Simviation Forum - VOR Navigating

Jan 20^th, 2008 at 12:08pm

Dr.bob7 Offline
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Ive learned as much as possible about flying. about the only thing ive missed is VOR navigating in the lesson in FSX the whole point is to get lined up with your heading from the VOR the indicator will get level then pass me by ill try a nothing turn about a 10 degree turn and i still miss it any one know why?

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Reply #1 - Jan 20^th, 2008 at 12:28pm

Brett_Henderson Offline
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Part 5 of the Sim Flight Training touches on VOR navigation... We'll get into it more deeply later, when we start instrument training.

http://www.simviation.com/cgi-bin/yabb2/YaBB.pl?num=1199323381

You have to understand what a VOR is, and what a radial is, and how the OBS and CDI work.. Read that thread and please feel free to ask questions there

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Reply #2 - Jan 20^th, 2008 at 4:05pm

beaky Offline
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First of all, remember: make sure the OBS is set for "to" if you are approaching the station ("to" the radial on the opposite side), or "from" if you are flying away from the station (along the radial on your side).
Also, bear in mind that as you get closer to a VOR, the radials are converging, so the needle will move a lot more. And at a great distance the signal; may not be reliable, even in MSFS... keep an eye out for that red flag on the OBS.

But how to properly intercept a radial once you know this stuff?

One thing not really covered in Brett's thread is the fine art of "bracketing".

In essence, you fly towards the radial and when the needle centers, you first turn to the mag heading that matches the radial you are trying to follow.
Since there's usually wind, holding this heading will cause the needle to deflect as you drift off the radial, so naturally you want to turn back towards it... but how much?

It would be dandy to have already calculated just what your correction should be, but quicker and easier to just bracket until you stumble on the best heading.
Here's how you do it:

Once it's clear you're drifting, turn ten to twenty degrees back towards the radial (towards the needle, assuming you have the OBS set up correctly for "to" or "from".
When you cross the radial again, turn back the other way, only this time go only halfway- in other words if your first corrective turn was 20 degrees to the right, go 10 degrees to the left with the next one.

As you cross the line again, turn back again, halving your heading change yet again.

Eventually you will nail it- usually takes only two or three turns.

Now of course you must note the new heading and maintain it... and if you fly on into an area where the wind is blowing differently, you may have to repeat this exercise.

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Reply #3 - Jan 20^th, 2008 at 5:33pm

Brett_Henderson Offline
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HEY !... you're getting into advanced VOR navigation; we'll get into THAT stuff later (oops.. this isn't my thread... sorry) LOL Cheesy

Seriously though.. that IS good information, but I think it clouds the issue, and doesn't do much good until the whole concept of what VORs & radials are... and that VORs aren't just waypoints :

Edit: Learning to intercept a radial by bracketing can be problematic if you're still kinda foggy on fundementals...i.e. what happens if your first correction after drifting and turning back isn't enough to re-center the OBS ? If you don't already have a good image and grasp of what's going on, you're gonna be a a point on that radial where the correction ratios will be dramatically different (if not past the VOR or out of its range.. or well past the intersection you might be groping for)...

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Reply #4 - Jan 20^th, 2008 at 11:54pm

beaky Offline
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Brett_Henderson wrote on Jan 20^th, 2008 at 5:33pm:

HEY !... you're getting into advanced VOR navigation; we'll get into THAT stuff later (oops.. this isn't my thread... sorry) LOL Cheesy

Seriously though.. that IS good information, but I think it clouds the issue, and doesn't do much good until the whole concept of what VORs & radials are... and that VORs aren't just waypoints :

Edit: Learning to intercept a radial by bracketing can be problematic if you're still kinda foggy on fundementals...i.e. what happens if your first correction after drifting and turning back isn't enough to re-center the OBS ? If you don't already have a good image and grasp of what's going on, you're gonna be a a point on that radial where the correction ratios will be dramatically different (if not past the VOR or out of its range.. or well past the intersection you might be groping for)...

