Tutorial: Approaches

[Aquila]

Mountain Approach

Hi there,
i've got problem with the ai-planes landing on a mountain airport, they fly the way i want, but TO HIGH, very high, the airport is at 6000ft and the fly 10000ft, i entered 6800ft for Approaching altitude, gut they never fly this altitude.

 

[tgibson]

Hi,

One possibility:

If the terrain along their approach path is higher than 5800 ft they will never descend to your altitude until it does. They will stay about 1000 ft above any terrain.

You will need to adjust their approach path to avoid the high terrain.

Hope this helps,

 

[Aquila]

Re:

Hi, thank you for your answer, but there is no possiblity to let them fly anywhere else, my airport is in a vally and around mountains, but I want hem to fly into the valley and land at my airport.

Bye Oliver Braun

 

[tgibson]

Hi,

Where did you place the 6800 ft value? It must be in the main ILS header, not in any IF, CF, etc. leg.

If there is no approach path that lets the planes reduce altitude before they get to within a few miles of the airport (around 1-4 miles, depending on aircraft type), then there is nothing you can do. They won't do things like make 360 circles.

If the valley is round or L shaped, one thing you can try is to have them make a perpendicular approach from the side of the valley, make a 90 degree turn back to the airport (from the far side of the valley), descend down the valley, and then land. I.e. try to find a way to maximize their approach path in the valley.

 

[Aquila]

Re:

Hi,
i haven't an ILS, only the ApproachLeg is ILS.
I uploaded the xml. file of my airport, the approach should be like Samedan LSZS, i made this airport myself into that valley but i tried the approachlegs on other selfmade airports and there it works.

By Oliver

 

[tgibson]

Hi,

The Main ILS header is this part of your XML:

<Approach
type="ILS"
runway="21"
designator="NONE"
suffix="0"
gpsOverlay="FALSE"
fixType="TERMINAL_WAYPOINT"
fixRegion="LS"
fixIdent="IFIL2"
altitude="6800.0F"
heading="207"
missedAltitude="7000.0F">

This is the only part that will be used by AI aircraft. Aircraft will arrive at waypoint IFIL2 at 6800 ft (if terrain allows), and then will fly at heading 207 degrees to the extended centerline of the runway, descending all the way (terrain permitting). At that point they will turn, line up with the runway, and attempt to land.

The rest of the approach has no effect on AI aircraft; they will ignore waypoints IFIL1, CFIL2, and CFIL1.

That said, as I understand it for a user approach to work correctly in the GPS, the first waypoint should be the Initial Approach Fix (IAF) - IFIL1 in your case. The next waypoint should be the FAF (IFIL2, since the waypoint in the main ILS Header is by definition the FAF). It is not even listed in any of your legs. I have found that this sometimes leads to no GPS display of the approach legs. If you want more legs to your approach, I assume you need to make them a Transition - that's what I had to do.

Hope this helps,

 

[Aquila]

Re:

Ok, thanks
i will test it, between CFIL1 and IFIL1 is a mountain and CFIL2 is for that, that the AI-planes should fly around that mountain..

 

[tgibson]

Hi,

No, unfortunately they will ignore that waypoint.

 

[lfe]

writing approach codes

Hello Aquila

Any Questions?

yes. that being said, i am a bit confused when everyone says "you have to create an approach code" to make an ILS work. by this, is it by clicking on the approach mode button and then add approach using ILS in the drop down menu; or do you have to manually "write" the code in the XML generated by the program after adding the ILS approach on the runway? and what are the codes for writing? sorry if the question sounds stupid but i don't know anything about XML coding. so, how do you exactly activate an ILS by "writing approach codes"?

another related question. i did the original in afcad and ATC recognises the ILS approach. but when i converted the afcad to ADE, the runway now becomes visual, which i assume, all those approaches in afcad were not converted. i tried adding an ILS approach but i still get a "visual approach" instruction from ATC.

and is there any references for definitions on the approach options? like what is a fix type, fix ident, IAF type, IAF ident. and can you find these things in the airport charts?

thanks

 

[jvile]

yes. that being said, i am a bit confused when everyone says "you have to create an approach code" to make an ILS work. by this, is it by clicking on the approach mode button and then add approach using ILS in the drop down menu; or do you have to manually "write" the code in the XML generated by the program after adding the ILS approach on the runway?

