the crashed plane.
Baharvand made the remarks in a meeting with the Ukrainian envoy to Tehran Sergei Burdyliak.
Iranian diplomat said his country is ready to negotiate on the issues related to the heartrending event.
Burdyliak, for his part, welcomed the suggestion.
He underlined that he will report the issue to the relevant Ukrainian officials and inform the Iranian side of the results.
The General Staff of the Iranian Armed Forces said in a statement on January 11, 2020 that the Ukrainian Boeing 737 plane was shot down as a hostile object due to human error at a time of heightened US threats of war.
The statement said an expert investigation by the General Staff of the Iranian Armed Forces after the Ukrainian airline company's Boeing 737 incident has found that flight 752 of the Ukrainian airlines has been shot down as a hostile flying object that was approaching a sensitive IRGC center and was shot down due to human error few hours after Iran's missile attack on the US and as Iran's military was expecting attacks by the US army.
A Boeing 737 plane carrying 180 passengers and crew, mostly Iranians, crashed shortly after takeoff from Imam Khomeini Airport in Tehran early January 8, leaving no survivors.
Supreme Leader of the Islamic Revolution Ayatollah Seyed Ali Khamenei in a message on January 11 extended his condolences again on the death of the Ukrainian plane's passengers, and ordered the Armed Forces to take the needed measures to find faults and flaws that have led to the bitter incident and prevent repetition of similar incidents in future.
In his message, the Leader renewed his most heartfelt sympathy and condolences to the bereaved families of the victims, and reiterated his "order to the General Staff of the Armed Forces to probe into possible faults and flaws in this painful accident," Ayatollah Khamenei said.
He also underscored the need for the relevant Iranian directors and officials to launch the necessary follow-ups to prevent repetition of such incidents in future.
Also, Iranian President Hassan Rouhani extended condolences to the families of those killed in the Ukrainian plane incident, and promised that all those who have been guilty in the unforgivable mistake of shooting down the jet will be prosecuted.
"The Islamic Republic of Iran deeply regrets this disastrous mistake... My thoughts and prayers go to all the mourning families. I offer my sincerest condolences," Rouhani said in a statement on January 11.
The president stressed that "the terrible catastrophe should be thoroughly investigated, and those responsible for this unforgivable mistake will definitely be identified and prosecuted".
Russian State Duma (parliament's lower house) Speaker Vyacheslav Volodin blamed the United States for the exacerbation of tensions in the Middle East that led to the launch of the Iranian missile at the passenger plane of the Ukraine International Airlines near Tehran.