Analysis: Would be a huge loss of prestige for Iran if that is true

That the Ukrainian plane was in good condition and had recently undergone security checks, that the crew did not send emergency signals and that an explosion appears to occur on board shortly before the plane hits the ground. According to international aviation experts, all this suggests that a terrible mistake caused the disaster outside Tehran on Thursday morning.

The US and Canada claim that Iran bears responsibility for the crash of the Ukrainian Boeing 737, and that the plane was hit by an air defense robot by mistake. But the chief of Iran's aviation authority says today that they know for sure that the aircraft was not shot down by a robot.

Iranian representatives claim that the information that the plane was accidentally shot down is psychological warfare and propaganda. Instead, the crash was caused by technical errors, they say.

Tensions between Iran and the US have escalated since the US killed top general Qassem Suleimani a week ago. The Ukrainian plane crashed outside Tehran just hours after Iran fired 23 ballistic robots at US targets Iraq. The Iranian missile defense was on the highest alert. Some form of counter-attack was expected and Iranian media reported that US combat plan had been lifted from a base in the United Arab Emirates.

Iranian investigators have found the black boxes but are unwilling to hand them over to the US where aircraft manufacturer Boeing is based. The lack of diplomatic relations between the United States and Iran complicates cooperation.

The Iranian Aviation Authority has previously had some technical cooperation with its US counterpart in the investigation of aviation accidents. But after the US signed the International Nuclear Energy Agreement in 2018, contact has been minimal.

According to international rules, it is Iran who is leading the investigation since the disaster occurred on Iranian soil. Iran has invited the United States to participate, and the United States has appointed an official. Iran has also asked Sweden and Canada to send experts and say it welcomes participants from all countries whose citizens were killed in the crash in the investigation.

International aviation investigations are usually complicated. The international rules that surround them are not binding and are criticized for being toothless.

For the Iranian regime, it would be a huge loss of prestige if it turned out that a passenger plane was accidentally shot down just hours after being praised for having met American targets in Iraq with great precision.

Although a large team of international experts will soon arrive in Tehran, Iran's willingness to cooperate in the investigation will be decisive for the outcome. Normally, an investigation is initiated after a catastrophe of a technical review of the wreckage parts. But Iranian aviation security authorities reported yesterday that the parts of the plane were "collected and taken to a safe place". At the same time, Iranian TV shows that the place where the plane crashed has been dug up by bulldozers.