If the DME at PUC airport is inoperative, what functionality changes for the airborne DME?

When the DME (Distance Measuring Equipment) at an airport is inoperative, it impacts the functionality of the airborne DME. The airborne DME relies on ground-based stations to provide accurate distance information. If the DME at PUC airport is not operational, the airborne DME will no longer receive the distance information it typically calculates from that ground station.

Regarding the transmission of a coded identification audio tone, when a DME is functioning correctly, it transmits this audio tone to indicate its presence and allow for identification by pilots. However, if the DME is inoperative, it will not transmit this tone, leaving the airborne equipment without the standard identification signal that could assist in navigation.

Thus, the correct answer reflects the change in operation of the airborne DME in the absence of a functional ground DME, resulting in the inability to transmit a coded identification audio tone.