Final answer:
Hot refueling cannot be performed until validation procedures are completed on the aircraft, fueling systems, and the facility.
Step-by-step explanation:
Hot refueling cannot be performed until certain validation procedures have been completed on the aircraft, fueling systems, and the facility. These validation procedures typically include thorough inspections and tests to ensure the safety and proper functioning of the equipment involved in the refueling process. For example, inspections may be conducted on fuel lines, pumps, valves, and tanks to check for any leaks or damages that could pose risks during fueling. Additionally, the facility where the refueling takes place may undergo inspections and checks to ensure it meets the necessary safety standards.