LLZ/DME

A Localizer/DME approach (in short LLZ/DME or LOC/DME) is a nonprecision instrument approach procedure for aircraft. It uses the localizer which provides lateral guidance and a DME in order to provide distance information. Vertical guidance by a glide slope is not provided. The pilot must use either visual aid or calculation from distance to run from the DME to determine the correct height. Some airports only have an ILS system in one direction of the runway, and localizer/dme approach is commonly used when the aircraft is approaching the runway in the direction that does not have full ILS guidance. It is called backcourse approaches which uses the localizer signal from the opposite direction.