What happened
As the pilot lifted the helicopter off the platform, he immediately sensed an abnormality in the aircraft's behavior. Approximately two feet above the deck, the aircraft began turning to the left. A surviving passenger reported that the rear of the aircraft felt as though it were being pushed or pulled downward, causing the nose to pitch up violently. This motion caused the helicopter to bounce side-to-side on the platform.
Realizing there was insufficient space to land, the pilot applied upward collective to move away from the platform. During this maneuver, the aircraft rolled into an inverted position and descended into the water on the north side of the platform. There were no fatalities among the occupants.
The investigation
Investigators examined the west end of the platform's hatch door and discovered a bent and deformed handle. This handle featured a rolled gouge of metal and an associated paint chip.
Upon inspection of the aircraft, investigators found that the left spring-steel extension of the helicopter had paint scraped off its upper outboard corner along the entire length of the extension. Subsequent paint analysis and geometric evaluations confirmed that the paint chip on the platform handle matched the paint from the aircraft's extension. Furthermore, the physical deformation of the handle coincided with the placement of the spring-steel extension under the handle, indicating contact with the platform hatch handle during the takeoff maneuver.