Accident Summary
At the conclusion of a spraying operation, the helicopter's engine lost power. The pilot reported that engine revolutions per minute (RPM) dropped to zero and airspeed fell to zero. An autorotation was initiated to manage the descent.
Pilot Report
According to the pilot, the helicopter made contact with rough hilly terrain during the landing. The aircraft bounced upon touchdown and subsequently rolled over onto its right side. No further details regarding the pilot's condition or the circumstances of the landing were provided.
Post-Accident Examination
Following the recovery of the aircraft, an inspection revealed a crack in the fuel servo unit. The crack was located adjacent to the mixture adjustment mechanism. Investigators noted that this crack would have permitted an excessive amount of air to enter the servo unit.
Probable Cause
The loss of engine power was attributed to the crack in the fuel servo unit. The crack allowed air to enter the servo unit in quantities sufficient to disrupt normal fuel metering, leading to a complete loss of engine power.