Is it true that the navigation radios cannot be selected to AUTO tune when DME hold is selected?

When DME hold is selected on the navigation system, the radios are prevented from switching to AUTO tune, a feature that is typically used to automatically acquire the appropriate navigational frequency. This restriction is in place because when DME hold is engaged, the aircraft is focused on maintaining a specific Distance Measuring Equipment (DME) function, which relies on a steady reference point for navigation. If the radios were to automatically tune to different frequencies, it could lead to confusion and potential loss of navigational position during critical phases of flight, particularly in situations where precise distance and positioning are required.

The functionality is deliberately designed to ensure that navigation radios remain stable and under manual control rather than automatically tuning away from the current DME reference that is being held. Therefore, stating that navigation radios cannot be selected to AUTO tune when DME hold is selected is accurate, and understanding this concept is vital for safe aircraft operation in scenarios that involve DME usage.