How is the empty weight CG calculated for an aircraft with various components like potable water and hydraulic fluid on board?

The correct approach to calculating the empty weight center of gravity (CG) involves using the total weight and moment of the aircraft, which includes all fluids, such as potable water and hydraulic fluid, that may be present on board. This method ensures that the CG calculation accurately reflects the actual loading and distribution of weight within the aircraft, as all components contribute to the total moment.

In the context of weight and balance, the empty weight of an aircraft is defined as the weight of the aircraft with all necessary fluids (like fuel, oil, and water) and any required equipment onboard, but without any payload or passengers. Therefore, to determine the empty weight CG correctly, one must consider the moment generated by all these fluids and properly account for their respective weights, incorporating them into the calculation.

By using the total weight and moment approach, the CG can be precisely situated, which is vital for safe aircraft operation and performance. This measure allows pilots and maintenance personnel to ensure that the aircraft remains within its operational limits and adheres to safety guidelines.