# Tutorial: Approaches

Jim: I have examined your curved approach technique and I believe I can duplicate (with some practice) though I don't fully understand the theory behind the technique. For example, is there a hard set rule on the 1-mile turn in the technique? I'm only asking in the event I observe some AI having trouble making the turn. Based on your experience, is it possible to make the turn at 2 or 3nm out and still maintain the curved approach technique? Can the heading vary and if so is there some threshold beyond which your technique no longer works? Sorry for all the questions, but it's nice to have some basis as I think I may need to use your technique in the future.

You can make the turn to final as far away as you want within reason (about 5 NM's.)

Set a Cess172 on runway 07R. Slew up and back toward the mountains that are behind you. Slew 1, 2 or 3 miles or where ever you want the AI to make the turn.

Now slew (rotate) the cessna 172 so it points at 140 degree as a starting point. If that approach path is clear behind you then that will be your target approach path. Turn 150 or 160 to tighten the turn if the turn needs to look more like a base leg to runway 07R.

We are doing 2 things

1. Where do you want the turn to occur from the threshold of the runway (distance from threshold)
2. What approach path do you want the AI to fly before the left turn to final (true heading in the approach header).

Once you have a clear approach path and know where the turn will occur to the runway set the IAF and the FAF T_Waypoints on the approach path of the AI plane (5 NM and 10 NM from center line of the runway on the angle) AND NOT in line with the runway which is a straight in approach.

As per FS9/FSX you are fooling the AI Plane to think the center runway line is the same as the approach path (heading of the AI plane).

The AI Plane is vectored to the approach heading path by ATC because of the 2 T_Waypoints are also on the approach path heading. The AI Plane is approaching the runway from a angle (see my Kai Tak approach toward the checkerboard on 88 degree heading).

When the AI plane gets very close to the extended runway center line the AI Plane say's whoa!!! I have to turn to align with the runway and land.

The closer the turn to final the less the turn can be. AT Kai Tak the turn at the checkboard to runway threshold is about 1/2 mile. The turn can only be about 45 degrees Max based on the poor FDE's AI Plane modler's make. Also the faster the plane on approach has to be considered since the turn will cover more ground distance (Cess 172 turn vs B747 turn).

If the turn to final is 3 miles from theshold the degree of turn can be 80 degrees since the AI Plane has 3 miles to recenter itself on the center line of runway.

A word about AI Plane modlers FDE's

I am only one person (for the last 5 years) trying to show AI plane modler's that in FS9 and FSX there are curves and circle to land approaches built into the default approach code.

Microsoft made their default planes NOT ONLY flyable but AI plane behavior also. A FS9/FSX flyable plane like the B747-400 can turn and align with a runway very well when used as a AI plane. A 3rd party AI Plane has very poor FDE's since it can only land on a straight final approach.

Look at how many AI Planes have trouble shooting my curved Kai Tak approach and then land on the side of the runway. I have been telling modler's that AI Planes MUST be able to turn on short final as per FS9 and FSX. Modler's just don't get it!!!

Modler's and FDE design groups brag about how well their planes look on approach and flair for landing but if you test their planes at PHNL using the default FS9/FSX LDA to rwy 26L which is a curved approach their same AI Plane is junk.

I say that because for 5 years I have ask them to give us AI Planes with proper wingspans/model radius (for parking), use the correct empty weights (for runway selection), use the 13 .cfg values to make a AI Plane behave the same as a default Microsoft plane, stop the sink rate in a turn when gear is coming down (turn to final), and all this continues to fall on deaf ears. Jan Martin is updating all his FDE's to look more like a real plane but I do not know if he is testing the FDE's as per what FS9/FSX requires (see below).

Test your curved approach with a Microdoft default plane of the same size that will use the airport. If the default B737-800 can turn and align then 3rd party AI Planes of same size should be able to do it also. Many can't so I have to push the turn to final back a little bit for the crappy AI planes FDE's.

There is another small problem. All of the FSX Microsoft planes are designed with flying characteristics which uses a updated different type aircraft.air file and companion aircraft.cfg file. ALL 3rd party Freeware AI Planes being uploaded today are designed using FS9 .air and .cfg files. There is no such thing has a 3rd Party Freeware FSX AI Plane and we import these FS9 AI planes into FSX.

