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A VOR pop quiz...try your luck

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Trying to understand something about VOR navigation. Took me a minute to figure this one out. For fun, try your luck. 10 second time limit (no cheating!).You've tuned the "ABC" VOR. You have selected the 90-degree radial (on the course index), your heading is 270 degrees, the CDI needle is to the left, and the To/From flag is indicating To. Roughly where would you turn your head to look in direction of the actual VOR (12 o'clock, 1 o'clock, 2 o'clock, etc.) and which direction (Left/right) would you turn to intercept the radial?

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No one correct yet, but one person (Ron) almost got it. no need to send the answers to me by PM. Just post here. cheers.

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let me try my hand:you would look to your 1 or 2'clock depending on how far away from the VOR you were and you would turn right to intercept the 090 radial.

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Well your location is SW of the VOR and since you are facing West you have to look to the right and rear (4-5 oclock position). To intercept the radial you would need to head about 045 to intercept and that all depends how far away form the vor you are from. If you are further you would take a heading of 070-090 but then again you may never intercept the radial. it all depends on how much of a cut you take.

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Hi CFO!Well, firstly you would want to turn to your left. How sharply you would want to turn would depend on several factors. How far away are you from the VOR? How much is the needle deflected? what's the wind speed and direction?. But first things first. since you are on a course of 270 I assume that is the direction of your intended destination. If that is the case then you would want to dial in a course of 270 on the course card to intercept the 090 radial not 090. That's why it's called a "Course Deviation Index" and not a "Radial Deviation Index" (Not trying to be a smart a** just trying to make a point :) ). Since the to/from arrow points "to" that means the station is in front of you. Now, if your 10nm away from the station and the needle is deflected fully then it could be anywhere fom your 9:30 psoition to your 11:30 position so you should probably make a 90 degree left turn to a heading of 180 to intercept the radial as soon as posible. If you are 75nm from the station and the needle is deflected only a couple of dots or 4 degrees then it's almost directly ahead of you and you could get away with making only a 30 degree left turn. Assuming that is that you don't have a strong wind from your left and don't already have a 30 degree wind correction factor.Cheers............Smokin256

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>Since the to/from arrow points "to" that>means the station is in front of you.Bzzzt, try again. The VOR receiver has no idea what your heading is.

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Hello.In general, I'm with Jack C. However, strictly speaking, there's no way to know where to look from the scenario you describe. You say the CDI is to the left. Is it one or two dots to the left or full-scale? If it's only a couple dots left, then you can calculate your angle of deviation and from there get a rough idea of how far to crane your neck over your shoulder to spot the VOR. If it's full-scale, I'd twist the OBS to get a reading on the CDI (or tune another VOR station) before I'd even guess at the aircraft's position. Also, interpretation of position is vastly different if that CDI is on a plain-old VOR head or on a HSI.The way I understand it, TO/FROM only indicates which "side" of the VOR you're on relative to the selected radial. It indicates FROM if the selected radial is within 90 degrees left or right of the radial you're currently on. It indicates TO if the selected radial is more than 90 degrees from the current radial. Good puzzle!Regards,Rob Prattrpratt(at-sign)wordandsound.com

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Your plane is to the SW of the VOR so right turn for sure. But how much of a turn depends. To turn and have the VOR at your 12 o'clock, you need a second VOR or dial the radial on VOR1 until the needle centers and then turn to that heading.

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Unless you are doing a back course localizer (similar to a VOR but more sensitive and then I use the inverse course when not on AP to left/right CDI indication is correct) to avoid this confusion:The COURSE setting should agree with the "hemisphere" indication of your aircraft heading. Set your CDI course to 270 since that is your heading and the FROM indication will appear correctly indicating you are flying away from the VOR. This avoids reverse sensing. Assuming you wanted to still go in the same general direction (flying away from the VOR) I believe the needle will now be to your right.This course 180 setting change is used by some when following race track holding patterns based on VOR parameters.Good training is in the aeronautics section on www.stoenworks.com.Now let's have flying to an intersection drill. :)

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Hi,From my limited understanding of this situation you are flying west (270o) and have the radial set to the east!This is a situation where you can never intercept your planned course change as you are flying parallel to your planned route, north of the VOR. By looking out of the window you might see the VOR at your 10'o'clock but I think that unlikely and the safest thing to do is check the map and have a cuppa before deciding to call it a day and find your way home!!I am speaking to you now as a person with one (1) flying lesson under my belt and my very own cordless mouse, so there's not much more I have to learn about avigation and if I've been of some help to you then jolly good show!Andy.

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Fascinating...for the record: It IS possible to determine where you are relative to the VOR with just the information provided (it is not a trick question), it IS possible to intercept it, and the degree of turn isn't important for the quiz. Just whether it is a left or right turn. Of course in real life it would matter. Also, in the interest of full disclosure: I did NOT solve this in 10 seconds. I had to think about a for a long time and sketch it out. I was led to when I was flying the sim last night in a similar circumstance, got confused, and turned the wrong way. Realized I will need to be a lot sharper and quicker when I begin flying for real :-)For the time being I'm keeping quiet on who if any one has nailed it...

