Eurocopter AS 350 B2 N106HN accident near Morgantown, West Virginia

Probable cause

The pilot’s failure to maintain control of the helicopter during the practice hovering autorotation. Contributing to the accident was the pilot’s lack of experience in night vision goggle helicopter operations.

NTSB analysis

About 1.5 hours after beginning an introductory instructional flight in the use of night vision goggles (NVGs), the pilot and the flight instructor returned to the airport to practice autorotations from a hover. After establishing the helicopter in a 3-foot hover, the flight instructor moved the fuel flow control lever toward the idle cutoff position. The pilot responded by increasing collective pitch, and the helicopter began to ascend, and as a result, the rotor rpm decayed. The flight instructor attempted to apply corrective action, but the pilot physically resisted his efforts. The helicopter descended rapidly to the ground, resulting in substantial damage to the tailboom. The pilot noted that during the maneuver, he had misjudged the helicopter’s height above the ground, due to the decreased peripheral vision afforded by the NVGs. This was the pilot’s first flight operating with NVGs.

Text from the NTSB. Open the NTSB docket for ERA09CA367 for the full record.