MSFS The Parking stand radii: "they are not what they seem"

[mottoth]

This is a repost of a message I posted at Alpha India Group boards: following experiments on offline AI traffic we had a conversation on why some parking stands seemed ignored by the sim, more specifically why it seems to often leave one stand empty between two occupied stands.

Now that an updated version of the MSFS SDK is online, I took time to read it again in depth.
First, noticed this about the debug tools:

WTF ? Now parking spots have two different sizes.. What are we supposed to to with this ?


Then, further on:

Which is how it worked since minimum FS9.. But it's very confusing: now there's only one size mentionned, and although whether it's the "minimum area for the parking stand" or the "maximum winspan permitted" is not being explicitely written it's implying the later since the SDK mentions the wingspan again. So: radius set in stand properties = outer debug circle according to the most logical read of the documentation.


Anyway, I loaded one of my current project, displayed parking stands, and turned on the airport debug overlay:
Now that's interesting: the inner circle, described as "min area for the parking stand", matches the stand radius defined in the Taxiway_Parking properties. Not the outer one that the documentation is suggesting.
Despite the stands themselves are not overlapping, the outer dotted circles clearly show conflict areas for some stands (104L & 104R):

Another example: We clearly see here why the center stand (#120) is not used by the sim as it's conflicting with already busy stands 118 & 122.. But still the design was good with inner circles not overlapping.

I set a small rectangle, easiest way to measure distances with the in-game scenery editor: I'm only showing you one example but I repeated the measurement on many others, the outer circle has allways an extra 6-meter radius compared to the designated stand radius by the inner circle.

To sum up:
- the SDK documentation is confusing if not misleading, introducing 2 different parking stand radii in consideration but being vague about it.
- The smaller radius, defined in stand properties (via ADE or MSFS SDK), is compared to AI aircrafts wingspan for AI allocation. As we already knew and as it did work in previous sim versions.
- The larger radius, defined by a fixed extra 6-meter value, is called "max wing span allowed" despite not playing any role in AI aircraft allocation, but just seems to block the stand occupation if it conflicts with a neighboring occupied stand.

So, until we know more about it or asobo change things, it seems wise ta have this extra 6-meter radius in mind when designing parking stands in our MSFS projects. Sometimes overlapping cannot be avoided if you follow real world specs, but often it can if one stick to recommended radii tables by AIG: most of the narrowbodies are set to maximum 18m (A321s, B739s), modern widebodies have generally 30 or 31m (A330s, A350s, B787s, B777s), while 'medium' sized jets have generally been phased out for pax operation (B757s, B767s, A300s, A310s, old russian airliners), bringing down the need of medium gates (19 to 26m) close to zero.
So, my general advice for now: most often you'll only need 18m and 31m gates at your pax terminals: most of the medium gates can (and should) safely be sized down to 18m, liberating enough space in-between not to get hit by that 6-meter extra margin that MSFS is taking. If you need extra gates (35m for B748s, 40m for A380s), just add the minimum required number. If you have a few pax 767s, 757s or 310s still flying to your airport: count them in the large gates.

 

[FlyingsCool]

So, I think I saw your other post, as I seem to remember discussion around these concepts. I just posted this question on the FS SDK Forum. I was trying to summarize what I remembered of your questions (I read this a while ago). I only develop GA airports, and was hoping to have some Ramp_GA_LARGE based on your advice here for A320's at KACK with 21m radii. And yet I regularly get C172's and even Xcubs in them. Is it because I have Use Generic option off?

*************************

Hi. I realize we have a long way to go. But I'd like to understand what the radius of a parking spot means to what types of planes get placed. And why aren't I seeing Planes I want more often?

This is a typical Living World General Settings section I'll create. I expect to control the types of aircraft by the types of parking spots I create. I work on only GA style airports, from sizes like KACK and KBED, down to NH31 and the like. I really want to have tight control over what types of planes show up in parking spots.

