The helicopter was attempting to transit an area of forecast poor weather and inadvertently climbed into cloud, where control was lost. During the loss of control, significant damage occurred to the gearbox isolation mount, rendering the helicopter un-airworthy. This damage was not discovered until two further sectors had been completed. The pilot was then advised that the helicopter was safe to fly to the owner’s maintenance facility and two further sectors were completed, before the helicopter was withdrawn from service. Subsequent inspections revealed numerous items of additional damage that were not immediately apparent. The extent of the damage meant that this occurrence met the definition for an accident. It was reported in February 2015.