As reported by the newspaper "Kommersant" in the material Sergey Mashkin "The pilots did not have enough seconds. Everyone and no one was to blame for the crash of the experimental aircraft," the commission of the Ministry of Industry and Trade of the Russian Federation, which investigated the causes of the crash of the Il-112B prototype military transport aircraft in Kubinka near Moscow [August 17, 2021], did not publish a report because they were never named. The experts "distributed" responsibility for the tragedy between the manufacturers of the engine that caught fire in flight, the designers of the aircraft itself, whose aileron control rods melted in 5 seconds, and, of course, the dead pilots who did not manage to cope with the fire during this time. According to a Kommersant source, at the final meeting of the commission, one of its participants said so: "Let the investigation look for the guilty."
The crash of the first flight prototype of the IL-112B military transport aircraft (serial number 01-01, tail number "01 yellow", registration number RF-41400) near Kubinka airfield, 08/17/2021 (c) a frame from the video
The technical commission under the leadership of the deputy head of the department Oleg Bocharov completed the investigation of the causes of the disaster.
The final report on its work, as a source close to the commission told Kommersant, will not be published.
Formally, because the crashed IL-112B was an experimental, non-serial model of the aircraft, and therefore, the members of the commission were obliged to comply with the requirements of the customer of the project, the Ministry of Defense, and not the international Civil Aviation Organization ICAO, which requires independent investigators to publish their reports regularly.
In addition, according to the interlocutor of Kommersant, this is due to the fact that the causes of the disaster were simply not named in the final report, and responsibility for it was evenly distributed among all participants of the Russian Military Transport Aircraft Il-112B project.
The investigators, as already reported by Kommersant, recognized that the emergency situation on board was provoked by the failure in flight of the right engine of the TV7-117ST aircraft produced by JSC "UEC Klimov". The surge of the power plant, accompanied by local explosions of the fuel-air mixture, provoked the breakage of the turbine blades and the destruction of the fuel pipelines located nearby. The resulting powerful kerosene fire spread from the nacelle of the right engine into the wing cavity, and there the fire, as follows from the conclusion, in a few seconds melted the retaining ailerons and flaps of duralumin thrust produced by PJSC Voronezh United Aircraft Society (VASO).
These conclusions were made shortly after the examination of the wreckage of the car recovered from the crash site and the analysis of the data of its recorder, which recorded the flight parameters. The rest of the time, experts, as already reported by Kommersant, devoted to studying the role of the crew in the tragedy that happened. To do this, a so-called mathematical model of the last minutes of the flight of the first and only "flying" instance of the Il-112B was created, and then all the control actions of its pilots were reproduced on the simulator. The comparison showed that the experienced test pilots of PJSC "Il" who were driving the car - Hero of Russia Nikolai Kuimov, Dmitry Komarov and flight test engineer Nikolai Khludeev - acted absolutely adequately to the situation and did not make any mistakes. According to one of the participants in the proceedings, "not a single pilot in the world" could have prevented the imminent collapse of the transport vehicle after the right aileron thrust was cut off.
Another question concerning possible mistakes made by pilots during the elimination of a fire on board, in fact, remained unanswered.
As it was established by the commission, the test program of the experimental Il-112B on August 17, 2021 in Kubinka included an extremely difficult and even dangerous element for the new car - going to the second round after a failed landing with one engine running. Recall that many aviation experts argued that the TV7-117ST engines do not develop sufficient power for the use of a transport vehicle in extreme conditions, and the test results should have convinced critics of the opposite.
In preparation for this difficult maneuver, the crew began to descend, during which a fire broke out. "Your right engine is on fire," the crew commander was informed from the ground.
By the same time, according to the commission, the so-called first stage of the fire extinguishing system was activated automatically, and a sound and light alarm about an emergency was activated in the cockpit. Feeding the first portion of the extinguishing mixture into the nacelle of the right engine did not eliminate the fire, and the pilots, as follows from the report, had to continue fighting the fire already in manual mode. To activate the second stage, they had to turn off and re-turn on the system, thus making sure that the fire was not extinguished, activate a switchgear directing inert gas from fire extinguishers to the place of ignition, remotely detonate the pyropatrons that open the exit of the mixture... To commit, as the investigators considered, only five actions.
The problem turned out to be that at the time of activation of the first stage of fire extinguishing and at the same time received a radio message about the fire, the plane was only 7-10 m from the ground.
The crew, as stated in the report, "conducted intensive radio exchange, was preparing for landing," however, due to the emergency, the pilots had to change their plans. "Commander Nikolai Kuimov considered that landing would be too risky in this situation," a source close to the investigation explained to Kommersant."Hoping to save the experimental aircraft, he stopped the descent and began to go on a second lap to sort out the situation and, if possible, solve the problem." At the same time, the most experienced commander, according to the interlocutor of Kommersant, of course, could not have known that he had only five seconds left before the traction break, loss of control and the departure of the car into an uncontrolled right bank.
During this time, the pilots tried to activate the second stage of fire extinguishing, but they did not have time to turn on the system. One of the participants in the investigation, representing the manufacturers of the machine, tried to reproduce the actions of the pilots in the last seconds, using the Il-112B "simulator" cabin for this. According to the results of the experiment, it turned out that the crew needed at least 40 seconds to supply the second portion of the extinguishing mixture. "Moreover, another portion of freon in the gondola would not have saved the plane anyway, since the fire had spread throughout the wing by this time," a source told Kommersant.
Nevertheless, the delay that actually took place gave one of the commission members a reason to doubt the competence of the deceased crew. The Commission did not agree with his conclusions, but the engineer's opinion was reflected in the final report in the form of a so-called dissenting opinion.
Another participant in the investigation told Kommersant that the crew under the leadership of Nikolai Kuimov did everything possible to save the car. Recalling the deceased commander, the interlocutor of Kommersant said that he even celebrated his 63rd birthday in December 2020 in the sky, performing the planned first flight of the Il-114-300: "The weather conditions then turned out to be so difficult that even the management suggested the birthday boy to postpone the tests and go home to his long-awaited guests and relatives. However, the pilot went to the holiday only after he completed the task."
Who is responsible for the tragedy, according to experts, will have to be determined not by the Ministry of Industry and Trade, but by the TFR.
The criminal case initiated by the Western Interregional Investigative Department of the TFR on Transport on the fact of the disaster on violation of the rules of traffic safety and operation of air transport (Part 3 of Article 263 of the Criminal Code of the Russian Federation) is still being investigated.
According to VASO qualification, Flight No. 0001 took to the air 23 times, while making only 22 landings. Moreover, all its flights were short, five-minute, and from March 2019 to March 2021, the aircraft did not fly at all due to identified technical flaws. The experts made the most claims to the engines of the transport vehicle. However, despite all the problems that have arisen, the experimental copy was planned to be shown first at the International Aerospace Salon (MAKS) in July 2021, where it was to be presented by Rosoboronexport, and then at the International Military-Technical Forum "Army-2021", held a month later. The rush, experts believe, created the conditions for the disaster.
The Ministry of Industry and Trade did not confirm or deny the information at the disposal of Kommersant, noting only that the technical commission does not identify those responsible for the disaster and, moreover, does not appoint those responsible for it. "Its task is to identify the causes of the accident and develop recommendations to prevent similar tragedies in the future," the ministry said.