PAI did not have the best looking textures and were not Frame rate friendly but they had the best FDE's which the behavior is more toward a FS9 default plane. Arrdvark have the worst FDE's and all the rest fall in between. Most Arrdvarks cannot land/roll out very well unless a ILS approach code exist. Thank goodness for a ILS approach code which can make any AI Plane look good on the approach and landing. Roll out is another story.

If a 3rd party AI Plane is as good as a default FS9/FSX Plane it must

1. Fly a default ILS approach where the approach code controls the atitude of the AI Plane and target point on the runway for touchdown.
2. Fly a non ILS approach such as the RWY 09 at TNCM (visual app)
3. Fly the PHNL LDA 26L approach when airport is IMC
4. Fly the PADU Circle to land approach for either end of rwy 12/30

The default FS9/FSX planes have no trouble with these default approaches. If the 3rd party AI Plane can fly them as well as the default MS planes then I will say that impresses me.

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Ok,
now i try it at LSGC, this Airport has an ILS Approach!

Oliver

Look at the approach chart for that ILS runway. Open ADE in approach mode and choose that same ILS. Compare the approach chart such as where the IAF T_Waypoint and the FAF T_Waypoint are located.

Now look at what the approach charts shows for the approach altitude crossing the FAF T_Waypoint and see all the is listed in ADE approach mode. Read the Missed approach instructions from the chart and then see how FSX writes these instruction using proper leg types and altitudes.

Look at the IF, CF, CF legs in ADE and then look at the legs from the IAF T_Waypoint (IF), the leg to the FAF T_Waypoint (CF) a the leg to the runway (CF Localizer).

Once you can see what goes where in ADE approach mode then you will not have as many compiler errors.

Jim: Thank you for the explanation, it really helps to put things into perspective. I recreated your curved approach for KLAS, only I used the ADE line draw and a fake dme and start to set the cesna172 up for the curved part of the approach. It's a bit crude but it worked. I used your 1nm suggestion and observed over 50 AI flying the approach from every direction. ALL landed on the runway with the exception of 1 or 2 heavies. No AI impacted to any terrain. I'm using the STB to view the AI on approach. This method is wonderful! I'm going to do the same for 19.

I set my FAF at 5.2 nm and 4,300 ft and IAF at 11.3 nm and 5,400 ft. I noticed that some AI are directed directly to the FAF while others intersect the IAF. This was based on some testing I did this week. I may move the 1nm out a bit to see if it helps the heavies land on the centerline as well. Again, thank you for your explanation and also for another wonderful technique.

kagazi

Oliver

Look at the approach chart for that ILS runway. Open ADE in approach mode and choose that same ILS. Compare the approach chart such as where the IAF T_Waypoint and the FAF T_Waypoint are located.

Now look at what the approach charts shows for the approach altitude crossing the FAF T_Waypoint and see all the is listed in ADE approach mode. Read the Missed approach instructions from the chart and then see how FSX writes these instruction using proper leg types and altitudes.

Look at the IF, CF, CF legs in ADE and then look at the legs from the IAF T_Waypoint (IF), the leg to the FAF T_Waypoint (CF) a the leg to the runway (CF Localizer).

Once you can see what goes where in ADE approach mode then you will not have as many compiler errors.

Hopefully this will all get a bit easier when the next build is released since it dynamically draws the approach (like the GPS) as you create or modify it.

Jon: This will save a lot of time between coding and verifying in the sim using the gps. Looking forward to the next release.

Jim: I completed the two curved approaches and have tested both extensively. I pulled the curve back to 1.5 nm for both as this seems to be the point where even the sloppiest of FDE's can recover. The approaches work like magic. I did notice that activity on the 19's is somewhat muted as compared to the 25's; however, 7R has as much if not more activity as compared to the 1's. I would have expected 1L to have more landings compared to 7R but that wasn't the case.

Thank you for this approach

Jim: I completed the two curved approaches and have tested both extensively. I pulled the curve back to 1.5 nm for both as this seems to be the point where even the sloppiest of FDE's can recover. The approaches work like magic. I did notice that activity on the 19's is somewhat muted as compared to the 25's; however, 7R has as much if not more activity as compared to the 1's. I would have expected 1L to have more landings compared to 7R but that wasn't the case.

Thank you for this approach

When you parallel the 01/19's to the 07/25's it gets a little confusing to see what will use what. Takeoff is easy to see since parking spot position is a visual in respect to what inter runway will be used.

