The Civil Aviation Organization spokesman said in a statement that based on the sovereignty right of Iranian Civil Aviation Organization and in light of procedural regulations and instructions related to controlling Iran's air space, is responsible for flight permission, reviewing accidents and setting required penalties.
Since the beginning of the air disaster, the national CAO based on professional procedures, international regulations and International Civil Aviation Organization (ICAO) instructions has followed the process of clarity investigating the process which led to the air disaster in cooperation with the domestic and international bodies.
All conversations have been gathered since the day of the air disaster.
Various conversations have been recorded in the control tower from one of the pilots of incoming flights to Tehran with regard to observing lights similar to missile or a melted object flying in the sky and which was then exploded.
Aseman flight crew has been interviewed for referring to the word missile to elaborate clearly on their observation.
They said that they observed a light in the sky for over one minute moving, expanding and then being exploded.
The crew said that the time of the movement of the light was so long that they had invited another crew member to the cockpit for more consultations.
After watching the footage of the Ukrainian plane which was in fire, members of the group concluded that the object was the Ukrainian plane which then hit the ground and was exploded.
After analyzing the evidence and also remarks made by the crew members, the experts concluded fire in engine of explosion inside the plane has been the cause of accident.
The related officials in air defense system had not announced any warning to CAO with regard to missile actions in Tehran air traffic system.
The recording conversation along with some other documents has been given to Ukraine's legal representative based on usual working procedure followed by multi-national expert delegations.
The audio file was not monopolized as other flights under the control tower had heard it simultaneously.
So, any measure to leak and analyze the data like the recording which was under examination is against the air disaster investigation rules.
According to the 1944 Convention on International Civil Aviation (also known as Chicago Convention), public opinion should not be attracted by leaking the findings, but through finding the reasons behind the air disaster in order to avoid their repetition.
So, the sole person eligible to release information about the disaster is the one had been responsible for examining it.
Civil Aviation Organization of Iran will continue reviewing different aspects of the January 8 Ukrainian plane crash within the framework of the international and national regulations.
And, the Organization will also continue with cooperation with the countries involved.
Meanwhile, Iran expects all sides to avoid politicking the air disaster and creating obstacle to its technical and expert process.
After the US increased tensions in the Middle East by assassinating Iran's Lieutenant-General Qasem Soeimani, the country took reciprocal action and hit the US airbase in Iraq with missiles.
Iran's military had been put on alert to counter any US adventurism. But unintentionally, a Ukrainian Boeing 737 was shot down near Tehran minutes after takeoff.
Iranian officials have admitted that human error was responsible for downing the passenger plane and expressed regret and apologized for the tragedy.
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