That's really interesting, A&C. I would have thought that the FMS navaid databases would have corrections built in for this; let's face it; it is pretty well known
Is DME more accurate than GPS? It is more robust for sure (interference wise) but I thought the resolution (and thereofre the accuracy limit, unless you can manage to interpolate) is 0.1nm.
unless it says Narco on front of the DME box.
Scarily accurate
The other problem with a DME is that the aircraft box can fail without any warning yet return plausible values. I used to fly with one such in my IMCR training, in a PA28-181. It always read something plausible between 3D and 10D - perfect for instrument approaches
