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wipeout01

Doubt about waypoints, unnamed waypoints, intersections?

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Hi, I have a confussion about this.

 

waypoints3_zpswpfeftga.jpg

 

As far as I know an airway is a straight line that connect several waypoints, which has names of five letters.

The waypoints are represented as white or black triangles. When it is white, you won't have to contact the ATC, hence it is a noncompulsory notification waypoint... when it is black, you'll have to contact the ATC, compulsory notification waypoint.

However, the waypoints normally has names easy to spell TOLVO, ALCAR, VICAR...

...but there are some waypoints, called unnamed waypoints... not shown in some ENROUTES coming from the local aeronautical authorities of several countries. For example, in Spain, AENA, our local authorities providing charts to the pilots, don't show these unnamed waypoints...

I mean waypoints with strange names as... JRZ27... D005F... these waypoints are called unnamed waypoints... and I don't know what function they perform? specially because some of them are outside the airways...? they are in the middle of the field and are not connected by any airway whatsoever... ?

so what function perform these unnamed waypoints?

And also I don't know when a waypoint is an interesection?

Perhaps is when a triangle (waypoint) be black or white, connect with several airways? in that case is an intersection?

I really would appreciate if someone could clarify me these basic concepts, because I would understand much better the charts.

Cheers

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I believe that's a terminal fix for a runway approach for LEZL. It appears to be used like an amay Arrival Gate.

 

Please excuse my initial post, it was right in the info you posted!

 

 

 

 

Best wishes.

Edited by DaveCT2003

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Dave is correct, these are terminal waypoints. Used either in arrivals or in departures but not enroute, hence they won't be shown on the enroute charts. Today with the "advent" of RNAV procedures you'll see plenty of RNAV SIDs, STARs which contain lots of these waypoints with "strange" names. This is a good example, the runway 20 RNAV departures from LEJR

 

Now, in this case it says "JRZ27" belongs to LEZL Sevilla, while "JRZ" is the code for the Jerez VOR. The "27" could be alluding to the 27 DME from JRZ. I can't seem to find this waypoint on any of the chars for LEZL.

 

Regarding intersections, when a waypoint is very close to an airway but does not belong to it, the airway line will usually "surround" this waypoint so as to indicate it's not part of the route. If the waypoint is right on top of the line, then it's part of the airway. Same applies for intersections, if 2 lines cross the waypoint, said waypoint belongs to both airways. There's plenty of examples here:

 

U9MbKvX.jpg

 

See chart here. ROLDO for instance belongs to UZ409 but NOT to UL185.

 

By the way, if anyone is curious, all official charts for Spain can be found here.

 

Hope this helped,

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The waypoints like JRZ27 are part of specific approach or departure procedures for specific airports. They may or may not appear on an enroute chart. To see them "in context", you would need to look at the approach or departure charts for the airport in question.

 

Compulsory vs. non-compulsory reporting points are only used in the rare case that ATC does not have radar contact with an aircraft - ordinarily, an aircraft in flight will be continuously tracked by ATC radar, so pilots do not have to report passing specific waypoints.

 

The exception to that would be on oceanic flights beyond ATC radar coverage, where aircraft do report passing each enroute waypoint. However, with ADS-C using SATCOM data links (part of FANS), ATC can now track aircraft position over oceanic routes without radar.

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Wow thank you for everyone. Crystal clear !!!

Jim Barret, more clear impossible, great explanation, thank you.

 

However... I still don't understand when a point is an intersection?

I mean... every waypoint is an intersection? or perhaps only those waypoints that connect with several airways?

 

I have a little mess here, because Jeppesen show intersections (I think like a star, I mean a real physical star (I don't mean the chart), draw as a star I mean, not a triangle)... with Enroutes in Spain I only see always triangles, and some of them connect with several airways.

So that is my doubt... when do we have an intersection? how can we see if we have an intersection or not?

 

Cheers

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Star waypoints, as in the way they're drawn, are usually blue in color and represent RNAV waypoints if it's on a high altitude enroute chart. If it's on a sectional it's usually black and called a VFR waypoint.

