VOR Approach

I don't remember the exact lesson you're working on, but in general if you need to fly outbound on a certain radial: leave your heading bug on the VOR set to that heading, but as you fly over and past the VOR station, the direction indicator on the VOR indicator will point DOWN, indicating that the station is behind you.

For instance, if you're supposed to fly outbound on the the 45 degree radial, set your heading bug 45, and continue to keep the needle centered, but as soon as you pass the station the indicator will point down, telling you that you are now OUTBOUND on that radial. In other words, if you're inbound on 45 degrees, the arrow points up; if you're outbound on the same radial, the arrow points down.

BUT: what confused me about this for a while is that the VOR indicator doesn't know (or care) which direction you're flying, IT ONLY TELLS YOU WHICH SIDE OF THE VOR you're on. It only tells that you're on the 45 degree radial and WHICH SIDE OF THE VOR station you're on-- the inbound side or the outbound side. You can fly either direction on a given radial, and the arrow will tell you which side you are on-- but not which direction you're flying.

So while you're flying on a VOR radial, keep an eye on the Heading Indicator, too. If you're flying a heading of 45 degrees, AND the VOR is set to 45, AND the arrow points up, the station is in front of you. If you're on that same radial, and the arrow points up, BUT you're flying a heading of 225 degrees (45+180), the station is BEHIND you. You're still on the 45 degree inbound radial, but you're flying away from the station.

Make sense?

Ed

I kind of get what you talking about, after opening the game, but I still can't quite figure out what I am suppose to do. You'd probably have to remember/go through the lesson I'm working on to understand where I am getting confused. I just can't figure out where I am suppose to go after I get to the VOR station, where I turn for how long and such.

Well, you need to imagine that the VOR station is a sun, drawn by a child. The rays emanating from the center are the "radials". The one on the top of the sun is the 360, the bottom the 180, the left the 270 and the right the 090 radial. All the ones inbetween are 1 degree apart.

These rays mark "roads" in the sky. So, if you take the 090 radial OUTBOUND from the VOR, you will be travelling east, away from the VOR. If you take the 090 radial INBOUND to the VOR, you are travelling west, going towards the VOR station. Make an actual drawing of this on a piece of paper and ponder it for a bit. That is the meaning of inbound and outbound.

You will ask: "If I am inbound to the VOR on the 090 radial, am I not travelling on the 270 radial??".

No! Your heading will be 270, but the radial you're on, the "road" you're on is called 090. Once you pass the VOR station, the "road" is renamed 270 and now you're travelling on the 270 radial OUTBOUND instead of the 090 INBOUND to the VOR. Your direction hasn't changed.

So why bother? Because that's a good way to navigate. Let's say you want to go direct to a VOR called ABC and then you want to fly the 014 radial outbound.

You tune your NAV1 to ABC and fly direct to it. Easy, right? Going "direct" is very easy (just "point and fly") but it's not the usual way. Ok, so now you're approaching ABC and you want to fly the 014 radial outbound. Why? Why the 014 and not "approximately north"? Well, because it's a precision navigation procedure (if I may be allowed the term). Because on that exact radial you will find your next waypoint.

So you approach ABC. Your NAV1 is tuned to ABC's frequency. Now you turn your CRS (or OBS or whatever it is called) [but NOT the heading bug, not the HDG button] so that it shows "014". This has aligned the navigation equipment (not your plane) to show the right radial of the right VOR station. Now you will need to find and fly on that radial. From this point on, read the lesson again and try it or read one of the many excellent tutorials on this site. If you still have questions, I'll be happy to take another stab at an answer.

The explanation of VOR navigation Bindolaf gave is one of the best I have ever read for a beginning pilot to begin to understand VOR's. Great job!

Radarman - you should bookmark this one to use when future inquiries are made on the same subject.

Don Wood wrote:

The explanation of VOR navigation Bindolaf gave is one of the best I have ever read for a beginning pilot to begin to understand VOR's. Great job!

Radarman - you should bookmark this one to use when future inquiries are made on the same subject.

Very true, the simplest explanations are always the best, Here he drew a mind picture.

Thanks for your help Bindolaf, it helped me understand the terminology a little better, but I still got stuck .

After you get to the VOR station, you are told to adjust your OBS to 34 outbound radial. I do so, no problems. Then you are told to fly to someting like 340 degrees (using heading bug) and when you get there, it tells you to adjust slightly to the left to take some course (but it still says whatever number it said before, like 340). But I am already on that course, why do I need to adjust, and to what angle/radial? By the way, the OBS is not centered at that point. If I don't adjust (because I don't understand what I am suppose to adjust to), it eventually tells me I am too far to the left...

To avoid confusion, VOR radials are always referred to using all three digits. When you say the 34 radial, you may mean the 034 (zero three four) radial or the 340 radial.

There are two reasons (except for pilot error) for having to make course corrections while navigating on a VOR. First, from a distance, minor course deviations barely register on the VOR needle. As you get closer to the VOR, the same minor deviation will result in a larger needle deflection, making the need for a course correction more obvious. When you get very close, your course corrections need to be subtle ones, often just nudging the rudder slightly instead of making an aileron turn. Flying close to a VOR is exactly the same as flying final on an ILS. If you make broad corrections, you'll be continually chasing the needle and never get stabilized on the intended radial.

The second reason course corrections are necessary is wind. The only times you can fly the exact heading of the radial you want and stay on that radial are when there is no wind at all or when the winds are directly on your nose or tail. If you have any cross-wind component, you must make course corrections to remain on the inteneded radial. The stronger the wind, the more correction you need to make.

As an example, if you are flying outbound on the 180 radial and there is a direct cross-wind from the east, you will have to turn the nose of the aircraft toward the east a few degrees to remain on the 180 radial. Again, the stronger the wind, the larger the course correction must be.

Don Wood wrote:

If you make broad corrections, you'll be continually chasing the needle and never get stabilized on the intended radial.

That is what I seem to be doing. The needle is not in the middle after I turn around (completd my last question), now going inbound and I keep turning to get it to the middle, but it never comes, it gets to middle and then goes right back to the other side 🙄. How can I figure out where I am suppose to be going?

When the needle is in the middle, you are going the right way (or totally the wrong way 180 degrees off 😉 ). IF the wind is zero knots AND the needle is centered AND your HDG is equal to your CRS, the needle will stay in the middle.

However, this is almost never the case. For one, even with everything above true, as you get closer to the VOR station, the needle will drift a little. Wind will kick you off course a little too. So you constantly need to make small corrections, without "chasing" the needle. In time you'll get the feel for this.

One way to practise this (while "cheating" a little) is the following:

Tune the VOR frequency, select a radial and fly outbound (let's say 030 radial outbound from the station). Try to intercept the radial and stay on it. Watch the drift, correct etc. Then do the same thing while using the "NAV HOLD" feature of the auto pilot. See how the AP holds the radial, how it corrects for wind etc. The only downside is, in FS2004 the AP sometimes uses standard turns to intercept a radial, overshoots, uses a standard turn again the other direction, overshoots etc. So in the end you have not flown a straight line, but a series of dwindling "8"s. Check it out though and see how you do 🙂