Aircraft Editor (FSEdit)

Aircraft Editor Overview

Introduction

Installing and Starting FSEdit

What This Document Contains

Basic Guidelines

The .air File

Creating New Components from Scratch

Modifying and Deleting Default Aircraft 

Creating New Aircraft from Templates

Modifying Add-On Aircraft

Tips

Modifying .cfg Files

Adding or Deleting an Aircraft

Introduction

To add an existing aircraft using FSEdit

To add a new aircraft using FSEdit

To delete an aircraft using FSEdit

Aircraft Info

Modifying a Panel

Introduction

Undoing Changes

Panel Guidelines

To open a panel

To view the name of a gauge

To navigate though the gauges

To increase the viewing area of the gauge area

To resize the view of the panel

Inserting a Gauge

To copy and paste a gauge from another aircraft panel

To copy a gauge from the gauge area onto your panel

Changing a Gauge on a Panel

To view the name of a gauge

To increase the viewing area of the gauge area

To see how the gauge will look from within the cockpit

To test a gauge

To reload an aircraft

Tips

Sounds

Introduction

Modifying a Sound

To listen to the existing sound, replace it, or remove it

Textures

Introduction

Flight Dynamics Editor (FDE)

Introduction

Additional Considerations

Configuration Tab

Table 1: Reference Datum Properties

Table 2: Wing and Tail Geometry

Controls Tab

Table 3: Controls Geometry

Flaps Tab

To add a flap set

To delete a flap set

Table 4: Flap Components

Table 6: Airspeeds

Weight and Balance Tab

Table 7: Gross Weight

Table 8: Empty Weight Parameters

Table 9: Moments of Inertia Parameters

Engine Tabs

Piston Engine Tab

Table 10: Piston Engine Properties

Table 11: Turbocharger Properties

Table 12: Engine Position Properties

Turboprop Engine Tab

Table 13: Turboprop Engine Properties

Table 14: Turboprop Engine Position Parameters

Jet Engine Tab

Table 15: Jet Engine Parameters

Table 16: Jet Engine Position Parameters

Propeller Tab

Table 17: Propeller Properties

Fuel Tab

Table 18: Fuel Properties

Gear Tab

Table 19: Gear and Scrape Points

Table 20: Static Geometrical Parameters

Tuning Tab

Flight Control Effectiveness

Table 21: Flight Control Effectiveness Tuning Parameters

Stability Characteristics

Table 22: Stability Tuning Parameters

Lift Forces

Table 23: Lift Tuning Parameters

Drag Forces

Table 24: Drag Tuning Parameters

Engine Parameters

Table 25: Engine Tuning Parameters

Aircraft Editor Overview

Introduction

The Aircraft Editor (FSEdit) in Microsoft Flight Simulator 2004 is a tool with a graphical user interface. You can use it to:

Modify, add, or delete aircraft.

Add, delete, or change aircraft panels, including gauges, instruments, and radios.

Change, play, or remove sound files.

Modify aircraft textures.

Alter flight dynamics.

To make the changes, FSEdit modifies the following files: Aircraft.cfg, Panel.cfg, and Sound.cfg.

To use this editor, you need basic knowledge of aircraft and aerodynamic terms and concepts. You may also need a Pilots Operating Handbook (POH) or similar reference material for the aircraft you want to modify, or you can use the default values provided by the editor.

Installing and Starting FSEdit

By default, the following files were installed to your c:fs2004sdkfsedit_sdk directory:

readme.txt

eula.rtf

FSEdit.exe

FSEdit.exp

FSEDIT.HLP

FSEdit.lib

FSEditSDKFS2004.doc

Move (or copy) the following files to directory in which fs9.exe is installed (by default, it would be C:Program FilesMicrosoft GamesFlight Simulator 9).

FSEdit.exe

FSEdit.exp

FSEDIT.HLP

FSEdit.lib

Once you have placed these files in this directory, you can launch the editor by double-clicking the FSEdit.exe file.

This editor does not provide a visual model for your aircraft. To create a visual model, you must create a new 3-D model or edit an existing visual model with the gmax tool created by discreet and provided in Microsoft Flight Simulator 2004.

