Tu 154 pilot version. What happened over the Black Sea . "No full automation"
On the morning of December 25, a Tu-154 plane of the Russian Ministry of Defense, which was heading from Sochi to the Khmeimim base in Syria, crashed in the Black Sea. There were 92 people on board the plane, among them were artists from the Alexandrov Song and Dance Ensemble, journalists from Channel One, NTV and Zvezda, and philanthropist Elizaveta Glinka. All of them most likely died.
The Ministry of Defense plane was heading to the Russian air base in Syrian Latakia. He took off from the Chkalovsky airport near Moscow at 01.38 Moscow time on December 25. The airport duty officer told RBC that before takeoff, “everything was checked on the plane.” In the morning he landed at Sochi airport in Adler to refuel. At 05.25 Moscow time, the plane took off again, but disappeared from radar two minutes later.
The official cause of the disaster has not yet been announced. Among the most discussed versions are a technical malfunction of the aircraft, pilot error, sudden interference and a terrorist attack.
Aircraft technical malfunction
An Interfax source in the emergency services stated that the version of “technical malfunction” is the priority. The life of the aircraft is cited in favor of this cause of the disaster: the crashed Tu-154 was produced in 1983, its total flight time was 6689 hours. The flight safety service of the Armed Forces said that the crashed airliner was technically sound. The last time it was repaired was in December 2014; in September of the same year, the aircraft underwent scheduled maintenance.
Since 2013, production of aircraft of this model, which began operation in the 1960s of the last century, has been discontinued. Over the entire history of the Tu-154, more than three thousand people died in accidents on this particular modification. At the same time, experts interviewed by Dozhd call the Tu-154 one of the most reliable aircraft.
RIA NewsIt’s not for nothing that the Tu-154 has been used by aviation for so long, says Air Force Major and instructor pilot Andrei Krasnoperov. According to him, an aircraft of this modification, in the event of a technical malfunction, can glide and land along the coastline, even with the engines not running. The pilot is sure that the plane broke up in the air, otherwise the pilot would have contacted the ground and turned on the distress signal.
At the same time, aviation expert Vladimir Kormuzov calls the 30-year-old Tu-154 “morally obsolete”: these aircraft are practically no longer used in civil aviation; they are operated mainly by government agencies. And they have “very little flying time” - the crashed plane flew 26 hours a month, adds Kormuzov. With such passive operation as this aircraft, the age of the aircraft practically does not matter, notes former Deputy Minister of Civil Aviation of the USSR Oleg Smirnov. According to him, the main task of the commission is to find out how carefully the plane was monitored.
Piloting error
As one of the versions, the investigation is considering a pilot error. The first two minutes after takeoff is one of the most critical stages of the flight, says pilot Andrei Lamanov, who in 2010 urgently landed a Tu-154 at an abandoned airfield in the city of Izhma, the aircraft is unbalanced, and pilots must constantly react. According to him, if the crew was not technically prepared, such a disaster could occur. At the same time, as Krasnoperov notes, for experienced military pilots it is not a problem to perform an emergency landing on the water surface in case of imbalance and send a distress signal.
The crashed plane was flown by pilot first class Roman Volkov, who served in the 223rd flight detachment of the Ministry of Defense, which is based at the Chkalovsky airfield. He was a first-class pilot and had flown more than three thousand hours, the military department said in an official statement. The flight safety service of the Armed Forces stated that the aircraft commander had repeatedly flown along a given route. The Tu-154 navigator, Lieutenant Colonel Alexander Petukhov, took part in the rescue of the “dancing airliner” in April 2011, Rambler News Service reports. Then a plane of the same model landed at Chkalovsky airport with a faulty control system. For this, he and his colleagues were awarded the Order of Courage.
Pilots call Sochi airport “difficult” - takeoff is complicated by the fact that clouds, icing, and thunderstorms often occur over the sea. According to Roshydromet, on Sunday morning in the area of Adler airport there were normal weather conditions, good visibility and light wind.