Arrival's take a map to fiqure how many planes come from what 4 quadrents of the surrounding sectors. Since more planes arrive from the east then say coming out of Calif. the 07/25 is more active then the 01/19's.

When you parallel Vegas think how KLAX is working. Many AI Planes come from the north and from the East so the northern runways (north of the main terminal) get a lot more traffic. Not a whole lot of traffic lands on the south runway (south of the terminal)

You map out Vegas and draw the 4 runways in parallel and you have to factor in which runway you listed last in the Xwind technique. The question then becomes, if I draw 4 runways in parallel which 2 do I parallel to the other 2. Do I draw all 4 runways as 07/25 or as 01/19.

If a 07/25 is listed last in the ADE runway list (sort order) then based on winds it is controlling the 01/19's. If 01/19 is listed last then it is controlling the 07/25's. This determines who was paralleled to who. Did you make the 01/19's think they are now parallel to the 07/25's or the other way around.

There are different configurations you can set up by what runway is listed last and what runway you can close on both ends since all 4 runways think they are parallel to each other.

There is still another configuration. Using ADE change the runways so each is 25/07 and 19/01 (don't forget the start locations). This sets the original base end of 07 to 25 (same with the 19/01's). Now Xwind from 19 up to 25 using the high numbers. In some cases this can reverse the usage so the 19/01's take the bulk of the arrivals. I cannot give specific rules but if you don't like what runways are being used the most you reverse the process. It's all trial and error at this point.

If you the User plane is going to use ATC vectors so you fly curved approaches that can get you lost real quick. Using my example of runway 07R you slew backwards 1.5 miles then lets say you turn the plane to heading 150 which is the new approach path that you set in the ADE approach mode Header.

ATC uses a 30 degree offset angle for intercepting the approach path for any landing. Straight in landing for 07R ATC will put you on a 40 or 100 degree intercept angle for the approach to that runway. You know what happens next, you are flying through the mountain range west of vegas. However, your new approach path is 150 degree. You are approaching KLAS from Reno or KSFO. ATC is going to vector you onto a 120 or a 180 degree intercept angle to fly the approach path of 150 degree.

That resembles more of a left Base Leg when VFR. You can do one of two things to help understand what a User Pilot must do to fly the curved approach.

1. Go out and follow a AI Plane when ATC is vectoring it toward the approach path of the 150 degree. You get a since of where to be and when to turn for the approach path of 150 because you have no runway to align up with. If your approach path to runway 07R is more then 45 degrees the KLAS Tower will clear you to land on 07R by way of a left base which Tower will actually say even though you are on a IFR FP.

2. At the old Kai Tak the Localizer Antenna was behind the checkerboard up on the hill in real world. I placed a Localizer symbol with ADE for FlyTampa scenery on heading 088 back behind the checkerboard. I placed the GS symbol on the side of runway 13 in its normal position. You can do the same at Vegas by placing a Localizer symbol on heading 150 if that is the approach path but it must be past the 1.5 curve to final so your plane turns before reaching the symbol.

Now when ATC vectors you on the offset 30 degree intercept angle you know when to turn the plane to 150 degree approach path by watching the CDI needle center. Track the CDI needle just like you are flying straight to the runway but you are on a Base Leg. Once you get into a thought process of what we call awareness situation take down the localizer (delete from ADE).

When you Xwind and curve approach runways at airports you have increased the level of skill many times in order to land. When you can fly a MD11 or A340 into Vegas on those curved approaches and nail the center line of the runway at the alignment bars you can then say 'I have arrived'.

Now you can go out and start fixing all those straight through the mountain approaches with a proper curved approach that many airports in the world have

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Jim: very informative discussion regarding x-winds. I was not aware that the order of the x-wind made a difference.

In my modified KLAS I have 01s/19s x-winded to the 07s/25s. I think it may be worth a look to possibly reverse the bases at KLAS as I observed several times the number of arrivals on 25L as compared to both of the 19s combined.

Something to think about for the future.

1. Go out and follow a AI Plane when ATC is vectoring it toward the approach path of the 150 degree. You get a since of where to be and when to turn for the approach path of 150 because you have no runway to align up with. If your approach path to runway 07R is more then 45 degrees the KLAS Tower will clear you to land on 07R by way of a left base which Tower will actually say even though you are on a IFR FP.