What This Document Contains

Basic guidelines
Basic information on FSEdit.

Adding or deleting an aircraft
Instructions on how to add or delete an aircraft.

Changing panels and gauges
Instructions on how to modify panels, gauges, instruments, and radios.

Replacing sound files
Instructions on how to delete, change, or add sound files.

Modifying textures
Instructions on how to modify the textures (graphics) on the exterior of the aircraft.

Altering flight dynamics
Instructions on how to alter the flight dynamics.

Important! The information included in this SDK is not supported by Microsoft Product Support Services.

Basic Guidelines

Introduction

With FSEdit you can add, delete, or modify the following parts of existing aircraft:

Panel
Replace and modify panel bitmaps representing panel backgrounds, or add/delete individual gauges, instruments, and radios.

Sound
Delete .wav (sound files) and replace them with new .wav files.

Textures
Modify the textures (bitmaps) representing the exterior of the aircraft (using Microsoft Paint or another graphics application).

Flight Dynamics
Alter the flight dynamics by modifying the aircraft geometry and/or tuning scalars.

The .air File

The .air file for each aircraft controls how the aircraft flies. You cannot modify the .air file directly, but some of the parameters from the .air file are incorporated into each aircrafts .cfg (configuration) file. Many of these .cfg parameters are modifiable in FSEdit. The changes you make in FSEdit alter the aircrafts .cfg file, which in turn creates new aerodynamic parameters in the .air file.

For more information about the aircraft configuration (Aircraft.cfg) file, see the Aircraft Container SDK. The aerodynamic parameters in the .air file can be modified only by using the FSEdit program, which contains an internal function that determines the aerodynamic coefficients based on the changes you make in FSEdit.

Creating New Components from Scratch

FSEdit is not a tool for creating new components of aircraft from scratch. To create new panels and/or gauges, or for more information on panels and gauges, see the Panels and Gauges SDK.

Modifying and Deleting Default Aircraft

You can modify any aircraft except the Flight Simulator 2004 default (read-only) aircraft. You can, however, make a copy of read-only aircraft (using the Save Copy As command on the File menu), and then modify that copy. For example, if you want to customize the panel in the default Cessna Skylane 182S, you can use FSEdit to copy the default (read-only) Cessna Skylane 182S and give it a new name. Then you can modify the panel in this new Cessna.

You cannot delete the default (read-only) aircraft. You can delete only aircraft that you have added.

Creating New Aircraft from Templates

You can create a new aircraft based on a template of the type of aircraft you want to create. These templates, however, contain no visual model. To see your new aircraft from an exterior view, you need to create a visual model using the gmax tool from discreet, which is provided with Flight Simulator 2002 Professional Edition.

Modifying Add-On Aircraft

You can use FSEdit to modify add-on aircraft created for Flight Simulator 98 or later versions. Aircraft created for versions prior to Flight Simulator 98 must be converted. For more information, see Adding and Deleting Aircraft later in this document.

Tips

Remember the following tips as you modify aircraft:

There is no Undo command. To undo changes, exit FSEdit without saving the aircraft.

Be sure to save your work often. The Save command saves all the changes you have made in the current session.

Modifying .cfg Files

The .cfg files (configuration files) referenced in this document are text files with a .cfg extension. You can view and edit them with any text editor such as Microsoft Notepad. They are located in the appropriate aircraft subfolders of the Flight Simulator 9Aircraft folder. These files should be modified-and only-with caution--by experienced developers, because changes could render aircraft inoperable.

Adding or Deleting an Aircraft

Introduction

There are two ways to add new aircraft to Flight Simulator 2004.

Note: Because of the large-scale changes that were made in the aircraft system, aircraft not compatible with Flight Simulator 98 or with the original Combat Flight Simulator are not directly supported in Flight Simulator 2004 or FSEdit 2004.

Note For more information about configuration files, see the Aircraft Container SDK.

To add an existing aircraft using FSEdit

On the File menu, click Open.

Navigate to the location of the folder that contains the aircraft you want to add.

Click the aircraft folder (the one that contains Panel, Texture, Sound, and Model folders) for the aircraft you want to add, and then click OK.

