What is one of the primary functions of a Payload Distribution agent?

The primary function of a Payload Distribution agent is to plan a load distribution using the ALIS, which stands for Advanced Load Information System. This involves ensuring that the weight and balance of the aircraft are optimized for safe operations. Proper load distribution is crucial as it directly impacts the aircraft's performance, safety, and compliance with regulations. By using the ALIS, the agent can analyze various parameters, such as cargo weight and positioning, to create a balanced load that helps prevent issues such as unstable flight characteristics or overloading.

In contrast, the other selections refer to responsibilities that do not align with the core duties of a Payload Distribution agent. Monitoring flight duration, supervising maintenance, and coordinating passenger check-in are distinct functions handled by other specialized roles within the aviation industry, focused on operational efficiency, safety compliance, and customer service. Therefore, focusing on load distribution through the ALIS is the distinctive and essential duty of a Payload Distribution agent.