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SIDs/STARs/Transitions/Vias. Some practical advice, please?


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I am trying to understand how these work in the real world (so that I can take full advantage of the ToLiSs A319 fully-functional FMC in X-Plane11). Maybe someone who knows all about this could kindly give me some help?

 

I am OK with programming SIDs and STARs, but the FMC often then presents me with a list of transitions and then vias. In essence, how do I choose whether to use one, and if I do, which to fly?

 

As an example, I am flying VOMM (Rwy07) to VOHS (09R). Chosen DOHIA as SID and SARKA8 at STAR. In this example, no STAR transition is offered.. but if it were (on another route say), how would I go about choosing the most appropriate one? I can't see them on my map (I use LittleNavMap) - maybe I haven't activated them - so I might as well choose by sticking a pin in...

 

Then I am offered Vias - BIMO2, HIA1, HIA2, LEDOB, OSEM2 or VIKA2. Again, though I have Googled this, I still am not confident enough to choose one (it would be random again). On this flight, whatever I choose, I get a discontinuity towards the end of the flight plan.

 

If anyone can explain this in practical terms, or point me too a not overly techy article, that's be appreciated.

 

Finally, although I choose and programme SIDs & STARs OK, I am not sure of the logic of some of them. In the above example, if you are able to look at the SARKA8 STAR on your won flight map, why the odd shape (sharp turns at HS321 and then HS228)? Why wouldn't the STAR go straight to HS228 and miss HS321. Don't think there are any terrain issues here - in fact given the elevations, why go to HS321 at all?

 

Thanks in advance!

 

Martingrab_030.jpg

Edited by martinstebbing
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In LittleNavMap have you updated the scenery database? You must do this with each airport, etc added to the Sim so its reflected in LittleNavMap. Also, you can just make up your own transitions and not follow real-world procedures. I have done this in the PMDG 737 back when I ran it in FS2004. I used to use FSBuild to create my flight plans. Both for the game and the FMC. I'd go into the FMC and load the flight plan and away I went. I did follow the SID and STAR for the most part, but my transitions were all different. I'd usually pick a VOR or NDB.

 

I'm not a real-world pilot, but if I can remember right, a DISCO (discontinue) is something to be expected since at that time ATC will vector you. But since this is the Sim you can chose how you want to approach the FAF (Final Approach Fix).

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Thanks. I will check LittleNavMap - I have probably missed this.

 

Yes, I know a DISCO is sometimes inevitable, especially with a 'manual' indication. Not really a problem: I just fly the manual part and then set the APPR when more or less pointing in the right direction. The a/c lines up, descends and lands just fine. From what I read, that is pretty much what happens in the real world too. (Learned this week that in an Autobus, the localiser is almost never used - straight to APPR, so that's what I do now: I always did LOC?APPR in my PSS Airbuses in FS9).

 

But the question really is how transitions and vias function. What are they for? Why are they needed over and above the SID or STAR? And how do I choose the one most appropriate? Are the transitions and vias supposed to show in LNM? I couldn't locate any of them (I assume they are (like) waypoints and should appear on a map??) on LNM, even with max info setting. I am becoming painfully aware of my ignorance in this area!!

 

Thanks again.

Edited by martinstebbing
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Well, all I know is that SIDs and STARS help ATC know where you are and it helps them route traffic. So a via this waypoint, etc would help keep the flow of things I guess. I'm not an expert in this area either.

 

What is LNM? I don't know what that stands for.

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If you're asking how to use a transition then that's easy. It's just a waypoint, VOR or NDB from the SID or STAR. After the SID or STAR you fly direct to that waypont and on to the other waypoints until you reach your STAR for example. After the STAR will get a DISCO and it will be at that point ATC will more than likely give you vectors. But in the Sim you can just fly the STAR all the way to the runway. Unless you fly with VATSIM.
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"What is LNM? I don't know what that stands for."

Sorry, lazy abbreviation. Little NavMap.

"If you're asking how to use a transition.."

Basically, yes, and then in addition, why would one add a 'via' to a transition, or STAR (I think you can add a 'via' point even with no transition?). The X-Plane 11 ToLiSs A319 CDU simulates and acts upon all this data, so I wanted to set things up as realistically as possible. For now I fly to the end of the STAR, which isn't always of course to the runway, and then, as necessary fly manually and engage the APPR, where the airport permits it (otherwise I just switch off the AP and hand fly - that always sets the pulse rate up a notch or two!)

Thanks for the short explanation, but as far as I had noticed, the transition is not one of the waypoints in the STAR - it's a kind of 'addon', and one that I still can never locate in any map (would transitions only appear on the airport chart??).