The contents of the aircraft container are copied to the location where you installed Flight Simulator 2004. You can edit the aircraft contents and then take the new aircraft for a test flight in Flight Simulator 2004.

Note Make sure you select the aircrafts main folder. If you select a subfolder, the OK button will remain unavailable.

To add a new aircraft using FSEdit

On the File menu, click New.

Select the aircraft template you want to start with (engine type is the most important feature to select).

Click OK.

In the Save Copy As dialog box, enter a new name for your aircraft or keep the suggested name.

Click OK.

A complete aircraft container is created for you, except for a visual model (you must create the visual model using the gmax tool from discreet, which is included with Flight Simulator 2004, or by using another compatible tool for editing 3-D models).

To delete an aircraft using FSEdit

Open an aircraft you have modified or created. (You cannot use FSEdit to delete any of the default aircraft.)

In the left pane, select the aircraft title under the Aircraft folder.

Press the DELETE key, or on the Edit menu, choose Delete.

Note: You will see only the Save and Delete menu commands if you have made a copy of a default Flight Simulator 2004 aircraft, have made a new aircraft using a template, or are selecting an aircraft that is not read-only.

Save your work often.

Aircraft Info

This section provides information that helps you add unique identification properties to your aircraft. The following table lists the properties and how you can use them.

You can also use FSEdit a to modify the ATC (air traffic control) properties for your aircraft. The ATC system in Flight Simulator 2004 references this information when communicating with your aircraft.

Modifying a Panel

Introduction

You can use the Panel feature in FSEdit to change the gauges, instruments, and radios that appear on your aircrafts panel. The only restriction in adding a gauge is that your aircraft must be equipped to drive that gauge. For example, if you add an engine gauge to a glider, the gauge will not work.

Important Note: Some of the newer aircraft (Beech Baron and Boeing 747-400) contain gauges that are incompatible with FSEdit. For more information on how to modify gauges for these aircraft, see the Panels and Gauges SDK.

You cannot use FSEdit to create new panels or gauges. For information about creating panels or gauges, see the Panels and Gauges SDK.

Undoing Changes

FSEdit does not include an Undo command. To undo changes, exit FSEdit without saving.

Note: After you add a gauge, you can use FSEdit to test its operation (see below).

Panel Guidelines

The Aircraft folder contains a Panel folder. The Panel folder contains the aircrafts Main Panel plus one or more sub panels (such as Radio Stack, GPS, or Compass).

To open a panel

In the left pane of FSEdit, double-click the panel icon. The panel opens in the upper-right portion of the screen, and the gauge well opens in the lower right.

Note: The gauges are not listed in a particular order.

To view the name of a gauge

Click on a gauge in the bottom portion of the FSEdit window. The name (label) appears below the gauge.

To navigate though the gauges

Use the scroll bars at the bottom of the FSEdit window or use the arrow keys.

To increase the viewing area of the gauge area

Move the horizontal and vertical window frames.

The View menu allows you to choose various views (resolutions). These resolutions enlarge or reduce the size of the panel view. Choosing Auto-Fit resizes the entire panel to fit in the size of the viewing area that you have chosen.

To resize the view of the panel

Click the View menu and choose the appropriate resolution.

Note Although all the gauges are stored in the Gauges folder (C:Flight Simulator 9Gauges), there is not a one-to-one correspondence between the gauges in the gauge area and the Gauges folder because one .gau file may contain more than one gauge.

To modify a Flight Simulator 2004 default (read-only) panel in FSEdit, you must first make a copy of that aircraft and then modify the copy.

Right-clicking a gauge in the right panel window displays the following menu choices.

Inserting a Gauge

There are two ways to insert a gauge in an aircraft panel:

Copy and paste the gauge from another aircraft panel.

Drag the gauge from the gauge area onto the panel.

To copy and paste a gauge from another aircraft panel

Select the aircraft from which you want to copy the panel.

Right-click the main panel and choose Copy on the shortcut menu.

Open the aircraft to which you want to paste the panel.

Click the Panel icon (not a subpanel), and on the Edit menu, click Paste.

To copy a gauge from the gauge area onto your panel

Locate the gauge using the scroll bars or arrow keys.