Yeah, I know... in fact, looking again at drbob's question, I didn't really answer it. Grin

I don't know why he's failing to re-acquire the beam... possibly because of the reasons you cited (like not understanding how it works in the first place). Grin

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Reply #5 - Jan 21^st, 2008 at 2:32pm

RickG Offline
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This thread seemed to make it a whole lot less confusing for me, Dr.bob Even has pictures

http://www.simviation.com/cgi-bin/yabb2/YaBB.pl?num=1196275768/3#3

Win7 Home Premium X64, P55-USB3 mobo, Intel Core i7 860 @ 2.80 ghz, 4gb ram, GeForce GTX 460 FSX Deluxe SP1&2

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Reply #6 - Jan 21^st, 2008 at 11:19pm

Dr.bob7 Offline
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yay pictures Cheesy

I did some training on my sim

my route: Airport: KAPA to HGO (VOR then to KITR (airport)

now istudied this is put my heading into the OBS and i was heading to the VOR the game put it in as a "from" instead of a to. how do i change this from to and from?

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Reply #7 - Jan 21^st, 2008 at 11:44pm

Brett_Henderson Offline
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This is covered in the threads we've mentioned... You can't use a VOR for navigation, until you understand what a VOR is, and how it works.

For example.. you don't put your heading into the OBS. You use the OBS to select one of the 360 radials emitting from the VOR. .. and then use the VOR to keep track of where you are, relative to that radial. It's not telling you if you're going "to or from".. it's telling that IF you were on that radial AND flying that heading.. then you'd be going to or from.

This is explained in those threads. I know it can be confusing at first, because it's not an easy thing to master... so the best thing to do, is study those threads carefully and thoroughly.. and ask questions about the specific parts that you aren't understanding right there where they're being discussed... Trust me.. we'll stick with you, until you get it

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Reply #8 - Jan 22^nd, 2008 at 7:07pm

Dr.bob7 Offline
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i sorta phrased that wrong i did pick the corse from the VOR the needle was pointing from had it set at 330 Degrees from the VOR the needle was far right as the course would naturally bebut i could never get lined up with it barely even budged in fact it didnt, but how would i change the to and from?

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Reply #9 - Jan 22^nd, 2008 at 8:08pm

Brett_Henderson Offline
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Quote:

i sorta phrased that wrong i did pick the corse from the VOR the needle was pointing from had it set at 330 Degrees from the VOR the needle was far right as the course would naturally bebut i could never get lined up with it barely even budged in fact it didnt, but how would i change the to and from?

I'll go ahead and answer this here (even though it's covered in those threads, that you'll study eventually, right ?)

After you selected the 330 radial with the OBS knob, the only thing that the VOR gauge can tell you, is whether or not you're on that radial. If you're on it, the needle will be centered. This has nothing to do with your heading. You can be on that radial and pointed in any direction, and the needle will still be centered. Picture that you're in a helicopter hovering right on that radial but turning in complete circles. Your heading indicator will go full circle along with your turn, but the CDI needle will stay centered.

Now.. if the needle is not centered, it's telling you that IF you were flying a heading of 330, the 330 radial is to the same side of your plane as the needle. If the needle is to the right, the 330 radial is to your right... IF you're flying that 330.

The "TO/FROM flag tells you whether you'd be flying to or from the VOR.. IF you were on the 330 radial AND flying a heading of 330.

To answer your one question..You can make the TO/FROM indicator, or the CDI needle do anything you want by simply spinning the OBS.

The simplest example of how this works is to imagine that you're not sure where you are, but know that you want to fly to a certain VOR. Start by spinning the OBS knob until the CDI needle centers AND the TO/FROM indicator shows "TO" (the needle will center twice.. once with a TO indication and once with a FROM indication). Once it centers with a TO indication, you then turn the plane until you're flying the same heading as the OBS setting and you'll be flying straight TO the VOR. And to help keep you on a straight line to the VOR (or in other words, "track the 330 radial").. you must keep the needle centered. If the needle drifts to the right, then you need to turn to the right to get back on the 330 radial.. and so on. Rotty touched on the bracketing method for doing this .. especially when there's a wind that's trying to keep blowing you off the radial.

Is it starting to make sense ?

Edit: If this is still confusing.. let's please continue the discussion in the VOR radial tracking thread. Not only for our benefit, but for those who might be having the same questions Wink

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