Method for mounting rotor blades of a wind turbine

A method for mounting rotor blades of a wind turbine, wherein the wind turbine has a rotor hub having first, second, and third rotor blade ports, the method comprising:

• fastening a mounting arm to the first rotor blade port, wherein the mounting arm has a first section and a second section that are coupled to each other via a swivel hinge, wherein an angle between the first and second sections is variable by the swivel hinge;
• turning the rotor hub so that the first rotor blade port is in a 90° position or in a 270° position;
• while the first rotor blade port is in the 90° position or in the 270° position, fastening a first end of the first section of the mounting arm to the first rotor blade port of the rotor hub;
• turning the rotor hub with the help of the mounting arm so that the second rotor blade port is in a 270° position or in a 90° position, wherein the angle between the first and second sections of the mounting arm is varied while turning the rotor hub;
• lifting a first rotor blade so that the first rotor blade is horizontally mounted to the second rotor blade port of the rotor hub;
• turning the rotor hub with the help of the mounting arm so that the third rotor blade port is in a 270° position or in a 90° position;
• mounting a second rotor blade to the third rotor blade port;
• turning the rotor hub with the help of the mounting arm, until the first rotor blade port is in the 90° position or in the 270° position, wherein the angle between the first and second sections of the mounting arm is varied by the swivel hinge;
• removing the mounting arm from the first rotor blade port;
• and
• mounting a third rotor blade to the first rotor blade port.