Russia's Sukhoi Superjet-100 crashed in Indonesia because of a whole complex of reasons, including the human factor, investigators said. The specialists studied the information that they could obtain from the flight recorders and came to conclusion that there was a potential customer staying in the cockpit shortly before the aircraft slammed into the mountain. However, the customer was not interfering into the actions of the crew. The person was only interested in the technical performance of the airplane.
A source close to investigation told RIA Novosti news agency on conditions of anonymity that the Terrain Awareness and Warning System was active during the demonstration flight. The pilots, investigators believe, received visual and audio signals warning of the mountain slope ahead. However, they ignored the signals because they were certain that they were flying above a valley, at a safe altitude. An Indonesian flight control officer approved a descent from 10 to 6 thousand feet. The pilots could not see the mountain on time because of thick clouds.
The crew supposedly received a signal from another onboard signal. The system said that the aircraft was flying low above the ground and prompted the extension of the landing gear. Being at a loss about the relief of the area, the commander decided to deactivate the automatic equipment to descend independently. "It could be possible that the crewmembers were certain until the very last moment that they were flying above a valley," the source said.
The pilots contacted the Indonesian flight control officer to find out whether it was possible to continue the flight as before. However, the officer did not respond. The Indonesian side had problems with either communication or location, which may often happen in mountainous areas.
Officials with Indonesian aviation authorities said that the Russian plane had all documents for demonstration flights in Jakarta. No technical malfunction was reported during the first demonstration flight of the passenger jetliner. The plane was fuelled with high-quality fuel accordingly, investigators said.
Russia's Sukhoi Superjet-100 crashed into the vertical slope of Salak Mount on May 9th. There were 45 people, including eight Russians, on board. The crash left no survivors.