Progressive Taxi(ways)

paulg · 16 Aug 2007

Hello All

Can you create progressive taxiways on a newly designed airport?

I would have presumed that if all taxi points, hold short points, with their paths etc. all connected, I would have the option to turn progressive on or off. I don't.

Has this to do with com's; type of surface on runways or taxiways or both;
or have the taxi ways lighted?

I will, as always, appreciate any help.

Kindest regards

Paul

Mace · 16 Aug 2007

ATC should automatically give you progressive taxi option, if the airport has taxiway links established that lead to parking.

Obviously if the taxiway links are not valid, etc. then ATC won't give you the option of progressive taxi.

There is nothing that a designer "has to do" in the xml to get progressive taxi working. It is automatic provided the above are true...

jvile · 16 Aug 2007

Has this to do with com's;

YES

If you create a Airport you must also assign a ground or Tower freq or the progressive taxi line will not show.

You must contact Ground or Tower for taxi instructions. When Ground gives you the taxi route to the runway this code is written into the dll which will now add the additional line item into the ATC menu for progressive taxi.

If you do not have a ground or tower freq the there is no ATC to interact with. No taxi instructions are given to you and no Progressive taxi line can appear.

AT Airports that do not have Ground/Tower Freq's but only Unicom you interact with other aircraft only and not ATC.

paulg · 16 Aug 2007

Thanks mace & jvile, I appreciate the time you took to answer me.
All runways, parking and taxiways are connected with their respective points etc. also I have coms - ground.
All I get is the option to choose another runway.

Kindest Regards
Paul

jvile · 17 Aug 2007

You have to callup the Ground controller and ask to Taxi to a runway. Once the Ground Controller gives you the taxiways to use to a runway then the progressive line item will appear in the ATC menu.

paulg · 17 Aug 2007

OK, I realise that you have to contact GROUND, otherwise I would not receive the option to select another runway.
There is something missing - for example - do I need to put taxiway signs in place to "activate" ATC into saying Taxi to holding point for runway 6 using taxiway B....etc

Kindest Regards
Paul

Mace · 17 Aug 2007

paulg said:
OK, I realise that you have to contact GROUND, otherwise I would not receive the option to select another runway.
There is something missing - for example - do I need to put taxiway signs in place to "activate" ATC into saying Taxi to holding point for runway 6 using taxiway B....etc

Kindest Regards
Paul

Taxiwaysigns don't have anything to do with it. They are visual only and don't affect what ATC says.

If you want ATC to say "Taxi to Gate D4 using taxiway B, C, C1, S..." then the respective taxiway links must have those taxiway designators assigned to them.

This can be viewed or changed in the xml/AFCAD/FSXPlanner/ADE, etc.

If no designators are assigned to a taxiway, ATC will just say "Taxi to Gate D4 using taxiway.".

paulg · 17 Aug 2007

Hello Rhett

Please bear with me and lets see if I understand you.

I have a Parking (Ramp_GA_Small) number 2. This is connected to a Parking Taxiway Path (no Name). This is connected to a Taxi Taxiway Path (Alpha) which in turn is connected to another Taxi Taxiway Path (Hotel), then a Hold Short point on H, another Normal point on H which is then connected to Runway 25 ( which has a Runway Type Taxiway Path).
Now ATC will should say " taxi to holding point....." and I should also have the option to turn on Progressive Taxi.

That, in brief, is what I've done. It compiles without error, but I still don't have progressive taxi.

Kindest Regards
Paul

jvile · 17 Aug 2007

Paul

Forget about naming all the taxiway links and concentrate on why you have no progressive taxi line showing.

You do not need taxiway link letter/numbers for the progressive lines to show.

Lets review

First, is this a brand new airport you added to the database or an exsiting airport you modified.

Your original question is

Can you create progressive taxiways on a newly designed airport?

Please explain what you mean by a newly designed airport.

Second, if this is a modified default FSX airport then does the progressive lines show before you used FSXP? It would also help if you told us what airport you are working on.

Third, If this is a new Airport you added to the database what did you use to condition the ground prior to adding the airport.

Forth, I am not clear on one area. Does the line item "Turn on Progressive Taxi" show up in the ATC window after ground gives you taxi instructions?

Fifth, Be sure the Ground Freq is not conflicting with another airport within 108NM of your airport. Choose a Ground Freq that is not in use by any other airport in your area.