In 2006, a few kilometers from the coastline in Sochi, an A-320 of the Armenian airline Armavia crashed due to a pilot error; in 1972, an Il-18 of the Aeroflot company crashed into the Black Sea near Adler, the cause is still unknown installed.
Sudden disturbance
The cause of the disaster is also considered to be a bird getting into the engine - there is an ornithological park near the airport. Flight safety specialist Alexander Romanov calls this version unlikely. “When a bird collides, some partial destruction occurs, even to the point where the windshield breaks. Even if the engines fail, the plane does not fall, but goes into a smooth descent,” says the expert, adding that “the birds could not have played this fatal role.”
Terrorist act
The authorities almost immediately rejected the version of the terrorist attack. A source in the security forces told Interfax that a terrorist attack is not considered among the main causes of the disaster and such a version is practically excluded.
“The plane took off from the Chkalovsky airfield, which is a well-guarded military facility. It is not possible to penetrate there in order to plant an explosive device on board. In turn, the airport in Sochi is a dual-use airport and is heavily guarded. The entry of unauthorized persons or the carrying of unauthorized items by any employee is excluded,” the agency’s interlocutor said.
Military journalist Alexander Golts, however, in a conversation with Dozhd, spoke in support of this version. According to him, the authorities cannot allow a terrorist attack to occur at such a high level. At the same time, the former head of the anti-terrorist unit of the FSB, Alexander Gusak, claims that “any object can be penetrated.” He noted that “everything depends on the preparation and the possible assistance to the infiltrator.”
According to a Fontanka source, the FSB is working on a version of the terrorist attack. According to the publication’s interlocutor, FSB officers are checking everyone who had access to the plane at the Chkalovsky military airport and at Adler airport. Dozhd's source in the Federal Assembly confirmed this information.
Alexander Shnyakin, a consultant to the Federation Council Commission on Defense and Security, is confident that the cause of the plane crash was a terrorist attack, since the Tu-154 was heading to the Khmeimim military base in Syria. According to him, terrorist groups will soon take responsibility for what happened.
Non-synchronous cleaning of wing mechanization
Test pilot, Hero of Russia Magomed Tolboev, in a conversation with the newspaper VZGLYAD, noted that when determining the causes of the Tu-154 crash, it is worth considering technical problems. The expert said that he discussed the disaster with colleagues.
All of them, as a priority version, note that “non-synchronized retraction of the flaps” could have led to the death of the aircraft. “In general, this is called “non-synchronous retraction of the wing mechanization,” Tolboev noted.
The interlocutor explained that in this case, the flaps and slats are retracted on one side of the wing, but not retracted on the other side. “It turns out that the plane instantly turns around its axis. Neither the commander nor anyone has time to say a word, they are thrown there like a herring in a barrel,” summed up Magomed Tolboev.
There are no parallels with the Tu-104 disaster of 1981
Let us note that earlier there were suggestions in the media that the cause of the death of the Tu-154 was the same as the Tu-104 crash that took place in 1981 in the Leningrad region. Then the plane crashed due to overload in the tail section: the command of the Pacific Fleet, flying on this side, stored heavy suitcases and other cargo in the tail of the liner. During takeoff, the “gifts” moved back, causing the plane to crash. However, as Magomed Tolboev explains, parallels cannot be drawn between the Tu-104 crash in 1981 and the current Tu-154 crash. Such a situation, in which the cargo suddenly shifted to the tail, cannot happen on the Tu-154, Tolboev noted. “The Tu-154 has a central compartment under the wing near the center section and tail section, in addition, there is an automatic alignment device, which itself determines the transfer of fuel and the presence of a threat on board,” the interlocutor explained.
“The plane sets its controls so that the alignment is in one position,” the expert noted. “The Tu-104 did not have an automatic tracking system, and generals and admirals could load whatever they wanted into the tail.”