Drag the gauge onto the panel and resize it if necessary.

Changing a Gauge on a Panel

To view the name of a gauge

Click on a gauge in the gauge area. The name (label) appears below the gauge.

To increase the viewing area of the gauge area

Move the horizontal and vertical window frames.

Use the selections in the View menu to change the resolution of your viewing area.

To see how the gauge will look from within the cockpit

Click the View menu, and then click Auto-Fit.

To test a gauge

Click the Test Aircraft icon on the toolbar.

If the gauge does not look right on the panel, you can change the panel background in FSEdit or resize the gauge.

To see the effects of a change in Flight Simulator 2004, you must reload the aircraft.

To reload an aircraft

On the Aircraft menu in Flight Simulator, click Select Aircraft, and then choose another aircraft in the dialog box.

Choose the original aircraft again.

Tips

Remember to save your changes frequently and before you exit FSEdit.

Any changes to the gauge layout on the panel since the last save cause the aircrafts name and the panel name to appear in bold until the current changes to the aircraft are saved.

After you add a gauge to a panel, the gauge name appears at the bottom of the list in the [Windowxx] section of the Panel.cfg file for that aircraft.

Sounds

Introduction

You can use FSEdit remove, replace, or play a .wav file, but you cannot create a new sound event. Clicking the Sound icon in the left panel of FSEdit opens two lists in the right panel:

The Section list refers to the section parameter in the aircrafts Sound.cfg file. This list lets you set when youll hear the sound during flight.

The File Name list contains the names of the .wav (sound) files that you can replace.

Files with similar names may represent similar events or simultaneous events. For example, the files listed in the Combustionxx parameter may represent:

The engine sound on startup.

The engine sound while airborne.

A mix of two .wav files that play simultaneously for a layered effect.

Modifying a Sound

To listen to the existing sound, replace it, or remove it

In the left pane of FSEdit, click the Sound folder.

In the right pane, right-click a sound file and on the shortcut menu, choose Change Sound, Play Sound, or Remove Sound.

Note: The Change Sound and Remove Sound commands are not available for default (read-only) aircraft. For more information, see Modifying and Deleting Default Aircraft earlier in this document.

Textures

Introduction

Use the Texture icon in FSEdit to modify the exterior appearance of an aircraft.

You can only modify writable aircraft. To make a read-only aircraft writable, on the File menu of FSEdit, click Save Copy As. For more information, see Modifying and Deleting Default Aircraft earlier in this document.

When you open a bitmap that represents the exterior of the aircraft, you see 2-D images wrapped around the 3-D model.

Each image in the bitmap contains coordinates that map to a location on the 3-D model of the aircraft. If you move an image, you may lose its coordinates and the image will not appear.

Flight Dynamics Editor (FDE)

Introduction

The Flight Dynamics Editor (FDE) portion of FSEdit helps you create custom flight models.

Notice the row of tabs at the top of the right-hand window when you choose the Flight Dynamics icon. The first of these tabs, the Configuration tab, is the default tab when you open or create an aircraft for the first time. The other tabs open pages that present additional information about specific aircraft characteristics and systems (e.g., the Fuel tab presents information about the fuel system). By adding and changing information in these tabs, you can create a new flight model with FSEdit.

The following flowchart below (Figure 1) diagrams the arrangement of the Flight Dynamics Editor.

Figure 1. How the FDE

As is evident from the diagram, the aerodynamic coefficients that control the flight characteristics of an airplane are computed when you save the aircraft. This information is then placed into the aircrafts .air file, which is not editable. The input values, however, are placed into the Aircraft.cfg file, which can be viewed and edited with any text editor (such at Microsoft Notepad).

Most of the information you require should be readily available from any Pilots Operating Handbook (POH) or Flight Manual for the particular aircraft you are interested in creating. If you cannot find certain information, you can use the enhanced Tuning tab to adjust the flight dynamics of your aircraft.

