Hey meshman,

 

Now that would be confusing to me. "Lanai @ 030" sounds as though Lanai would be located at 30 degrees from the aerocache location.

 

Jim F.

 

You have to think the other way around. It's not about where Lanai is located from the aerocache but where the aerocache (and hence the intersection of the radials) is located. You aren't trying to figure out where the VORs are from the location where the aerocache is, you are trying to figure out where the aerocache itself is, period! And the ONLY proper way to describe that location is by giving the numbers of the intersecting radials.

 

Radials ALWAYS and ONLY go outbound of a station. On the picture below I drew the three radials that intersect at the location of the aerocache. It's the 030 radial from Lanai, the 105 radial from Molokai and the 268 radial from Maui. Only those three radials intersect at that point. The 210 radial from the Lanai VOR would run almost over the Lanai ILS which is in the complete opposite direction!

 

 

Now it is up to the pilot to figure out the headings he or she has to fly: that may be the same heading as one of the radials, but it might as well be the reciprocal of another.

 

Imagine the pilot will take off from the big airport on Maui: then he would fly the outbound heading of the Maui VOR (268), which would be not even close to the numbers of the Lanai and Molokai radials, to get to the intersection.

 

Imagine the pilot will take off from the airport at the top of Molokai (Kalaupapa): then he of she might intercept the 105 Molokai radial outbound. But imagine he has to take off to the north-east and can't get over those high mountains south of the airport, he could fly to the east, around the mountains, and then decide to intercept the 030 Lanai radial inbound on a heading of 210 (the reciprocal). The possibilities are endless but there is only ONE proper way of defining the intersection where the aerocache is!

 

Here is a picture showing that last example. The pilots ends up flying a heading of 210 but he is ON the 030 radial and using the same three numbers as posted above to find the aerocache.

 

Hey Jeroen,

 

It seems to me that using the term radial is causing a lot of confusion. When you look at the instruments you either see "To" or "From". The word radial never appears. This is what I've only ever considered and have never been confused.

 

Jim F.

How is that confusing?

 

The "030 radial" is a fixed line extending from the VOR to an infinite distance at an angle of 30º. It matters not a bit whether you are flying "TO" or "FROM" the VOR, you are still "on" the 030 radial...

 

If you are driving on I90 near Chicago, it matters not a bit if you are going North or South, you are still on I90

Hey Jeroen,

 

It seems to me that using the term radial is causing a lot of confusion. When you look at the instruments you either see "To" or "From". The word radial never appears. This is what I've only ever considered and have never been confused.

 

Jim F.

 

The WORD radial never appears but all the numbers you see on that gauge are the numbers of radials...! TO and FROM are totally dependant on which radial the VOR is set to. If you only look at TO and FROM without minding the radials, you may get completely lost. Only looking at TO and FROM and forgetting about the rest may be fine for flying straight to a VOR, but for more complicated navigation you need to work with radials.

It seems to me that using the term radial is causing a lot of confusion. When you look at the instruments you either see "To" or "From". The word radial never appears. This is what I've only ever considered and have never been confused.

 

Without defining the radial, you have no way to know which side of the VOR station you should be on. TO/FROM simply tells you if you are pointed toward or away from the station, not which side of it you are on. Not by itself.

 

TO/FROM may be all you really need if you are merely trying to fly to an actual VOR station.

 

However, if you want to use the VOR system to find locations that don't have VOR stations (like, a spot out over the middle of an ocean channel), you have to specify VOR radials that cross at that spot. You are triangulating the target from known fixed references.

 

Trying to provide those references in the vague, open-to-interpretation way MS is doing it causes confusion, because you have to figure out which information they are actually giving you.

 

If they simply listed the radials which intersect at the target it would be simple and easy, with no guessing or wondering.

TO/FROM simply tells you if you are pointed toward or away from the station

 

O, hold it, LOL I am sure (I think ) that's not exactly what you were trying to say but this isn't true. TO/FROM simply tells you if you are within 90 degrees (left or right) from the radial you set the VOR gauge to. You may be on the TO side while pointing (flying) away from the VOR and you may be on the FROM side while pointing (flying) to the VOR... TO and FROM says nothing about where you are going but only says something about where you are in relation to the VOR, and to be more precise, in relation to the radial the gauge is set to!