Small raid
Civil aviation expert, director of the ICAA Flight Safety programs Viktor Galenko believes that the most plausible version of what happened is a human factor, and not a technical malfunction. In a comment to the newspaper VZGLYAD, Galenko noted that “the statistics of plane crashes indicate a ratio of 8 to 2: out of ten such incidents, in eight cases the cause is the human factor, in two - everything else.”
The Tu-154 aircraft after repair was practically like new - the service life of this aircraft was 11%, the expert emphasized. “Tu-154 is one of the most reliable aircraft in the world. It has a huge power supply and a very high degree of wing mechanization,” the interlocutor noted. “This allows the aircraft to take off and land in any conditions - in particular, in high altitude conditions, thin air and heat, which are much more difficult for pilots than the weather conditions that were in Adler.”
“But there is one detail: this is a very strict aircraft to fly,” the expert emphasizes. “The aircraft requires full pilot training at a flight school course. In the USSR, for the “carcass” they first took an exam on the An-24 or Yak-40 from the pilot as a second pilot, then they made him the crew commander of the An-24 or Yak-40, then again after a short retraining they “put him in the right seat” (second pilot - approx. VIEW) Tu-154, and only then, at the age of 40, the pilot could lead the crew of the Tu-154.”
The commander of the crew of the crashed plane, pilot first class Major Roman Volkov, is an experienced aviator, his total flight time was more than 300 hours, Galenko points out. “But the annual flight time of the crew of this aircraft was 200 hours, and this is not enough,” the interlocutor continues. “At the same time, different crews flew on it, so the hypothesis about the low flight time of the crew on this board is confirmed.”
The main problem for front-line pilots in almost all countries is the very small number of flight hours of the crew, Galenko believes. “Corporate aircraft with high fuel consumption and comfortable cabins fly extremely rarely; the military pilots flying them have little annual flying time. And this greatly affects the level of training of the crew,” the interlocutor believes. Back in Soviet times, pilots were forced to undergo simulator retraining even after vacation, but military pilots on these aircraft (the “ceremonial aircraft” of the Chkalovsky airfield) have breaks in flights of more than one month, Galenko notes. Piloting this aircraft is an inadequate task for pilots with short flight hours, the expert summarizes.
"No full automation"
“Plus, this is a previous generation aircraft; it does not have full automation. It has a conventional autopilot, a standard inertial navigation system, and is piloted manually,” emphasizes Victor Galenko.
He explains that the Tu-154's automation only maintains the aircraft's position at altitude and at a given speed and allows it to land in a semi-automatic mode or, if the airfield equipment allows it, automatically. “The equipment is still Soviet, and the foreign cars land in fully automatic mode,” the source adds.
However, he believes, the possibility of a technical malfunction cannot be ruled out. But the interlocutor would consider the technical version of the crash of this aircraft last, “since the plane is incredibly reliable.”
“Oncoming on takeoff, passing on the flight level”
The expert believes that unfavorable weather conditions could not have been the cause of the disaster. “There were no dangerous weather conditions during the incident, the wind was fair during takeoff. At an elevation angle of 20 degrees, it was five meters per second,” Galenko emphasizes.
The peculiarity of Adler Airport is that takeoff and landing are carried out towards the sea. You cannot take off towards the mountains under any circumstances, there is fog there, the expert adds. “Unfavorable conditions would be a tailwind (take-off is always carried out against the wind, pilots even wish each other “a headwind on takeoff, a tailwind on the flight level”), as well as heat - a plane takes off much better in the cold than in hot weather. However, even in the case of a tailwind and heat, the Tu-154 engine has a huge reserve of thrust. There was no icing or thunderstorms; other aircraft did not report high turbulence,” adds Galenko.