One or the other

When this post was started we manually had to add the approach code for any ILS. ADE9X will add a automatic ILS approach code for you which is not a published approach. If you want a published approach then you use the approach charts and the Approach mode of ADE9X.

and what are the codes for writing? sorry if the question sounds stupid but i don't know anything about XML coding. so, how do you exactly activate an ILS by "writing approach codes"?

The simplist approach codes are IF, CF, CF with a published missed approach. You can open many stock airports and look at how ILS approach codes are made in FS

another related question. i did the original in afcad and ATC recognises the ILS approach. but when i converted the afcad to ADE, the runway now becomes visual, which i assume, all those approaches in afcad were not converted. i tried adding an ILS approach but i still get a "visual approach" instruction from ATC.

AFCAD does not allow you to make any approaches. THere is no way in AFCAD to add any type approach so I do not know what you are refering to.

and is there any references for definitions on the approach options? like what is a fix type, fix ident, IAF type, IAF ident. and can you find these things in the airport charts?

You study the approach charts and then use them to add the approach using the approach mode of ADE. Many of the fixed navaid Idents, types, IAF, FAF are listed on the charts.

 

[lfe]

thanks jim.

after i sent my earlier post, i came across your tutorial in writing ils approaches (http://www.fsdeveloper.com/forum/showthread.php?t=13751) which was a lot of help as i have been looking for this for sometime now as i am new to ADE.

a few questions if i may to really get the basics, assuming i want to add an ILS approach. do i need to add a missed approach leg or is it not necessary for the ILS approach to work? ( i followed your tutorial and added missed approaches and when i tested it, ATC don't seem to follow the pattern, so i'm just going to save myself the effort and time doing it).
also, although already have the ILS assignmet, i don't see those pink lines in the GPS display when i activated the approach.

also, i understand that ATC assigns runways on a priority order. if i have one reciprocal end with ILS and the base end is VOR/DME (as this is the case in the airport i am making), will this limit the airport to just the ILS approach? or runway assigment would still be base on wind directions.

One or the other
AFCAD does not allow you to make any approaches. THere is no way in AFCAD to add any type approach so I do not know what you are refering to.

i guess those ILS approaches i am getting are from the default afcad.

best,
lfe

 

[jvile]

thanks jim.

a few questions if i may to really get the basics, assuming i want to add an ILS approach. do i need to add a missed approach leg or is it not necessary for the ILS approach to work? ( i followed your tutorial and added missed approaches and when i tested it, ATC don't seem to follow the pattern, so i'm just going to save myself the effort and time doing it).

You do not need a missed approach added. However, ATC does not automactically follow your new missed approach. For the User plane you have to ask ATC in the window for the published Missed Approach which is the one you add. For AI Planes ATC only instructs a L/R type turn and altitude based on ADE9X Approach Mode entrys in certain fields.

also, although already have the ILS assignmet, i don't see those pink lines in the GPS display when i activated the approach.

Not sure why you do not see them. You have to select the approach page in the GPS receiver to Load and Activate in order for the Plane to follow the approach.

also, i understand that ATC assigns runways on a priority order. if i have one reciprocal end with ILS and the base end is VOR/DME (as this is the case in the airport i am making), will this limit the airport to just the ILS approach? or runway assigment would still be base on wind directions.

Runway assignment is still based on winds. The ILS approach to that end of the runway will always be assigned regardless of what type weather you have.

The runway end with the VOR/DME will be a visual approach as per ATC if weather is clear. If weather falls below 3 mile visiblity (IMC) and the winds favor the runway with the VOR/DME then ATC will instruct both the User Plane and the AI Plane to fly the VORDME approach.

i guess those ILS approaches i am getting are from the default afcad.

Since AFCAD cannot add approaches it sets the approach flag to FALSE. This means that FS falls back onto the default approaches that shipped with FS. ADE9X copy's all the stock approaches into the bgl and sets that approach flag to TRUE. That tells FS to use the approaches in ADE9X plus any you add or edit and not the stock approaches in the default database.


hope this helps

 

[lfe]

Not sure why you do not see them. You have to select the approach page in the GPS receiver to Load and Activate in order for the Plane to follow the approach.

i am attaching a screenshot of the approaches i made and also a screenshot of the activated approach in the GPS. earlier, those white lines did not appear. though they now appear, one leg is different from the missed approaches i did. and strangely, i don't see the pink line even if i have loaded and activated the approach.

even if i don't put missed legs there should be a pink line in the gps display when an ils approach is activated, right?

 

[jvile]

In some cases why you won't see the lines is because the IAF and the FAF are not listed properly in correct order.

