Incident Overview
A pilot reported that while cruising, a loud noise was heard and the helicopter yawed to the left. In response, the pilot initiated an autorotational landing into a residential area. During the landing, the helicopter impacted trees and the terrain.
Engine Examination Findings
Following the accident, an examination of the engine revealed two pieces of plastic lodged in the induction tubes. These pieces were identified as originating from the induction housing. However, the reason for the fracture that produced these pieces was not determined. The two pieces were found to fit together and could be positioned in such a way as to block the fuel injection control.
Sequence of Events
According to the pilot's account, the incident began in cruise flight with an unexpected loud noise and a left yaw. The pilot then performed an autorotational descent, which ended with the helicopter colliding with trees and the ground.
Investigation Status
The investigation concluded that the plastic pieces in the induction tubes could obstruct the fuel injection control, but the root cause of the housing fracture remains unidentified. No further analysis or causal factors were provided.