Final answer:
To ensure that the unmanned aircraft center of gravity (CG) limits are not exceeded, one should follow the aircraft loading instructions specified in the manual and consider weather conditions.
Step-by-step explanation:
The unmanned aircraft center of gravity (CG) limits can be ensured by following the aircraft loading instructions specified in the manual. These instructions specify how the payload should be distributed in order to keep the CG within the prescribed limits.
Weather conditions can also impact the CG of the aircraft. For example, flying in windy conditions may require adjustments to the CG to maintain stability.
It is important to note that air traffic control instructions and pilot's discretion do not directly affect the CG limits of the aircraft.