Mi-8 crashed in Yakutia due to inclement weather conditions
The investigation has withdrawn the technical documents and questioned the flight controller and personnel that inspected the helicopter.
Staff personal files and pilot logbooks of the Polar Airlines crew have also been withdrawn.
The Mi-8 was performing a flight between the villages of Deputatsky and Kazachiye when it carried out rough landing on the 2nd of July. Only four out of 28 passengers aboard have survived.
Voice of Russia, Interfax