2. At the old Kai Tak the Localizer Antenna was behind the checkerboard up on the hill in real world. I placed a Localizer symbol with ADE for FlyTampa scenery on heading 088 back behind the checkerboard. I placed the GS symbol on the side of runway 13 in its normal position. You can do the same at Vegas by placing a Localizer symbol on heading 150 if that is the approach path but it must be past the 1.5 curve to final so your plane turns before reaching the symbol.

Now when ATC vectors you on the offset 30 degree intercept angle you know when to turn the plane to 150 degree approach path by watching the CDI needle center. Track the CDI needle just like you are flying straight to the runway but you are on a Base Leg. Once you get into a thought process of what we call awareness situation take down the localizer (delete from ADE).

Jim: When I contructed the curved approach I followed your example at KLAS and added the localizers from the start. I used guides to place them and inserted a runway start at the intersection of the guides with the approapriate heading for the base leg. I then started my cesna 172 at the start location and slew back to add the T_waypoints.

I spent some time tonight following AI for both curved approaches at 19R and 7R. I have not yet tried the approaches myself, but I was wondering that if I delete the localizers at 7R and 19R, would the vectors to final option for the user also get removed with ATC? I realize that AI don't use the localizers but what about the user plane?

Now you can go out and start fixing all those straight through the mountain approaches with a proper curved approach that many airports in the world have

KLAS has and continues to be a challenge! My next airport is going to be located in a remote part of the world with no buildings or hills within a reality bubble radius of the airport

Jim: When I contructed the curved approach I followed your example at KLAS and added the localizers from the start. I used guides to place them and inserted a runway start at the intersection of the guides with the approapriate heading for the base leg. I then started my cesna 172 at the start location and slew back to add the T_waypoints.

I spent some time tonight following AI for both curved approaches at 19R and 7R. I have not yet tried the approaches myself, but I was wondering that if I delete the localizers at 7R and 19R, would the vectors to final option for the user also get removed with ATC? I realize that AI don't use the localizers but what about the user plane?

KLAS has and continues to be a challenge! My next airport is going to be located in a remote part of the world with no buildings or hills within a reality bubble radius of the airport

You can remove localizers that you added to asist in your coding. It has no affect on what ATC will do. THe User Plane and the AI will still get the same vectors from ATC. ATC is using the Approach path and the T_waypoints to vector a plane to your heading you used in the approach header.

THe easiest way to think of it is, all ILS's placed only do one thing. They allow the User plane to dial in a freq and make the CDI needles come alive to align you on the runway center line and give you vetical glide slope descent profiles if a GS exist.

ATC does not have a clue if a ILS exist for the runway and that is only for you the pilot to use if ATC says fly the ILS.

You coded a ILS heading in the ADE Approach mode and that is what ATC knows.

1. You can have a ILS approach with no actual ILS on the runway.
2. You can have a ILS on the runway and no ILS approach code.
3. You can have both such as all the default ILS's on the runway and in the default approach code that FSX added.

Jim: That makes perfect sense, thank you for all of your insight! I will practice a bit with the localizers in place before I remove them. I'm still learning to fly a cesna 172 so I shouldn't have any trouble making the turn

Approach Altitude

Hi,
my Airport LIIL is surrounded of mountains like Samedan (LSZS), but there the AI-Planes are landing very well, but at my Airport LIIL the Planes dont fly my approach at my altitude.
What is wrong? I want, that they are at 7800ft at the first T_Waypoint, but there, they are at 11100ft.

Thanks for Help
Approach designed with v.1.39.22

The first file is the FSX File and the second the FS2004 file.

#### Attachments

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• AFX_LIIL.xml
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Aquila

<Approach
type="RNAV"
runway="03"
designator="NONE"
suffix="0"
gpsOverlay="FALSE"
fixType="TERMINAL_WAYPOINT"
fixRegion="LS"
fixIdent="CFLI1" <<<<===== Must be the FAF
altitude="7800.0F"
missedAltitude="8100.0F">
<ApproachLegs>
<Leg
type="IF"
fixType="TERMINAL_WAYPOINT"
fixRegion="LS"
fixIdent="CFLI1" <<<<==== Must be the IAF
altitudeDescriptor="+"
altitude1="8100.0F"
/>
<Leg
type="DF" <<<<======= Should be a TF leg type
fixType="TERMINAL_WAYPOINT"
fixRegion="LS"
fixIdent="IFLI1" <<<===== Must be the FAF
flyOver="TRUE"
turnDirection="L"
/>
<Leg
type="DF" <<<<====== Should be a TF leg type
fixType="RUNWAY"
fixRegion="LS"
fixIdent="RW03"
flyOver="FALSE"
turnDirection="L"
/>
</ApproachLegs>
</Approach>

You are using DF when it should be TF and your Terminal Waypoints are not properly listed for each leg.

