On September 15, 2016, a Robinson R66, registration RA-05783, was involved in an aviation accident in the area of the Narva settlement within the Krasnoyarsk Territory. The aircraft was operated by the State Enterprise KK "KrasAvia."
During the investigation, data analysis of the engine performance showed normal operation during start-up, ground idle, and the transition to flight idle. However, fluctuations in the power turbine speed were observed prior to an increase in power turbine N2, which were likely caused by an external influence.
Technical findings indicated that a decrease in power was related to the downward movement of the pitch lever. A subsequent sharp increase in power turbine speed N2 was associated with the removal of load, triggering the activation of the power turbine overspeed protection system.
The investigation concluded that the aircraft experienced an uncontrolled descent and collision with the ground during the takeoff phase.