AFCAD STAR Method

Jumpshot724 · Post by **Jumpshot724** » 18 May 2009, 14:23

Can anyone give me a quick tutorial on how to set up the STAR method in AFCAD for crosswind runways?? I would like to make it so my KLGA has both runways active, as right now the queue is ridiculous with only one lol

Post by **campbeme** » 18 May 2009, 14:49

Joe are you using default or custom scenery? I have a afcad for some freeware scenery which uses all runways but I will have to find who the author was.

Mark

Jumpshot724 · Post by **Jumpshot724** » 18 May 2009, 14:53

I'm using the "Jetways & Terminals" scenery. Thanks!!

kungfuman · Post by **kungfuman** » 18 May 2009, 17:29

The general principle is this:
FS only allows simultaneous runway operation on runways that it considers to be parallel. For FS to treat two runways as parallel, they must not differ in heading by more than 7.9 degrees. For three runways to be considered parallel, each runway heading must be within 7.9 degrees of only one of the other runways in this parallel group (it could be within 7.9 degrees of more than one runway but only one is necessary). Thus, by constructing a set of runways whose headings increase incrementally by not more than 7.9 degrees, you will have constructed a group of runways that FS will consider parallel. The star technique exploits this fact.

For KLGA you will need eleven "dummy" runways, with headings that fall between the headings of the real runways. This will cause FS to treat the real runways as parallel, thus enabling simultaneous operations.
The angle difference between the real runway headings is:
122.22 - 32.08 = 90.14
It follows that the smallest angle between runway headings is 89.86 degrees. This is between rwy 13 and rwy 22, or equivalently rwy 31 and rwy 04. The dummy runway headings will fall between these headings ie. within the range from 122.22 degrees to 212.08 degrees (or equivalently, between 302.22 degrees and 32.08 degrees).

Each runway heading will be 7.4883 degrees from the next in this case. Starting from the real runway heading of 122.22, add 7.4883. This gives 129.708 degrees, which is the heading of the first dummy runway. The runway must be at least 10 x 20 ft, from what I remember. Place it in a clear part of the AFCAD screen, away from other airfield elements. Close the runway for both landing and takeoff, in both directions. Also make sure it has no markings or lights. Now create another dummy runway like the first dummy runway, but with a heading of 137.197 degrees.

Continue clockwise until the last dummy runway you make has a heading within 7.9 degrees of 212.08, the heading of the real runway 22. By my calculations this last dummy runway's heading will be 204.592 degrees. Arrange these dummy runways on top of or close to each other for convenience, and don't forget to make sure they are all fully closed to traffic. Now move them to the north or south pole, or to the opposite side of the world. You can either select them all and drag them (after having zoomed out) or just double click and enter the required co-ords in the relevant box.

FS will treat all these runways as being parallel. In the menu bar click on "Lists" then "Runways". FS decides which direction to operate runways (in relation to the wind) by referring to the last runway in this list. So drag whichever runway you wish to serve this purpose to the bottom.
Finally, in the main AFCAD view of the airport, you will need to reassign the black runway links to the correct designation. This will have been lost if you changed the runway order in the list.

Hope I haven't missed anything out - step in anybody if I have...

I have tried to keep it simple by not dragging out lengthy explanations for everything. I have also chosen to have the dummy runway headings within the smallest interval between the real runway headings. This will result in a North/South dual runway "mode of operation". But because the real runways are almost at right angles to one another, you could choose to have an East/West dual runway "mode of operation". To do this you would have your dummy runway headings in the range between 32.080 degrees and 122.22 degrees, rather than the range I used in the above instructions.

Let us know if you get any probs, or have further questions.

Edited for additional clarity.

Post by **petebramley** » 18 May 2009, 19:02

Thats a very good explanation that for once I actually understand (so why does my head hurt ??)

Time for the Malt again

Pete

Victory103 · Post by **Victory103** » 19 May 2009, 00:45

Great and should be a sticky. I was trying to figure out why the latest KLAS I downloaded has so many runways, as the first time I pulled up the ATIS inbound, and it was at least a paragraph long!

I misread the thread title, as I thought there was a way to get the AI planes to fly SID/STAR's at major airports.

maddog65 · Post by **maddog65** » 19 May 2009, 10:00

Here is an excel file that will do the calculations for you. I have had this for a long time and it helps.