As for the 'via' on top of the transition, I am totally clueless!

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why would one add a 'via' to a transition, or STAR (I think you can add a 'via' point even with no transition?).

 

A TRANSITION is just a way of getting from the initial portion of the STAR to the instrument approach that you'll be using. Note this quote from chapter three of the FAA's Instrument Procedures Handbook:

 

This often results in a seamless transition between the en

route, arrival, and approach phases of flight, and serves as

a preferred route into high volume terminal areas.

 

It sounds as if you're thinking of "via" as a procedure, in itself. It's just another way of saying "by way of" or "using the following path." When I drive from my home in Denver to Kansas City, I go via I-70. That's shorter than saying that I travel on Interstate 70. A STAR is literally just a preplanned clearance that saves the controller from having to give a long-winded clearance, and the pilot from having to copy it.

 

Note this quote from chapter three of the FAA's Instrument Procedures Handbook:

 

A STAR is an ATC-coded IFR route established for application

to arriving IFR aircraft destined for certain airports. A STAR

provides a critical form of communication between pilots

and ATC. Once a flight crew has accepted a clearance for a

STAR, they have communicated with the controller what

route, and in some cases what altitude and airspeed, they

fly during the arrival, depending on the type of clearance.

The STAR provides a common method for leaving the en

route structure and navigating to your destination. It is a

preplanned instrument flight rule ATC arrival procedure

published for pilot use in graphic and textual form that

simplifies clearance delivery procedures.

 

The principal difference between standard instrument

departure (SID) or departure procedures (DPs) and STARs

is that the DPs start at the airport pavement and connect

to the en route structure. STARs on the other hand, start

at the en route structure but do not make it down to the

pavement. This is primarily because STARs serve multiple

runways and sometimes multiple airports.

 

You can find that manual here. You can find pointers to the FAA's aviation handbooks and manuals on this page. There's a tremendous amount of information available for the downloading, or even just for reading online. There's nothing mysterious about it, though it takes time and effort to go through the publications to find information.

 

Larry N.

As Skylab would say:

Remember: Aviation is NOT an exact Science!

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Thanks Larry. I do know what 'via' means (I did Latin at school for a start! Now I am an English language teacher :)), but I just don't yet see why, if there is a STAR selected, plus a transition, the pilot would be asked for input for a 'via' as well. I suppose there must be more than one way to get to the transition point - that makes sense from the use of the word 'via' at least, but as I still can't locate (on the map) any of the transition or via points I am offered by the FMC (which is quite possibly me being a bit dense, I wouldn't deny!) I still have no way to choose one transition, or 'via' over another. Is the via an actual point, like a waypoint, or a path, like an airway? (I assume the former, but it could be either. Using your analogy of a car - not so good for me as I have never driven a car in the 60 years of my life! - I can go from Southampton to Luton, via Staines (point), or via the M25 (route))?

 

I choose SIDs and STARS using LittleNavMap, which highlights the chosen route. I then adapt my flightplan as needed (deleting now obsolete waypoints, which are within the area of the SID or STAR), but after that I am working in the dark when trying to select which transition and/or via to input into the FMC.

 

Thanks again... I'll have a look at your links too, of course.

Edited by martinstebbing
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OK, progress: the simple reason I couldn't see the transitions or vias is that I stupidly wasn't looking far enough out - they are much further away from the airports than I imagined. They do show on LittleNavMap (I located them first on good old FS Navigator for FS9!). I think (?), with that sorted so simply, I should be good to go!! Edited by martinstebbing
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OK, progress: the simple reason I couldn't see the transitions or vias is that I stupidly wasn't looking far enough out - they are much further away from the airports than I imagined. They do show on LittleNavMap (I located them first on good old FS Navigator for FS9!). I think (?), with that sorted so simply, I should be good to go!!

 

Martin,

 

I'm glad you found what you're looking for.

 

but as I still can't locate (on the map) any of the transition or via points I am offered

From this statement, it still appears to me that you are thinking of "VIA" as a separate procedure, rather than just wording incorporated into a procedure, though perhaps I'm misunderstanding you.

 

Perhaps it would help (maybe this is already clear to you) to recognize that each TRANSITION is a path that ultimately leads to the point for which the STAR is named, and from there it points to a spot where an instrument approach may be made to the airport. Each transition begins in a different place. And in the real world, you don't pick a STAR -- ATC gives you a clearance that includes a STAR and which TRANSITION, and you may accept or reject the clearance. But ATC chooses the TRANSITION based on where you are coming from, as well as what wind, weather and traffic are doing at the moment.

 

So perhaps the sim or your FMC might be confusing you a bit. Still, it's good that you found what you need at this point.