Note: The theory used to determine the aerodynamic coefficients is based mainly on the conventional configuration of an aircraft (i.e., wing in the middle of the fuselage and tail in the rear). This model also works for a so-called canard configuration with the horizontal tail in front of the wing. However, the model may not provide the stability found in conventional aircraft if you create an aircraft that uses a flying wing, rockets, or a no-tail configuration. Most such unconventional aircraft require a Stability Augmentation System (SAS), which has not been incorporated into this version of FSEdit. If you create an unconventional aircraft, you might need to do a great deal more tuning to achieve the stability you want.

Additional Considerations

First, note that the type of engine used by the aircraft is the most important variable to consider when deciding how to design an aircraft. Whether you start from scratch (using a template), or start from an existing aircraft, make sure that the type of engine you want to use on your aircraft is the same as the one you start with. This is important because the tabs in the FDE are determined directly by the type of engine your aircraft uses.

Second, if you do not save your aircraft, the changes youve made are not incorporated, and the new aerodynamic coefficients are not computed. In addition, we recommend that you make a copy of any existing aircraft you want to modify, because once you save a modified aircraft, there is no way to revert to the previous aerodynamic coefficients. After you save changes to the FDE section, additional changes cause the aircrafts name and the word flight dynamics to appear in bold until you save the aircraft again.

Configuration Tab

The Configuration tab contains the fields with which you can edit the geometry of the lifting surface and the empennage (tail feathers). You can also change the Reference Datum location of your aircraft. During the following discussion, refer to Figures 2, 3, and 4.

The visual model of every aircraft has a center. To ensure that the behavior of the aircraft in the simulation matches that of the visual model, you must define a reference datum relative to the visual model center point (see the table below). You can choose any reference datum. However, most aircraft reference documents define the position of certain parts of an aircraft relative to a reference datum, so choosing a similar location may make it easier to design your aircraft.

Once the reference datum is set, all dimensions you provide in FSEdit should be relative to this reference datum, not relative to the visual model center. For example, you might define the longitudinal reference datum 35 feet forward (positive) of the visual model center. If your wing position is 7 feet forward (positive) of the visual model center, then the longitudinal position of your wing would be -28 feet behind (negative) of the reference datum (28 + 7 = 35). For help regarding these definitions, refer to Figures 2 through 4.

Table 1: Reference Datum Properties

In addition to the reference datum, the wing and tail geometry are needed.

Table 2: Wing and Tail Geometry

Controls Tab

The Controls tab provides the fields in which you can change the geometry of the aircraft controls and deflections.

Table 3: Controls Geometry

Flaps Tab

The Flaps tab allows you to add, delete and modify a flap set. An aircraft can have a maximum of five flaps sets (indices from 0 to 4), and a minimum of no flaps. The Flap Set Selector window displays the currently available flap sets, and by selecting a flap set, the information in the Flap Set Editor changes to reflect the properties for that particular flap set. If no flap sets are available, the information in the Flap Set Editor is set to NULL defaults.

To add a flap set

Click the Add Flap Set button on the top left of the Flaps tab.

To delete a flap set

Select the flap set you want to delete from the Flap Set Selector.

Click the Delete Flap Set button on the top right of the Flaps tab.

You cannot delete the last flap set in the window. However, if you want to have an airplane with no flaps, make sure that the Flap Type in the Flap Set Editor for the only flap set is set to None.

Table 4: Flap Components

The components of the Flap Set Editor are related only to the flap set you have selected. You can modify each flap set individually to whatever values you like. The three fields at the bottom of the Flaps tab are considered static. These fields contain values that are set regardless of how many flap sets you have (or dont have).

Table 6: Airspeeds

Weight and Balance Tab

As most pilots know, the weight and balance of an aircraft is extremely important to its overall stability and performance. There are four main groupings on the Weight and Balance tab:

Gross Weight

Empty Weight

Payload Weight

Moments of Inertia

Note that the location of the weight components is very important to the aircrafts stability. Therefore, if undesirable handling qualities result for your aircraft, you may want to shift the weight components longitudinal location fore or aft until a stable configuration results.

The Gross Weight is the total weight the aircraft was designed to carry, including fuel and payload. This value is not used directly to simulate the aircraft in Flight Simulator 2002, but it is a very important component when determining the aerodynamic coefficients that make up the flight model. You must be sure that the Gross Weight value is greater than or equal to the empty weight + payload weight + fuel weight for your aircraft.

