You can take a lookf at my answer to @Habu2u2 if you’re interested.
And I have another exemple too, my last F28 flight was from AYSE (not referenced in Navigraph but in MSFS you’ll find it, very small airport) to AYNZ. As you can see, without any GPS there are pretty much no NAVAIDS here. So I RELY on the VORs and NDB a lot. I flew a 218° heading from AYSE until I received the NZ VOR on 113.9 (once again, frequency superior to 111,95 means to me that it’s not a terminal VOR, and Navigraph once again agree). When in range of NZ, I’ll fly a direct to this VOR and start the VOR DME Runway 09 approach. Guess what ? I never received the VOR. Once again I looked outside and changed my heading according to the VFR map on Navigraph. I picked the NZ VOR at 29nm
In this case, without ATC following and if there is a big cloud cover : impossible to navigate, except if you do a pretty good dead reckoning.
I’ll take note of the VOR and its range each time I fly and report it.
Thanks for your answers, have a great day and happy new year.
@Habu2u2 In my response, I forgot to link you my source for the range and math formula. It’s a known French webiste but I guess traduction will be precise enough : It turns out I can’t include links in my posts on this forum (??). The website is a known french aviation website called lavionnaire. Go to the Instruments Radio Nav section and you’ll have my source. it’s a general knowledge site of course, but still pretty good to make a general idea of things.
Thanks.
Hi Jowen,
My original testing was just to check out the issue you had of only picking up MKS at 7.9 miles, not to see if the VOR’s are accurate, because most of us are seeing varying degrees of error with VOR’s in various parts of the world. Some errors are extreme, and some relatively not “too far” off actual range.
BUT, now to muddy the waters a bit more, I flew the route you used, and discovered a few things.
I flew the first leg of your flight, and (surprise, surprise!!), I picked up MKS at ~22 NM’s (FL 280). Not even the same range (37 NM’s) as I picked it up when testing flying from to it from west-to-east and east-to-west earlier! There’s no real terrain masking coming from your original course or coming from the West, and I picked it up ~15 NM’s different on each route!
So I think your comment “The ranges of the VOR are completely random in MSFS. Never reliable. I don’t ask for always max range, off course, but something you can actually rely to properly fly an aircraft.” is really accurate in this case specifically.
I went direct from MKS to MJU at FL280 (heading mode with nav armed for VOR) and picked up MJU at ~32 NM’s. I restarted the flight and came into MJU from the west and picked it up ~22 NM’s. Again, not consistent, especially given there’s no terrain issues coming in from the west.
I went straight out from MJU toward PAL and picked up PAL ~32 NM’s out (@ FL220). There was definitely some possibility of terrain masking further out, as there some terrain that visually didn’t unmask the airport/VOR area until I was closer in than the VOR’s max range should be.
So all I can conclude from limited testing is that there are some major differences in the VOR ranges of various ones I tested.
At the end of the day, there’s no apparent consistency in the range that some VOR’s are received in the sim. Which we knew, but I can’t find a common link between the different range issues I’ve seen.
Regards, and Happy New Year!
Thanks again for your answer and the further testing.
It seems we have a similar experience and we can clearly say that there is something wrong with VOR. I just flew with the BlackSquare TBM to the same VOR I mentionned to @hobanagerik, taking off from Goroka (AYGA) and going to Nadzab (AYNZ) and the NZ VOR on 113.9. This time I picked it at 37.8nm precisely, instead of 29nm in my previous exemple with the Fokker F28. I was far lower with the TBM, at 11 000ft, instead of 26 000ft with the Fokker. This time I was coming from the west however.
Another proof that nothing is consistent.
How do we bring those feedbacks to the dev ? I don’t understand where we can send a ticket.
Start by going to the “Support” link at the top of the page.
With the height difference between those two flights, you might be observing the effect of slant range? When you were measuring the distance, were you using DME or GPS? That said I’m not sure an altitude difference of 14,000ft would account for a nearly 9nm difference. Interesting enough to test though.
It’s the engineer in me…
Wouldn’t bother testing slant range as a factor. Most folks grossly overestimate the effect of slant range. Basic right triangle formula (a squared + b squared = c squared, where a is distance from VOR, b is height, and c is slant range). A quick GA-type result is:
30 miles from the VOR at an altitude of 2 miles (to keep it simple) means the slant range is 30.1 miles. If you go to 5 miles up, the slant range only goes to 30.4 miles.
A gross example is: 100 miles from VOR with an altitude of 3 miles, the slant range is 100.04 and if you’re at 7 miles up, the slant is 100.2 miles.
So don’t think that’s a real factor in how they’re determining when you pick up a VOR signal in the sim.
I did see something earlier in this thread that intrigued me concerning setting a what I believed to just be a filter, seemed to affect the receiving range of a VOR in the sim. I haven’t done any testing on that theory, so take it with a big grain of salt at the moment.