Weather conditions in the area of the airport in Adler at the time of the Tu-154 crash were assessed as easy for piloting an aircraft, reported Roshydromet, which was quoted by Interfax. “About five in the morning Moscow time, the temperature at the ground is +5, the wind is 5 m/s, visibility is 10 km. The weather conditions are quite normal,” the department emphasized. Sochi airport, from where the Tu-154 took off, continued to operate as normal, media reported.
At the same time, according to the online scoreboard, four flights were canceled in Adler on Sunday morning.
Weather conditions have repeatedly caused the death of aircraft around the world. On March 19 of this year, a Boeing 737-800 flying from Dubai crashed while landing in Rostov-on-Don. Due to bad weather, the airliner was unable to land after two attempts, and after making another circle, it crashed near the runway, killing 55 passengers and 7 crew members. The investigation into the causes of the disaster continues.
On August 22, 2006, a Tu-154M airliner flying from Anapa to St. Petersburg crashed near Donetsk after a collision with a severe thunderstorm. There were 170 people on board. The cause of the disaster was blamed on the pilots' erroneous actions when trying to avoid a storm front. On February 12, 2002, an Iranian airline Tu-154 crashed near the Iranian city of Khorramabad, with 119 people on board. The plane crash occurred after difficult weather conditions.
In the case of the Tu-154B-2 plane crash on the Black Sea, a priority version appeared even before the discovery of the flight recorders, Kommersant reports, according to sources close to the investigation. According to it, the airliner, which was carrying artists and journalists en route to Syria, could have fallen due to an error by the pilots, who during takeoff brought the Tu-154 to supercritical angles of attack. Because of this, the car, which lost speed, instead of gaining altitude, sank to the sea, touched the surface of the water with its tail, after which it fell apart and sank. For now, however, this version is based on the testimony of the only eyewitness to the tragedy, who observed the development of the disaster from the sea.
Search and rescue, eastnews. ru
On Monday, the Russian FSB reported that “eyewitnesses to the crash of the airliner have been identified.” According to Kommersant sources close to the investigation, who are now checking the testimony of these witnesses, one of them was an employee of the coast guard of the FSB border troops, who was at the time of the boat accident in the waters of Sochi. The border guard said that early on Sunday morning he became an unwitting eyewitness to the emergency. According to him, the plane that took off from Adler airport, instead of gaining altitude, began to quickly descend towards the surface of the sea, as if it was about to land on it.
The witness noted that even for landing, the position of the aircraft in space seemed strange to him. Allegedly, the Tu-154 was traveling at low speed with its nose unnaturally raised up. An eyewitness, according to the source, even compared the position of the plane at that moment with a motorcycle placed by its driver on its rear wheel. Another moment later, he said, the plane touched the surface of the sea with its tail, which fell off upon impact, crashed into the waves and quickly sank.
According to experts, several factors, one way or another related to the actions of the aircraft crew, could have led to the picture of the incident described by the witness. The Tu-154 took off from the runway at its standard speed, as the FSB reported on Monday, 345 km/h, and began to climb. However, after a few seconds, the car, according to experts, began to lose speed and, accordingly, altitude. This, experts believe, could have happened primarily due to the erroneous actions of the pilots, who tried to lift the car up too vigorously. Thus, presumably, the aircraft was brought to supercritical angles of attack, which led to a loss of speed and lift on the wings and the Tu-154 descending towards the sea surface.
Search and rescue, eastnews. ru
“There is a high probability that the TU-154 was shot down by a missile from Turkey or Georgia. It is not the first time for the Turks to shoot down Russian military aircraft, but the Georgians could have done this on the orders of the State Department.
However, the most likely version is a malfunction of the TU-154 itself, which was many years old, or a mistake by the pilots. Accidents during takeoff and landing are quite common. The plane took off at night, in conditions of limited visibility, which further aggravated the risk of disaster. Let me remind you that the same TU-154 plane carrying the Polish president near Smolensk crashed in 2010 while landing. Perhaps takeoff and landing are the weak points of the TU-154.