 

Since I don't know what you really have available to you in the way your sim/add-ons are configured, I thought I'd show you a STAR page from real world operations -- Orlando's GOOFY FIVE ARRIVAL is shown below, with its three TRANSITIONS, and including information for nearby airports other than Orlando International. Do note that the chart says it is not to scale.

goofy-five-arrival.png

 

Larry N.

As Skylab would say:

Remember: Aviation is NOT an exact Science!

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Thanks again for this.

 

Yes, I may have some 'wrong' ideas in my head about aspects of this.

 

Perhaps, as an example of the use of the 'via'.. If you have a choice of three or four in the FMC, how would you go about choosing the most appropriate? The ones I have been offered seem to be, in essence, waypoints, but quite a way away from my programmed route+STAR, so I usually opt for 'No Via'. I think I need to keep programming flight plans into the a319 FMC and comparing with the LittleNavMap information and map page (or vice versa) to work things out.

 

I am still a bit nonplussed as to why the SIDs and STARs themselves can be so oddly formed though! For instance, flying into Mumba VABB Rwy 27 from the south-east, I chose STAR MOLG1A. This seems a very unwieldy path (like the one I posted a few days ago), with its 'dog-leg' sudden change of direction. It goes to MB372, then MB394, after which there's a sharp turn east to get to MB395 and then some 150 degs back again, leading to a 'manual' section, north of the airport. I don't understand these odd twists and turns. They aren't usually governed by terrain considerations.

 

grab_031.jpg

 

I think you are right that even a very well-modelled FMC is not going to be able to interact with ATC in a totally realistic way, due to the limitations of the ATC programmes for the most part. The more I fly this a319 (and it's the first a/c I have flown in 20 years that models all this so comprehensively (hence my incentive to do it justice!). I am sure after a while, it will all fall into place!

Edited by martinstebbing
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Have a look here at the yellowstone one SID. https://flightaware.com/resources/airport/KDEN/DP/YELLOWSTONE+ONE

 

 

Now depending on where you are going you have several transitions to chose from. Say I want to go to Chicago to the east. I would then chose the Cheyenne transition and then from there I'd turn right to HANKI and continue on with my route. CYS is my transition.

 

Looking at the sectional here:

 

https://i.imgur.com/R8BDQUW.jpg

 

You can see where to go and create your route after that transition. So after HANKI I would be on J148. From there there's a VOR I connect with called O'Neill or ONL.

 

So thus far my flight plan looks like this: YELLO1.HANKI.J148.ONL... etc...

 

You can use this site to look at charts. https://skyvector.com/

Edited by CRJ_simpilot
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I could take the HANKI transition for a more direct route east instead of going north to Cheyenne.

 

You can use this to plot your route and see what you are going over visually. http://mapper.acme.com

Edited by CRJ_simpilot
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He's primarily concerned with STARS, which are a different kettle of fish.

 

True, the SIDs aren't a problem on the whole, but it is still useful to read the stuff CRJ linked to.

 

LittleNavMap does pretty much everything I need (I use it in association with SimBrief).. but quite frequently the number of usable SIDs or STARs are relatively few. LittleNavMap brings up a visual image of the path as soon as you click on the SID or STAR - most are obviously not appropriate for the incoming flight path. The one for Mumbai VABB which I posted is the best of the few options available when flying up from the south-east (VOHS here), but having flown the route since I last posted, I am even more amazed at the 'detour' to MB395, which is at some of the highest terrain in the region (northern end of the Western Ghats mountain range). Why (I ask partly rhetorically, as I guess no one on the forum would know, unless he/she is part of the FAA or whatever) is MB395 included in the STAR? Having flown the route, as I say, missing out that point would give an easier approach, in my humble (but doubtless misguided!) opinion.

 

Well, the good thing is that I have quickly changed from regarding SIDs, STARs and Transitions as a complication I can avoid (and did) simply by flying to the runway's 'LOC/GS point' and engaging the APPR mode, to something that is actually an enjoyable part of the pre-flight programming (which now take some ten times as long as before, but that's all good!).

 

Thanks as ever to folks for taking time to reply.

 

Martin

Edited by martinstebbing
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I don't understand these odd twists and turns. They aren't usually governed by terrain considerations.

 

Not being familiar with the aviation aspects in India, I can only speculate that airspace (including restricted areas), instrument approach layouts, traffic patterns they wish to maintain, and similar things may have an effect.

 

Not being familiar with your nav program (I'd never heard of it until your post), I am presuming the pictures you are posting are screenshots of your program (they look like some of that in the manual). And since the manual says that when using the downloaded nav data that the program may ignore differences between the sim and the downloaded date, perhaps you are seeing a mismatch, unless you also have the chart/description of the STAR in question at hand and the same thing is depicted there.

