What should be done if a second aircraft confirms a malfunction reported by the first?

When a second aircraft confirms a malfunction reported by the first, the appropriate action is to notify the Flight Leadership Management (FLM). This step is crucial because the FLM is responsible for the oversight of air traffic operations and safety. By alerting them, you ensure that the necessary resources and decisions can be mobilized to address the situation effectively.

This action serves multiple purposes: it allows for an immediate assessment of the issue, which could involve evaluating the malfunction's impact on safety, scheduling additional investigations, and potentially putting measures in place to prevent further complications. Additionally, notifying the FLM helps maintain situational awareness across the control team and informs ongoing operational decisions.

The other choices do not adequately address the importance of a systematic response to confirmed malfunctions. Continuing to use the NAVAID after notifying all pilots would not be prudent without first evaluating the situation in depth, while rerouting an affected aircraft without coordination can lead to further complications. Ignoring the report could jeopardize safety, as confirmed malfunctions could affect multiple aircraft and necessitate a coordinated response. Therefore, notifying the FLM is the most responsible and effective action in this context.