Answers to frequent questions on this forum (it’s a bit of a long post).
There is a host of posts on this forum about parking spot sizes, types, etc. In many cases people think that some of the problems they encounter with GSX are FSDT related, where in effect they are due to a faulty AFCAD. GSX looks at the AFCAD –data and aircraft.cfg and acts accordingly. If the AFCAD and/or aircraft.cfg is wrong, things within GSX go wrong. It is certainly not entertaining for Umberto and anyone else for that matter to have to answer the same questions again and again, so some explanations are called for. You may have noted that some of the experienced and knowledgeable guys that hang out on these forums tend to get annoyed by these ‘stupid questions’ (which for newcomers aren’t all that stupid) and start to answer in a less polite way and scare you away.
Maybe Umberto can make this a sticky?!
First of all, what’s an AFCAD and an aircraft.cfg?
Let’s start by saying that, related to FSX, the use of the acronym AFCAD is basically wrong. AFCAD is a little utility to edit airport parking/taxiway systems and so on in FS2002 and FS9. It no longer works in FSX, since the related files have a different structure. However, the word AFCAD got stuck in the minds and is still used in FSX. So, if we talk about an AFCAD, it’s the file that determines gate types and sizes, taxiways, runways, runways holding points, etc. in FS. It’s basically a scenery file with the standard .bgl extention and resides in the scenery folder relevant to the specific scenery. For FSX (we only discuss FSX since GSX does not work in the previous versions of MSFS) there are two utilities to make new or edit existing AFCADs; e.g. ADEX9 (a freeware product from scruffyduck software) and AFX ( a payware product available through Flight1). ADEX9 is extremely powerful, allowing for many more operations than just basic AFCAD-editing. It is therefore slower, requires a lot of PC resources, but also trickier. There are some behind the scene actions that are not always desirable and you have to edit them out in the .xml file that AXEX9 produces when it compiles the AFCAD.bgl, which then has to be re-compiled manually. AFX on the contrary is much lighter in concept, therefore much faster and does not do anything hidden from your eyes that needs to be corrected manually. One major difference between ADEX9 and AFX is that the latter allows you do determine the pushback at every specific gate: none for drive-through parking, tail to the left, tail to the right or both. ADEX9 does not let you do that, you’d have to edit the .xml file for that, not something for the faint of heart. It’s easy to screw up an .xml file and get hopelessly lost. The advantage that ADEX9 has over AFX (and it’s a strong one) is that it doesn’t do anything to your default AFCAD until you tell it to do so. When you save a project, it does so in a specific form in its own folder. It will only do something with that file when you ask it to compile the airport and have specified the relevant scenery folder of that airport to compile it into. When you save in AFX, you automatically compile and overwrite the default AFCAD, unless you specifically tell AFX to save outside of FSX in a different folder! YOU HAVE BEEN WARNED, so back up your defaults, always!
I use both ADEX9 and AFX, depending on what I need to achieve! Let’s say ADEX9 is the Lamborghini Cheetah for the sophisticated, heavy duty stuff, AFX is the small utility for the fast trip to the supermarket around the corner (funny part is that the Cheetah comes for free, the utility wants to get paid for).
What, now is important in the AFCAD file and aircraft.cfg as far as GSX is concerned? Not that many features, but they are basic for any AFCAD to work:
- Parking type. Basically we know: GATE, RAMP and CARGO. GATE can be subdivided in SMALL, MEDIUM and HEAVY. RAMP is used for GA planes divided in SMALL, MEDIUM and LARGE , and has a sub-type as MILITARY_COMBAT. CARGO is CARGO, with the MILITARY_CARGO added as sub-type. To the inner workings of FSX SMALL, MEDIUM, LARGE and HEAVY doesn’t mean anything. FSX only looks at: GATE, RAMP, CARGO, MILITARY_CARGO and MILITARY_COMBAT, period, end of story gate type! Where a plane is going depends on what is specified in the aircraft.cfg file, a sub-file of the aircraft file in your SIMOBJECTS folder. This sub-file is all about repaints (most will know this file from adding repaints) and a lot of other settings better left alone. What is important here are three specifics: for every repaint you should/must have the atc_parking_types= entry! Without it FSX parks you or an AI-plane wherever it sees fit, which is always there where it shouldn’t park! A very important note in this context for repainters and those that add repaints: scheduled and non-scheduled airlines should ALWAYS specify atc_parking_types=GATE !!!!!! Too often we see either RAMP or GATE,RAMP. WRONG, No Good, big NO-NO, monumental Screw-Up, and so on. Seeing a Delta flight go to a ramp on the other side of the airport for de-boarding where usually freighters do their thing really sucks! FSX is not able to handle traffic overflow situations very well, so if there is an overflow situation (which in real life means planes with a long rotation schedule, like long-haul flights, get parked on ramps away from the terminals to free up gates), turn down traffic percentage in FSX-settings or get a good IA-traffic file! And let FSX idle away for 5-10 minutes after you fired it up, it needs time to digest AI-traffic and settle in on the schedules.