The ILS header gets the FAF
The first IF leg gets the IAF
The first CF leg that follows gets the FAF again
The second CF leg gets the runway.

 

[lfe]

hmm, i think i got that right. i'll try to figure this out. thank you so much for your patience.

btw, there is an option to import approaches and i am thinking of starting from there. maybe i can figure out where i am doing wrong if i see a working file for my airport. the only thing is, where can i find them in FS (i'm still with fs9).

 

[scott967]

Q on AI with IFR plan on clear day. I have runway 12/30 with no ILS. AI have a problem with terrain when attempting the hard code visual to rwy 30. If I put a fake ILS appr on the rwy 12 end, will that cause ATC to prefer that end for AI and user (both VFR and IFR?) I take it the IFR user will also get assigned the fake ILS approach by ATC as well, correct?

scott s.
.

 

[jvile]

Q on AI with IFR plan on clear day. I have runway 12/30 with no ILS. AI have a problem with terrain when attempting the hard code visual to rwy 30. If I put a fake ILS appr on the rwy 12 end, will that cause ATC to prefer that end for AI and user (both VFR and IFR?) I take it the IFR user will also get assigned the fake ILS approach by ATC as well, correct?

scott s.
.

In most cases yes the ATC will favor the ILS approach code over a non-ILS. Normally the weather engine picks up on the fact a ILS exist and ATC will not use the non-ILS end of the runway until winds exceed a higher value. That value of wind seems to be different per individual airport/runway.

Another consideration is that ATC favors the primary end of a runway more then the secondary end (primary gets a higher score). In FS we can find runways were the secondary end is listed first when that runway end should be used with normal winds. (30/12).

The above applies to both the User and the AI plane. FS uses a scoring system for runway selection. We try and increase the score over one end vs another by making the ends unequal in what the end of a runway offers.

In my studies of the Kai Tak approach many users never want the secondary end (31) of 13 to be used. Impossible!! For each setting we make for the 31 end we can lower the score over the IGS 13 end. We close runway 31, remove start locations, delete the approach codes, etc. ATC will now always favor the IGS 13 runway even with high tail winds. Only when the wind exceeds 64 kts from the north does the Kai Tak runway 31 open as the active in clear weather.

Another small bit of information. All IFR FP planes will always land. VFR FP planes can be caught on top of weather and not be given clearence to land at an airport that is IMC. IFR FP planes will always land on a runway that exist. It does not matter what the runway has or does not have so winds is the deciding factor. Take any small GA type airport with no default approaches and max runway length lets say 2500 ft. Create a FP for a B747 to that airport and set weather to zero zero. The plane will land on the runway that favors the wind since all runway ends are equal. Will the B747 stop before the end of runway, NO. User planes will also be giver clearence to land the same as the B747 regardless of the user plane size.

 

[scott967]

got it. thanks as always.

scott s.
.

 

[lfe]

In my studies of the Kai Tak approach many users never want the secondary end (31) of 13 to be used. Impossible!! For each setting we make for the 31 end we can lower the score over the IGS 13 end. We close runway 31, remove start locations, delete the approach codes, etc. ATC will now always favor the IGS 13 runway even with high tail winds. Only when the wind exceeds 64 kts from the north does the Kai Tak runway 31 open as the active in clear weather.

hi,

this sounds promising to a situation i am trying to achieve. but how do you make it work with non-parallel runways?

the scenario is that the base runway has either end active depending on wind condition. but the secondary (non-parallel) runway will only have the primary end active no matter what the wind condition and the secondary end always close.

i already have both runways running using the star method.

 

[jvile]

hi,

this sounds promising to a situation i am trying to achieve. but how do you make it work with non-parallel runways?

the scenario is that the base runway has either end active depending on wind condition. but the secondary (non-parallel) runway will only have the primary end active no matter what the wind condition and the secondary end always close.

i already have both runways running using the star method.

Hi lfe

Let me try and explain.

Parallel runways belong to a group

Non-parallel runways are individual (no grouping)

The two types (group or no group) have different rules.

When you Xwind one runway to another runway you now have grouped the 2 runways so parallel rules apply. It becomes very hard to close just one end of a runway and in most cases you must close both ends of the same runway since now they are grouped to other runways.

The process of Xwinding a runway to another runway takes it out of the individual code and forces it into a grouping code. At that point we are saying we want more runways active not less. You could try closing your Secondary end but ATC may not honor that closed runway since it got grouped to another runway.

The rule for parallel runways is if we close one end we must close the other end and that rule is in place when you Xwinded the runways to each other.