VOR 2 tracking question?

[Razor5-1]

This is a technical question that i'd like an answer to please. I often practice IFR flying in other sims.

Today I was practicing an NDB DME approach to a local airport. I picked up the 026 degree approach and tracked it in.

This is where i'm confused. I drifted off to the left a bit so i flew towards the needle to the right. However the tracking got worse. I actually had to fly away from the needle to correct the approach. If the needle was to the left I had to fly to the right to correct. I'v never seen this before and the approach was really messy because I kept flying to the needle as i'm used to.

Can anybody please shed any light on what/why this happened? Why was the tracking reversed basically.

 

This is the VOR indicator I was using.

[Kaiza]

I am not familiar with the HSI that you have attached however:

 

NDB approaches are different to VOR in that you will not get a course bar/CDI bar. All you get is a needle that points to the station. You will only get a course bar on a VOR, TACAN, ILS or GNSS approach. What was you course bar dialed up to? I suspect it may have been a VOR, in which case the deviations that were displayed were not reference the NDB, they were reference a VOR that was elsewhere.

 

To fly a NDB approach you need to dial up the course, but only for reference for your inbound track. Use the needle to track inbound rather than the course bar. Remember "push the head, pull the tail" so if your ADF needle is right of the inbound course (this means you are left of track) you need to "push the head" ie come further right to "push" the head back on track.

Edited November 6, 2012 by Kaiza

[Razor5-1]

I set the VOR 2 to the DME of the airport. When I fly the arc the needle then comes "alive" when I cross the runway off to my wing. I have flow like this before without problems, I use the ADF to fly the arc then swith to track the VOR 2 needle(set to the DME frequency) when I am abeam the runway heading.

 

There is no VOR at the particular airport, only DME and NDB.

[whartsell]

This is a technical question that i'd like an answer to please. I often practice IFR flying in other sims.

Today I was practicing an NDB DME approach to a local airport. I picked up the 026 degree approach and tracked it in.

This is where i'm confused. I drifted off to the left a bit so i flew towards the needle to the right. However the tracking got worse. I actually had to fly away from the needle to correct the approach. If the needle was to the left I had to fly to the right to correct. I'v never seen this before and the approach was really messy because I kept flying to the needle as i'm used to.

Can anybody please shed any light on what/why this happened? Why was the tracking reversed basically.

 

This is the VOR indicator I was using.

 

Were you flying a VOR approach or a NDB DME approach? For a NDB approach you would not use the VOR indicator at all. On an NDP approach the main instrument would be your ADF indicator or RMI if equiped. If the NDB approach references DME fixes you would use the VOR only for verifying those fixes.

 

On charts the radial reference would be (as shown in your VOR indicator) FROM the station. When you are tracking a VOR with a FROM reading you fly away (from) from the needle to center it. When the VOR has a TO reading you fly TOwards the needle.

 

If you let me know what approach you were flying I can look over the chart and give you some pointers on it.

 

Hope that helps

[whartsell]

ADF is not used to fly a DME arc. You use VOR/DME for that.

Flying DME arcs is a bit confusing at first.

 

Im curious which approach you were flying.

[Razor5-1]

This is the approach I was flying, I tracked the crk VOR until 8 miles DME then turned right to heading 163 degrees. I flew the arc until I reached the bearing of 026, the VOR indicator then comes alive and I follow it down to land, I now realize that I may have been doing this completely wrong! The only things tuned in are DME and NDB, but VOR needle activates.

 

http://www.flywaterford.com/images/eiwfad2.24-6%20NDB03.pdf

[whartsell]

This is the approach I was flying, I tracked the crk VOR until 8 miles DME then turned right to heading 163 degrees. I flew the arc until I reached the bearing of 026, the VOR indicator then comes alive and I follow it down to land, I now realize that I may have been doing this completely wrong! The only things tuned in are DME and NDB, but VOR needle activates.

 

http://www.flywaterford.com/images/eiwfad2.24-6%20NDB03.pdf

 

On this approach you dont use the VOR's OBI at all. The ADF's Radio compas or RMI if equipped is your primary nav instrument with DME providing distance only. You would track 073 QDM till about 8.5-9DME (depending on your airspeed) then turn right 90 degrees to 163. When the ADF slides down to 063 QDM you turn left 10 degrees to 153. When the ADF moves down to 053 QDM you turn left another 10 degrees 10 143. Keep repeating this until you are approaching QDM 026. Depending on winds and such you may need to adjust your heading increments to stay within the Arc. Normally +- 1 NM is fine. Once you are ready to intecept the IF track QDM 26 and start your decent below 2000. depending on the winds you may not actually be heading 026 so adjust your heading to maintain the QDM026 bearing all they way to MAP or when you have visual.

 

Hope that helps

Edited November 7, 2012 by whartsell

[Razor5-1]

Thanks for explaining this whartsell, I was flying the approach as you describe up until 026 where I then followed the VOR. Have you any idea of why the VOR became active?

I tried to add to the rep, but forgot that it's not possible in chit-chat, sorry.

[whartsell]

Which sim were you using? In FSX and alot of other sims they don't do DME right.

They put a VOR/DME station. That's probably why you got an active VOR needle.

In real world you would have received a NAV flag on the OBS or no to-from indicating no bearing indication. Some of the DME units also allow you to put a separate freq outside of VOR 1/2 for DME only readings.

 

Will

[some1]

Exept at EIWF there IS an ILS/DME station, both working at the same frequency, but the ILS is for the other end of the runway.

 

http://www.iaa.ie/safe_reg/iaip/Published%20Files/AIP%20Files/AD/Chart%20Files/EIWF/EI_AD_2_EIWF_24-3_en.pdf

 

 

I just checked and this is correct in FSX, probably FS9 too.

Your VOR gauge showed that ILS signal. Because ILS wiill always show deviation from localizer regardless of what radial (course) setting you have, you got misleading indications.

When doing 026 approach, you were actually approaching from the other end of ILS (backcourse), so what you saw on the VOR gauge was reversed. Left was right and vice versa.

http://stoenworks.com/Tutorials/ILS%20Back-Course%20Approaches.html

So from your description, everything is ok in this particular situation. You should ignore VOR reading during NDB/DME approach.

Edited November 8, 2012 by some1

[monotwix]

What’s the name of that ILS thing when the ILS approach is offset by more than 3 degrees from the runway angle? It’s like following ILS on 160 and then landing on runway 180? Not that I’m interested at this time but it’s nice to know that you could be doing an ILS approach and then observing your landing strip in your side window.

[some1]

LDA: http://en.wikipedia.org/wiki/Localizer_Type_Directional_Aid

 

In case of airport like LOWI (Innsbruck), when localizer is not even where the airport is, you have LOC/DME approach. http://data.x-plane.com/Docs/LOWI.pdf