All we are doing here is going in circles. Please be more specific on what you are working on.

paulg · 18 Aug 2007

Hello Jim

The Airport is FAPA - 43 Air School (actually an AirField) and it is a modified one. I have moved it to the correct location (about 3kms NW from the default one) and added the extra runway that was missing - brining it to a total of four runways. The airfield is grass, as are the runways and taxiways.

I have used SBuilder to lay the foundation of the newly created airfield as well as remove all airport boundaries polygon for the default one. Altitude is correct at 83.82m with no visible problems with floating runways,aircraft sinking below ground etc.

I then used FSXP to restructure the airfield to what it should look like. ie added the runways,taxiways,aprons,helipads etc. & coms (which I have left as the default of 122.000) and changed the default primary R10 to R28L & R28R. I also used the delete airport functions to make sure the default does not show.

In real life this is an extremely busy airfield with up to 500 ( could be more) takeoff and landings daily. It has a fairly complicated taxiway system with no taxiway signs.

Anyway, the default FAPA had no taxiways and used UniComs, thus it had no need for progressive taxi. My modified new one has Ground Coms and as I said, I kept the default frequency (whether this is a conflict with the default, I don't know).

Yes, after you make contact with Ground for takeoff instructions and Ground gives you taxi instructions, you have the option to turn on Progressive TAxi and again once you have confirmed taxi instructions, the option is available if you did not use it the first time. If you do not have this option ( only Select Another Runway ) then your progressive Taxi is non functional, provided you are not on UNICom, then you are on gen aviation traffic and you have no contact with ground.

The only Airports in FSX I know of, that have progessive taxi, are all asphalt or concrete runways, taxiways, aprons, all have lighting,center lines,edging and all have ILS etc. But then again I have not explored all the airports - yet.

Hope this helps Jim.

Kind Regards
Paul

jvile · 18 Aug 2007

Now that HELPs alot.

Let me test a Airport with Grass which I have never done using progressive taxi.

I will also use a Unicom as a ground freq to see if any of this is the problem.

jvile · 18 Aug 2007

Paul

I have not been able to duplicate the problem.

I used a exsiting Grass airport and kept everything grass. I added a taxiway structure using Path (Apron) style taxiways so no textures are added and no lines. I also used 122.00 as Ground and the Progressive taxi showed up.

Altitude is correct at 83.82m with no visible problems

I am wondering if the problem is with the elevation of the airport runway vs the CVX bgl elevation and default APX Airport header elevation. Sometimes after you move a airport you have to create a dummy airport header with the new elevation and preload even though everything on the surface appears to match.

If all of these elevations are not an exact match the Progressive line will not display.

paulg · 18 Aug 2007

Hello Jim

Thank you for trying to duplicate this on your system, really I,m very grateful.

In the meantime, I decided to get some flying time in and quite by accident I decided to land at FAPA. Ground asked me to exit runway and lo and behold I saw the progressive taxi right up to the parking spot. However, when I want clearance for take off, I get nothing except the normal "hold short...." with no progressive taxi.

The other thing I noted on my "one way" progressive taxi is that it is off to the left, near the edge of the taxiway and not centered.

Could you explain what a dummy airport header is?

Thanks Jim

Regards
Paul

jvile · 18 Aug 2007

When you start at FAPA vs flying to FAPA says once again that the elevations are probably off a very small amount.

The following is a dummy Airport header. Once you make the changes I listed below then copy and compile.

<?xml version="1.0" encoding="ISO-8859-1"?>
<FSData version="9.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="bglcomp.xsd">

<Airport
country="South Africa"
city="Port Alfred"
name="Port Alfred"
lat="-33.5833332315087"
lon="26.8833334743977"
alt="275.000F"
magvar="25"
trafficScalar="1.0"
airportTestRadius="5000.0M"
ident="FAPA" >

</Airport>
</FSData>

The first thing is to change the LAT/LON so it agrees with your FSXP ARP (airport reference point) LAT/LON.

Now look at the alt="275.000F"

This is the old default Airport that FSX is reading when FSX loads on startup. We need to force FSX to preload a new Airport header prior to the default with your new Airport altitude (elevation).

Look at your ground elevation that you used in SBuilderX for the Airport GUID. You say the Airport elevation is 83.82M which is also precisely 275 ft.

It would be best at this time to use TcalX (here on the forum somewhere) for FSX and get a true measurement of the ground elevation (somewhere on the airport grass) to see exactly what the airport elevation is.

SBuilderX may have rounded down the elevation of the Poly2 by .02 of a Meter which is enough to stop the progressive line from showing on startup.

