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Tutorial: Approach Legtype Definitions and Attached Picture

This is new to me, I know how to use ADE to add ILS. But not how to get the ATC to use them, or how to get the GPS to display. And missed approaches. Is their a tutorial for this knowledge in using ADE. Feeling numb here. May be it's in the ADE documents?
 
This is new to me, I know how to use ADE to add ILS. But not how to get the ATC to use them, or how to get the GPS to display. And missed approaches. Is their a tutorial for this knowledge in using ADE. Feeling numb here. May be it's in the ADE documents?

Have you checked the manual?
 
In fairness, he says he knows how to add them using ADE..so the manual part should not be the problem.. Jim was looking into this problem a while ago for me. While I was over in the Ukraine a few weeks ago. He messaged me that he had found some very interesting things about the problems and would get with me once I got back... He has not done that yet.

So apparently, there are some things that are creating a problem with ATC using the approaches, and the info is locked away in Jim's head. :)

Hopefully he will read this and chime in on it now.. Because I want to finish my approaches, but there is no real push for me to create them if the ATC's won't see/use them.

HELP JIM!!!!!

- Greg
 
This is new to me, I know how to use ADE to add ILS. But not how to get the ATC to use them, or how to get the GPS to display. And missed approaches. Is their a tutorial for this knowledge in using ADE. Feeling numb here. May be it's in the ADE documents?

There are post type tutorials (sticky) here that help explain how to add a ILS approach to an existing runway. ADE also adds the ILS approach automactically for you based on a checkmark added to a box when adding a ILS.

Just one example of a post that helps explain the ILS approach coding.

http://www.fsdeveloper.com/forum/showthread.php?t=14074
 
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In fairness, he says he knows how to add them using ADE..so the manual part should not be the problem.. Jim was looking into this problem a while ago for me. While I was over in the Ukraine a few weeks ago. He messaged me that he had found some very interesting things about the problems and would get with me once I got back... He has not done that yet.

So apparently, there are some things that are creating a problem with ATC using the approaches, and the info is locked away in Jim's head. :)

Hopefully he will read this and chime in on it now.. Because I want to finish my approaches, but there is no real push for me to create them if the ATC's won't see/use them.

HELP JIM!!!!!

- Greg

You are developing a airport that was not finished as a default airport. FSX has a major flaw in the runtime code where as added runways and approaches are not passed through the AI PLayer and ATC.dll properly. The GPS.dll is also not processing certain runway approach data.

In my spare time away from getting a working ADE9X out the door I have been back tracking the runtime issues to see if a repair can be made at the user level.

In a nutshell without getting too deep in coding, any runway opened at a airport like NKL (incomplete) opens all runways at one time (without a Xwind code). This nullifies any approach code which confuses ATC, the ATC window, GPS and related AI Plane behavior.

The first key to the problem is when contacting approach inbound to NKL. The ATC window list all runways including each end as being active. Do you remember seeing this? Every single incomplete airport in the database (mosty Military airports) where the runway and taxiways are made complete by the ADE designer are showing this flaw.

When my studies are complete I will post a full report on what can or cannot be done when opening all the airports in FSX that are in an incomplete stage.

ACES did not employee many 3rd party contractors in the area of airports for FSX since airports/AI where not a priority in the FSX version. World scenery was the priority and it appears that all the attention in round world scenery design caused many airport/AI code problems not seen in the FS9 version.

In the design/development of ADE we are finding that FSX is no longer working the way FS9 works. I am sorting through 3 different versions of FSX too see at what point something stopped working and it is very time consuming.
 
Thanks Jim!!!! I know you are extremely busy and appreciate all this work you are doing on this problem, more than you can know.

I think if it comes right down to it, when all is said and done, and NKL is ready to release, and if it can not be fixed, I will look at a way to just kill the original, (hide it, or whatever I have to do) and change NKL to KNKL. Then it hopefully would be seen as a totally new airport not having the problems of an unfinished stock airport.

I know this is not the best answer for a released product, but I will do whatever I have to do. Proper MS procedure or not.

- Greg

ps: I very much look forward to your full report in the future.
 