 

At least, that's all I've seen, I've not read through the AIM to learn 'em all.

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However... I still don't understand when a point is an intersection?

 

I mean... every waypoint is an intersection? or perhaps only those waypoints that connect with several airways?

 

Hi wipeout,

 

No, not every waypoint is an intersection of airways.

 

Have a look at the chart I posted in my previous comments.

 

Examples of waypoints that ARE NOT an intersection of two airways:

ROLDO, KASTA, AVILA, KAMPO, DOLES

 

Examples of waypoints that ARE an intersection of two or more airways:

MELON, ZORBA, DIPOL, KALMA, RIDAV

 

Can you figure it out now? :)

 

Regards,

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Hi everyone and thanks a lot for the replies.
Hi Alpha Floor


Crystal clear ;)
To summarize the thread I quote the explanations given which are extremely clear to understand.

WAYPOINTS


Alpha Floor:
Examples of waypoints that ARE NOT an intersection of two airways:
ROLDO, KASTA, AVILA, KAMPO, DOLES


Exactly. These waypoints (waypoints are always represented by a white triangle or black triangle) ARE NOT intersections... because they are in an airway but do not connect with other airways. In other words... these triangles (waypoints) are not connected by several lines (airways).

INTERSECTIONS


Alpha Floor:
Examples of waypoints that ARE an intersection of two or more airways:
MELON, ZORBA, DIPOL, KALMA, RIDAV

...if 2 lines cross the waypoint, said waypoint belongs to both airways.

 

Yes. These waypoints are intersections because they are connected by several lines (airways), so they intersect, with several lines, airways.
We can see that, MELON, for example, is connected by several airways, so this is an intersection. ;)

UNNAMED INTERSECTIONS


DaveCT2003
I believe that's a terminal fix for a runway approach for LEZL. It appears to be used like an amay Arrival Gate.

 

JRBarret

The waypoints like JRZ27 are part of specific approach or departure procedures for specific airports.

They may or may not appear on an enroute chart.

To see them "in context", you would need to look at the approach or departure charts

for the airport in question.

 

When waypoints are not shown in an ENROUTE charts and they are called unnamed intersections, is because they are used for other purposes different than the navigation in an Enroute chart, for example, to be used during an departure / arrival or other procedures.

WAYPOINTS OR INTERSECTIONS NOT BELONGING TO AN AIRWAY


Alpha Floor
ROLDO for instance belongs to UZ409 but NOT to UL185.

 

When a waypoint or intersection do not belong to an airway... it is circled by the line (airway) and surround it...
We see that ROLDO is surrounded by the airway (line) UL185. However, it is crossed by the line UZ409... so it is clear that if we are flying following the airway UZ409 we will find ROLDO, however if we fly the airway UL185 we will not find ROLDO, although we do not have physical space in the Enroute to show every waypoint far away from the points that do not belong to their relative airways. In these cases, we see how the waypoints or intersections that do not belong to an airway are surrounded by that airway.

We see that ROLDO is surrounded by the airway (line) UL185. However, it is crossed by the line UZ409... so it is clear that if we are flying following the airway UZ409 we will find ROLDO, however if we fly the airway UL185 we will not find ROLDO, although we do not have physical space in the Enroute to show every waypoint far away from the points that do not belong to their relative airways. In these cases, we see how the waypoints or intersections that do not belong to an airway are surrounded by that airway.

 

WHITE WAYPOINTS / BLACK WAYPOINTS

Compulsory vs. Non Compulsory Notification. When to contact the ATC?


JRBarret

Compulsory vs. non-compulsory reporting points are only used in the rare case that ATC does not have radar contact with an aircraft - ordinarily, an aircraft in flight will be continuously tracked by ATC radar, so pilots do not have to report passing specific waypoints.

 

 

Great explanation. I did not know that ;)

 

THANKS A LOT TO EVERYONE. You are the best. ;)

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I did a click in your name, Jaime Beneyto... and saw your linkedin :D

So... Jerez de la Frontera, Right?

Guess where I am ? Huelva ;) hahaha :P this world is very very very little :D

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