Were the reasons for the fall in Sochi the crashed Tu-154
Experts involved in the investigation of the crash flying to Syria military Tu-154 airliner on December 25, 2016 in Sochi, came to the conclusion that the plane was overloaded instead of regulatory 98 tons takeoff weight was more than 110 tons. The crew of the overload was not aware and took off, based on normal take-off weight of the manned machine.
As found “Газета.Ru” for the calculation of the mass of the crashed aircraft were equipped with special techniques, including using the parametric data recorder recovered from the bottom of the Black sea.
In the result, it became known that on 24 December during takeoff from the airfield near Moscow Chkalovsky, where Tu-1542Б-2 began your route, take-off weight of the aircraft, together with dressed in him 24 tons of fuel was 99.6 tonnes. It exceeded standards, but the deviation 1.6 t was not significant. At this weight the plane usually takes off without any problems.
In Adler of the Tu-154B-2 nobody left except the commander and co-pilot. In the plane nothing extra is loaded, but the plane was refueled to the maximum. His tank was 35.6 tons of fuel.
According to experts, in the result, the takeoff weight of the liner instead of the standard 98 tons was about 110 tons.
Early on the morning of 25 December the Tu-154B-2 took off on the big runway (in Adler two of them). After that, the plane had to turn at first right, then left, and then to take a course at Latakia, on the base Hamim. However the problems began during the ascent.
The separation of the aircraft from the runway Adler was only 37 seconds after start of takeoff, at a speed of 320 km/h, the pitch angle was 4 to 6 degrees. All these parameters indicate that the aircraft struggled into the air. The climb rate was 10 m/sec instead of the usual 12-15 m/sec.
2 seconds after takeoff, the crew dragged over the helm, with his nose of the aircraft so that the pitch amounted to 10-12 degrees. For the control of overloaded plane, it was a very rash actions. Retraction of flaps, the crew began at an altitude of 150 meters and at speeds of 345 km/h. Given the significant regulatory excess take-off weight of the Tu-154 these actions should be made at a higher speed.
The stall speed of the aircraft (low speed flight when the angle of attack reaches a critical value, and the aircraft becomes uncontrollable) grows with the mass, but also depends on the position of the flaps (the more they released, so it is less). In addition, at a certain weight, the speed may be such that, before retracting the flaps it will be more stall speed, and after less.
On the records of the cockpit voice recorder heard the co-pilot asked the commander for permission to harvest mechanization, but the latter said nothing. The second pilot, apparently, interpreted his silence as assent. The lifting force from the moment of the beginning of harvest mechanization naturally began to fall sharply.
The plane managed to reach a height of 200 m, when the commander once again made a surprise move — he gave the control column myself, and then suddenly took it on themselves by losing to the maneuver of the already small height.
Not yet fully cleaned up the flaps, like in the cockpit of the Tu-154 has signaling about dangerous rapprochement with the earth. The angle of the flaps was 5-7 degrees, when the commander made a movement of the steering wheel and the rudder pedals to the left. As planned he was supposed to do the opposite. The plane went into a roll 30 degrees.
At this moment the alarm sounds dangerous roll, which no one pays attention. “We’re falling!”, — screams right pilot.
The commander makes the movement of the steering wheel and pedals in the opposite direction and takes the wheel column itself. At this point the angle of attack was 10 degrees. With the continued acceleration of the aircraft up to 500 km/h. The speed increased, the roll increased and the lifting force of the fall. No stock at the height of the Tu-154 almost was not.
A few seconds later with a roll of 50 degrees and at speeds of 540 km/hour, the plane’s left wing touched the water. In such circumstances, the impact with the water surface equivalent to the collision with the rock. The aircraft was destroyed, its wreckage scattered over a large area.
In total, the last flight of the Tu-154 lasted only 74 seconds.
Until the moment it hit the water the aircraft was fully serviceable. The weather conditions at the airport of Adler at the time of take-off were favorable: ambient air temperature — 5 degrees above zero, humidity — 76%, pressure 763 mm Hg. article, side wind — 5 m/sec. Hazardous weather phenomena were observed.
It was also found that the deceased crew with experienced captain Roman Volkov performed the take-off in the crashed car with the same runway in Adler, just two months before the crash — October 1, 2016.
Then separation from the runway were made at speeds of 310 km/h. With a climb rate of 12-15 km/h the crew began to climb. At an altitude of 450 m was implemented corrective turn to the right with the right roll of 20 degrees, then the aircraft made a turn to the left, and then, at an altitude of 450 m for 13-14 seconds if you remove the flaps, before standing in takeoff position — 28 degrees.
The actions of the experienced crew and the behavior of the healthy machine during your next takeoff in Adler can be explained only by the fact that the commander of the Tu-154 did not know neither the nature nor the exact weight of the cargo on Board, and consequently about overloading his plane. Therefore, in Adler on a plane and poured the fuel. Probably it would have filled less, if I knew the exact weight of the assets that were loaded into the plane at the Chkalovsky.
Perhaps on the plane put something small in scale but significant in its specific weight.
If the crew knew about the exceeding regulatory take-off weight more than 10 tonnes, or he would refuse the flight, or flew would be given that the plane is overloaded.
The recent actions of the crew can be explained by the fact that the pilots guessed that with plane something wrong and tried to return to the aerodrome of departure to sit on another, smaller runway in the afternoon. However, not enough height.
Not the best role was played in the dark: a visual representation that the water surface remains very little, the crew was not.
On the Tu-154 plane, which crashed early morning of December 25th, I flew artists song and dance Ensemble of the Alexandrov, who had to give new year’s concert at the Russian base in Syria Hamim. They were accompanied by the crew of the First channel, NTV and “Stars”. Only 92 people were killed — 84 passengers and 8 crew members.