Question to Jim

Jim...

please... I have learned and understood a lot of things reading your teachings (I have enjoyed to apply) but this gives me problem :

regarding the GPS drawing of missed-approaches (KIAD)
- you start with a CA leg ==> easy to understand
- my questions are for the following leg (VI). When you write

Now I need to turn and intercept the 270 degree radial from AML. That willl be done by choosing a VI Leg and adding the 270 degree value as seen in the next picture

* how, choosing 270 as a "course deg", can you intercept a 270 degree radial from AML?? The course isn't it parallel to the radial?
* and how, under GPS navigation, do you know that the intercepted radial comes from AML rather than any other VOR (or point!)? (and here... I am very afraid to ask a stupid question)
But that is what I would to understand : Among all parallel roads, one only leads to the desired location. (If it is not the infinite of course...)

A good understanding of this concepts would help me to solve the original missed-approach of LFMT, which doesn't work (though apparently correctly described in its code). None of my attempts to correct, including a VI leg at least, are positive so far.

big thank you in advance

Philippe
 
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Hi to all
I'm starting by say what an excelent thread.
I've also learn a lot reading all the teachings of Jim, but there's something I can't do in a missed aproach.
I'm talking about Istres - LeTube AB - France - LFMI.
As per the approach chart (attached file)
Missed APCH : Climb straight ahead up to 1500 ft QFE.
At 2.5 ITR turn right MT 340° to join and follow
RDL 310° ITR. Crossing RDL 241° ITR climb up to
2000 ft QFE. At 11 ITR turn right for a new presentation.
I have managed to do all up to the point 11Nm outbound ITR, radial 310º.
The problem is when i try to add the right turn to intercept ILS at 153º, the turn is too small, it does not reach the 11Nm inbound. (dashed red in the approach chart).
Also in attach is the XML file.

Thanks in advance
Regards
 

Attachments

  • Istres.jpg
    Istres.jpg
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  • LFMI.txt
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Just been reading this for about the 5th time and I can say it's really help me along the Approach path:D

However when I get to the point where I have a nice approach plotted, I sometimes need to adjust the Missed approach path too espically in mountainous area's.

I always left it as it was, but I'm going to start work soon on a very approach and missed approach demanding project where the default missed app.s are way off what any Jepp chart tells me.

Is there a similar pictorial run through of this one, or can it be done in a similar way?

I will be looking into this in the manual of course, but something in pictures means a hell of a lot more to my brain than the usual thousand words syndrome.
 
Missed approach legs are constructed in the same way as approach legs. The only difference is that rather than starting with an IF and ending at a runway, they start with an actual leg (that just continues on from the last leg of the approach proper), and usually end with an HM leg (a holding pattern). A quick look at the default stock approaches will give good examples, generally.

HTH,

Dan
 
Thanks for that Dan.
Soon as I've the first approach done, I'll post details of it here.

Hope I don't screw it up too badly :D
 
Theta & Rho

First of all, thanks for all the info. For some time now, I have been tired of FSX controllers running me all over the place when flying IFR. I finally entered Approach Mode and found out why and added real transitions.

I corrected most everything according to real approach charts. I use Opennav.com to find the names of the fixes in the area of an airport, actual approach charts, and Globalair.com for Lat & Lon of the listed Fixes to place them into ADE. Actual OM, MM, and IM by distance and Lat/Lon are also found in this manner.

I am lost only regarding Theta & Rho listed in some of the procedures of FSX as shown in ADE. What are these, to what do they refer, and what is their purpose?

Again, thanks for the great info of the Leg Type Defs and pics.
 
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Rho-theta refers to the earliest attempts at providing an RNAV navigation system. Traditional navigation typically involves flying to or from VORs or possibly NDBs following established radials. Rho-theta navigation was based on VORs having collocated DME. This allowed for the creation of navigation waypoints based on a bearing (radial) from a VOR (Rho) and a distance from a DME (Theta). Likewise aircraft position could be determined the same way. Then courses could be computed to go from waypoint to waypoint, instead of following radials. An early GA navigation system using this principle was the Bendix-King KNS-80.

Subsequent to this it became feasible to store precomputed waypoints and courses in a database for recall during flight. This led to the development of a paper on database design (424) which was adopted by ARINC as a standard in 1975. The initial database was designed strictly on point-to-point navigation, but was expanded in 1982 to the "path-terminator" concept to match what approach designers did when defining approaches using either TERPS (US) or PANS-OPS (elsewhere) procedures.

I don't know how the path-terminators were initially defined (in terms of required data for the database), but it appears that where the legs are based on courses to traditional rho-theta waypoints, the VOR/DME or other navaid, the rho bearing and the theta distance from which the waypoint is defined are stored in the leg definition. Since the original set of leg types was defined, the list has been expanded based on other types of navigation in addition to the original rho-theta. These legs won't have the rho theta data in them.

