Accident of Tu-134 near Chkalovsky

The second prototype of the Tu-134 with the serial number 0001 and known as the " Understudy " was built in the summer of 1964 at the MMP "Experience" (according to other sources - at the Kharkov Aviation Plant ^[1] ). Compared with the first prototype ( CCCP-45075 board , factory - 0000), the second prototype had an elongated fuselage for half a meter (an insert was made behind the wing), additional fuel tanks in the detachable parts of the wing, which increased the fuel stock to 16.3 thousand liters ( 13.2 tons), and passenger compartment capacity increased to 64 seats. An on-board automatic control system was also installed, thanks to which the liner could perform an automatic approach , including at night and during bad weather conditions. Two turbofan engines belonged to the model D-20P-125 . The total mass of the empty aircraft was 24.9 tons. Some sources indicate the model of the Tu-124A, but the model name was changed to Tu-134 back in 1963 at the design stage.

On September 9, the board 45076 made its first flight, and in the period from February 20 to April 7, 1965, factory tests were conducted, during which it made 36 flights with a total duration of 60 hours. In June 1965, the aircraft 45076 was presented at the Le Bourget Air Show , after which it completed flights to Berlin , Warsaw and Prague . On July 18, the second prototype was handed over to state tests, which were conducted by the Scientific-Research Institute of the Air Force (based in Chkalovsky), which allowed the aircraft to be known for military applications.

On January 14, 1966, the board 45076 carried out its 89th flight, and it was piloted by a crew of 8 people, including the ship's commander V. Yevseyev , the assistant ship commander Yu. I. Rogachev and test navigator V. L. Malygin . In this flight, it was planned to take the characteristics of the stability and controllability of the aircraft, while consistently carried out platforms at altitudes of 5000, 8000 and 10 000 meters. But when the plane began to perform the last mode, the “Steering ... [inaudible]” was transmitted from the board. The car at an altitude of 10 kilometers suddenly went into decline, and then crashed into the ground near a pond in the village of Rozhdestveno, Sobinsky District, Vladimir Region. The whole crew died. It is believed that at the last moment the crew was able to take the falling plane away from the nearby school. The car still caught one of the houses, where the cow standing in the yard crushed.

When opening the flight recorder, it was revealed that the section with the latest flight data was illuminated, and the flight data recorder K-3-63 was uncharged. Thus, it was impossible to establish the flight parameters.

According to the commission from the Tupolev design bureau , the cause of the catastrophe was a crew error, which, in order to quickly perform the flight, began to make a U-turn at a speed of 0.86 Mach number . At the same time, the crew was used to flying heavy Tu-104 , Tu-124 and An-12 aircraft , which were not equipped with booster amplifiers, and therefore at high speeds the oncoming air flow did not allow the rudder to be strongly deflected. However, the Tu-134 had control system amplifiers, so when the commander Evseev pressed the rudder pedal, he immediately deviated by all 25 °. Because of the high speed of the flight, the airliner entered the list, and the unknown to such behavior the pilot tried to get out of it, but only complicated the situation by putting the car into a dive.

According to specialists from the State Research Institute of Civil Aviation and the Air Force Academy named after N. Ye. Zhukovsky, the plane did not fall intact, but began to collapse even in the air. At the same time, in 250 meters from the place of the fall, separate parts were found, and the attachment of the hinge points of the rudder were cut off. According to studies of previous flights, it was found that the rudder oscillations had already been observed, and if at an altitude of 5 kilometers they were still insignificant, then at an altitude of 8 kilometers they became stronger as the air density decreased, which worsened the steering damping. Flights at an altitude of 10 kilometers to the fateful flight were not conducted. Probably, at an altitude of 10 kilometers, the rudder oscillations were already so strong that the crew lost control of control.

After this catastrophe on Tu-134 planes, a spring loader was included in the rudder control system, which reduced the steering deflection angles to 5 ° in each direction. The cruising speed of the aircraft was reduced to 0.82 Mach number. Also after this incident, state tests of airliners began to be carried out by civilian pilots from the State Research Institute of Civil Aviation .

• N. Yakubovich. Tu-134: from the past to the future // AviaArhiv . - 2008. - № 1 .
• Dmitry Komissarov. Tu-134. The diversity of appearance (rus.) // Aviation and time . - 2010. - № 02 .