When on ILS glide slope, aircraft is 320’ below check height. At 4.1nm IHB aircraft is 980’, check height is 1300’.
Also observed that when over rwy threshold IHB DME reads 1.8nm.
Correct QNH set.
Similar issue at YMLT 32ILS.
Hi,
do you use any 3rd party scenery for YMHB? Have you tried the same with ie. FBW A320, instead of any Garmin GPS?
Cheers
Richard
Hi,
thanks - can you try the same without the 3rd party sceneries please? My assumption is, that the sceneries (elevation) is possible not 100% accurate …
Therefore, please try it only with thw stock sceneries as a next step.
Cheers
Richard
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Hi, I’m having the same issue at these places. Tested with both stock and 3rd party scenery and various different aircraft and same result. Correct QNH set.
I will try to reproduce it with the latest FBW A320 and the stock scenery.
Cheers
Richard
I have redone ILS approaches at YMLT and YMHB with both default and aftermarket sceneries.
The altitude/dme discrepancies exist with both sceneries when using the Garmin. I used the MSFS C172 Garmin1000.
Using the FBW A320 and PMDG 737, data seems to be correct!
Hi,
thnaks again for your help to identify the issue. It really seems that this is a Garmin issue. I have tried it with the FBW A320 and the stock scenery, and I don’t see any ALT/DME issue …
… but I will make some further tests to be clear, if this is at least not a navdata issue.
I will keep you informed 
Cheers
Richard
This might be applicable:
Also, read this in Discord (not having MSFS, I do not know whether the statement below is correct, although I suspect it actually is):
By not changing the pressure for temperature changes, MSFS is sort of doing the temperature correction for them that would normally be necessary on cold days to maintain obstacle clearance. Since MSFS doesn’t reflect the temperature effect, an MSFS pilot continues to maintain the same obstacle clearance regardless of temperature.
IIRC, X-Plane 11 doesn’t require temperature correction (probably for for similar reasons), whereas X-Plane 12 has an improved/more complete atmospheric model where the effects of temperature on pressure are simulated and thus, among other things, temperature correction is required when/where it would be IRL.
It’s possible the Garmin avionics use a trick to simulate the effect of temperature on pressure where MSFS itself doesn’t?
Regards,
Tim