active New Zealand South issue

[Stefano Biasiotti]

An example to explain:

 

1.I am on the rnwy of NZGY small field

2. I look at the GPS coordinates of PrepareD (top left corner) and they match perfectly with the google earth position

3. I have also set the exact position of the  QN VOR 113.6 on google map (I can see the VOR on google map) and the position is taken from skyvector map..

4. I see the VOR radial 269° whilst the correct radial measured on google map is 292.

5. I have checked the radial using also another airplane and the answer is the same.

 

My conclusion is that it seems that the VOR GPS position in the scenery is wrong.

This issue happens also with at least the NV VOR 116.8

 

Is this a known issue?

Is there a way to solve it?

 

Thank you,

Regards,

Stefano

 

 

[Stefano Biasiotti]

UPDATE

It is worst than what I wrote:

 

test descritpion

- I am at NZNV, runway 04.

- VOR is set to NV 116.8

- My DME and radial says that the VOR it is not exactly in the correct GPS position (compared to the google earth position) , but the error is more or less 1 mile. So nothing dramatic.

 

I take off from NZNV to NZRC (Oban small arifield)

The radial from NV is 176° and I fly toward my destination.

When I am nearby the destination I loose (why?) the VOR signal.

After some minutes flying above the NZRC destination, the VOR signal is received again but....and this is very strange, the radial is uncorrect: this time I see the NV VOR not to 10° 30NM BUT  I see it for 346° 30 NM.

The DME seems to be correct but the VOR is left of about 24°.!!!!

 

If I try to take off directly from NZRC...as soon as I receive the NV VOR signal, I get the wrong position again. DME almost correct  but radial shifted to the left of 24 degrees.

The same issue that I found for the QN VOR 113.6

When I am nearby it it iseems to be in the (more or less) correct position. But if I intercept the signal when I am far from it...the radial read is shifted.

 

Very strange and very bad considering I like to fly VFR with only VOR/ADF aids.

In the Norway scenery that I have flown everywhere I have never had this error.

 

To conclude: it does not seems to be a wrong VOR position, but is like to have to VOR in different position, same frequency: one is right, the other is a "ghost" that leads me in the wrong direction.

 

Any idea of how to correct it?

 

Thank you

Stefano

 

[wulfbindewald]

The "mismatch" between geographical radials and displayed navigational value comes from the magnetic variation of -23° in this area next to Queenstown. This value varies according to the location too and are hard coded in the sim (for FSX as of 2006).

Deviation examples for 2017:  NZQN Queenstown  ~ -25°, CYYZ Toronto ~ +18°, EBBR Brussels ~ +1° , ENGM Oslo ~ -2°.

So the displayed radial on your navigational unit is ok.

[Stefano Biasiotti]

Thank you for the answer:

 

It explains the error but does not explain why sometimes the error happens and sometimes not:  when I take off nearby the VOR I can read the radial without a significant deviation. Then when I am "far" from it, should we say 30 NM, I loose  the signal and when it is locked again the deviation occurs.

 It is a random behaviour.

 

Is it due to the wrong behaviour of prepar3D?

 

Thank you,

Stefano

[Stefano Biasiotti]

Thinking on your answer I have the suspect that the magnetic deviation consideration is wrong

 

The VOR acts using radial radio beams that are not related to the magnetic earth field.

 

When I get the VOR signal flying I should see the needle pointing in the VOR position. Following that needle I should arrive over the VOR position. 

If I do it, I arrive over a WRONG position, very very far from the correct (initial) position.

 

This has nothing to do with the magnetic deviation.