Thread: VOR Usage

Hi all,

Just enquiring about a query that has been hanging around in my mind for a while about VOR.

I have an understanding of how VOR works, going TO and FROM the station and reciprocals etc.

Just wondering how you implement them into planning. Do you literally make them a way point in your planning and fly directly to the station?

I understand that you can triangulate your position based on VOR stations.

Also, since the Midlands only has a handful of VOR stations, what height do you tend to be at to get more than one at once? Since its line of sight I imagine it would need to be fairly high round here?

Looking at my chart I can only see Honily and Daventry as the two nearest stations unless you travel a bit further afield?

Just a brief usage of VOR for Navigation would be great! 8o)

Originally Posted by Aviator|Chris

Just wondering how you implement them into planning. Do you literally make them a way point in your planning and fly directly to the station?

Chris

You can use them as a way point- fly directly to where the needle points until you eventually pass it and the needle swings around. You can also use them to fix your position if you find yourself lost: If you twist the needles until you get "FROM" and until the arrow is directly centred, then take the DME distance and the radial you are on, you can then plot this on your chart whilst airborne to find out where you are. eg- The needles centre with FROM flag on the radial 216 degrees at 30nm on the DME. Plot the radial 216 from the station on your chart (remembering to add or deduct variation as appropriate) and then measure 30nm along the line you have just drawn. This gives you your position.

You can also use a VOR for navigating- but not just by flying directly to one. In your planning stage (when you are drawing your routes on the chart) you can litterally place a point anywhere on the chart, then find out what radial it is on from the VOR and what distance it is away from the VOR. When you are then airborne and wanting to fly to this imaginary point, simply select the radial on the VOR that this imaginary point sits on, and fly on the planned course until the VOR needle begins to centre itself on the selected radial. When the needle centres it means you are on the radial from that VOR and providing the DME distance matches the distance that you have planned on your chart then you are exactly overhead the point.

This sounds very difficult but it really isnt once you practice. Perhaps have a play on flight simulator? At following the needle to and from a VOR first of all, then advance on to fixing your position using the FROM function, then perhaps try some navigating to a specific radial and distance. You cover all of this in detail in the IFR phases of training, however for a PPL holder, just knowing how to fix your position from a VOR is more than helpful when you find yourself a little lost.

Originally Posted by Aviator|Chris

Since its line of sight I imagine it would need to be fairly high round here?

Quite true. If my memory from flying around Wellesbourne serves me correct, you can get both HON and DTY from about 3000ft. All you can do is tune it, identify it using morse then use it. If you cant get a good morse ident from it then using it would result in low accuracy. The higher you are the stronger the signal. There is a formula for working it out but dont ask me what it is because I cant remember.

Remember that VOR's and DME's are completely separate things. You often find co-located VORDME's but get it into your head that just because you are using a VOR it may not have a DME facility too.



Does any of that help? If you need anything clearing up further I can try to explain. VOR's and NDB's etc are quite confusing at first to get your head around, but with a little practice they suddenly become very easy to use.

Hotdog

Hi Hotdog,

Thanks very much for that.

Quite a lot of what I understand about VOR is from Flight Sim as I was still doing my navigational excercises last time and getting used to requesting services from London Information.

At least I know what I understood from Flight Sim is correct and I have been using but not abusing the information it provides.

The Cessna I flew didn't have DME (just about had me! lol) so thats why I'm not used to getting distance readings from the VOR stations themselves.

I think I will ask my instructor to show me VOR on the next lesson as we planned to take the C172 out for an hour next month, weather permitting.

You are limited without DME though aren't you? As you could be anywhere along the radial from the station, like choosing a road as a VRP!

I will have a play around as I do have the exact model 172 on Flight Sim (C172N) so this helps with maintaining familiarity.

Cheers!! 8o)

You can do a cross fix Chris. You get select, ident and display a VOR. Work out which radial you are on and plot it on your chart. Then repeat the process for another VOR that is in range. Try to stay in the immediate area as you do this and the resulting point where the lines cross should indicate fairly accurately as to your location.