What procedure is used for grounding an aircraft?

The proper procedure for grounding an aircraft typically involves ensuring that the aircraft is electrically grounded to prevent static electricity build-up and to safely dissipate any electrical charges. Grounding is primarily done to protect personnel and equipment from possible electrical hazards, especially during fueling operations or when working on the aircraft.

The selected answer emphasizes grounding by connecting it to a ground source to ensure that there is no potential difference between the aircraft and the earth, eliminating the risk of static discharge. This step is crucial, as it creates a path for any static electricity to flow safely to the ground, mitigating any risks of igniting fuel vapors or causing electrical shocks.

While the other options might have elements of safety procedures for working on or around aircraft, they do not represent the complete or proper grounding procedure. For instance, ensuring the aircraft is powered off is important for safety, but it does not directly address the grounding process itself. Similarly, connecting to a lightning rod and attaching straps to the tail can be associated with grounding in specific contexts but are not the standardized procedure outlined for grounding an aircraft overall.