What must be filed no later than D-2 in relation to load distribution?

The requirement to file a Weight and Balance System (AWABS) no later than D-2 is essential because this system is crucial for ensuring that the aircraft remains within its weight limits and is properly balanced for safe operation. The weight and balance of an aircraft directly affect its performance, including stability, control, and fuel efficiency.

Filing the AWABS allows for the necessary calculations to be completed ahead of the flight, ensuring that the load is correctly distributed among passengers, cargo, and fuel. This proactive approach helps to identify any potential issues with load management before the departure, thus enhancing safety and compliance with regulations.

While other options such as a Load Distribution Report (LDR) may also be important, the requirement for the AWABS is specifically tied to the fundamental principles of aviation safety and regulatory compliance, making it critical to address it by the D-2 deadline.