Jim would know more, but when the waypoint in a leg is derived from rho-theta data, the leg will have a "recommended ident", "rho", and "theta" entries. Rho and Theta being the radial FROM the navaid and Theta the corresponding DME distance. I assume this data is designed so FMS systems with automatic VOR tuning can switch to the appropriate VOR for most accurate tracking and meeting navigational accuracy requriements.

Now in FS9/FSX I think the aircraft and all positional data is stored and maintained strictly in a lat/long format, so no use is made in the sim of the rho-theta info. It's apparent though that MS bought a commercial ARINC 424 database and just extracted the data elements needed for lat/long navigation. The rest of the data is ignored.

I will have to dig through some of Jim's notes to see if the rho-theta is actually used for some legs.

scott s.
.
 
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Theta & Rho

Thanks to both Scott & Helli for the info. I guess I didn't study all of that for my Commerical Multi-engine Instrument ticket back in 1968 <grin>. Had to give it all up when the doc wouldn't certify my physical anymore <smile>

Helli: I noticed that deutsche Fahne on your profile - I was born some 71 years ago in Karlsruhe, but have been an Ami since I was 7. When the wife and I get on the bus to EDDF, I "help" by flying the route on my lappy (but while the drivers nap over the Atlantic, I use the 16X speed-up button from Gander to just off the Irish coast). <grin> John
 
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Thanks for the reference and update on how waypoints are given their naming conventions. Both FS9 and FSX use the AIM's and the ARINC424 Documents where applicable.

We can look at many of the stock waypoints / T_waypoints in FS and see some of the same naming that your link shows. Here is a quote from the link document.

D stands for DME arc waypoint. Aaa is the radial that the fix is on from the reference VOR. B will be a letter corresponding to the distance from the reference VOR. For example, G is the seventh letter of the alphabet so D234G would be a point on the 234° radial 7 nm from the reference VOR. DME arcs greater than 26 nm will have waypoints where the first two characters are the first two letters of the DME identifier. The next three characters will be the radial that the arc waypoint is on.

If I look at a typical DME arc in FS using the ADE Approach Mode Editor I would see a IF (Intial Fix) unnamed terminal_waypoint D016P. This tells me the IF is a DME arc waypoint, it is 16 NMs from the VOR and the P is the 16th letter of the alphabet.

fsscr022.jpg


In the next picture the DME arc continues to the Terminal_Waypoint unnamed D336P. This is the AF leg type which has all the ARINC 424 Document data.

P is the 16th letter of the alphabet so D336P would be a point on the 336° radial 16 nm from the reference VOR.

fsscr024u.jpg


In the following picture I use the helper distance line (red) to confirm the placement of the D336P Terminal_Waypoint. It shows (from the VOR) the length of the line is 16NM - heading 342 True / 336 Mag

fsscr025l.jpg


The AF leg type must have the following in order for the arc to draw properly.

Fix Type = Terminal_Waypoint
Fix Region = K3
Fix Ident = D336P
Turn Dir = Left
Recommended Type = VOR
Rec Region = K3
Rec Ident = HUT which is the VOR Ident
Theta Deg = 336 Mag which is the degree from the VOR
rho NM = 16 which is the distance from the VOR
Course Type = Mag
Course Deg = 16 and this tells us where the magenta line you see starts. This is the entrance point to the DME arc.

If we were to draw a helper line from the HUT VOR on a heading of 16 Mag Deg it would extend just to the left of the IF D016G terminal_waypoint.

If I was updating this DME arc I would increase the Course deg to something like 20. This would lengthen the magenta line entrance point so it is exactly at the D016P Terminal_waypoint.
 
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When I create a new approach in ADEX, it asks me for the approach type, I selected RNAV because the approach can be conducted with a VOR instrument.

However, it then asks for Fix type/ident AND IAF type/ident. The IAF I know, Initial Approach Fix. But what would be the other? the FAF? a transition point?
 
When I create a new approach in ADEX, it asks me for the approach type, I selected RNAV because the approach can be conducted with a VOR instrument.

However, it then asks for Fix type/ident AND IAF type/ident. The IAF I know, Initial Approach Fix. But what would be the other? the FAF? a transition point?



Are you working from a chart?

the FAF is the final approach fix and it is a CF type leg. It takes a minimum of 3 fixes to make a ILS approach. The IF (inital fix) the CF which is the final approach fix and another CF which is the runway number.

Please look at any stock airport that has a ILS. The approach mode will show you what you need.
 
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