Les

maddog65 · Post by **maddog65** » 19 May 2009, 10:06

kungfuman wrote: The runway must be at least 10 x 20 ft, from what I remember. Place it in a clear part of the AFCAD screen, away from other airfield elements. Close the runway for both landing and takeoff, in both directions. Also make sure it has no markings or lights. Now create another dummy runway like the first dummy runway, but with a heading of 137.197 degrees.

Also from what I remember is that the new runways have to be placed no more than a 100NM from the airport and that 95NM seems to work the best. I will try to find the tutorial I had for it.

Les

Post by **bismarck** » 19 May 2009, 11:35

Les, from what I remember this is not completely true.I have a modified Holloman AFCAD and the dummy runways are in south Argentina.
Don't know if they work better if they are closer.

Cheers, Giorgio

kungfuman · Post by **kungfuman** » 19 May 2009, 12:48

I'm not sure what the minimum distance is that one has to move dummy runways, but there is no maximum distance in my experience. I have read the same advice about 95 miles, but this is too close to the "ai-active" zone. The dummy runways need to be far enough away not to "distract" any arriving ai aircraft towards them.

Having said that, you could probably have the dummy runways much closer and yet still rarely see a "distracted" ai aircraft, as the conditions in which a dummy runway would be chosen remain very stringent. (EDIT but that depends on traffic volume, and is NOT what I'm recommending)

If you are not comfortable with a calculator, then the readily prepared spread-sheet will probably suit you better than my brief explanation (nice one Les). Give it a try!

Cheers...

(Edited for clarity)

maddog65 · Post by **maddog65** » 19 May 2009, 13:19

I have played around with the distance thing also and really never found a happy place. I have had on occassion a aircraft land at the false runways (FS9 bug right after startup) and then taxi in the 90 some miles in. Meanwhile, the remaining aircraft are going missed as the runway is fouled. Once that aircraft gets to the actual airport everything returns to normal.

kungfuman · Post by **kungfuman** » 19 May 2009, 13:46

This is why I make sure the dummy runways are well out of the active ai zone (like the other side of the world), to prevent such occurences.

Just had a look at the xl sheet, and it should work fine. Don't worry about magnetic variation though, as afcad uses true headings. The naming of dummy runways is also not important, as long as they're different from the real runways.

Edited to say: What follows is due to a foggy memory, and is probably not completely true!!!

On a further point of subtlety, you should never need more than eleven dummy runways, as this is all that is required to fill a heading difference of 90 degrees. If the real runways are not at right angles, then the dummy runways' headings should be in the range between the acute angle interval of the real runways. Otherwise ai aircraft could be landing and taking off on different runways in directions that may tend to oppose each other, dependant on the specific airfield and wind conditions in question. By way of example:

Think back to when London Heathrow had rwy 04/22 in use. If you were to activate the STAR technique there, the following active runway use would be good: 27L/27R/22, or if wind is blowing the other way, 09L/09R/04. But if you activated the afcad with dummy runways linking between rwys 09L/R and rwy 22 (ie. more than 90 degrees), you could have a situation where an Easterly wind would result in active runways 09L/09R/22, resulting in traffic on 22 opposing the rest of the 09L/R traffic (and a similar argument holds for a Westerly wind). Additionally, if the "wind decision" runway is either of the 09/27 runways, certain wind directions will result in traffic on 04/22 landing and taking off downwind, rather than into wind. I know that's a bit laborious, but do you see what I'm saying?

The following is NOT a good idea in fact

On consideration of that final point, it may be a good idea to set the "wind decision" runway as being the dummy runway whose heading is closest to the angle bisector between the real runways, as the issue of landing with the wind remains a (lesser) potentiality even when the angle between Star linked runways is acute.

maddog65 · Post by **maddog65** » 19 May 2009, 13:46

If anybody can find the whole tutorial done by Adam Sereika that would be great. I think Ron Fields has a copy of it. He has helped me out in the past with AFCAD issues.

I have only found part 1 of the tutorial but it was enough to jar my memory.

Les
http://www.projectai.com/forums/index.p ... t&id=16006

kungfuman · Post by **kungfuman** » 19 May 2009, 14:56

A quote from STAR Master Reggie Fields:

But the really key thing is the early tutorial talked about using magnetic headings.