 

Example (which probably only makes this more complicated LOL). At a certain moment in time the pilot is flying (no matter what direction!) on the 270 radial and the OBS is set to 270. FROM will be enabled. FROM will stay enabled as long as you set the OBS to the radials between 180 and 360. When the pilot sets the OBS to a number between 0 and 180, let's say 64, you will see TO! And all this without changing the position AND heading of the airplane!

O, hold it, LOL I am sure (I think ) that's not exactly what you were trying to say but this isn't true. TO/FROM simply tells you if you are within 90 degrees (left or right) from the radial you set the VOR gauge to. You may be on the TO side while pointing (flying) away from the VOR and you may be on the FROM side while pointing (flying) to the VOR... TO and FROM says nothing about where you are going but only says something about where you are in relation to the VOR, and to be more precise, in relation to the radial the gauge is set to!

 

Yes, I was grossly over-simplifying it, making the assumption that the OBS was properly aligned to the flown course and the CDI was being kept centered, and the rest of reality slipped through my fingers.

Hi,

 

A radial is the "bearing from". If it's clearer to define a point as being on a VOR 210 radial as opposed to being 210 degrees from the VOR then feel free.

 

Jim F.

A radial is the "bearing from". If it's clearer to define a point as being on a VOR 210 radial as opposed to being 210 degrees from the VOR then feel free.

 

It's not so much "clearer" as it is using correct, non-ambiguous terminology.

 

For example, if you said "Lani VOR bearing 225" somebody else would ask "bearing to" or "bearing from"? Then, "From the plane or from the station?"

 

The term "radial" is specifically used to eliminate that confusion. The problem began when MS started out using "radial" to attempt to define a bearing to a VOR station.

 

If you say "Lanai VOR radial 225" there is no question of exactly what you are saying, as you are specifying a line extending from the Lanai VOR station to the south-west on a bearing of 225 from the station.

Hi,

 

I can't imagine anyone using the phrase "Lani VOR bearing 225". Setting up a strawman to knock down seldom if ever helps a discussion.

 

Jim F.

I can't imagine anyone using the phrase "Lani VOR bearing 225". Setting up a strawman to knock down seldom if ever helps a discussion.

 

You clearly have not met Microsoft. Or, at least whoever at MS has been writing the vaguely-worded VOR Aerocache tips.

 

Anyway, you may not see value in hypothetical examples for explanatory purposes, but I believe they do have some. They also should not be construed as an "attack" on you, as they are simply hypothetical.

I can't imagine anyone using the phrase "Lani VOR bearing 225". Setting up a strawman to knock down seldom if ever helps a discussion.

 

There are various ways to define or describe something but it's easier for everyone if one method is being used. Simple as that. And in real world flying it's not only easier but mandatory!

 

I don't really know what you mean with that strawman remark, but that may be because English isn't my native language...

 

EDIT

Just read RoboRay's reply about that strawman remark: if you think we are posting all this just to prove we are right and you are wrong, you couldn't be more far off. I (let me speak for myself) am simply trying to help you and others to understand it all better, hoping you will benefit from it in the future. That's it. I wouldn't go through all the trouble of creating and posting screenshots with examples just to show 'I know it all better' and that you are dumb or whatever... :Thinking: I don't know what gave you that idea, but believe me, that's not the case here.

Hey Jeroen,

 

I haven't been insulted but have been trying to understand what the source of confusion has been. My best guess was that when the term radial is used you have to mentally think "that's the bearing from". I just like to keep things simple.

The strawman remark refers to using an easily refutable example in order to prove a point. A man made out of straw would be easily knocked down.

 

Jim F.

Only problem being... it's not "an easily refutable example" when it's actually happened previously.

 

But, call it a strawman if you like. I'll keep calling them "examples that help with explanations."

 

My best guess was that when the term radial is used you have to mentally think "that's the bearing from". I just like to keep things simple.

 

But you seem to understand the system correctly. If everyone understood that, there would be no issue. However, some people have different "understandings" and get confused by the use a term that can imply multiple things, depending on how it's used.

 

That's why specific technical terms (like "radial") exist... to both keep things simple and remove any possibility of confusion.

Ah, ok, sorry for the misunderstanding. Well, as RoboRay said bringing radials into the mix isn't about making it easier (or more complicated) but what DOES make things more simple in the end is consensus on the used terminology. If everyone uses the same terminology it will become very hard to get confused. And since radials are part of a pilots regular vocabulary I think it's best to work with radials when it comes to VOR and things like intersections.