Press TV - Iran’s civil aviation agency has released its second preliminary investigation report on the accidental shooting downing of a Ukrainian passenger plane near Tehran earlier this month. 

The report, published by the Civil Aviation Organization of Islamic Republic of Iran (CAO.IRI) on Monday, published new data on the status of Ukraine International Airlines flight PS752 until it crashed.

The Kyiv-bound Boeing 737-800 took off from runway 29R at Imam Khomenei International Airport at 06:12 a.m. local time on January 8 and was then delivered to approach unit at Mehrabad Airport in the capital.

From 06.18 a.m. onward, the radar controller repeatedly tried to contact the pilot as the flight information was lost, but he received no answer, the reported added.

The radar data showed the plane was flying at an altitude of 8,100 feet, but its identification and altitude information later disappeared from the radar screen, and no radio messages were received from the pilot regarding unusual circumstances.

After samples were examined at the crash site, the possibility of damaging rays — including laser and electromagnetic (radioactive) ones — having hit the aircraft was excluded.

On the day of the incident, samples were also taken for tests at laboratories to look for traces of explosives both inside and outside the plane.

Further analyses of the plane’s debris show that the existence of explosives on the aircraft’s surface should be investigated.

The report further noted that the flight data and cockpit voice recorders — commonly known as black boxes — are “some of the most advanced equipment of their kind in the world” and Iran lacks the facilities to decode them.

“If devices are provided, the information (on the black boxes) can be restored and retrieved in a short period of time,” it added.

Iran's civil aviation agency also said that it had asked French and US accident investigation agencies, the BEA and NTSB, respectively, to provide a list of the equipment required to decode the black boxes.

However, it pointed out, neither the BEA nor NTSB had “so far responded positively” to the transfer of the required equipment to Iran.

It said it had acquired the list nonetheless and hinted that it would use it to buy the equipment itself.

The report emphasized that Ukraine’s team of investigators, under the supervision of an Iranian team, are inspecting the plane’s debris to find the effect of any foreign object debris, or FOD.

Two Tor-M1 missiles had been fired at the aircraft from the north, but how the projectiles contribute to the incident are under investigation, it went on to say.

Ukraine, the US, France, Sweden, the UK and Canada had introduced representatives to get access to the incident’s data, but Afghanistan has not done so, the report concluded.

The Tehran-Kiev flight was unintentionally shot down by an Iranian air defense unit shortly after taking off from Tehran on 8 January, killing all 176 passengers and crew members on board.

The Iranian operator had mistaken the Boeing for a cruise missile.

The incident came as Iranian air defenses were at the highest level of alert following the country’s missile attacks against US bases in Iraq, which came in retaliation for Washington’s assassination of senior Iranian commander Lieutenant General Qassem Soleimani.