Beginner’s Guide to FS2002 Traffic



It is best to think of FS2002’s AI traffic as dynamic scenery and not as artificial intelligence in motion. Other than when aircraft have their wheels on the ground, the AI seems blind to the risk of midair collision except in relation to the flier’s aircraft. AI planes will fly through each other without any ill effects nor even any acknowledgment from the “AI controller”. It is only when a plane’s wheels hit the ground that the AI controller recognises that there was another plane just a few metres behind it and orders a go around or chastises the other pilot for landing.

On the ground it is a different story and the AI will marshal the aircraft around the airport, avoiding most but not all conflicts, hold the planes short of active runways until it is clear to cross or enter the runway and in general live up to its AI tag.





Essential tools for working on AI

There are several programs essential for modifying AI traffic.

Traffic Tools - this freeware program by Lee Swordy compiles and decompiles the traffic.bgl file which holds the AI data. It is the basic program behind all software for altering AI traffic.

AFCAD - another Lee Swordy program which is used to modify the components an airport which are used by AI traffic. It does not alter the visual elements of the airport. AFCAD comes with excellent instructions and a brilliant interface. It can be linked to FS2002 for placing gates, etc.

AFDtree - AFD tree is used to examine the details of airports in FS2002 in a “tree” format similar to Windows Explorer. It is by Manfred Moldenhauer.

AI Traffic - an interface for Traffic Tools which makes it easier to use. AI Traffic has a few limits but is the best program to introduce AI novices to creating flight plans. It is the work of Arne Helge Haaland.

AI Traffic Mover - a great program for studying and working on flight plans. It is much more sophisticated and complex than AI Traffic but comes with an excellent manual. It is the work of Thomas Molitor.




What AI traffic needs

To allow AI traffic to land, an airport must have:

1. A control tower radio frequency. It does NOT need a static scenery control tower;

2. A network of invisible AI taxiways for the AI planes to follow. These are NOT the taxiways which can be seen as ground scenery.

3. Parking of the appropriate size (or larger) for the aircraft. The size is determined by radius and each parking space and each AI plane has a radius figure. Aardvark 737s and DC9s use “small gate” parking. If there is no available  parking spot, the plane will vanish after landing.

4. A runway of sufficient length. Aardvark aircraft use the default 737 files and might not land on runways less than 6000 feet in length. The default 747 wants 10,000 feet. Inadequate runways will force the plane to go missed and try to land again. Three missed approaches and the plane vanishes.

Flight plan files

When Traffic Tools decompiles the traffic.bgl, it creates three .txt files - aircraft.txt , airports.txt and flightplans.txt . Any of the files can be altered, then compiled to create a new traffic.bgl. The Tcompiler.exe function will find significant omissions and stop compiling.


Aircraft.txt

This file lists the aircraft used in the flight plan. It presents its data as follows:

AC#10,477,”AIA 737-300 Qantas”

“AC#10”  is the aircraft number  the flightplans.txt file uses to determine which aircraft to use;
“477” is the cruise speed in knots which the AI uses to calculate when the aircraft should appear, either at the destination airport or anywhere in between. It assumes the aircraft has been travelling at this speed since the flight started.
“AIA 737-300 Qantas” is the description of the aircraft exactly as it appears in the title= section of the individual aircraft’s aircraft.cfg file entry.  By changing the details here, it is possible to replace all flightplans using one type of aircraft with another type of aircraft, for instance installing Aardvark planes in an existing flightplan.




Airports.txt

This file contains details of airports used in the flightplan. Most major airports are included in the default set-up. The information is presented like this:

YSSY,S33* 56.93’,E151* 10.61’,20,Sydney Airport, Australia

“YSSY” is the ICAO code for the airport as used in the flightplan;
“S33* 56.93’,E151* 10.61’” is the longitude and latitude of the airport;
“20” is the airport’s height above sea level in feet. It triggers the point where the aircraft will start descending. Be aware that aircraft cruising at flight levels above FL310 might have descending to a sea level airport and mightl be too high to land when they appear;
The airport details are self-explanatory and optional. They do not have to be included to attract AI traffic to the airport.




Flightplan.txt file

This file sets out when and where the AI aircraft will fly. The data looks like this:

AC#10,VHTAH,50%,4Hr,IFR,00:34:59,01:37:51,290,F,0402,YMML,02:34:59,03:37:51,280,F,0403,YSSY

AC#10” is the type of aircraft as listed in the aircraft.txt file;
VHTAH” is the aircraft’s registration or tail number;
50%” relates to the level of traffic density which will activate this flightplan. This level can be adjusted in options menu in FS2002. Start FS2002 and set the option at 100% to ensure all flightplans created will be activated. Use 99% or less in your flightplan;
4Hr” is the frequency the flightplan cycle repeats. The options are 1Hr, 2Hr, 4Hr, 6Hr, 8Hr, 12Hr, 24Hr and WEEK. Before setting an option, make sure the aircraft can complete the cycle in the time allowed. The time should include a minimum 45 minutes turnaround time at each airport;
IFR”. The choices here are IFR and VFR. Schedulers report problems with VFR plans, so avoid them;
00:34:59” is the departure time in hh:mm:ss. It is also Greenwich mean time. A program such as AI Traffic gives the option of working in local time but will still compile in GMT. GMT is basic to the AI;
01:37:51” is the arrival time at the destination airport. It is actually the time the plane will arrive in the vicinity of the airport and must then manoeuvre for landing and taxi to its parking spot;
290” is the flight level or cruise altitude, in this case FL290 or 29,000 feet;
F” directs the AI to use flight number, in this case Qantas 402. The option is R, which is the tail number, in this care Victor Hotel Tango Alpha Hotel;
0402” is the flight number used by the ATC;
YMML” is the destination airport for the first leg of the flightplan, in this case Melbourne, Australia;
02:34:59” is the departure time of the second leg of the flight plan;
03:37:51” is the arrival time of the second leg;
280” is the flight level of the second leg;
F” is the flight number option;
0403” is the flight number for the second leg;
YSSY” is the destination airport of the second leg. Because this flight completes the flightplan, it is also the starting airport for the first leg. All flight plans must complete a loop to the starting airport;

As many as 100 legs can be programmed in one flight plan subject to there being adequate time to complete the schedule and the final flight returns the aircraft to itsstarting point.




One final word on the .txt files. There is one line of text for each entry, be it a flight plan, aircraft or airport. Switch off word wrap when working on long flightplans. There are NO full stops, commas, colons or semi-colons at the end of the lines and inserting them will cause problems.