"Information we have as of today points towards everything having happened very abruptly," Uibo said, speaking on Friday morning's ETV magazine show Terevisioon.

"There was no data transfer from the plane, there was no communication whatsoever, indicating that something very sudden and fast happened. According to the data available today, missile strike seems most likely," Uibo continued.

A statement by Iranian authorities within hours of the disaster claiming it had been the result of technical fault did not add up, Uibo said.

Given the plane was almost entirely destroyed, with pictures showing fragmented wreckage of the plane, which crashed shortly after takeoff on Wednesday morning, it would be very difficult to draw such a conclusion so quickly, he noted. 

There were also no reports that the crew had informed the controllers about any problems; in the event of engine failure, the pilots would have time to report this.

"Why no notification about a technical malfunction when it happened? In fact, something happened that made the pilots instantly incapacitated. External forces are the most logical explanation. One [further consideration] is the radio interruption, and the second is the flight data was interrupted abruptly - it also ended at 2,400 meters [altitude]," Uibo later said on ERR radio show Uudis+.

The statement by the Iranians that the plane's engines had overheated and the claim that there had been witnesses who were flying at a higher altitude than the stricken plane, also made no sense, in his view.

"Let's just say this is a pretty absurd statement," Uibo said.

Responding to a question from ERR's Liisu Lass, as to possible future development of the case, Uibo said that Iran's behavior is making it more difficult to find a solution.

"Iran is in a very difficult situation in that sense, and it still refuses to say it was a missile [that was responsible]. In any case, we still don't know today if it really was," Uibo said.

"But without being a military expert, I still think firing a missile is not quite like firing a gun. It is preceded by a very clear procedure: detecting a target, investigating it, and then getting permission from somebody else [to fire]. On the other hand, the Americans have said the missile could have been fired in error, giving Iran a 'get out' in saying 'yes', it was this type of an unfortunate incident, but it seems Iran is not taking them up on this offer," Uibo added.

Iran's confrontation with the U.S., home of the aircraft's (which was only about four years old-ed.) manufacturer Boeing, and at the same time Iran being a closed society, prevents clarity, Uibo felt.

"Americans have the ability to see missile launches from their satellites - but again, there are certainly people who do not trust this information. So when such disasters occur in opaque societies, it really is extremely difficult to determine the ultimate truth," Uibo continued.

Mistrust between Iran and the West could also hinder the investigation of the plane's black box recordings, one of which records crew conversations in the cockpit and the other, technical, Uibo said. 

"It is not known at present what has happened to the black box(es). The best know-how in the world  belongs to the Americans, British and French. Now, if Iran takes these as western societies that they do not trust, the question arises who will analyze these boxes," he continued.

The so-called black boxes would certainly give a very clear testimony of what happened, if their data has not been manipulated. Of course, Iraq has the right to lead the investigation, but it is good practice to include another party.

If Iran does not want to provide data to the U.S., it could be passed on at least to British or French people, Uibo said.

When asked by Uudis+ presenter Arp Müller how long it would take to analyze the on-board recordings, Uibo replied that this depends on how badly they were damaged. 

"It is one thing to retrieve this data, which should not take very long, and another to analyze it. In the electronic sense, retrieval does not take much time, but analysis can do," he said.

176 people, including 9 crew members, boarded the Ukraine International Airlines Flight 752 Boeing 747 passenger plane, due for Kyiv, early Wednesday morning at Tehran Imam Khomeini International Airport. 

There were no survivors from the crash. Eighty two Iranian citizens, along with 63 Canadian citizens and 11 Ukrainians, 10 Swedes, four Afghans and three Britons, were killed. 

Caution can be urged in the reporting of nationalities by the Iranian authorities, due to many of them holding dual citizenship, it is reported.

Canadian Prime Minister Justin Trudeau also said Thursday evening that there is evidence the plane was shot down by a missile, possibly in error.

The crash came just hours after Iran launched multiple missile attacks on two U.S. bases in Iraq, in retaliation for the U.S. drone strike last week which killed high-ranking Iranian General Qasem Soleimani. One of the bases hosted some Estonian Defence Forces (EDF) personnel, who were reportedly not on site. The latter relocated to Kuwait overnight on Thursday.

The original Terevisioon segment (in Estonian) is here.

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