Table 7: Gross Weight

The Empty Weight is the total structural weight of the aircraft, minus fuel and payload. You must also indicate a Center of Gravity (CG) location for the empty weight of the aircraft, relative to the previously defined Reference Datum. This location can be found through a summation of all the individual aircraft component weights and their locations, or you can use a best-guess estimate. Normally, the Empty Weight CG lies somewhere along the lateral and vertical centerline of a symmetrical aircraft, and between the leading edge and trailing edge of the wing-fuselage intersection.

Table 8: Empty Weight Parameters

You can use the Payload Weight Editor in the same way that you use the Flap Set Editor. Each station_load has a weight, as well as longitudinal, lateral and vertical position associated with it. You can add payload stations, delete payload stations, or modify the characteristics of a particular payload station. In addition, suggested values will be given that are dependent upon your empty weight and geometrical inputs. Although these values are a good guideline, some aircraft can have moments of inertia (MOIs) that vary significantly from these estimated values.

Table 9: Moments of Inertia Parameters

Engine Tabs

The Engine tabs available depend on the type of engine used for your aircraft. For example, a jet aircraft does not have Piston Engine or Propeller tabs, and a glider does not have any engine or Fuel tab.

Piston Engine Tab

The Piston Engine tab is available for any aircraft that incorporates a piston engine. Normally, these aircraft also require a propeller to produce thrust. The propeller properties are on a separate tab, discussed later in this document.

The Piston Engine tab includes three main sections:

Piston Engine Properties

Turbocharger Properties

Engine Position

The Piston Engine Properties and Engine Position sections are required fields; the Turbocharger is optional.

A piston engines power can be determined through a series of equations that represent the Otto cycle of a four-stroke piston engine, multiplied by the number of pistons available. This section contains all the information that Flight Simulator needs to determine how much power the engine can produce.

Table 10: Piston Engine Properties

If you want a turbocharged engine, select the Turbocharged? check box at the top-right corner of the Turbocharger Properties section. After you select this check box, you can edit the other fields for that section.

Table 11: Turbocharger Properties

In addition to the parameters needed to compute the power available from a piston engine, the engine position(s) must also be identified. After you select the number of engines from the Number of Engines drop-down box, you can edit the corresponding position fields.

Table 12: Engine Position Properties

Turboprop Engine Tab

A turboprop engine is similar to a jet engine (turbine), but it incorporates the use of a propeller turned by the shaft of the turbine engine to produce thrust. The parameters here determine the power output of the turboprop engine.

Table 13: Turboprop Engine Properties

In addition to the parameters needed to compute the power available from a turboprop engine, the engine position(s) must also be identified. After you select the number of engines from the Number of Engines drop-down box, you can edit the corresponding position fields.

Table 14: Turboprop Engine Position Parameters

Jet Engine Tab

The Jet Engine tab is available for an aircraft that is a pure jet (turbine engine with no propeller). This type of engine is also synonymous with a Turbofan or Turbojet engine. For example, the Learjet 45 and the Boeing 737-400 are both aircraft that incorporate the use of a Jet Engine.

Table 15: Jet Engine Parameters

In addition to the parameters needed to compute the thrust available for a jet engine, the engine position(s) must also be identified. After you select the number of engines from the Number of Engines drop-down box, you can edit the corresponding position fields.

Table 16: Jet Engine Position Parameters

Propeller Tab

You can use the Propeller tab with piston or turboprop engines. The propeller is the main producer of thrust for these types of engines. This tab is available only for aircraft with a piston or turboprop engine.

The thrust generated by the propeller is a function of the power delivered through the propeller shaft (determined from the respective engine properties), RPM, blade angle, airplane speed, and ambient density. The following parameters are needed to compute the thrust for aircraft with propellers.

Table 17: Propeller Properties

Fuel Tab

The Fuel tab is available for any aircraft with an engine; if you are developing a glider, the fuel tab is unavailable.

You can include up to 11 fuel tanks, but if the Total Capacity value for a tank is zero, that tank is not used. The following values apply to each of the 11 possible tank configurations.