But there could also be a terrorist attack. The plane was landing in Sochi to refuel. Perhaps it was refueled with low-quality fuel in Sochi, which is why it was unable to fly for a long time and crashed 7 minutes after takeoff.
The strangest thing, of course, in this story is refueling. Syria is not so far away; the plane from Moscow does not need refueling. They fly to Thailand without any refueling.”
Published the opinion of the deputy editor-in-chief of the Aviapanorama magazine, Major General, Candidate of Technical Sciences Vladimir Popov:
“Several tragic accidents could have led to the plane crash. First: the difficulties of takeoff and landing, the crew is always busy here, a lot of manipulations and technological processes are performed. That is, you need to remove the landing gear and flaps in time, set a certain climb mode, change the operation of the engines. This is the second one. Then check the operation of the power units, then check the mechanics of the power units, etc. At this moment, time is very scarce and there is almost no opportunity to change anything.
Do you represent Adler airfield? These are two stripes at an angle to each other, takeoff and landing are carried out only towards the sea, only from the mountains, there will be at least one wind, at least the other. These are already difficulties. Second. It was night. Third. The crew, when performing the departure technology, takeoff and exit from the airport area, had to be under the strict control of air traffic control authorities. It was reported that it disappeared from radar only 15-20 minutes after it took off. Accordingly, somewhere there was an omission that he was not under control, probably as required. Why didn't he go along the coastline? It was found right in the Khosta area, the first fragments have already been discovered.”
“The option of planting an explosive device in an airplane seems unlikely. The procedure for inspecting and preparing an airplane for flight at Russian airports is one of the strictest in the world. But it’s hard to believe in a technical malfunction that destroys an airplane so quickly. It’s strange why an attack from the ground is not being considered ... The plane crashed before gaining altitude, actually during takeoff. The range of the MANPADS and the altitude of destruction is about 5 km.
Despite the fact that such versions are not being considered, there is still an opinion that a very likely way to destroy the aircraft is to use MANPADS on taking off and landing aircraft. A civilian airliner is completely defenseless against such weapons! There is no need for complex methods of penetrating the aircraft's security zone, and there is no risk of being detected when attempting to plant explosive devices in the aircraft. All an attacker needs to do is take out a MANPADS and take a place on the takeoff or landing trajectory.
Is it difficult to get MANPADS? I will not reveal the details, but it is obvious that this is possible in our turbulent times. The cost of MANPADS is also not an insurmountable barrier... Is it difficult to take a position on the take-off trajectory? In most cases, no, it’s not difficult. This is also not difficult at sea, all you need is a motor boat, or an attack directly from the coast. It is reported that the wreckage of the plane is located no further than 6-7 km from the coast. Generally speaking, this coincides with the combat use radius of MANPADS. All this says that the version with MANPADS is probable, not impossible.
MANPADS have small weight and dimensions, allowing them to be secretly moved to the attack area. Combined with the short time it takes to get ready to fire (no more than 30 s), the concealed location on the ground and the suddenness of the use of these systems are ensured. In addition, MANPADS are characterized by ease of training and combat use, as well as high operational reliability in various physical, geographical and climatic conditions."
The parametric flight recorder of the Tu-154 that crashed near Sochi has been preserved in excellent condition, and specialists are preparing to lay out fragments of the aircraft collected at the bottom of the Black Sea. The media, with reference to the transcript of the voice recorder, put forward various versions of the reasons for the crash of the airliner. Experienced pilots interviewed by Gazeta.Ru are inclined to believe that the plane is out of balance, possibly due to incorrect distribution of passengers in the cabin.
The second flight recorder of the crashed Tu-154 aircraft was preserved in excellent condition. At least, this is how his condition was assessed during the initial examination. This was announced on Wednesday on the Rossiya 24 TV channel by Dmitry Popov, senior engineer of the disaster investigation commission.
