Incident Overview
During a takeoff from an area shielded from the wind by a large building, a helicopter initially obtained translational lift and began climbing. As the helicopter rose above the building, it encountered a right quartering tail wind with gusts reaching 20 knots. The pilot reported losing translational lift, causing the rotor rpm to decay. The helicopter then descended. Upon touchdown, the front toe of the right skid sank into soft soil, and the helicopter rolled onto its right side.
Sequence of Events
The pilot initiated the takeoff from a location that was protected from the prevailing wind by a large structure. After achieving translational lift and climbing above the building's height, the helicopter was exposed to a wind from the right quarter with gusts up to 20 knots. This wind condition led to a loss of translational lift, a critical aerodynamic state for helicopter flight. Consequently, the rotor rpm decayed, reducing lift. The helicopter descended and contacted the ground. The right skid's front toe penetrated soft soil during touchdown, causing the helicopter to tip over onto its right side.
Operational Context
The takeoff area's proximity to a large building created a wind shadow, but once above that obstacle, the helicopter faced a significant crosswind component. The pilot's control inputs were unable to maintain rotor rpm and lift after the translational lift was lost. The soft soil contributed to the rollover by allowing the skid to sink, destabilizing the helicopter further during the touchdown.
No Injuries Reported
The source does not indicate any injuries or fatalities resulting from this occurrence. The helicopter sustained a rollover, but specific damage details are not provided.