Patent ID: 8601688

Claim:
A method for mounting a wind turbine blade to a wind turbine hub of a wind turbine by a crane boom, comprising: keeping a blade orientation horizontal when lifting the wind turbine blade off a ground and mounting the wind turbine blade to the wind turbine hub; bearing a weight of the wind turbine blade by a bearing wire; and controlling the blade orientation by a control wire and a winch arrangement; lifting the wind turbine blade with a lifting system comprising a lifting device which is attachable to the wind turbine blade and connects the control wires and the bearing wire; controlling the blade orientation horizontal when lifting the wind turbine blade off the ground using the control wires; and fixing the wind turbine blade in a horizontal position to the wind turbine hub, wherein the control wire connects the wind turbine blade to the winch arrangement via the crane boom and keeps the blade orientation horizontal and controls the blade orientation within a horizontal plane, and wherein the winch arrangement is located at the lifting device and controls the control wire for controlling a distance of the wind turbine blade from the crane boom and the blade orientation within the horizontal plane, wherein: the winch arrangement comprises a first winch and a second winch, the first winch controls the distance of the wind turbine blade from the crane, and the second winch controls the blade orientation within the horizontal plane.