“The condition in appearance is excellent - the thermal insulation and armor protection are slightly damaged. Even the fact that the handles are in place is the first sign that, probably, if there was no exposure to salt water, then the magnetic tape should be in excellent condition,” the specialist said.
He clarified that we are talking about a parametric recorder, which was installed in the tail of the aircraft. This device, like the first discovered “black box”, will be delivered to the Air Force in Lyubertsy near Moscow.
In addition, in the coming hours it is planned to begin laying out fragments of the crashed plane in Sochi. To clarify the circumstances of the disaster on the ground, the real contour of the Tu-154 will be outlined, for which a site is already being prepared, sources in law enforcement agencies told TASS.
Earlier, the agency's source reported that during the search operation more than 1.5 thousand fragments and debris of the aircraft were discovered, about a third of which - about 570 - had already been raised to the surface.
- ...Speed 300... (Inaudible.)
- (Inaudible.)
I took the racks, commander.
- (Inaudible.)
Wow, oh my!
(A sharp signal sounds.)
Flaps, s...ah, what the *****!
Altimeter!
We... (Inaudible.)
(A signal sounds about a dangerous approach to the ground.)
- (Inaudible.)
Commander, we are falling!
The head of the flight test center of the Research Institute of Civil Aviation, Tu-154 tester, hero of Russia Ruben Yesayan doubts the authenticity of this dialogue.
“On the Tu-154 plane, no one says “took the landing gear” or “took the struts.”
After takeoff at an altitude of at least 10 meters, the commander gives the command to “retract the landing gear.” The landing gear valve is closest to the co-pilot. The co-pilot takes this crane, understands that an alarm immediately goes off, the sign that the landing gear is down goes out, and then the sign that the landing gear is retracted lights up. All. So all these dialogues are inventions of some writers,” Yesayan insists.
According to him, the flaps on the Tu-154 aircraft are part of the control system, and all aircraft control systems have double and sometimes triple redundancy. If any failure occurs, the backup systems will work. “Refusal - and everything turned off and was cut off... This doesn’t happen in aviation.
And if the pilot allegedly shouted “Commander, flaps!” - this does not mean that they were the reason,” the test pilot concluded.
An experienced Tu-154 pilot, who wished not to give his name, told Gazeta.Ru his version of what could have happened to the plane.
According to the specialist, the landing gear is retracted when the aircraft takes off at an altitude of 15-20 meters. At this moment, a slight re-centering of the aircraft occurs, which is removed by a trimmer - a compensating device. In the Tu-154, this is a trim effect mechanism (MET), which adjusts the tension in the spring system, keeping the steering column from deviations. To control the MET, switches are used on the steering wheel handles, when turned on, the steering column smoothly moves to the position specified by the pilot.
At an altitude of 100 m and at a speed of approximately 400 km/h, the flaps are retracted during takeoff at 25 degrees. This operation is carried out by a flight engineer. He can stop it at any time, especially in cases where the retraction of the flaps is not synchronized.
When retracting the flaps, the pilot feels a pulling force on the control wheel as the aircraft's lift decreases. These efforts are also countered by trimming so that the plane does not “hang on your hands.” With an increase in speed and an increase in lift, on the contrary, pressing forces arise on the steering wheel, which are removed by the “recoil of the trimmer.”
“If the commander shouted “Flaps!”, then it is quite possible that such pressing forces arose at the helm that the ship’s commander could no longer counteract by trimming,” explains the pilot.
As the interlocutor of Gazeta.Ru suggested, perhaps the alignment of the plane was still disturbed. “Why didn’t this have an effect during takeoff in Chkalovsky and landing in Adler? Then, quite possibly, all the passengers were placed closer to the nose of the plane, and already in Adler they were seated as they wished.
The flight engineer simply did not wake them up and move them closer to the nose. It is possible that this was quite enough to create a rear alignment of the aircraft and catastrophic consequences,” explained the pilot.