Once you know exactly what the poly elevation (GUID) is then this must be in all associated elevations including

The dummy ARP above
The FSXP airport header
All Runways
All Start Locations

Example; TcalX says the ground elevation of the default FAPA airport is
83.8199996948242 Meters

and the runways are
83.8200073242188 Meters

You moved the airport and added a new Airport GUID (with SBuilderX) that should be this one

Airport_Backgrounds_Flatten_MaskClassMap_ExcludeAutoGen

and then set a altitude. It is easier to adjust all elevation to the GUID now that it is already in place to all other elevations.

Once you have all elevations to what the GUID is set at including the dummy header above, Compile the dummy header.

Give the bgl a name such as FAPA_dummy.bgl and copy to your .....FSX\Scenery\World\scenery folder. This will preload the dummy altitude and LAT/LON (on startup) before the default APX airport header and everything should agree as close as possible.

Moving a airport is not a good idea in most cases because of unseen complications. In your case it is a simple grass airport and the only complications is getting all the elevations to agree with the ground poly as per SBuilderX.

You DO NOT need a dummy header if the airport elevation is exactly the same after you move it and lay down the GUID but I can't see your cvx bgl data so this is the work around.

The dummy header sets the Startup elevation of FSX vs the FSXP runway elevation that is used for arrival Airplanes based on the runway/start location elevation.

paulg · 20 Aug 2007

Hello Jim

I now understand what a dummy airport header is and how it works. Thank you.

I have used your detailed instructions and completed the task. However it is still the same.

I checked out what the cvx.bgl on the new airport and all my altitudes on the AB_Flatten_MAskClasMap...and the default Exclude_All_Airport_Boundaries were set to 83.82m, My LatLon on the new fapa was taken from Google so I presume that is correct.

I found TcalcX, downloaded and what a nifty little programme. I found that there were too many variations with altitude, both on the default and new ( for example; 83.8176 on the grass before RW28 and 83.8358 on RW28) to change them. So I initially left them at the default altitude of 83.82.(later I changed them, played around with the numbers to see what would happen.)

I created a dummy header, compiled it and inserted it into scenery/world/scenery. With the dummy in or out of fsx, makes no difference to the airfield but in particular the elusive progressive taxi on start.I still only have it on landing.

SBuilderX did round off the figures and I found the easiest way to change things was editing the xml files directly and then using BGLCompX to compile.FSXPlanner also gave a few small problems with figures.

So the long and short of this is that if I use the default elevation of 83.82 and associate this with all the relevant elevations including the dummy,FSXP airport header,all runways and all start locations, I should have the correct elevation to see the progressive taxi.

Even with this set, I get many variations on TCalcX and even in fsx if you turn on the Aircraft Labels/Altitude, I have a reading of 279 feet.

Jim, I'm sorry to have to put you through all of this, and again I really do appreciate it very much. I know how difficult this must be when you cannot see the files and have to rely on discriptions.

Kindest Regards

Paul

paulg · 21 Aug 2007

Ok Jim

Found the problems. FSXP was also rounding my altitude numbers off. I decided to use 3 decimal places instead of the 10 or 11 that TalcX was giving me. Probably in the confusion, I had incorrect altitudes on my runways, some starting points and the airport elevation.

I have learned a great deal, thanks to your efforts.

Cheers for now

Kindest regards

Paul

jvile · 21 Aug 2007

If everything is 83.82 which is also the default ARP in the APXnnnn.bgl you can remove the dummy. It is only required when a Airport and all associated elevations differ from the default APX bgl.

The dummy preloads its elevation and keeps FSX from using the default APX elevation if the airport is designed higher or lower then the default airport.

Rounding of numbers has always been a thorn in our side and we have to work with it as best we can.

Daveo · 1 Feb 2009

paulg said:
Hello Jim

Thank you for trying to duplicate this on your system, really I,m very grateful.

In the meantime, I decided to get some flying time in and quite by accident I decided to land at FAPA. Ground asked me to exit runway and lo and behold I saw the progressive taxi right up to the parking spot. However, when I want clearance for take off, I get nothing except the normal "hold short...." with no progressive taxi.

The other thing I noted on my "one way" progressive taxi is that it is off to the left, near the edge of the taxiway and not centered.

Could you explain what a dummy airport header is?

Thanks Jim

Regards
Paul

Same here. Even with the newest version of ADE on a new airport.
Did you ever get yours working.?