Ми-8 RA-25607 14.07.2013

     The accident involving Mi-8 RA-25607 helicopter owned by "Gazpromavia" aviation enterprise" Ltd occurred in Kargasoksy district, Tomsk region (RF) on July 14, 2013. Three crew members and 14 passengers were on board. According to the preliminary information first officer and passengers suffered injuries of various degrees of severity, the rotorcraft was partially destroyed.
     The Interstate Aviation Committee has assigned the Investigation team of the accident in accordance with the Russian Aviation Legislation. The Investigation team has started its work.
     

      Flight recorders of Mi-8T RA-25607 helicopter involved in the accident in the Tomsk region (RF) on July 14 were delivered to the Interstate Aviation Committee on Julyn18.
      The Interstate Aviation Committee experts carried out activities on data recovery and readout on July 18-22, 2013.
      All FDR and Navstar receiver recorded data was copied and transferred to the Investigation team for further analysis. 
      All read voice data contained on MC-61 tape recorder reels detected at the accident site does not refer to helicopter operation on July 14, 2013.
    

The Interstate Aviation Committee Investigation team has completed the investigation of the accident involving Mi-8Т RA-25607 helicopter owned by Gazpromavia Aviation company, Ltd occurred in the Tomsk Region (RF) on July 14, 2013

Most probably, the accident involving Мi-8Т RA-25607 helicopter was caused by crew uncoordinated actions during take-off resulted in helicopter accelerated left rotation and its ground impact. 

Contributing factors could be: 

•          PIC override in helicopter control without providing information to the rest of the crew;

•          partial loss of situational awareness and/or spatial disorientation in helicopter accelerated left rotation. 

Hazard factors were determined during the investigation: autopilot connector contamination caused by its leakage and a wide range of individual performance characteristics of specific RA-60B control units in control directional axis (in case of compliance of each  prototype with requirements) which in certain conditions can significantly increase inflight emergency situation risk. However no aeronautical equipment failure evidence which could have effected the accident flight result were identified. 

The appropriate safety recommendations based on the investigation results were developed.