 

Keep in mind that the sim data goes back to around 2005, while your nav data may reflect the current real world, in which case there could be lots of incompatible changes.

 

Larry N.

As Skylab would say:

Remember: Aviation is NOT an exact Science!

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Without having the actual charts to look at, selecting appropriate SIDs and STARs is a bit like Pin the Tail on the Donkey. Choosing from a list of waypoints without seeing them on a map is challenging at best.

 

The route map that you posted simply does not provide enough info, all it shows is a selected route.

 

One question, where did this "manual" waypoint come from, is that something you added?

Capture.JPG

 

At a glance, that route does seem confusing until you look at the actual approach plate...

Capture-2.JPG

Here you can plainly see how traffic would flow depending on the active runway and that for 27 you would leave MB395 on a 360 heading and not turn straight for the airport as shown in your route pic. At this point (if not before) you would most likely receive vectors to final, you are done with the STAR.

 

As to why this STAR is set up the way that it is? Who knows? Terrain avoidance, noise abatement, traffic sequencing, any number of considerations could have gone into the design.

 

Note that controllers may have the option to deviate from the STAR at their discretion. You may, for example, be told to proceed north from MB394 and eliminate some 25 miles of flying provided you can safely fly that heading. As is, it seems to me that the STAR will set you up for a loooong final. Maybe that is needed for the traffic volume into Mumbai.

 

BTW, is it a coincidence that your route takes you almost directly over the SC NDB, which happens to be the LOM for the 27 ILS?

Capture-3.JPG

 

DISCLAIMER- the charts I used are not current and were found, via a Google search, on a virtual airline website

 

peace,

the Bean

WWOD---What Would Opa Do? Farewell, my freind (sp)

 

Never argue with idiots.

They drag you down to their level and beat you with experience

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All screenshots from LittleNavMap. not the manual.

BTW, is it a coincidence that your route takes you almost directly over the SC NDB, which happens to be the LOM for the 27 ILS?

Yes, it is.

where did this "manual" waypoint come from, is that something you added?

No, it is generated by LittleNavMap along with the STAR. From what I have been told on X-Plane forums, this is perfectly normal.

 

To be honest, I think all this is starting to swim around in my head rather: I should leave it a while and come back to it. Perfect timing really as I am going abroad on holiday for two weeks in a couple of days time. I'll have a fresh look when I get home again.

 

Thanks.

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where did this "manual" waypoint come from, is that something you added?

 

No, it is generated by LittleNavMap along with the STAR. From what I have been told on X-Plane forums, this is perfectly normal.

 

If the software is going to add waypoints that do not actually exist, all bets are off.

 

peace,

the Bean

WWOD---What Would Opa Do? Farewell, my freind (sp)

 

Never argue with idiots.

They drag you down to their level and beat you with experience

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If the software is going to add waypoints that do not actually exist

Manual is not a waypoint. It is an indication that a heading, track or a hold is held until terminated by ATC ('Manual termination').. If you Google 'Procedural Leg Types', it is explained in most of the pdf files that come up (at least the ones I have downloaded).

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Manual is not a waypoint.

On your screen shot it sure looks like a waypoint. In any case, that means it's not part of the STAR, just an artifact of the software. And those of us who don't run that software can't help with that -- in fact it might be that X-Plane does something weird, for all I know, since I don't use it either. Whatever it is, it's different from the real world, so you need experts on that.

 

Perhaps the X-Plane forum might have been more help for you, and since there are differences from what the real world does -- perhaps they can help. Or perhaps there's a forum for your software?

 

Larry N.

As Skylab would say:

Remember: Aviation is NOT an exact Science!

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Yes, I can get help with both on other forums, but I think that I have to accept that many things in X-Plane, good as they are, are never going to be perfectly exact replicas of the real world. (And since I am not a real-world pilot of Airbuses or Boeings, I probably wouldn't know the difference anyway when it comes to the finer details).

 

The 'Manual' indication on the map is not an invention of LittleNavMap - it is just how the map indicates the end point of a Manual Termination procedure. How closely that procedure in the map software reflects Manual Termination procedures in the real world, I couldn't say.

 

In essence, given that by adding Transitions and Vias to my flight plans over the past few days, I have got some odd results in the aircraft FMC (fairly long detours in the wrong direction, for instance), and that I am in front of my PC console and not real cockpit instruments, I think I should compromise between what I understand to be real-world procedure and what I can realistically achieve in X-Plane (taking into account the limitations of X-Plane, my ATC programme and of my ability to get my head around the finer points of this)... or I shall never get any actual flying done.

Edited by martinstebbing
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