Mi-2 crash in Perm Krai on 16 April 2008

The Mi-2 crash in Perm Krai was the crash of a transport helicopter of the Russian company Gazpromavia with 2 crew members and 2 passengers on board; 3 people were killed.

Circumstances of the accident

The crew was carrying out a gas pipeline patrol flight on the route Chaykovsky - Kungur - Berezovka - Leshchevka in the daytime under VFR. After taking off from the Berezovka site, the helicopter's nose landing gear struck a power line wire at the point where two lines crossed a branch of the gas pipeline. The helicopter broke the upper ground (earth) wire of the second line in the direction of flight, went into a descent and, 160 m from the power line, collided with trees and the ground.

The terrain in the area of the accident is complex, with significant differences in elevation. In this area, frequent changes in wind direction and speed are possible on hilltops and in lowlands.

Causes of the crash

The helicopter crash occurred in the area where the gas pipeline route crosses a high-voltage power line, owing to the helicopter's collision with the ground surface and trees as a result of the crew's actions to clear the detected power line wires by climbing, which led to the nose landing gear strut colliding with the lightning-protection wire of the power line and breaking it, as well as to the main rotor becoming overloaded (rpm droop) and a spontaneous descent of the helicopter.

The factors that caused the aviation accident should include:

the helicopter commander's unjustified decision to descend and to carry out a terrain-following flight over terrain with complex orography at a height below the safe height;

the late detection in flight of the power line wires, owing to their lack of marking and small cross-section diameter, in bright lighting conditions when flying into the sun;

the absence of information on the crew's flight charts about the presence of two power lines in the area where they cross the route of the trunk gas pipeline.