Engine And Rotor RPM Suddenly Decreased, The Helicopter Yawed To The Left And Started To Settle
On July 21, 2020, at 0558 Pacific daylight time, a McDonnell Douglas 600N helicopter, N208MP, was substantially damaged when it was involved in an accident near Thompson Falls, Montana. The pilot was not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 133 rotorcraft external load operation. The pilot stated that, as he was on an approach to a landing zone, he lowered the collective to start a vertical descent to land. At that time, the engine and rotor rpm suddenly decreased, the helicopter yawed to the left and started to settle.