The helicopter was on a Visual Flight Rules (VFR) flight from New Ross, Co. Wexford, to its base near Galway Airport. En route, it entered an area of rising terrain and low cloud base, near Derrybrien, Co Galway. Radar tracking indicates that the helicopter slowed down, and then made a sharp turn before disappearing off the screen. The helicopter then suffered an in-flight collision with terrain directly after the loss of radar contact. A passenger died at the scene and the pilot died later in hospital. Another passenger survived with serious injuries. The probable cause was the pilot’s loss of spatial orientation resulting from inadequate visual reference with the ground due to limited visibility. The Report makes two Safety Recommendations.