VOR Tracking question
Thread Starter
Joined: May 2007
Posts: 19
Likes: 0
From: Nowhere But Here
VOR Tracking question
Just started my IR training and i am getting confused about orientation.
For example, i am tracking outbound or inbound on the 090 radial of a VOR, what is my relative position to the VOR (Am i East or west of the VOR if inbound on a course of 270 and east or west of the VOR if outbound on a course of 090?)
I hope it does not sound stupid, i m just confused. Will appreciate other tips that will help me avoid this confusion also.
Cheers
For example, i am tracking outbound or inbound on the 090 radial of a VOR, what is my relative position to the VOR (Am i East or west of the VOR if inbound on a course of 270 and east or west of the VOR if outbound on a course of 090?)
I hope it does not sound stupid, i m just confused. Will appreciate other tips that will help me avoid this confusion also.
Cheers
Last edited by GroskinTheFlyer; 5th October 2007 at 00:54.
Joined: Mar 2007
Posts: 228
Likes: 0
From: Middle of nowhere
As said before, radial is always from the VOR, and the to/from indicator should give you your relative position to the station on that radial.
e.g. lets say you are on the 235 radial from the VOR and are heading 235 degress. Then your FROM indication will tell you the VOR is behind you. With the CDI centred you will track away from the VOR on 235.
On the same 235 radial, but heading 055, the TO indication would tell you the VOR is in front of you. With the CDI centred you should arrive overhead.
Obviously then there are situations where you are crossing radials etc., but the question was about tracking as opposed to crossing!
e.g. lets say you are on the 235 radial from the VOR and are heading 235 degress. Then your FROM indication will tell you the VOR is behind you. With the CDI centred you will track away from the VOR on 235.
On the same 235 radial, but heading 055, the TO indication would tell you the VOR is in front of you. With the CDI centred you should arrive overhead.
Obviously then there are situations where you are crossing radials etc., but the question was about tracking as opposed to crossing!
Joined: May 2007
Posts: 28
Likes: 0
From: the priory
bri1980,
thats not really correct. your HEADING has nothing to do with what is displayed by the CDI or the TO/FROM flags on the VOR instument. Its all about your POSITION relative to the ground station.
Say you are on the 090 radial (ie exactly to the east of the VOR ground station), it doesnt matter whether you are pointing towards the station or away from it, the display will look the same. What does matter is what you have dialled into the OBS (omni bearing selector). If you have selected 090, the display will read 'from', because you are on that radial 'from' the station. if you now dial in 270, the display will read 'to', because you have to first fly 'to' the station in order to track up the 270 radial you have selected. Make sense? If not - draw a diagram, thats a big help.
thats not really correct. your HEADING has nothing to do with what is displayed by the CDI or the TO/FROM flags on the VOR instument. Its all about your POSITION relative to the ground station.
Say you are on the 090 radial (ie exactly to the east of the VOR ground station), it doesnt matter whether you are pointing towards the station or away from it, the display will look the same. What does matter is what you have dialled into the OBS (omni bearing selector). If you have selected 090, the display will read 'from', because you are on that radial 'from' the station. if you now dial in 270, the display will read 'to', because you have to first fly 'to' the station in order to track up the 270 radial you have selected. Make sense? If not - draw a diagram, thats a big help.
Joined: Jun 1999
Posts: 978
Likes: 1
From: In the SIM
When I used to teach VOR tracking I would get the student to remember
FROM Top
TO Bottom.
Meaning if you have a FROM flag (needle centred) you read what radial you are on from the top of the instrument and if you have a TO flag (needle centred) you read the radial from the bottom of the instrument. I found it a good way to get the orientation correct in your mind.
What you need to try and do, is once you know what radial you are on, you need a mental picture in your mind about where the aircraft is with reference to the station and what you want to achieve, which radial do I want to track? As has been mentioned, its worth drawing a little picture on the ground to get your head round it.
Another thing is always use the instrument in the correct sense. In other words if you want to track towards it always have a TO flag and vice versa, otherwise you end up with reverse sensing.
Oh, by the way, no such thing as a stupid question in aviation
.
All the best with your IR, you will be fine, we have all been there
.
FROM Top
TO Bottom.
Meaning if you have a FROM flag (needle centred) you read what radial you are on from the top of the instrument and if you have a TO flag (needle centred) you read the radial from the bottom of the instrument. I found it a good way to get the orientation correct in your mind.
