Crash "Superjet": the pilots made a fatal mistake

At the Moscow Sheremetyevo airport, the domestic regional airliner “Sukhoi Superjet 100” of Aeroflot Airlines crashed. According to the latest data, out of 78 people on board, 41 were killed, including one crew member. This is the first serious accident of this type of aircraft in the last 7 years. In 2012, in Indonesia, the Superjet performed a demonstration flight, during which the airliner crashed into a mountainside. The official reason for the tragedy was then called the crew’s ignorance of the terrain features.





But back to the disaster in Sheremetyevo. I note right away that the aircraft was practically new (tail number RA-89098). He made his first flight less than two years ago - on June 21, 2017. Three months later, the liner was delivered to Aeroflot, where it flew by no means for wear. The average flight time of this type of aircraft in the airline is only 3,6 hours per day, compared to almost 11 hours for Boeing and Airbus machines. Most of the time "Superjets" spend on the ground. Perhaps this was one of the reasons for the tragedy. I will explain why.

Just half an hour after the crash, the main reason for what happened was that lightning hit the plane during the flight. Indeed, as confirmed by the pilot Denis Evdokimov, who was landing the aircraft (AF), about 20 minutes after takeoff, an electric discharge hit the liner. He disabled the radio communication equipment of the aircraft, the operation of which was subsequently partially restored.


Here I would like to note that absolutely all modern commercial airliners are designed in such a way that they are not afraid of even a very powerful lightning strike. The last plane crash, caused by lightning, occurred in 1963. Then, as a result of an electric shock on a Boeing-707 of a Pan American airline, the fuel tank detonated. The plane crashed near the city of Elkton, Maryland, USA. All people on board died. Since then, all aircraft began to be equipped with static arresters, which remove electric charge from the surface of the aircraft during flight. Despite the fact that hundreds of liners are subjected to lightning strikes every year, over the past 50 years this has not led to tragedies.

The failure of the Superjet communication facilities is, of course, associated with the electric discharge entering the aircraft, however, the reason for this behavior of the equipment remains to be seen. The first thing that comes to mind is the flaws in the design, assembly and maintenance of the aircraft.

Let us return to the record of the explanations of the pilot of the fatal Superjet.


- said the pilot.

There is no “direct control” on this type of aircraft. All interaction with the control planes of the liner occurs through a computer. However, there are two modes of operation. The normal mode is when the side stick (joystick) deviations are processed by the on-board computer, which uses various algorithms based on the position of the aircraft in space, the speed of the incoming flow, etc., that is, to some extent helps the pilot control the aircraft. Emergency mode (conventionally “direct”), when the control plane of the aircraft completely repeats the sidestick deviations. However, even in this case, the computer acts as an intermediary of signals. It is he who gives commands to hydraulic drives that deflect the steering surfaces of the liner.

The difference between the two modes is enormous: the plane reacts differently to the same sidestick movements. Of course, ideally, pilots should be able to control the aircraft in both modes, but in practice everything turned out differently. In this context, the statement of the pilot Denis Evdokimov seems extremely strange:



These words contradict the video published on the Web, which clearly shows how the plane "goat" in the strip. This is precisely due to the outstanding (too high) vertical speed of the aircraft. Simply put, the plane was dropping too fast. After a hard blow to the ground, the liner bounces like a ball and touches the ground again.


The last such jump becomes fatal for the aircraft. Due to a strong blow, the left landing gear pierces the fuel tank, and sparks from touching the tail of the aircraft on the ground provoke ignition of the fuel that flows out. Given that the tanks were completely full, the dynamics of combustion radically reduced the chances of escape by leaving the aircraft. Bottom line: more than half of the passengers died in the crash.


Of course, the desire of the pilots during an emergency to land the aircraft faster is understandable, but this was the crew’s mistake. Pilots made a progressive "scum", when with each subsequent jump the liner bounces off the ground even higher, and ultimately, having lost horizontal speed, it simply falls. In such a situation, you should immediately stop landing and leave for the second and subsequent circles. Most likely, the crew simply did not have experience in emergency control of this type of aircraft.

Be that as it may, soon we will find out the true causes of the disaster. As it became known on the morning of May 6, flight recorders have already been removed from the scene of the tragedy and sent for examination.