DME on HSI (pic)

[clayton4115 56]

has you can see it tells me i am 3.9 DME from touchdown on the ils ISS, however at some fields this is blank or 0 can anyone tell me why this is the case at some airports?http://forums.avsim.net/user_files/156555.jpg

[Triple7 1]

Hello,Not all ILS procedures radiate a DME distance.MichaelB

[Guest deltamike172]

DME is only displayed if the ILS or LOC is equipped with DME. Not to sound condisending, some procedures simply do not have the capability installed. In those cases, looking on the chart with indicate what other facility to use to determine distances. Sometimes, the DME is located at the localizer site (at the far end of the runway, the departure end) and so, as the chart would indicate, the threshold, arrival end of the runway is a mile or two from the DME site, so you get something along the lines of 1.2DME at the threshold for landing. Other times, the DME is located at the GS tower, which is about .2 miles from the threshold. Im sure someone could find other special instances. Just look on the approach chart, and it'll tell you on both the plan view and profile view what the DME distances from whtaever navaid each point on the approach is. DM