Which paired channel do most airborne Distance Measuring Equipment systems tune to automatically?

Most airborne Distance Measuring Equipment (DME) systems automatically tune to the VOR/LOC paired channels because these systems are designed to work in conjunction with ground-based navigation aids.

The VOR (VHF Omnidirectional Range) provides azimuth information, while the LOC (Localizer) is part of an Instrument Landing System (ILS) that provides lateral guidance during landing. DME works by determining the slant range distance between the aircraft and a ground station, which typically operates alongside VOR or ILS systems. This integration allows pilots to receive both lateral navigation guidance from the VOR/LOC and distance information from the DME, facilitating more accurate navigation and approach procedures.

The other options, while related to navigation as well, do not represent the paired channels that are most commonly utilized by DME. For instance, the NDB/VOR pairing involves a Non-Directional Beacon and VOR, but DME is not typically used with an NDB. Similarly, LOC/ILS refers specifically to the Localizer, which is part of the ILS rather than having a direct relationship with DME. The DME/ADF pairing includes an Automatic Direction Finder, which serves a different navigational purpose and does not automatically tune like the V