Sometimes, there are 2 ILS/DME approachs on opposite ends of a runway, with 2 different ILS frequencys, but with same DME (a DME arc). 在计算备降标准时，算作一套设备还是两套设备？

​Brett是这样回答的：

The determination of whether it is two different navaids is based upon the primary component of the approach in question. The DME is not considered primary, but rather the localizer would be what this is based on. So as long as it’s two different localizers, then it’s fine.

因此，这种共用一个DME的情况，可以算作两套设备。