He recalled that a Tu-104 with the command of the Pacific Fleet crashed in this way in 1981 in Leningrad.
Then, according to the version of Lieutenant General, honored military pilot and former commander of the Air Force and Air Defense of the Baltic Fleet Viktor Sokerin, which he told in the Independent Military Review, the commander of the Pacific Fleet, who arrived “very out of sorts”, wanted to fly in his cabin in the front part of the plane by oneself. About a dozen people were put in the “tail”, although it was necessary to do everything exactly the opposite, and then return to their places only after takeoff.
The crew commander expected that he would be able to lift the car off the runway at a slight angle at a speed higher than the calculated one with the maximum maximum permissible deviation, but rolls of paper rolling down the aisle after the start of the take-off run led to the alignment going beyond critical limits, and the car lost control.
“An airplane is a “pharmaceutical scale”, the rocker of which rests on a certain conventional bar, very small in width.
And it (the rocker) is parallel to the ground (and does not fall) only if there are approximately equal masses on both scales. The width of the bar in this example is the allowed “gap” between the maximum front and maximum rear alignments,” Sokerin wrote.
Gazeta.Ru's interlocutor, who is familiar with the preliminary results of the investigation, refused to talk about versions of the disaster, but clarified that in principle there was no overload of the Tu-154, as well as heavy cargo on board. According to him, except for musical instruments and a small number of boxes with humanitarian aid that philanthropist Elizaveta Glinka took with her, there was nothing on the plane.
“As has always been the case, the best were selected and got there, and I think that will be the case,” the minister said.
On Wednesday it became known that Russian President Vladimir Putin changed the format of the traditional New Year's reception in the Kremlin after the crash of the Tu-154. “You know what happened here, what a tragedy it was recently. Therefore, I want to change the traditional reception in honor of the New Year so that it is of a working nature,” RIA Novosti quotes Putin as saying.
On the Tu-154 military transport aircraft, which was heading to Syria from the Chkalovsky airfield near Moscow and crashed in the Black Sea after refueling in Adler on the morning of December 25, there were 92 people on board - eight crew members, eight military passengers, two federal civil servants of the Ministry of Defense , 64 artists of the Song and Dance Ensemble of the Russian Army named after Alexandrov, nine journalists from federal television channels and the head of the Fair Aid charity foundation, Elizaveta Glinka, known as Doctor Lisa.
The FSB named the working versions of the Tu-154 crash: foreign objects entering the engine, low-quality fuel, pilot error and technical malfunction. Experts interviewed by RBC doubt each of them
City residents at the mourning plaque for those killed in the Tu-154 plane crash (Photo: Viktor Korotaev/Kommersant)
Four versions
On Monday, December 26, the Federal Security Service (FSB) listed the main versions of the crash of a Tu-154 flying to Syrian Latakia. This was the entry of foreign objects into the engine, low-quality fuel, which led to loss of power and failure of the engines, as well as piloting error and technical malfunction of the aircraft, the FSB Public Relations Center (PSC) clarified in a message quoted by TASS.
All these versions are included in the list of the most common causes of plane crashes, Roman Gusarov, editor-in-chief of the Avia.ru publication, told RBC.
The FSB did not specify which of the listed versions is most likely. On Sunday, the authorities prioritized a technical malfunction of the plane, Interfax reported, citing a source in the emergency services. On Monday, Interfax, citing a source familiar with the situation, said that the cause of the Tu-154 crash could have been overload and equipment failure.
What happened to the Tu-154
The airliner, owned by the Ministry of Defense, took off from the Chkalovsky airfield near Moscow at 1:38 Moscow time on December 25. As RBC the airfield duty officer, before departure the plane underwent pre-flight training and “has flown before.” The plane refueled in Adler and headed for Syria.
The plane took off at 5:25, at 5:27 its mark disappeared from the radar, reported official representative of the military department Igor Konashenkov, quoted by the Zvezda TV channel..
