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Find your way into flight simulator cockpit construction

4.1 Microsoft Flight Simulator

The Microsoft Flight Simulator consists of an open architecture (a combination of editable configuration files and a SDK: Software Development Kit) that enables the addition of third party add- ons, the addition of your own developed aircraft / written software or the fine tuning of the aircraft you fly. Basically this means that from within the flight simulator (so from within operating a simulated aircraft) you can:

     1: Generate output in order to operate a cockpit

     2: Process input generated from the cockpit in order to operate the simulated aircraft

These are the 2 basic requirements to develop a real working flight simulator cockpit.

Starting with FSX the SDK's including detailed documentation are included with the deluxe edition. Regular updates will be provided at FSinsider. Behind every SDK is a world of its own. If you perform a search on the Internet you will find many examples of people specialized in 1 or more SDK's. To a certain extent the boundaries of what you can make are determined by you own imagination (in combination with "time"). The download libraries on AVSIM or FlightSim but also commercial suppliers like Aerosoft and Flight1 give an impression of what can be achieved. In the remainder of this section we will concentrate on the issues most relevant to building a flight simulator cockpit.

The definitions for the aircrafts within Microsoft Flight Simulator can be found in the "SimObjects\Airplanes" directory in the Microsoft Flight Simulator main directory (e.g "C:\Program Files\Microsoft Games\Microsoft Flight Simulator X" for a typical installation). (Before you really start editing it is recommended you make a backup of original files and take notice of the Microsoft Flight Simulator documentation.) In principle you will find 1 directory with all related files per aircraft. If the name of the aircraft would be "DC- 3 experience" you would find the following directory structure:

Chances are you will find more directories and/or files, but the above are the most important ones.

4.1.1 Flight model

When your objective with building a flight simulator cockpit for a specific aircraft is "as real as it can get" than tuning the flight model (the aircraft.cfg file) will play an important role. Certainly when you have acquired specific documentation / manuals on aircraft operations, performance and construction. The formal documentation on this subject can be found in the SDK directory "SimObject Container System". Starting with FSX the SDK's including detailed documentation are included with the deluxe edition.

The aircraft.cfg file can be edited by hand. Additionally there is the "<aircraft_name>.air" file, which can not be formally edited. The content of the .air file is not communicated by Microsoft because it seems to contains sensitive / copy righted information obtained by them from the manufactures of the aircrafts that are included with Microsoft Flight Simulator. The expectation is however that within the future releases of Microsoft Flight Simulator the user will be more and more able to exactly configurate their aircraft. Within the Microsoft Flight Simulator community (by means of reverse engineering) software has been developed to edit the .air file. Places to start are AirEd , MudPond, "Bob's Flight Dynamic Tutorial" downloadable from Simviation and Herve Sors. Of special interest is AvHistory, this group shares the methods of creating flight models that fly within 1% of the performance of their real world counterparts.

The aircraft.cfg file for Microsoft Flight Simulator allows you to specify a large number of characteristics of the aircraft, many of them influencing the flight simulator cockpit experience. To get an impression you will find a brief overview below. In order to change the settings in FS without leaving FS you will have to turn off AI traffic and reload the aircraft.

4.1.2 Sound definitions

Sound is an important element of simulation. Besides generating an audio experience it is additionally an important source for the vibrations that can be generated in a flight simulator cockpit (as described in the section 6). Investing some time to fine tune the sound files of your aircraft pays off. Many sound definitions provided with aircrafts do not make use of all the options. When applied in the right way (e.g. matching the variations of surface types with "touchdown" or "ground roll") it can trigger the corners of your imagination. It is not easy to record aircraft sounds yourself. However, you can (with the right software) modify the Microsoft Flight Simulator sounds (e.g. make them heavier or lighter or introduce additional sounds), take samples of other sounds (e.g. video or DVD) or use one of the many sites on Internet that provide sound samples. (Be aware of the use of copy righted material when you intent to distribute your sound files to others.)

The basic principle for sound files is that a .wav file is interpolated with respect to volume, pitch or amplitude against an axis of speed (ground, wind) or RPM (engine). This interpolation can be specified between 2 to 8 points, which is called an envelope. This envelope makes it possible to specify a detailed behavior of the sound against the axis (e.g. speed). Many aircraft sounds are composed of multiple linked definitions (definition = combination of envelope specification and .wav file) which is called a “sound list” and played in sequence as a group. For instance the ground sounds can be varied according to 17 surface types (groups) or for each engine a sequence of definitions can be defined. When relevant sounds can be defined as heard inside or outside, left, front, right, backside of the aircraft. This detailed interpolation mechanism, the sequencing and the variation makes it possible to generate a large diversity of spatial sound effects with high quality. The use of a program like FS Sound Studio (FSSS) or Aviacoustic (Andrzej Suwald) makes this even very easy (fool proof).

All together you can define very detailed (and large) sound files. As stated before, investing some time pays off! Describing all the details goes beyond the scope of this text. To give an impression the sound categories are: Starter, Combustion start, Combustion, Jet whine, Shutdown, Non combustion, Propeller, Wind, Touchdown, Ground roll (including water & snow), Gear, Flaps, Various warning sounds, Scrape, Crash / Splash. The formal documentation on this subject can be found in the SDK directory "SimObject Container System". Starting with FSX the SDK's including detailed documentation are included with the deluxe edition.

4.1.3 Panel definitions

Depending if you are building a (partial) "glass cockpit" (e.g. using CRT-based-gauges / gauges based on a computer screen) or your are building a "classic" flight simulator cockpit with only analog gauges (with dials/faces and pointers) you will need more or less the panel definition SDK to define your gauges. For instance on a multi monitor system some displays can be used to display the gauges in the cockpit panel, while others are used for the outside view from the cockpit.

A panel consists out of 3 elements: the panel.cfg file (definitions of the various panel windows and the location of gauges within these windows), *.bmp files that are used for the background of the panel windows and the gauges themselves in either *.gau or *.xml files. You can make / change your own panel (i.e. changing the panel.cfg file) by using ready made gauges from Microsoft Flight Simulator, downloaded freeware gauges, third party commercial gauges or gauges made by yourself. The use of a program like FS Panel Studio (FSPS) makes this even very easy (fool proof).

On an abstract level the principle of a panel should be seen as a collection of small programs (gauges) that are processed in a loop. Since this processing is done very rapidly the total movement of the gauges on the screen gives the impression of real time instruments. For complex gauge environments it is even possible to give priorities to the execution of gauges. Note that within the Microsoft Flight Simulator all elements on a panel (so also switches, lights, etc.) are called gauges. Until Microsoft Flight Simulator 2002 the gauges (*.gau files) where equivalent to DLL files. Starting with Microsoft Flight Simulator 2002 it is additionally possible to define gauges in XML format. Defining gauges in XML format goes very well as long as you do not need access to resources (like a database) outside Microsoft Flight Simulator or require very complex processing (not really the area for using XML). For the initial gauge definitions (the DLL variant) the SDK supports the development in "C", but there are also examples of gauges developed using Visual Basic. If programming in "C" is too much for you, perhaps EasyGauge (Blue Sky Software) is an option to make the specific gauges you need.

A gauges definition (XML) or program (DLL) can be divided in 4 parts.

The learning curve for the actual gauge development in "C" is (very) steep, doing it in XML -using for instance FS Panel Studio- is on average a better track to follow. The formal documentation on this subject can be found in the SDK directory "Panels and Gauges SDK". Starting with FSX the SDK"s including detailed documentation are included with the deluxe edition.