Regards
I knew you thought it was a stretch! It was in your !!
I’m going to try and play with that idea stated earlier in this thread to see if there’s validity to the idea that the filter on VOR’s may actually be tied to their range in the sim. Doesn’t sound right on the surface, but could be something someone coded that way for some reason (good or not!).
Regards
While you’re all doing this, don’t forget that the published service volumes of VORs are only applicable to guaranteed off-route coverage (outside of any limitations published in the chart supplement). Understandably, but unfortunately, flight sims have historically used these as the maximum theoretical range of the VOR, a binary on/off reception switch, which is not how it works at all.
Now, with the switch to the enhanced service volumes (ESV), I think there’s even more confusion in the databases. Whatever the interpretation, it’s often incorrect, as you are all finding.
All great points!
Wouldn’t it be great if they either (1) put out a “discovery video” for MS24 covering just the navdata and covered as many questions as possible that the community has on how the data is actually implemented in the sim,
or (2) Have one of their navdata functional experts give a presentation that addresses implementation of the navdata, just like Ms McGrail did for the marketplace.
It’s frustrating not having more information on this area (as a lot of others are about other aspects of the sim!). Let’s face it, simmers love information!
Regards
Hi @Jowen
Looking back on your earlier statement “114.7MHz means that it’s a high altitude VOR both in theory (will link a source at the end of the post) and according to Navigraph.”, I think I found part of the issue with MKS, MJU and PAL.
I pulled the VOR information up from the G3000 on the D930 for each of them. It appears MS implemented all three as terminal VORs! See screenshots. I suspect Navigraph has it right, and MS just implemented it incorrectly. That would account for why we’re not getting its signal until close-in.
I did another flight, this time from Nadzab (AYNZ) to Port Moresby (AYPY). I planned to track 124 radial from the NZ VOR until 49nm then right turn heading 179 until I pick the Port Moresby PY VOR (117 MHz). I lost NZ at 38nm, and picked PY at 17nm. Thus unable to plan my descent correctly. I should prepare dead reckoning for those flight actually.
I opened a ticket with link to this thread and our discussions, also linked an FAA document and the french website I talked about earlier. Also, I have a 2007 FCL1-A PPL (Cepaduès 7th edition) book and took a look at the VOR section, the same math formula is used to estimate VOR range, so we can say it’s a reliable source ; even if it’s quite old, VOR were not reinvented in the meantime.
I did another flight, from Port Moresby (AYPY) to Merauke Mopah (WAFF). Simple flight, following a 272 radial from the PY VOR (117) until I can pick the MKE VOR (115.8) and then VOR DME RW 34 approach.
I lost PY at precisely 38nm and picked MKE at 31.8nm. Once again, far too short. For me, it’s 100% of the tested VORs in the last 2 weeks which are completely broken in terms of their range.
Hi Jowen,
If you get a chance, can you test DGO VOR (114.5 and about 11 NM WNW of AYPY and, and YXM VOR (113.7) about 323 NM NW of DGO near Komo airport/AYXM and see what kind of results you get?
I’m getting what I’d consider normal results for those two, and I’m trying to nail down some issues with the others.
Thanks!
I’ll try them as soon as I have a flight in Papua New Guinea with the Fokker and give you the feedback.
However, just looking at Navigraph right now, I don’t find any VORs at DGO, near Port Moresby. I’ll look at it inside the sim tomorrow.
The YXM VOR will be interresting to see because my next flight with the Fokker will take off from WAKK and head in to the mountain chain where YXM is. I’ll tell you my results as soon as I play.
I have done further tests, I am crossing the US in small GA aircraft like the A2A Commanche and JF PA-28. And yesterday, the ARG VORTAC (Walnut Ridge on 114.5) gave me a plausible result, flying at 5000ft, I lost it at 64.7nm. I think it’s a coherent range.
I just played right now with the BS TBM 850 in Panama and I used the DAV VOR on 114.3 to do some RNAV, I was able to track it until my destination, Osa Sirena (MRSN), some 68nm from the VOR. I flew at 7000ft. Once again this time, I think it’s a good behavior.
Will head back to New Guinea or Oceania in general to do more tests.
Currently in the Fokker F28 for a WAKK-AYMH flight via the YXM VOR. I lost the MKE VOR at 38nm. It seems that it’s a reccurent value. However, I was able to switch to YXM as soon as I lost the MKE VOR and received the signal at 167nm. This is a good value indeed !
I can’t pick DGO VOR and indeed it doesn’t exist on Navigraph, but is here in MSFS.
Will continue to test other VORs and report it here.
Do you use Navigraph nav data to replace the default MSFS core nav data? I assume you don’t if DGO VOR appears in the sim, since it has been decommissioned and no longer exists in r/w, and should not be present in MSFS is Navigraph core nav data is installed.
!!