No, No, No.

Way, Way too much math to convert from magnetic to true heading.

As I said: Just use True headings. Adam Sereika I think most likely wrote that in the "early" days (when I was a mere twinkle in the eye) as he also does something odd with outer markers. Having said that, good luck searching for the rest of that text, as it might highlight something else worth remembering, or even refuting. Someone must have all of it?

I just found this thread at fs-developer:

http://www.fsdeveloper.com/forum/showthread.php?t=4965

Hope it helps...

Jumpshot724 · Post by **Jumpshot724** » 19 May 2009, 15:58

Thanks KungFuMan!!

The only question I have is how do you move things as a group?? I highlight all of my dummy runways but when I go to move them it only drags one out.

Also, instead ofmoving them to the S/N Pole, could you just make their elevation like 999,000 feet??

kungfuman · Post by **kungfuman** » 19 May 2009, 16:01

Once you have selected them all, hold down shift (or was it Ctrl?) and then drag while keeping it held down.

kungfuman · Post by **kungfuman** » 19 May 2009, 16:09

As far as changing the elevation, my suspicion is that this will only work if you have ALSO moved them. So no point. However, in the same menu screen as elevation, there is the co-ordinate entry fields. Try changing just the box saying (for example)

N40* 46.6310'

to something like

S89* 46.6310'

ie. just change a couple of digits that will put the runway near one of the poles - or any other out of the way place. I think you will have to do each dummy runway individually, but copy and paste will make light work of that. It's the method I use, not that it should count for much...

Jumpshot724 · Post by **Jumpshot724** » 19 May 2009, 17:27

That's ok, I just moved em to the North Pole anyway lol.

HOWEVER, I have run into an issue. Runway 13/31 is fine, however runway 04/22 has dissapeared

. It shows up in AFCAD, but it's just not there.

I did notice from listening to ATIS though that "ILS runway 13, visual runway 01, 02, 03 in use....". I renamed the dummy runways 01/19, 02/20 etc etc in order. It seems that my angles are off after runway 03??

Here are my runways and their respective angles as listed in "Runways" in AFCAD
04/22 - 32.080
01/19 - 129.708
02/20 - 137.197
03/21 - 144.685
04/22 - 152.173
05/23 - 159.662
06/24 - 167.150
07/25 - 174.639
08/26 - 182.126
09/27 - 189.614
10/28 - 197.103
11/29 - 204.591
13/31 - 122.220

Like I said, Runway 04/22 has dissapeared. The black runways links are there, and all of them with the correct designation, but the physical runway itself is gone.

I also noticed around the airport that the yellow taxiways lines seem to be flickering. Any idea??

maddog65 · Post by **maddog65** » 19 May 2009, 17:56

Jumpshot724 wrote:Here are my runways and their respective angles as listed in "Runways" in AFCAD
04/22 - 32.080
01/19 - 129.708
02/20 - 137.197
03/21 - 144.685
04/22 - 152.173
05/23 - 159.662
06/24 - 167.150
07/25 - 174.639
08/26 - 182.126
09/27 - 189.614
10/28 - 197.103
11/29 - 204.591
13/31 - 122.220

Like I said, Runway 04/22 has dissapeared. The black runways links are there, and all of them with the correct designation, but the physical runway itself is gone.

Joe,
This might be a problem. You have 2, 4/22 runways listed. Also 13/31 maybe a problem. In my exp with doing the STAR the finished product will be an arc between the two runways you are doing. Remember the total distance if I remember correctly should be no more than 90 degrees.
HTH

Les

Jumpshot724 · Post by **Jumpshot724** » 19 May 2009, 18:22

nks Les.

Ok I solved the disapearing runway trick, it was (I assume) as you said because I had 2 4/22's. I just changed the dummy list so it goes

....02/20, 03/21, 05/23, 06.24....

I didn't change the headings of the real 04/22 and 13/31, I left them how they were naturally in FS. So how would I fix that??

And now the ATIS says "....ILS runway 04 and visual runway 30 in use....", so now it's skipping all of the dummies. I do know if the STAR was working correctly the ATIS would list them all.

Plus, ther ei sno runway 30!!!!