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FAA written (VOR's)

kentlik

kentlik

Well Known Member
I just had to post for one of my first posts that the portion of the FAA written for the PPL, VOR'S, is dumbfounding...

I had thought I was a reasonably intelligent man with a good level of common sense. This must not be the case....I have been living in a dream world...

There seems to be no logic to the questions. To me anyway.

On a brighter note I am rebuilding a -7A and that is much more fun!
 
jetjok said:
What was it about VOR's that befuddled you?
Click to expand...

Pretty much getting my head wrapped around it. I would go through the process that I thought would have me arrive at the correct answer only to find out, any of my possible choices were not even offered. I understand, or so I think, the radial direction of travel through the compass rose, but on some of the questions they were totally different radials.

I understand the flip on the TO and FROM, I understand the perpendicular or over the VOR, but something I am not getting...not even sure what it is frankly...

Thanks for the response...
 
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The primary key to understanding VOR indication is understanding that it has nothing to do with the direction the nose on the airplane is pointed.

It is entirely related to what OBS heading is selected, and where the airplane is in relation to the VOR.
 
I also had a hard time getting VOR's. Think of it this way: If your selected VOR radial is say 360 , and your heading is 360, your on the 180 radial and your VOR is saying "TO" your dialed in 360 radial. As you pass over the VOR transmitter it will flip to "FROM". You are on the 360 but heading from the VOR transmitter.
 
Learning tools

There are several web sites to learn VORs. It really helped me get my head on the right radial!
Run a Google search on "VOR Training Tools".
 
VOR's are easier in real life than on the written. The Kings suggest making a quick hand drawn overlay that you can lay over the VOR and course shown on the test that makes them easy peasy. I'm not where I can post an image of one, but it should be easy to find.
 
Hey thanks a lot for the input. I have been using the google feature to its fullest extent! Without it would be like I was back in college in the library card catolog files! lol

I like the idea of the overlay. Like a transparencey? I think the questions are ambiguous at best. When they show a field of VOR's and ask which one fits...darn...

Thanks again I will look up some more sites. I have a couple books and a website I joined that was helpful up to this point. I might ask my instructor to shed a little light as well..

Thanks again!
 
Whats a VOR?

Kidding aside I actually used to navigate using those things. Thankful there is GPS today.
 
VOR Apps

Many exist. Google 'VOR trainer app'. I used one as a refresher before my IFR written.

And welcome and congrats on your 7A project!

v/r,
dr
 
360 Bicycle Spokes

I try to explain VORs as radio beacons that broadcast 360 bicycle spokes, one for each degree in the circle around the radio station. The 090 spoke sticks out directly east from the radio station.

A VOR receiver in an airplane that has the needle centered and is indicating FROM is showing you which spoke you are on. So if the needle is centered by setting 090 on the OBS and the indicator is FROM, you are on the 090 radial. While on that 090, and if there is no wind, and you fly 090 (due east) you should stay on that radial and fly east away from that station.

If you are on the 090 radial, and you spin the OBS to have the needle centered and TO indicated you should have 270 on your OBS. Then, in no wind conditions you could fly 270 (due west), along the 090 radial, and fly to the station. Once you cross over the station the indicator would flip from TO to FROM, and you would be established on the 270 radial/bicycle spoke.

As others have said, it tells you which spoke you are on. It doesn't tell you which way you are pointed/flying at that instant.

Hope this helps....

Carl
 
9GT said:
I also had a hard time getting VOR's. Think of it this way: If your selected VOR radial is say 360 , and your heading is 360, your on the 180 radial and your VOR is saying "TO" your dialed in 360 radial. As you pass over the VOR transmitter it will flip to "FROM". You are on the 360 but heading from the VOR transmitter.
Click to expand...

This is an easy way to look at it.
The thing that I was told that helped in addition to remember was that all radials (360) of them emit from the VOR. In other words in this case the 180 deg radial and the 360 deg radial together create a line you just have to figure out which side of the line from the VOR you are on. If you are on the line inbound to the VOR and your indicator matches your heading and you indicate TO you are on the radial from the opposite direction. Hope this doesent add to the confusion.
Ryan
 
131RB said:
This is an easy way to look at it.
The thing that I was told that helped in addition to remember was that all radials (360) of them emit from the VOR. In other words in this case the 180 deg radial and the 360 deg radial together create a line you just have to figure out which side of the line from the VOR you are on. If you are on the line inbound to the VOR and your indicator matches your heading and you indicate TO you are on the radial from the opposite direction. Hope this doesent add to the confusion.
Ryan
Click to expand...

Do you mean:

..."you are on the radial from the opposite direction."Meaning opposite side of the VOR.

I do understand you do use the radial in a TO direction that is opposite the radial pointing at you, for lack of a better term.

Navigating the FAA questions is the problem as they don't seem to be at all clear...
 
kentlik said:
Do you mean:

..."you are on the radial from the opposite direction."Meaning opposite side of the VOR.

I do understand you do use the radial in a TO direction that is opposite the radial pointing at you, for lack of a better term.

Navigating the FAA questions is the problem as they don't seem to be at all clear...
Click to expand...

If I could draw a picture it would help.
( Remember all radials emit from the VOR (360) of them)
Example.: If you are headed to the VOR and you are south of the VOR and your OBS is selected to 360 and your indicator shows TO and your compass matches your OBS roughly, you are on the 180 radial to the VOR. You will not be on the 360 radial until you cross the VOR on the same heading.
it can be a bit confusing but if you picture the VOR with 360 spokes and draw your airplane on one of those spokes it might make more sense.
Ryan
 
Nav Trainer

If you have an IPhone or IPad download NavTrainer. Free and really good, at getting you to understand how VORs work. Used it in training for my IFR written.
 