For the same reason, people that make AFCADs should specify a GATE as a GATE and nothing else. A GATE is a GATE and not a RAMP. Do you ever see a C172 parked at a GATE at JFK? In FSX that’s where it might go if you specify a GATE as RAMP!
- Again, in every repaint part there is another important entry: atc_parking_codes=XXX. These codes specify the airline. If you want an American Airlines plane to park at its specific terminal gates in KLAX or KJFK you enter AAL, DAL stands for Delta, UAL for United, KLM for KLM (surprise) and so on, you get the drift. There are plenty of listings out on the web with all these codes, which usually are the IATA codes. All available airlines in FSX are listed in a place holder file, missing airlines can be added in a variety of ways, EditVoicePack is one of them for instance. ADEX9 and AFX look at that placeholder list and allow you so to specify the code for each parking spot. You can add as many as you like (for code-share flights for instance). In this context good airport terminal info is crucial to make it as real as it gets (phew, what a cliché that has become).
- Third important entry in the aircraft.cfg file: the wingspan! FSX looks for a parking spot that equals half the wing span expressed in meters! The wing span value in the aircraft.cfg file has been specified by whoever conceived the aircraft. Since this value does not influence the flying behavior of the aircraft FSX aircraft much, you could make it basically as small or big as you like. However, make it too small and you can have your plane looking for the spot of a C172, too big and it may not find any parking spots at all. This fact allows for some interesting personalization, but that’s another story all together. So, look at the stated wing span in the aircraft.cfg file, convert it to meters (as it is expressed in feet) cut that figure in half and you have the parking spot radius that aircraft will be looking for! There is now a general consensus amongst especially AI-aircraft designers what radius/wingspan to use:
• 8-10 meters for GA aircraft with type RAMP (SMALL, MEDIUM, LARGE, who cares);
• 12-15 meters for commuters (CRJ, ATR, ERJ, Dash8) with type GATE (GATE small);
• 18-19 meters for short/medium haul airliners (B737 series, Airbus 2xx series) with type GATE(GATE small);
• 24-27 meters for medium size planes (B757, B767, AB306, etc.) with type GATE (GATE medium);
• 36-37 meters for the heavies (B747, AB343 series, etc.) with type GATE (GATE heavy);
• 40 meters for the super-heavies (AB380) with type GATE (GATE heavy);
• 50 meters for the big freighters (B747F) with type CARGO (however, if you have a small freighter like Aloha Cargo uses the Saab 340 cargo version, you can use a smaller radius for the CARGO dock and specify AAH as code and their B737 freighter will not park there, works great).
So, to summarize: the aircraft.cfg data for wingspan should about match the parking radius (or vice-versa if you will), the atc_parking_types= should match the AFCAD parking type and the atc_parking_codes= should match the AFCAD parking code. If that is the case, every aircraft will go there where it should, unless there is a hopeless overflow situation, in that case you will see AI popping in and out of the parallel universe like if the Adams Family was in charge of ATC.
GSX looks at the aircraft.cfg file and the AFCAD file for these 3 specifications, at least as I understand it, to determine if the spot where you are/should go is big enough, is of the right type and to know what pushback truck it needs and what service company to use. If there is a glitch in any of these 3 specifications, GSX could go bezirk.
In such a case you cannot blame FSDT, they did NOT produce the aircraft.cfg file and (apart from their own airports) did NOT produce the AFCAD. Stop barking up the wrong tree, find out who did this to you and email the guilty one, post on his/her/their forum, send them a rotten apple for Christmas, whatever it takes to get their attention and hope for the best. In case of no reply/action, it’s not that hard to correct the specs in the aircraft.cfg file (make a back-up!!!!). If you feel up to it, you can work on the AFCAD (can be tricky for newbies), if not hope for somebody to produce and upload a good alternative to the default.
One last thing, what really knocks GSX out off its shoes and completely off the beaten track are duplicate AFCAD files for the same airport. Many third-party add-ons, especially AI-traffic providers tend to sneak some AFCAD-like files into active FSX scenery files without you knowing it. Use something like FSX Airport Scanner (scruffyduck again) to hunt these down and dump them!
I hope some may find use in the above, any good questions, just shoot.
Hans Wilms
