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andreadebiase

FIX RAD/DIS....RAD meaning

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What does the RAD value mean under FIX? DIS is distance to the FIX but i cannot figure out RAD, i thought it was the "radial" meaning the direction I have to point to to get to the FIX on a 360 degree compass but it is not....what is it?

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Radius

It's not Radius but Radial. It let's you plot a line from the fix with the given radial.

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It's not Radius but Radial. It let's you plot a line from the fix with the given radial.

so if my FIX is let's say RAD=10 and DIS=45 means that the FIX is in front of me slightly to the right (10 degrees) and 45 miles away? is this how i should read it?

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so if my FIX is let's say RAD=10 and DIS=45 means that the FIX is in front of me slightly to the right (10 degrees) and 45 miles away? is this how i should read it?

 

It's your bearing and distance from the fix.  In your example you are on the 010 radial 45 NM from the fix.

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VOR - A VOR has 360 lines coming FROM the VOR.  Each one of those lines is referred to as a RADIAL. 

 

NDB - An NDB has an infinite number of lines (usually rounded to the nearest degree) going TO the NDB transmitter.  Each one of those lines is referred to as a BEARING.

 

The term BEARING is used in reference to an NDB and the term RADIAL is used in reference to a VOR.

 

To accurately answer your question, which radial is the RMI pointer (VOR) showing?  

 

blaustern

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take a look at this screenshot (i hope you can)

 

https://drive.google.com/open?id=0B3t-K3IVIol_Y1B2LWpHS2RzdjJhZHpHMmxZVTdVdGVWOWVR

 

On the left side, on the radar, the fix is aprox at 1 o'clock, you cant really read LIML but i assure you it is (a dashed line goes through it) and now look at the FIX on the right side, says 343/21. How is it possible that the airport (the FIX aka LIML) is ahead of me to the right (again 1 oclock-ish ) and the radial is 343? isn't 343 to the left of me (assuming i am always facing 0/360 radial). What am i missing? 

If this is confusing let me know and will try to explain... 

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The term BEARING is used in reference to an NDB and the term RADIAL is used in reference to a VOR.

 

Sorta..., any fix will have a bearing from you. The OP should refer to some basic navigation material, just wiki "navigation" and start reading and follow the also read links too.

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On the left side, on the radar, the fix is aprox at 1 o'clock, you cant really read LIML but i assure you it is (a dashed line goes through it) and now look at the FIX on the right side, says 343/21.

 

The radial is taken from the fix. 343/21 means you are at 21nm in the 343° from the fix. Therefore you will see the fix at 21nm in your 163°.

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any fix will have a bearing from you.

 

While I see what you're getting at....

 

Wayyyyyy back in my Navy Navigation schooling, the terms Bearing and Radial where not interchangeable (perhaps so that the two terms where never confused).

 

A bearing was from you to something, whereas a Radial was from something to something else (presumably you/your aircraft in the example above).

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The radial and distance settings on the FIX page are not relative to your position; they have nothing to do with your position at all.

 

They're just radial and distance lines you can draw from whatever the FIX is - and it can be an airport, a navaid, an intersection... anything in the nav database.

 

These lines are just for reference but can be handy. Let's say you're taking off from an airport on runway 27, and there's an engine-out procedure that dictates you fly straight ahead to 4.0 DME from a nearby VOR, then turn right to intercept the 335 radial from that VOR and fly outbound. You could throw the VOR in the FIX page, with a distance of 4.0 and a radial of 335, and you'll have the radial and a 4.0 DME ring drawn on the ND in green dashed lines. Now if you DO bang an engine at V1 and that entire meticulous briefing about what to do in the event of an engine failure is forgotten in the workload of actually flying... It's drawn right there on the ND.

 

Or, let's say you're departing a satellite airport underneath a larger airport's class B airspace. Your don't want to accelerate above 200kts (or clean maneuver speed) until you're either out from underneath the class B, or you've climbed into it. You can draw the airspace ring at the appropriate distance on the FIX page, using the class B airport as the fix. (No radial required in this case).

 

It's one of those things that the longer you fly with it, the more uses you find for it.

 

To clarify - my examples refer to drawing the distance and radial on separate lines in the FIX page. If you enter 335/4.0 on the same line, you'll get a radial out to a 4 DME fix. Useful, but try putting them in separate lines: /4.0 on the first blank line (don't forget the leading slash), and 335 on the second line. You'll get a 4 DME ring, and a radial line to infinity. (Ok not really, but a long way).

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The radial and distance settings on the FIX page are not relative to your position; they have nothing to do with your position at all.

 

I'm assuming he is referring to the information at the top of the fix page that shows your current rad/dist from the fix, which would indeed have something to do with your position.

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the way i think i understand it: the FIX is a FIX-ed point with radials all around, an airport for example. The FIX radial number indicates my position relative to that airport.  So if i read POS=270 for LIML means that if you look at LIML on a map with north facing ahead i am positioned to the left at 9 o'clock relative to LIML at a distance designated by DIS value. If POS is 180 i am south  at 6 o clock.... and so on.....agree?

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