Robinson Helicopter Company R44 II N395CE incident near Anchorage, Alaska

Probable cause

The overhaul facility's improper and excessive use of an approved lubricant during overhaul of the fuel injection servo, which resulted in a disruption of fuel flow and a total loss of engine power.

NTSB analysis

The flight instructor reported that the purpose of the flight was to do a postmaintenance check flight after servicing and overhaul of the helicopter's fuel injection servo assembly. The instructor stated that, after an extensive preflight inspection was completed, the helicopter was moved outside the hangar. The helicopter's engine was started and allowed to warm up for about 10 minutes, and all ground run-up checks were satisfactory. While operating at 100 percent rotor rpm and while raising the collective to begin the takeoff, the engine abruptly experienced a total loss of power.The helicopter remained on the ground and did not sustain damage.

A detailed examination, which included disassembly of the fuel injection servo, revealed white contamination ranging in consistency from grease-like to solid throughout the entire fuel servo assembly. The lubricant was used in excess and in locations not approved by the manufacturer's maintenance manual. It is likely that the contamination throughout the fuel injection servo caused a disruption in fuel flow, which resulted in a total loss of engine power.

Text from the NTSB. Open the NTSB docket for ANC16IA013 for the full record.