Primary finding
Probable cause
The pilot's selection of an unsuitable landing site, which caused "brown-out" conditions during departure liftoff and resulted in loss of control of the helicopter.
Investigator assessment
Analysis narrative
The pilot of the med-vac helicopter reported that, during liftoff at the remote site, he encountered a loss of visual reference due to a "brown out" condition created by blowing dust at 3 feet agl. He then attempted to land the helicopter without any visual reference; however, the right skid contacted the ground first. A rolling motion to the left was created and, after the left skid contacted the ground, a dynamic rollover ensued. The helicopter came to rest on its left side.
Source record
Factual narrative
On August 18, 2001, at 1425 hours Pacific daylight time, an Aerospatiale AS 355F1 helicopter, N53LH, rolled onto its side and came to rest during takeoff at a remote location, 4 miles east of Vinton, California. The commercial certificated pilot, two flight nurses, and one patient were not injured. The helicopter was substantially damaged. The on-demand, air taxi, medical transport flight was operated under 14 CFR Part 135, by Rocky Mountain Holdings, LLC. Visual meteorological conditions prevailed and a company VFR flight plan was filed. The flight was destined for Reno, Nevada. According to the operator, the pilot reported that, during liftoff, he encountered a loss of visual reference due to a "brown out" condition at 3 feet above ground level. He attempted to land the helicopter without any visual reference; however, the right skid contacted the ground first. A rolling motion to the left was created and, after the left skid contacted the ground, a dynamic rollover ensued. The helicopter came to rest on its left side.