The crash of Mi-8 in the Yamal-Nenets district on July 2, 2008

The crew of the Mi-8T RA-22599 helicopter of UTair Airlines OJSC carried out a transport-connected flight along the route Noyabrsk - the landing site of exploration well No. 774 of the Vorgensky field in order to deliver the commission for the commissioning of the drilling rig. On board the helicopter were three crew members, 13 customer passengers and 200 kg of cargo. When approaching the helicopter to the site and braking the flight speed, at an altitude of 30 meters, the PIC noticed a sharp decrease in the rotor speed to 90 - 89% and the helicopter began to “squander”. A helicopter with increased vertical and outstanding translational speed, with a large pitch angle for pitching, landed on the landing pad, which led to the tail heel and tail rotor touching the concrete surface of the landing pad. Having run 8 m, the helicopter separated from the ground and landed with a left turn of 280 ° on the main landing gear for the platform, on the ground located 5 m below the platform level. Immediately after landing, an intense fire began. As a result of the disaster, 9 passengers were killed, 4 passengers and crew members were injured of varying severity. The helicopter burned down.

At 03 hours 53 minutes, the crew, after compulsory inspection cards, with the permission of the Noyabrsk air traffic controller, took off from the Noyabrsk airport. On board were 13 passengers of the customer, 200 kg of cargo and three crew members. The flight along the route Noyabrsk - R-774 Vorgenskaya took place without deviations from regulatory documents. 20 kilometers prior to boarding, the crew started pre-landing preparation and completed it in full, according to the Instructions for interaction and technology of work of crew members Mi-8T (section: “Flights with the selection of sites from the air”), as evidenced by the crew’s internal negotiations recorded by the MC-61 on-board tape recorder. It follows from the explanatory crew members and the MC-61 on-board tape recorder that, in order to clarify the direction and speed of the wind, the FAC decided to carry out a control inspection of the landing site and performed it by going over the platform with a course of 70 degrees at a safe height. The helicopter was actively piloting the PIC, the co-pilot was the controlling pilot. After performing the inspection and a control card before landing, the crew made a right turn at the site with a heading of 20 degrees, with a north wind of 4 m / s. The landing was supposed to be performed using the “helicopter” method, outside the zone of influence of the “air cushion”. The helicopter reached the landing line at 05:21 a.m. (11 a.m. 21 a.m. local time). After the sound of the RV-3 radio altimeter, the preset of which was set to a height of 100m, was triggered, the FAC informed the crew: “We are getting in the crew.”

According to the PIC, when approaching the site and braking the flight speed, at an altitude of 30 meters, he noticed a sharp decrease in the rotor speed to 90 - 89% and the helicopter began to “draw down”. To maintain the revolutions of the NV, the FAC delayed the movement of the general pitch knob to increase the NV step, but the NV revolutions continued to decrease, and the vertical helicopter lowering speed increased. When approaching the landing site (from the explanatory PIC), the commander increased the pitch while simultaneously undermining the general step of the HB to damp vertical and translational speed in order to prevent the helicopter from rolling out of the site. A helicopter with increased vertical and outstanding translational speed, with a large pitch angle for pitching, landed on the landing pad, which led to the tail heel and tail rotor touching the concrete surface of the landing pad. Having run 8m, the helicopter separated from the ground and, turning around in the air with a left turn of 280 °, landed on the main racks behind the site, on the ground located 5m below the site level. Immediately after a helicopter landing, an intense fire began. Passengers were evacuated by crew members and workers of the drilling crew. As a result of the disaster, 9 passengers were killed, 4 passengers and crew members were seriously injured. The helicopter burned down. Video disaster reconstruction on YouTube ( obscene language ).

The crash of the Mi-8T RA-22599 helicopter was the result of a rough landing of the helicopter at the landing site with a large vertical and outstanding horizontal speed, which led to the displacement of the main gearbox of the helicopter from its regular position, a break in the kinematic connection: the main gearbox - engines, which led to the spinning of rotors of free turbines engines before their destruction and the occurrence of an intense fire in the engine compartments and inside the passenger compartment of the helicopter. The rough landing of the helicopter was the result of one of the following factors, or a combination thereof:

• a possible change in the direction and strength of the wind directly above the landing site in relation to the direction and strength of the wind indicated by the wind indicator;
• possible excess of helicopter landing mass for given landing conditions;
• a possible error in the crew’s actions during the landing, expressed in a late and vigorous increase in the overall HB step, which led to a decrease in the rotational speed of the propeller below the minimum allowable and sharp drawdown of the helicopter;
• possible failure of one of the engines with a partial loss of power when landing a helicopter.

The factor that aggravated the severity of the consequences of the accident is the lack of protection for the cargo and passenger compartment of the Mi-8 helicopter from non-localized destruction of free engine turbines, which led to the instant spread of fire from the engine compartments to the cargo and passenger compartment and the death of passengers.

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IAC Report