An unmanned aerial vehicle mountable to an aerial conductor of an electricity transmission line to monitor a component. The unmanned aerial vehicle has a body having a propulsion system to lift, lower, and navigate the vehicle. A component monitoring tool is mounted to the body and is vertically displaceable between a first position and a second position. The tool in the first position is vertically spaced from the component. The tool in the second position is engaged with the component. A displacement assembly is mounted to at least one of the body and the tool and includes at least one displacement member to displace the body and the tool along the conductor.