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>>You've tuned the "ABC" VOR. You have selected the 90-degree>radial (on the course index), your heading is 270 degrees, the>CDI needle is to the left, and the To/From flag is indicating>To. Roughly where would you turn your head to look in>direction of the actual VOR (12 o'clock, 1 o'clock, 2 o'clock,>etc.) and which direction (Left/right) would you turn to>intercept the radial?Thinking (barely, its friday late) out loud:I'm guessing it'd be somewhere to your left, probably behind you...But I don't think that way when flying. If I want to track right to it, I would just adjust the OBS until the CDI centered with the "TO" flag showing and fly that course.Or you could do the old "FROM" trick...AKA VOR CROSSCHECKING...center the CDI with "FROM" showing, and that's your bearing from the station...Rhett

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>Fascinating...for the record: It IS possible to determine>where you are relative to the VOR with just the information>provided (it is not a trick question), it IS possible to>intercept it, and the degree of turn isn't important for the>quiz. Just whether it is a left or right turn. Of course in>real life it would matter. >Of course in real life, we'd bag the VOR's, 'cause we'd "always" know exactly where we are from the moving map GPS.Then we could keep out eyes out of the cockpit, looking for traffic, while on this heavily traveled airway between VOR's, instead of dialing the OBS and trying to figure it all out! :-hah However, for flight simulator, it's something to do, I suppose. :7L.Adamson

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OK guys I will kinda explain how to do this really quick and hope some can pick up on this. I will make this a 2 step post since i gotta run to the gym. OK if you want ot find your position in relation to a VOR imagine it this way. He said he had 090 selected on the oBS. Now imagine your plane pointed 090 ( i know he said 270 but dont worry about that right now). So we all have our plane pointed 090 in our heads right?. OK now the needle is deflected to which side? To the left. SO we know the VOR is to the left of us. NOW the TO/FROM flag is pointed where? Well he said TO. SO we now just established 2 things. The VOR is to the LEFT and IN FRONT (since it is the TO flag) of us. WE are imagining we are facing 090. so if we are facing 090 and the VOR is to the LEFT and FRONT of us that would be anywhere from 12 - 3 oclock which is NE. Well if the vor is to the NE of us we are to the SW of the VOR. EASY? NOW you can do this with ANY one of these acenerios in the steps i just gave. Next post i will give a quick lesson on how to intercept and a certain radial and if it possible in a certain situation.Jack

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>had 090 selected on the oBS. Now imagine your plane pointed>090 ( i know he said 270 but dont worry about that right now).Jack,I agree this is the best method to tackle this problem.People ought to remember that what VOR shows you have nothing to do with which way the aircraft is pointing. This is so basic yet even my own CFII forgot about it once!!Michael J.http://www.precisionmanuals.com/images/for...argo_hauler.gifhttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg

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The station is anywhere from your 3:01 to your 5:59 o'clock :(A right turn to heading 360 is the surest way to intercept the radial.I like Jack's answer the best so far. I was going to say ignore the heading, because cardinal rules #1-#15 of VOR navigation are "the CDI does not care what heading you are on." If you had an HSI it would be different and also much easier to figure out.Anyway, I always tell my students to tune in the course, and imagine your plane is in the center of the nav display. Look at what direction the needle is. If it's on the left, any heading 90 degrees from the left of the heading tuned will eventually intercept it without turning you further away from the station (in this case 360-089). Of course if you pick too shallow of an intercept it increases the likelyhood that you will pass the station before intercepting the radial.In the example given, a right turn to 360 will pretty much guarantee intercepting the tuned course. Now, 90-degree intercepts are not the most desirable, especially in faster planes, because you could overshoot the course at a standard-rate turn if you are too close to the station or going to fast. It's also not as efficient.The rule of thumb is this:1. Turn to a heading to parallel the desired course, in the same direction as the course to be flown.2. Determine the difference between the radial to be intercepted and the radial on which you are located (find this by turning the OBS until the CDI centers).3. Double the difference to determine the interception angle (don't use an angle less than 20

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Jack's analysis is correct, except that he says that, when going on a 090 heading the VOR would be anywhere from a 12 - 3 o'clock (it would be between your 10 and 11 o'clock on that heading, or arguably between 9 and 12 o'clock. If it was at your 12 o'clock it would be centered, if it was at your 9 o'clock it would be showing "off"). Turning around it would be between your 4 and 5 o'clock, so you would look over your right shoulder at the VOR in question.I guess you might have to look between your legs if you've just passed over it.So - what are we missing ;-D

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True If it is actually at a perfect 12:00 position you would get the NAV or OFF flag (whatever it is). So to correct myself the VOR is at 12:01 to 14:59 to make it more correct. But it would not be at a 10 or 11 oclock like you said. If you were to point the aircraft on a heading of 090 the vor WOULD BE at 12:01 to 14:59

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Actually, clock position has no bearing (no pun intended) on whether you'll get the flag, as (my) rules #1-15 state, your heading has nothing to do with the indication in the nav receiver.In the example, but instead on a heading of 090, you could theoretically be anywhere from the 181 radial to the 260 radial (assuming the needle is full-scale to the left and not partial scale - full deflection on a VOR is 10 degrees). That puts the station at your 9:01 to 11:45ish, not 12:01 to 2:59 (we do not go higher than 12:00 when talking about bearing, so 14:59 is the wrong terminology). That would put the needle to the right. Remember even though you reversed your heading, the needle will still be on the left side.In order to get the "off" or "nav" flag (depending on your receiver), you'd have to be due north or due south of the station. This is known as the "area of ambiguity" where the receiver can't tell if the course dialed in is closer to "to" or "from". This happens whenever you are on a radial that is 90 degrees from the course tuned in.

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Actually what i am saying is if you were heading 090 and the station is at a perfecct 12 oclock position yes you would get the OFF flag. Please just trust me on this. To answer the original question you are at a bearing of 181 to 269 from the station. Since the example stated we WERE heading 270 that means to LOOK at the VOR you would have to turn your head to a 091 to 179 bearing (turn your head just past 3 oclock to almost 6 oclock). MY explanation of HEADING 090 was just a quick way to show the guys where the station is from your position.Jack CATPLDHC8 and soon to be B737-6-7-86000 TT

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Agreed... over your right shoulder (3:30/4/5/6 ish) and right turn to establish.Good quiz, like it.Iam

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