The investigation is checking the possibility of simultaneous failure of several Embraer control systems
Experts involved in the investigation of the crash of the Embraer Legacy 600 aircraft in the Tver region, which killed the founder of Wagner PMC Evgeny Prigozhin and another 9 people are skeptical about the possible connection of the disaster with the repair of the aircraft. A thorough check of the fuel with which the aircraft was filled is currently underway. According to MK, the version of external influence on Embraer is not currently being considered.
Recall that shortly before the crash, two manipulations were carried out with the plane. The replacement of the turbo-cooler was ordered after crew commander Oleg Volkov noticed an extraneous sound from the air system during a flight from St. Petersburg to Moscow on July 18. He reported this to the engineer of the MNT-aero airline, after which it was decided to suspend flights and replace the part.
In addition to the turbo-cooler, the brake temperature sensor was replaced on board Prigozhin's aircraft. Overheating of the brakes usually occurs when the aircraft is landing, and if the temperature reaches critical levels, the indicator lights up red. In this case, ground staff are even asked not to approach the minimum distance to the side of the aircraft tires where the thermal switches are located.
In the case of Prigozhin's Embraer, it was precisely about problems with the sensor that was replaced. However, neither its failure nor the failure of the turbo-refrigerator, according to experts, could cause a critical situation in flight.
Studying the development of events on board the aircraft, the experts involved in the investigation drew attention to several points.
When the emergency happened, Embraer was most likely controlled by autopilot. The second commander of the aircraft, Oleg Volkov, confirmed that the autopilot was usually turned on after climbing 300-400 meters. From this moment until landing, the crew influences the control of the aircraft to a minimum. The exception is speed control, since the Embraer does not have an autothrottle (a system that automatically controls the thrust of engines).
At the time of the accident, the plane was at an altitude of approximately 8.5 km. Experts believe that if the crew and passengers were conscious after some incident, they had a maximum of 40 seconds to put on their masks and try to send a distress call (assuming a depressurization occurred on board). However, this did not happen. This development of events again allows us to return to the version of the explosion on board, which is considered among others (as the presidential press secretary Dmitry Peskov put it, we can talk about a “deliberate atrocity”).
“The device could be quite low-power from the point of view of the layman, – says a source close to the investigation. – But it could be in the cabin in the emergency exit area – on the right side, where the right wing attachment point is located. This explains the abrupt separation of the wing, the reaction of the pilot (he pulled the helm sharply towards himself) and the sudden change in the trajectory of the aircraft.
At the same time, experts are trying to understand whether events could develop in this way not during an explosion, but in the event of a failure of one or more aircraft systems.
A similar incident occurred in September 2010 on board the Tu-154 during the Udachny-Moscow flight. The thermal runaway of the battery (a sharp increase in the temperature of the electrolyte) led to a short circuit and the failure of the entire power supply system on board. The electric fuel pumps also failed. But the crew, even in such a critical situation, managed to land the plane in the taiga at an inactive airfield in Izhma (Komi Republic). None of the 81 passengers and crew members were injured.
Recalling that story, air investigators emphasize that almost all Embraer Legacy 600 control systems are duplicated. For example, in the event of a jammed rudder, you can control the aircraft with the help of engines, then increasing, then decreasing thrust.
An analogy arises with a more recent case that occurred not in the sky, but under water. On July 1, 2019, a fire broke out in the Barents Sea at the AS-31 Losharik deep-sea station. 14 submariners were killed. Then the cause of the tragedy was the explosion of the battery and the subsequent fire in the battery compartment. Experts will also check the possibility of such a development of events on board Embraer.
By the way, eyewitnesses claim that members of Prigozhin's team, as a rule, did not take portable batteries (power banks) with them, since the plane was already equipped with them. But a fire and even an explosion of a power bank could hardly lead to such instant consequences as a wing separation.
Speaking about the possible damage to the aircraft while still on the ground, the investigators again return to the features of Embraer storage. The plane spent the winter in the hangar, the summer – in the open parking lot at Sheremetyevo, “for reasons of economy,” as a source at the airline explained.
If we talk about malicious interference, first of all, the manager of the aircraft, the engineers involved in the repair, as well as potential buyers who visited the aircraft on the morning of August 23, a few hours before the crash, fall under suspicion. The fact of the sale of the aircraft was not hidden from the airline employees – after the visitors had left, the crew commander Alexei Levshin informed his replacement Oleg Volkov about the “bride”.
Let's add that all airline employees, when hiring, underwent a polygraph examination, where one of the key questions was: “Do you have any intention to harm the main passenger?” (To Evgeny Prigozhin – Author).
The Embraer refueling scheme is checked separately. The fuel distribution mechanism for the fuel tanks is located to the right of the fuselage, that is, in a potentially dangerous zone, if we take the version of the explosion as a basis.
It has been established that before the last flight the aircraft was not completely refueled – 4 tons were filled, which are quite enough for a flight to St. Petersburg. The additional tank was not filled. It is noted that the refueling procedure at Sheremetyevo is standard, and no one noticed anything suspicious in the work of the tankers before the departure of Prigozhin's plane.
