Update on injuries
front pax - broken leg
rear pax - broken sternum, fractured pelvis, fractured spine L1,L2,L3
rear pax - broken sternum , fractured spine c1
rear pax - fractured c3
N835GC second of three ship charter , was hover taxing along Taxiway at about 1.5m above ground, as it approached a small asphalt road to head into apron area it started to yaw to the left 10m prior to the road , suggesting maybe not pilot induced. The first 90deg of yaw was slow then it become quick and the aircraft pitched around. About 3.5 revolutions it hit the ground still rotating.