What should be done if the VOR or TACAN indications show unreliable data?

When VOR or TACAN indications display unreliable data, seeking confirmation of the readings before taking action is the most appropriate response. This approach allows pilots to ensure they are not acting on faulty information, which can lead to navigational errors or dangerous situations. By verifying the accuracy of the navigational aids or cross-checking with other instruments, pilots can make informed decisions and maintain safety.

It's important to consider other navigation methods and visual cues as potential alternatives, but these should only be employed after confirming that the primary instruments are indeed unreliable. This careful validation process minimizes the risk of making erroneous navigational choices based solely on potentially inaccurate data from the VOR or TACAN systems.