MOSCOW, March 20. /TASS/. Experts and specialists from the Interstate Aviation Committee so far have no clear understanding of what might have caused the crash of a passenger plane in Russia’s southern city of Rostov-on-Don, sources close to Russia’ air transport authorities and the Interstate Aviation Committee told TASS on Sunday.

"So far, they have only theories neither of which is definitely proved," the sources said, adding that specialists have only reconstructed a preliminary picture of the crash.

"According to preliminary data, the Boeing carried out go-around after it failed to land on the first try. The pilots cut short the second go-round to execute a third one. At an altitude of about 900 meters and a speed of more than 400 kilometers per hour, the plane banked left and hit the ground in the left edge of the runway almost vertically, at an angle of 60 degrees," the sources said.

Weather conditions in Rostov-on-Don were unfavorable at the moment but there was no sidewind. "Wind gusts reached 11-17 meters per second but there was no sidewind," the sources said.

Having hit the ground, the plane exploded and caught fire. Its fragments were scattered on both sides of the runway.

According to the sources, the pilots reported no technical malfunctions during the flight and the landing. "The flight was carried out in a routine mode," the sources said.

They found it difficult to say how long the investigation might take. "It may take a lot of time, so far it is difficult to be more exact. It will depend on the results of deciphering of the flight recorders," the sources said. "So far, it is not absolutely clear how many go-rounds the plane carried out trying to land. As for the radar information, it is only taken into consideration."

A FlyDubai’s Boeing 737-800 crashed at Rostov-on-Don’s airport in the small hours on March 19 during a second attempt to land in complicated weather conditions of strong side wind and rain. The plane served regular Flight FZ 981 from Dubai. The passenger jet capable of carrying 189 passengers had 62 people aboard, including the crew. None has survived.

The investigation looks into several leads: a pilot error, a technical malfunction, bad weather conditions, and others.