What happened
Prior to liftoff, the pilot confirmed that all flight controls were free and that no warning or caution lights were illuminated. The cockpit lighting was noted as being very dim, consisting only of instrument and navigation radio lights. Despite a full and bright moon, the pilot elected not to activate the searchlight, landing, or taxi lights for the takeoff.
As the helicopter began a vertical ascent, the nose started to drift to the left. The pilot attempted to correct this by applying right pedal, but the control felt stuck or blocked. Within one to two seconds, the aircraft began a right roll. The pilot attempted to apply left pressure with the cyclic, but this control also felt extremely stiff or stuck. The aircraft subsequently rolled over on its right side, resulting in substantial damage.
At the time of the accident, weather conditions were clear with 10 miles of visibility and winds from 170 degrees at 4 knots.
The investigation
An examination of the aircraft's flight controls and other systems revealed no mechanical anomalies. The helipad was situated in a former gravel pit surrounded by pale, white-colored sandy soil that rose above the pad in all quadrants.
Investigators observed ground scars and paint transfers that were consistent with the right skid spring making contact with the pad. The pattern of these ground scars indicated that the helicopter was moving laterally and aft when the spring first contacted the surface, which subsequently initiated a dynamic rollover.