On August 23, 2021, an ANSAT helicopter operated by OOO AK "RusAvia" was performing emergency medical assistance flights. The flight route included departures from Ivanovo (South) airport, stops at the "Ivanovskaya OKB" facility and Kineshma facility, and a return to Ivanovo (South).
During the landing phase at the Ivanovo Design Bureau landing area, the aircraft, registration RA-20059, experienced a failure of the main rotor system. The crew members were in their designated positions and wearing seat belts at the time of the event. Following the landing, the crew successfully evacuated the helicopter via the cockpit doors without injury.
An investigation by the Federal Aviation Authority "Aviareestr Rossii" examined blade No. 3 of the main rotor. The examination revealed that the blade had broken into four primary fragments, including the root part of the spar, central spar fragments, and the tail section. The investigation determined that the destruction of the blade was not due to manufacturing defects.
Technical analysis indicated that a portion of the blade broke off due to high-speed contact with a solid surface, likely concrete, during the landing. The fragmentation of the blade occurred at sections where the spar's structural stiffness changed, specifically at the centering weight joints and areas where the rear wall thickness and configuration changed.