<GeneralSettings>
    <AmbientVehiclesQuantityByParking>
         <ParkingEntry ParkingType="RAMP_GA_SMALL" Rate="0.06"/>
         <ParkingEntry ParkingType="RAMP_GA_MEDIUM" Rate="0.1"/>
         <ParkingEntry ParkingType="RAMP_GA_LARGE" Rate="0.2"/>
         <ParkingEntry ParkingType="RAMP_CARGO" Rate="0.15"/>
         <ParkingEntry ParkingType="GATE_SMALL" Rate="0.1"/>
         <ParkingEntry ParkingType="GATE_MEDIUM" Rate="0.1"/>
         <ParkingEntry ParkingType="GATE_HEAVY" Rate="0.1"/>
    </AmbientVehiclesQuantityByParking>
    <ParkedAircraftsQuantityByParking>
         <ParkingEntryWeighted ParkingType="RAMP_GA_SMALL" Rate="0.9" GoodToBadMatchRate="0.7"/>
         <ParkingEntryWeighted ParkingType="RAMP_GA_MEDIUM" Rate="0.9" GoodToBadMatchRate="0.8"/>
         <ParkingEntryWeighted ParkingType="RAMP_GA_LARGE" Rate="0.9" GoodToBadMatchRate="0.95"/>
         <ParkingEntryWeighted ParkingType="RAMP_CARGO" Rate="0.9" GoodToBadMatchRate="0.95"/>
         <ParkingEntryWeighted ParkingType="GATE_SMALL" Rate="0.9" GoodToBadMatchRate="0.8"/>
         <ParkingEntryWeighted ParkingType="GATE_MEDIUM" Rate="0.9" GoodToBadMatchRate="0.95"/>
         <ParkingEntryWeighted ParkingType="GATE_HEAVY" Rate="0.9" GoodToBadMatchRate="0.95"/>
    </ParkedAircraftsQuantityByParking>
    <FrequencyOfServicesOnEmptyParkings Rate="0.01"/>
    <RatioOfAmbientVehiclesThatAreImmobile Rate="0.05"/>
</GeneralSettings>

This one is for KCON, which has a large preponderance of GA_SMALL spots and a something like 5 GA_Medium and 2 Cargo, and 2 MIL_COMBAT and 1 MIL_CARGO. To give a sense to my choice of Rates for Ambient Vehicles, I have 81 Parking spots, at the airport, 10 of which are vehicle spots. (Although, I think I'll be getting rid of some of the vehicle spots. I was hoping operations trucks would head out to places like ILS stands and such. Instead, fuel trucks, do. It would be nice if we had Vehicle_Fuel and Vehicle_Ops type parking spots).

First question:

The Good to Bad Match rate... How does it figure out where to put a plane? As seems to be described in the SDK, it chooses a plane based on its Wingspan vs the parking spot radius. With a good to bad match rate of .8 for RAMP_GA_MEDIUM and a radius of 12 m, I expect to see TBM's and Longitudes, and CJ's and the like. Instead I get Xcubs and Stearman. It's awful. Fortunately, I can keep them out of Gates, but I can't keep them out of any GA parking spots. I fly into KACK and I want to see a large number of Jets and Turboprops, and instead I get Bleriot XI's and Xcubs. I finally had to remove the Bleriot because it showed up so often.

So, What radii are expected for each of the three sizes?

GA_Small, GA_Medium, and GA_Large.

I typically use 5 - 8 for GA Small

9 - 14 for Medium, and 18 to 30 for GA Large.

If I try to create a GA_Small at 10, it tends to automatically change it to a Medium.

Are these correct values? What is expected?

Second Question: How close can we put parking spots to each other and still have planes show up?

At any airport you go to, aircraft are often parked almost wingtip to wingtip. But FS seems to avoid this. Can parking spot radii overlap each other and still each get an airplane? How do we know what the limits of this are? How closely can parking spots be to each other? Is this what the "View/Render Parking Spots" means? If that extra diameter overlaps with another, then only one spot can get an airplane?

Third Question: Does the radius set an upper limit on wingspan, but anything below that will go in it? That would be awful. Can this be changed at some point? I really don't want Xcubs spawning with a pushback and baggage loader in my GA_Large spots. Or is there an upper and lower bounds on the parking spot radius value (say +/- 3m), and it's just not working properly?

Fourth Question: How do Mil_Combat and Mil_Cargo spots fit in with parking spot radii? It seems like there are ranges that GA small, medium, and large are expected to fall within, what about the Mil spots? As more military aircraft are created, or AI military aircraft, I'd like to see them populate in airports appropriately where they are supposed to be, since, usually, they have one area of the airport they congregate in. So I'm interested in how these spots work. It would be nice to have some ability to control this, but I'm ok with doing it by atc_parking_types= and it is what it is.

Fifth Question: And maybe this solves my general problem, but I'd still like answers to the above questions because I think there are important details to be understood regardless... Is it not working properly because I have "Use Generic" set to off? I was getting major CTD issues with it turned on, but I think it was due to some old liveries and I'm going to test it again. I would have to ask, if so, why would "Use Generic" set to off turn off all respect of parking spot radii?

Thanks. I've been working really hard at this since October, and I think I'm finally understanding how to properly write a Services and Living World Config file, and I would really like to get my sim working properly and have appropriate vehicular traffic and services for all the types of airports there are. I'm getting there. This information would help.

For reference, a lot of what I think I know came from this thread (and others, but this is the best), but I don't know how correct they are https://www.fsdeveloper.com/forum/t...and-radii-they-are-not-what-they-seem.451632/ and I was hoping for some official answers to these questions.

 

[mottoth]

First question:

The Good to Bad Match rate... How does it figure out where to put a plane? As seems to be described in the SDK, it chooses a plane based on its Wingspan vs the parking spot radius. (...)