Table 18: Fuel Properties

Gear Tab

Every aircraft should have ground reaction contact points associated with it (otherwise, your airplane would never touch the ground). On this tab, you can add, delete, or modify individual contact points. The Point Selector identifies the active point in the Gear/Scrape Point Editor section.

You can configure and adjust the way aircraft react to different kinds of contact, including landing gear contact and articulation, braking, steering, and damage caused by excessive speed. You can also configure each contact point independently for each aircraft, and there is no limit to the number of points you can add.

You must specify the gear (or skid or float) points and any scrape points that identify aircraft contact with the ground. For example, you should place a scrape point at each wing tip so that if the tip scrapes the ground, the aircraft is damaged and the wing does not go through the ground. You should place scrape points at the following locations:

Nose

Wing tips (2)

Tail

Belly

Top of vertical tail

The following parameters apply to all types of contact points.

Table 19: Gear and Scrape Points

In addition to the above point-specific parameters, two static parameters apply to the aircraft, regardless of the number or type of contact points.

Table 20: Static Geometrical Parameters

Tuning Tab

The Tuning tab is a very important part of process of aircraft flight models. Although the theory used to calculate the aerodynamic coefficients is reliable and well-proven, you must make many assumptions made in order to simplify the aircraft design process. You will invariably need to change the values of some parameters to make an aircraft behave in the air as you expect it to.

You can tune five main areas:

Flight Control Effectiveness

Stability Characteristics

Lift Forces

Drag Forces

Engine Parameters

The tuning of these parameters can be considered mostly independent of each other, although some coupling (the effect of one parameter on another) can occur.

Flight Control Effectiveness

The following parameters are multipliers on the aerodynamic power of the control surfaces. For example, an Elevator Effectiveness value of 1.1 increases the elevator effectiveness by 10 percent. Likewise, a value of 0.9 decreases the effectiveness by 10 percent. A negative number reverses the normal effect of the control.

Table 21: Flight Control Effectiveness Tuning Parameters

Stability Characteristics

The following parameters are multipliers on the aerodynamic stability (damping effect) of the aircraft, about the corresponding axis of the airplane. For example, a Pitch Stability value of 1.1 increases the pitch damping by 10 percent. Likewise, a value of 0.9 decreases the pitch damping by 10 percent. A negative number results in an unstable characteristic about that axis. A positive damping effect is simply a moment in the direction opposite of the rotational velocity, or a restoring moment.

Table 22: Stability Tuning Parameters

Lift Forces

The Cruise Lift Scalar is a multiplier on the coefficient of lift at zero angle of attack ('cruise lift' in this context refers to the lift at relatively small angles of attack, which is typical for an airplane in a cruise condition). The effect of this parameter is decreased linearly as the angle of attack moves toward the critical (stall) angle of attack, preventing destabilization at low speed and high angles of attack.

Modify this value to tune the angle of attack (and thus pitch angle) for your aircraft while in the cruise condition. A negative value results in extremely unnatural flight characteristics.

Table 23: Lift Tuning Parameters

Drag Forces

Drag is the aerodynamic force that opposes thrust, which in turn helps determine the aircrafts speed and acceleration. You can adjust two basic types of drag:

Parasite Drag (due to friction)

Induced Drag (due to lift)

Parasitic drag is composed of two basic elements: form drag, which results from the interference of streamlined airflow, and skin friction. Parasitic drag increases as speed increases.

Induced drag results from the production of lift, which increases as angle of attack increases (until the stall angle is reached). The total drag force on an aircraft is the sum of these two components.

The following parameters are multipliers on the two respective drag coefficients. For example, a Parasite Drag value of 1.1 increases the respective drag component by 10 percent. A value of 0.9 decreases the parasite drag by 10 percent. Negative values result in extremely unnatural flight characteristics.

Table 24: Drag Tuning Parameters

Engine Parameters

The tuning scalars (which affect engine performance) that are available depend on the type of engine your aircraft uses. Thrust is associated with a turbine engine or propeller, while power is associated with a piston or turboprop.

The mechanical efficiency and friction scalars are associated only with a piston engine, and they provide a means by which the maximum RPM and the idle RPM can be tuned.

Table 25: Engine Tuning Parameters