Approach

Ok,
but in v.1.39.22 i can see the line where the planes fly. This is ok, but they are too high and at other Airports i also use the DF-Legs and there they are working, i think the DF legs are the easiest.

Ok,
but in v.1.39.22 i can see the line where the planes fly. This is ok, but they are too high and at other Airports i also use the DF-Legs and there they are working, i think the DF legs are the easiest.

Aquila

The line draw has nothing to do with the AI Planes. The Lines are for the User Plane to fly the RNAV Approach when the GPS is locked to the autopilot.

The AI Plane flys the RNAV header and the IF leg. These have to have the proper Terminal_Waypoints.

If the airport weather is clear the AI Plane cannot fly the RNAV Approach but will fly a visual approach. You must have a ILS approach if you want the AI Plane to use the altitude of 7800 ft or set the weather to IMC airport conditions.

Approach Transitions

How do you make 'transitions' for approaches?

Transitions (waypoints for legs)

ex.... KDCA= rwy 19 in real life the planes follow the Potomac River to the runway, turning at least 10-20 degrees in the last ~2000 feet of the approach

How do you make 'transitions' for approaches?

Transitions (waypoints for legs)

ex.... KDCA= rwy 19 in real life the planes follow the Potomac River to the runway, turning at least 10-20 degrees in the last ~2000 feet of the approach

mdm248111

Those Transitions and approaches are already a part of FSX.

VORDME 19 with Transition BONDS
LDA 19 with Transition FERGI
ILS 19 Localizer IASO with Transition AML VOR

All of these are River approaches in FSX same as real world. You can see these approaches with ADE when in Approach mode or with the GPS Receiver when running FSX.

well how do I make transitions for another airport?

Jim: In FSX and using ADE 1.39 and later, I can add an RNAV approach or a gps approach or both. Some approach plates (especially the newer ones in the US) show either RNAV(GPS) or RNAV(RNP). The difference in the plate is subtle. I have not seen an RNP approach for FSX, but I was wondering if it is appropriate to include both versions (transitions) of the RNAV in one approach as the transitions may vary? The missed approaches are also different so I believe I would need to choose one or the other. The example I'm looking at is KIAD. I'm trying to include the newly published RNAV(RNP) approaches but I want to work within the rules of FSX. Any insight would be welcomed.

Jim: In FSX and using ADE 1.39 and later, I can add an RNAV approach or a gps approach or both. Some approach plates (especially the newer ones in the US) show either RNAV(GPS) or RNAV(RNP). The difference in the plate is subtle. I have not seen an RNP approach for FSX, but I was wondering if it is appropriate to include both versions (transitions) of the RNAV in one approach as the transitions may vary? The missed approaches are also different so I believe I would need to choose one or the other. The example I'm looking at is KIAD. I'm trying to include the newly published RNAV(RNP) approaches but I want to work within the rules of FSX. Any insight would be welcomed.

Since FSX does not allow (RNP) after the RNAV but does allow (GPS) then I always use the RNAV(GPS) approaches. The difference between (GPS) and (RNP) is the minimum sight distance which FSX does not understand.

The approach type in the GPS and the approach plate that someone can download should agree. If the GPS cannot show RNAV(RNP) then I do not add it to the database. If the user Pilot cannot see a RNAV(RNP) listed on the approach page of the GPS then how would they know that you wrote the approach as a RNP.

The RNAV(GPS) type approach does not have vetical descent profiles so I tune the radio to the ILS (if equip'ed). I use the RNAV(GPS) Transitions I write but once established on final I fly the ILS so the GS controls the vertical descent.

FSX does not know what a CAT I, CAT II, or CAT III approach means and they all have to do with minimums prior to a missed approach. The same applies to a RNAV(GPS) vs a RNAV(RNP) type approach. I write all the RNAV(GPS) type approaches which is what the USA is going to. These Transitions get me off the STAR and to the IF of the ILS. I stop using the RNAV(GPS) approach and fly the ILS. If the ILS is a CAT IIIb then I fly to the minimum of 300 ft RVR and zero surface ceiling which looks like a Zero Zero approach landing.