Ultranomad wrote:
The main risk of using GPS for DME
So once again: With the wide-spread use of GPS for DME in the US, one would expect to see significant evidence (stats) to support the perceived added risk of such practice.
Plus the offset zero of ILS DMEs (in the UK at least)….
But it cannot be beyond the wit of man (or Garmin) to dispkay a virtual DME distance when a given VIR/DME is selected….
With the wide-spread use of GPS for DME in the US, one would expect to see significant evidence (stats) to support the perceived added risk of such practice.
No, because just about every hay barn in the US has a GPS approach.
But it cannot be beyond the wit of man (or Garmin) to dispkay a virtual DME distance when a given VIR/DME is selected….
Indeed, but you would need a database of DME=0 waypoints.
The slant range error would be taken care of by the GPS knowing the altitude 
Just a side note: many places now have some sort of GPS based approach with at least advisory glide path. It happened frequently that on my last destinations the ILS was out of service.
I still have to come across a place I want to go to where DME is required and there is no GPS approach.
Slant range versus what a GPS will display for typical instrument approach altitudes, distances, and speeds, the difference will be on the order of fractions of a seconds, in other terms: insignificant.
Michael wrote:
insignificant.
I think the main problem might be the DME offset, which is a strange thing. Possibly this is not used in the USA?
AOPA Air Traffic Services Brief
1998 to 2016 : That’s 18 years that US pilots have been LEGALLY substituting GPS for ADF & DME.
I think the main problem might be the DME offset, which is a strange thing. Possibly this is not used in the USA?
They have those allright e.g. KCHD where I did the FAA IR
However KCHD has an RNAV approach also so presumably most people will fly that.
That’s 18 years that US pilots have been LEGALLY substituting GPS for ADF & DME.
I think, Michael, you misunderstand the issue here. The issue is that often there is no waypoint in the GPS database which corresponds to DME=0. In Europe.
Peter wrote:
The issue is that often there is no waypoint in the GPS database which corresponds to DME=0. In Europe.
I’m not sure I understand what your’e saying here – care to educate me please ?