I had trouble getting my head around this as well, so here?s what I came up with:

First, replace that little airplane shown on the diagram with a simple non-directional dot. Direction of flight is irrelevant, and the illustrations can be lead you astray.

Second, draw a line from the (airplane) dot to the VOR.

Third, draw a line perpendicular to the first line crossing through the VOR. This line is infinite, and separates a 180 degree semicircle that you are CURRENTLY in from the 180 that you are NOT in. Think of this line as a fence line separating your backyard from your neighbor?s backyard. Now ? the 180 radials that are on YOUR side are all ?From?, and the 180 radials on your neighbor?s side are ?To?.

In short, you have to ?jump the fence? to get to all the ?To?s? (at which point they become ?From?, and the former become ?To?s?).
 
131RB said:
If I could draw a picture it would help.
( Remember all radials emit from the VOR (360) of them)
Example.: If you are headed to the VOR and you are south of the VOR and your OBS is selected to 360 and your indicator shows TO and your compass matches your OBS roughly, you are on the 180 radial to the VOR. You will not be on the 360 radial until you cross the VOR on the same heading.
it can be a bit confusing but if you picture the VOR with 360 spokes and draw your airplane on one of those spokes it might make more sense.
Ryan
Click to expand...

Wow I have this backwards then. I must have heard it wrong on the online school I have. That will help out immensly! Thank you.
 
my 2 cents:
1. Rotate the airplane pictures so they all are headed in the direction of the OBS setting. e.g., if OBS is set to 090, point all airplanes east.
2. Draw a line thru the VOR, perpendicular to the OBS setting (in this case, north-south). If you are headed toward that line, the CDI should say "TO"; if you are headed away from that line, the CDI should say "FROM". Throw away any little airplanes that are wrong.
3. If you are on the FROM side, you can read the radials directly. The CDI should show you which way to turn (from 090 heading) to intercept the 090 radial. e.g., if you are north of the 090 radial, the cdi needle should be deflected right.
4. If you are on the TO side, you need to figure the radial which is also the BEARING TO the station. It's the radial + or - 180. In this case the desired bearing to the station is 090, which is inbound on the 270 radial. If you are north of the 270 radial, you should get a "fly right" (right needle deflection) indicating you need to turn right to get to the desired bearing to the station.

That's for tests. For real flying:
1. If you are tracking to or from a VOR, the OBS and the DG should always be about the same (plus/minus wind correction). Make small adjustment by turning towards the needle. Watch the to/from reading. It's easy to fly over the VOR and not notice.
2. For cross fixes adjust the OBS to get a "FROM" reading (use the radial from the VOR), center the needle by turning the OBS while keeping FROM. Draw a line from VOR along the radial (what the OBS reads when the needle is centered, and FROM), you are on that line somewhere. If you pre-set a cross fix, always use the radial, then the needle will point in the general direction toward the VOR (that is, if the VOR is on your right, the needle will point right) if you are not yet at the fix. It will center at the fix, and will point away from the VOR (if the VOR is on your right, it will point left) after you pass the fix.

It's not as complicated as it sounds. Practice in front of a blackboard (make up your own problems similar to the test problems) for 20 minutes and it will seem like second nature.
 
BobTurner said:
my 2 cents:
1. Rotate the airplane pictures so they all are headed in the direction of the OBS setting. e.g., if OBS is set to 090, point all airplanes east.
2. Draw a line thru the VOR, perpendicular to the OBS setting (in this case, north-south). If you are headed toward that line, the CDI should say "TO"; if you are headed away from that line, the CDI should say "FROM". Throw away any little airplanes that are wrong.
3. If you are on the FROM side, you can read the radials directly. The CDI should show you which way to turn (from 090 heading) to intercept the 090 radial. e.g., if you are north of the 090 radial, the cdi needle should be deflected right.
4. If you are on the TO side, you need to figure the radial which is also the BEARING TO the station. It's the radial + or - 180. In this case the desired bearing to the station is 090, which is inbound on the 270 radial. If you are north of the 270 radial, you should get a "fly right" (right needle deflection) indicating you need to turn right to get to the desired bearing to the station.

That's for tests. For real flying:
1. If you are tracking to or from a VOR, the OBS and the DG should always be about the same (plus/minus wind correction). Make small adjustment by turning towards the needle. Watch the to/from reading. It's easy to fly over the VOR and not notice.
2. For cross fixes adjust the OBS to get a "FROM" reading (use the radial from the VOR), center the needle by turning the OBS while keeping FROM. Draw a line from VOR along the radial (what the OBS reads when the needle is centered, and FROM), you are on that line somewhere. If you pre-set a cross fix, always use the radial, then the needle will point in the general direction toward the VOR (that is, if the VOR is on your right, the needle will point right) if you are not yet at the fix. It will center at the fix, and will point away from the VOR (if the VOR is on your right, it will point left) after you pass the fix.

It's not as complicated as it sounds. Practice in front of a blackboard (make up your own problems similar to the test problems) for 20 minutes and it will seem like second nature.
Click to expand...

This helps very much, thanks a ton. The questions all seem to be pictures of the OBS in various configurations. I am going to take my knew information and have another go at it!
 
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