Helicopter Rolls Over After Power Loss During Blade Tracking Landing (N552CS)

Incident Description

The pilot reported landing in an open, unpopulated area to allow a mechanic to make adjustments to the main rotor blade tracking and balancing. The engine was not shut down; the clutch was disengaged. After the adjustment, the pilot engaged the clutch and brought the helicopter to full power, performing all pre-takeoff checks. Everything appeared normal. The pilot had landed into the wind and departed into the wind. At an altitude of about 25 to 30 feet, the helicopter sounded as if it was losing power, and a vibration was felt. A quick glance revealed loss of both rotor and engine tachometers. The pilot lowered the collective and added more power, but there was no effect. Upon landing, the helicopter rolled over onto its left side. The pilot stated that no controls were effective due to loss of engine and rotor rpms.

Post-Inspection

The helicopter had been moved before officials arrived on scene. A later inspection revealed no evidence of a mechanical malfunction or failure of any system.