When an airborne military aircraft changes its destination, what action is required?

When an airborne military aircraft changes its destination, the appropriate action is to forward the information to the Flight Service Station (FSS). This is essential as it ensures that all relevant authorities are aware of the change in flight plans, which helps maintain situational awareness and safety in the airspace system.

Notifying the arrival airport is important but primarily within the context of communication obligations; however, FSS serves as a central point to manage flight data, especially for military operations. Reporting to the nearest Air Traffic Control (ATC) may occur, but the primary requirement remains forwarding the updated information to FSS. Changing the flight plan is also critical, but this step is typically procedural and follows the notification to appropriate parties, including FSS. Thus, forwarding information to FSS serves as the key action that ensures compliance with air traffic regulations and coordination.