What you need to try and do, is once you know what radial you are on, you need a mental picture in your mind about where the aircraft is with reference to the station and what you want to achieve, which radial do I want to track? As has been mentioned, its worth drawing a little picture on the ground to get your head round it.
Another thing is always use the instrument in the correct sense. In other words if you want to track towards it always have a TO flag and vice versa, otherwise you end up with reverse sensing.
Oh, by the way, no such thing as a stupid question in aviation
.All the best with your IR, you will be fine, we have all been there
.
Joined: Sep 2007
Posts: 263
Likes: 0
From: inside of a pretty bustard
1.When you have selected OBS 090, and you read FROM , regardeless of heading (it can be 090, 270 ,180 ,030,...), you are in the east of VOR.
2.When you have selected OBS 270 ,and you read TO ,also you are in the east of VOR.
3.If you selected OBS 090 ,and you read TO, you are in the west of VOR.
4.If you selected OBS 270 and you read FROM, you are in the west of VOR.
2.When you have selected OBS 270 ,and you read TO ,also you are in the east of VOR.
3.If you selected OBS 090 ,and you read TO, you are in the west of VOR.
4.If you selected OBS 270 and you read FROM, you are in the west of VOR.
Joined: Mar 2007
Posts: 228
Likes: 0
From: Middle of nowhere
Originally Posted by sick_bag
thats not really correct. your HEADING has nothing to do with what is displayed by the CDI or the TO/FROM flags on the VOR instument. Its all about your POSITION relative to the ground station.
Say you are on the 090 radial (ie exactly to the east of the VOR ground station), it doesnt matter whether you are pointing towards the station or away from it, the display will look the same. What does matter is what you have dialled into the OBS (omni bearing selector). If you have selected 090, the display will read 'from', because you are on that radial 'from' the station. if you now dial in 270, the display will read 'to', because you have to first fly 'to' the station in order to track up the 270 radial you have selected. Make sense? If not - draw a diagram, thats a big help.
Say you are on the 090 radial (ie exactly to the east of the VOR ground station), it doesnt matter whether you are pointing towards the station or away from it, the display will look the same. What does matter is what you have dialled into the OBS (omni bearing selector). If you have selected 090, the display will read 'from', because you are on that radial 'from' the station. if you now dial in 270, the display will read 'to', because you have to first fly 'to' the station in order to track up the 270 radial you have selected. Make sense? If not - draw a diagram, thats a big help.
I was making the example based on the fact you were tracking towards or from the station-rather than passing abeam or crossing a radial-but yes, my answer wasn't clear enough!
Of course what matters is the OBS-that's what determines the TO or FROM indication as you say.
Agreed-diagrams help a lot with VORs, and even more with ADFs!
Joined: Dec 2005
Posts: 644
Likes: 1
From: UK
Try visualising it in a non-aviation environment, for example your car.
As you're driving along the road try and think that the postbox, sign, etc is the beacon. What would you expect your dial to read with an ADF it would point straight at the landmark. Whilst driving abeam it what would you expect to seem and once again as you drive away from it. This should hopefully help, if not then point at the landmark and see how your finger changes direction as you drive (safer to do this whilst someone else's driving).
Remember with the lamp -post on your left the needle will not mysteriously point to the right, so that's 50% of the dial that you don't need to worry about!
As for the VOR, just imagine the radials projecting outwards and imagine (once again) that as you move past you're on a different radial. Realising that the initially 'centered' needle will start to show a deflection between the original radial you selected and the one you're on.
Sorry if this all sounds silly but it's how I learnt radio navigation whilst jogging at night.
As you're driving along the road try and think that the postbox, sign, etc is the beacon. What would you expect your dial to read with an ADF it would point straight at the landmark. Whilst driving abeam it what would you expect to seem and once again as you drive away from it. This should hopefully help, if not then point at the landmark and see how your finger changes direction as you drive (safer to do this whilst someone else's driving
).Remember with the lamp -post on your left the needle will not mysteriously point to the right, so that's 50% of the dial that you don't need to worry about!
As for the VOR, just imagine the radials projecting outwards and imagine (once again) that as you move past you're on a different radial. Realising that the initially 'centered' needle will start to show a deflection between the original radial you selected and the one you're on.
Sorry if this all sounds silly but it's how I learnt radio navigation whilst jogging at night.
