Abstract: The invention relates to an unmanned aerial device for performing a resistance, current and/or voltage measurement at an object, in particular a lightning protection measurement at a wind turbine, comprising a contact element with an electrically conductive contact area, which can be brought into contact with a surface of the object, in particular with a lightning protection receptor of a rotor blade, of a nacelle or of a tower of a wind turbine, and comprising an electrically conductive measurement cable, which, with a first end, is connected in an electrically conductive manner to the contact area, and, with a second end, can be connected to a resistance, current and/or voltage measuring device and/or a grounding contact of the object.

Abstract: The invention relates to a mobile rotor locking device for locking a rotor of a wind turbine, the rotor locking device being designed to lock a rotor in such a way that it is prevented from rotating about a horizontal axis, and that a longitudinal axis of a rotor blade is fixed in a vertical plane. The invention also relates to a kit and a locking member for a mobile rotor locking device and to a method for locking a rotor of a wind turbine. According to the invention, the rotor locking device is characterized in that the rotor locking device is designed to fix a main shaft, on which a rotor is disposed torsionally stiffly, so that it is prevented from rotating about its longitudinal axis.

Abstract: The invention relates to a method of servicing wind turbines having a hub containing a slewing ring bearing to which a rotor blade is fastened such that the pitch angle is adjustable. The rotor blade is brought into a position pointing vertically downward, lowered by means of threaded rods and hoisting means and attached suspendingly to the hub. The slewing ring bearing is then turned. The rotor blade is then hoisted again and fastened to the slewing ring bearing.

Abstract: The invention relates to a method of servicing wind turbines having a hub containing a slewing ring bearing to which a rotor blade is fastened such that the pitch angle is adjustable. The rotor blade is brought into a position pointing vertically downward, lowered by means of threaded rods and hoisting means and attached suspendingly to the hub. The slewing ring bearing is then turned. The rotor blade is then hoisted again and fastened to the slewing ring bearing.

Abstract: The invention relates to a mobile rotor locking device for locking a rotor of a wind turbine, the rotor locking device being designed to lock a rotor in such a way that it is prevented from rotating about a horizontal axis, and that a longitudinal axis of a rotor blade is fixed in a vertical plane. The invention also relates to a kit and a locking member for a mobile rotor locking device and to a method for locking a rotor of a wind turbine. According to the invention, the rotor locking device is characterized in that the rotor locking device is designed to fix a main shaft, on which a rotor is disposed torsionally stiffly, so that it is prevented from rotating about its longitudinal axis.