What action should be taken if more than one component of an ILS is unusable?

When more than one component of an Instrument Landing System (ILS) is unavailable, the appropriate action is to use the highest minimum required by any single component. This approach ensures that safety is maintained during the landing process by adhering to the stricter minimum standards that are typically established for ILS operations. The rationale behind this choice is that even if certain elements of the ILS are inoperative, pilots are still required to follow operational guidelines that prioritize safety, thus using the higher minimums protects against the risks presented by the compromised system.

This decision reflects an understanding of the importance of maintaining a safe approach environment, especially when multiple dependencies within the ILS are not functioning as intended. By utilizing the highest minimum, pilots ensure that any decision-making aligns with the regulatory standards set forth for safe instrument operations. Therefore, this choice embodies a conservative approach to safely managing the landing process under compromised conditions.