What happened
The accident occurred during a local sightseeing flight conducted along a ridge line. The pilot was maneuvering the aircraft to avoid a developing cloud build-up when the plane unexpectedly encountered wind shear. This sudden change in wind conditions caused the aircraft to pitch down abruptly, entering a vertical dive with an approximate attitude of 75 degrees.
The pilot managed to regain partial control of the aircraft just before it would have impacted a line of trees. Despite this recovery effort, the aircraft subsequently collided with the terrain while maintaining an approximate attitude of 45 degrees.
The investigation
Meteorological analysis of the area indicated specific atmospheric conditions conducive to wind shear. In these mountainous regions, catabatic winds frequently flow downslope as solar heat radiates from the terrain, cooling the surface. Additionally, trade winds crossing the ridges obliquely create eddies that produce off-ridge flow.
The investigation determined that a wind shear event occurred when these eddies and catabatic gusts coincided, directly contributing to the loss of control.