Stephan, what you need is :
KN63 REMOTE DM with Indicator KDI572
The offer (with a used DME) was almost exactly € 10.000)
Peter,
the difference between a GPS distance and a DME distance is really small, makes no difference. It worked perfectly on all the approaches I have flown in the last year.
Well, Achim, that’s how all the US pilots fly, and it sure works.
I did NOT say it is legal.
PS. You know that flying in IMC below the MVA is just as illegal, right? How come i know so many who do it all the time? With, or without DME.
We’ve had that discussion before, you completely miss the point that a DME can have an offset in its indication which a GPS distance to DME will not give you. This advice is nonsense and dangerous.
Yes, you said that before. But you also never had an example when I asked.
GPS is working with a waypoint representing DME=0.
Isn’t that the case? A DME has an identifier which is registered as a waypoint in the GPS database, doesn’t it?
So apart from the difference due to slant range, what other factors would introduce a significant difference between GPS and DME distance?
the difference between a GPS distance and a DME distance is really small, makes no difference. It worked perfectly on all the approaches I have flown in the last year.
I am sure it worked for you in the past year.
Which waypoint are you using for the GPS distance?
Peter,
i really don’t have the IFR experience to know if it really works always, and since I don’t fly IFR approaches in (very) bad conditions, it’s not that relevant for me. But of course i do not want to recommend this illegal procedure to others.
Example: For the ETSI Z ILS to Rwy 25 (which i use to get below the clouds to land VFR at EDML) I use IGL TAC for DME, just like it is prescribed on the approach chart. The one dangerous mistake would be to use IGL NDB (345) for DME … thats what I did the first time.
This one?
@Flyer59 here are your examples:
NL Ponta Delgada 0.897NM
PR Porto 0.177NM
SPA Lulea 270m
ILB Lisboa 0.189NM
ILI Lisboa 0.176NM
And no, you cannot emulate the displacement by moving the waypoint, the displacement is a constant added to the measured value no matter on what DME “radial” you are.
what other factors would introduce a significant difference between GPS and DME distance?
The displacement programmed into the DME transponder. The DME transponder may have a delay other than the nominal delay, which causes a constant number to be added to the DME measurements done by the interrogator. This is sometimes done to make a DME read zero at the threshold even though the DME is not located at the threshold
Yes, Peter, that’s the one.
Tomjnx,
thank you for the examples. Have to study that. First look i’d say that 0,89 NM might make a difference ….
You have to keep in mind that in the Cirrus you have a large live approach chart that shows your position the approach. So the correct DME distance is not as relevant as in aircraft where the whole approach scenario is only numbers and bearings. Flying about 30 approaches using the GPS as DME i could never see a relevant difference.
I can’t see anything in the Jepp chart for Ingolstadt or in the Ingolstadt AIP entry to suggest that the TACAN DME IGL has any displacement.
In the AIP for Lulea you can infer that there is a displacement by the comment that it reads zero at the threshold of RWY32, even though the coordinates for THR 32 and the DME are different.