Well I don't know that GoodtoBadMatchRate as I never relied on Parked Aircrafts to bring life to airport (I set this slider at 0).
Having a GA_medium or GA_small parking doesn't change anything about how the sim is allocating it. The only things taken in account are:
- AC Model radius (e.g. wingspan) vs. parking radius. Can't park an aircraft is a stand too small. The sim tends to favor the smallest suitable parkings but won't use those that are smaller than the model radius.
- atc_parking_types in aircraft configuration files (used to be in aircraft.cfg). GATE -> parking with type GATE_* are prioritized. RAMP -> parking with type RAMP_GA_* are prioritzed.
- atc_parking_codes in aircraft configuration files: primarily used for airliners with airlines ICAO codes, but can be set for GA traffic using some conventions. For example 'GA3J, GA2J, GA1J' for different sizes of bizjets, or 'BBJ' for 737s BBJ or A319CJs.

The bottom line here is that a correct configuration of parkings stands in not enough: you have also to configure your airplanes, with at least atc_parking_types for each repaint and maybe generic parking codes. You also to be well aware of the model wingspan to be sure you parking sots are wide enough. Same for mil traffic, both AI planes and dedicated parkings must be set accordingly.

Second Question:
Can parking spot radii overlap each other and still each get an airplane?

Definitely not ! It's even more restrictive: you have to account an extra 6-meter radius around each parking spot, making sure that it won't overlap anything. Enable the 'show parking space' option in the scenery editor rendering menu to visualize those extra 6-meter margins.

Third Question: Does the radius set an upper limit on wingspan, but anything below that will go in it?

Yep, this in exactly how it's working. Like a A380 gate can can also get narrowbodies, largest parkings are not exclusive to largest planes.

Fifth Question: And maybe this solves my general problem, but I'd still like answers to the above questions because I think there are important details to be understood regardless... Is it not working properly because I have "Use Generic" set to off? I was getting major CTD issues with it turned on, but I think it was due to some old liveries and I'm going to test it again. I would have to ask, if so, why would "Use Generic" set to off turn off all respect of parking spot radii?

Well, so many things got broken with every sim update since I opened this thread that I don't know anymore how to deal with these matters. I'm not experimenting anymore with AI traffic since I need a stable sim to make progress on my airport scenery projects. You'd better head up to Alpha India forums to get the latest tips about configuring AI models and repaints. FYU since SU5 only a max of 13 'legacy' models (FSX models) can be loaded at a time before the sim CTDs. I think I'm now waiting for Alpha India's OCI with native gltf models to start again on a fresh and clean basis.

EDIT: also, Vehicules parkings are only meant to spawn Fuel trucks, nothing more.

 

[xavios]

Hello there and happy new year.
It 's a pleasure for me to renew with this forum after a very long time out the ADE world (and Sim world) but now that I have a modern computer and time to spend with my hobby, I decided to start again with airports designing as I did with FS9 or FSX.
As an airport designer with ADEX it was quite a change to assimilate some languages and options inside ADE and I'm still learning...
I focus on my favorite airport(s) and especially parking allocation.
My first concern was to discover the insane AI vehicles behavior that is far more complicate to handle than in FSX but it's an another story...
The Radius problem.
In ADEX/FSX everything was, if I can say, simple : half-wing span is the radius and you can/could place your parking in FSX with ADEX using this postulate. The radius is the norm and you have to pay attention of what is on the left/rigt, front and back (aircraft length, a crucial problem believe me).
Some weeks ago I started to rework one of my favorite airport paying attention to the official radius. In ADE H/M/S default radii are 36/27/18 and I was glad with it.
Of course I had noticed the dashed circle around every parking but did not pay to much attention to it. Big mistake.
If these darn dashed circle are overlapping too much then the adjacent(s) parking will remain vacant. There is in fact a very small tolerance.
In short : the HWS is not anymore relevant to assign and position aircraft parking.
I have reduced this value in ADE but it's not enough.
Solution one : you don't care and put your parking according to the truth and you lose a non-negligible amount of planes.
Solution two : you remove purposely one parking every two or three and you will also lack parking.
Solution three : you reduce some radii to keep a good cohabitation but it is an absolute nonsense in most situations.
One example :
B777/A35K WS 65m HWS 32.5 --> 33m
In FSX OK to park in a 36M radius parking (or less).
In FS2020 with this new standard and including the dashed-extrapolation, it becomes a 78 meters wingspan. This is unmanageable.
Now open GE and go to any major-size airport that you want and measure the distance between two centerlines leading to parkings able to receive 777's side by side. The minimum distance is about 72/73 meters. For example in the reality three 777's can be accommodate at the same time. With this new rule only one or two can be...
According to what I have exposed, I am in a situation where it is now impossible for me to go ahead and upgrade my airport according to this.
Now can we expect this thing to be corrected sooner or later? I believe its is a feature inside MSFS...