There were 92 people on board: eight crew members and 84 passengers, including 64 members of the Alexandrov Ensemble. They were flying to the Khmeimim military base to perform there at a New Year's concert.
On board was a member of the Presidential Human Rights Council (HRC) Elizaveta Glinka, as well as the director of the Department of Culture of the Ministry of Defense Anton Gubankov and his assistant Oksana Batrutdinova, journalists from the television companies NTV (Mikhail Luzhetsky, Evgeny Tolstov and Oleg Pestov), “Zvezda” (Pavel Obukhov, Alexander Suranov and Valery Rzhevsky) and Channel One (Vadim Denisov, Alexander Soydov and Dmitry Runkov).
The military investigative department of the RF Investigative Committee for the Sochi garrison opened a criminal case into the crash under Article 351 of the Criminal Code of the Russian Federation (“Violation of flight rules or preparation for them”). On behalf of the Chairman of the Investigative Committee of Russia, Alexander Bastrykin, the investigation is being conducted by the central office of the Investigative Committee.
On the morning of December 26, the Ministry of Defense announced that 11 bodies of the dead and 154 fragments of the aircraft had been found. The bodies of ten dead and 86 fragments of bodies were flown to Moscow on Monday morning. As TASS reported with reference to the press service of the Ministry of Defense, two fragments of the control system structure were raised from the bottom, and their serial numbers determined that they belonged to the Tu-154; other elements are located at the bottom at a depth of about 30 m at a distance of 1.6 km from the coast; The scattering radius of the debris was about 500 m.
The department also reported that 100% of the surface of the crash area and a significant part of the bottom (7 out of 15 sectors) had been examined. The search operation involved over 3.5 thousand people, 45 ships and vessels, 12 aircraft, ten helicopters and three unmanned aerial vehicles.
A loss of power can occur when refueling an aircraft with “summer” fuel in winter, a source in the aircraft industry told RBC. At the same time, the expert noted that refueling with “summer” kerosene in the case of the Tu-154 could not lead to the failure of all engines, since it was not too cold. Even if the engines had failed, the source added, the shutdown of other systems would not have happened at lightning speed. “The auxiliary power unit, which also runs on kerosene, is responsible for generating electricity on board the aircraft. Unlike engines, it is not picky about fuel. And in a critical situation, it would be possible to transmit a signal about an emergency on board,” noted RBC’s interlocutor.
The version with fuel is also considered untenable by the honorary president of the International Aviation and Space Salon (MAKS), test pilot Magomed Tolboev. He noted that aviation fuel undergoes several checks: upon arrival at the storage facility, during reloading into the tanker and directly during refueling. The latter involves crew members, namely the flight engineer, the expert emphasized.
Wing problem
The last plane crash, the cause of which was officially named as a technical malfunction of the aircraft, was the crash of a civilian An-140 in Iran on August 10, 2014. As TASS reported, the electronic engine control failed.
Experts interviewed by RBC do not believe in the version of a technical malfunction of the Tu-154. RBC's source in the aircraft industry noted that its design has been studied so well over decades of operation that it is almost impossible to miss any faults.
The Tu-154 has a mechanical control system based on hydraulic boosters. According to Tolboev, complete failure of this system is possible only if all the liquid leaves it. “This system can fail only if a projectile hits the tank with hydraulic fluid, which is located in the center section. But even with a leak in the tank, you can continue the flight,” the expert said.
However, he caused a disaster due to fatigue failures in the wing mechanization. “When retracting the flaps, the mechanisms on the wings could not work synchronously - one section was completely retracted, but the other was not. The plane began to rotate and collapsed,” Tolboev suggested.
At the same time, none of the experts interviewed by RBC could identify any official version as the main one. Final conclusions can be drawn after examining the wreckage and deciphering the flight recorders.
With the participation of Philip Aleksenko