X-Plane 10 Expert Essays

Tuning the Handling of Aircraft X-Plane
If X-Plane is set up and flying, but aircraft seem to be too sensitive in pitch, or if they pull to one side, the simulator&rsquo;s handling may need to be tuned.

Before performing the following, make sure the joystick and/or other control devices are set up and calibrated. See the section &ldquo; sec:config_controls&rdquo; of Chapter  for instructions on doing this.

To easily see whether the controls are properly calibrated, go to the Settings menu and click Data Input & Output. There, select the rightmost of the check boxes labeled joystick ail/elv/rud. When you close the Data Input & Output dialog box, you will see, in the upper left corner of the screen, the aileron, elevator, and rudder inputs from the flight controls (such as a joystick, yoke, rudders, etc.).

With properly configured controls, the aileron, elevator, and rudder joystick inputs all read around 0.0 when your flight controls are centered. When the controls are pushed full left and forward, they should read around - 1.0. When the controls are pulled full aft and right, they should read around 1.0. If this is what you see, then your controls are properly calibrated. If not, it&rsquo;s no wonder the plane is not flying correctly! You need to configure the controls as described in the section &ldquo; sec:config_controls&rdquo; of Chapter.

If the controls are indeed properly calibrated as per the above test, but the plane still is not flying correctly, it&rsquo;s time to look at the first level of control response tuning. Go to the Settings menu and click Joystick & Equipment. In that dialog box, select the Axis tab. Leave the flight controls centered and hit the button labeled Use this position as center.

With that done, close the Joystick & Equipment dialog box and move the flight controls to the centered position. Check to see if the data output (which should still be on the screen from the pre-test in the above paragraphs) is around 0.000 when the controls are centered. If it is, then the hardware works fine and the center point was set successfully. If the data output does not read near 0, the hardware is either of poor quality (or failing) or the center point was not properly set.

With the center point set correctly, try flying the plane once again. If it still does not handle correctly, read on to tune the next level of control response.

Open the Joystick & Equipment window and select the Nullzone tab. Look at the three sliders labeled control-response one each for pitch, roll, and yaw) in the upper right of the screen.

If these three sliders are fully left, then the control response is linear; that is, a 50% stick deflection in the hardware will give 50% control deflection in the aircraft. Likewise, 100% stick deflection in the hardware will give 100% control deflection in the aircraft.

If the problem being experienced is that the plane feels too responsive in the simulator, try dragging the sliders all the way to the right. This will give a non-linear response. Set this way, 0% hardware deflection will still give 0% control deflection in the simulator, and 100% hardware deflection will still give 100% control deflection. The difference lies in between&mdash;50% stick deflection in the hardware might only give 15% control deflection in the simulator. In other words, while the hard-over roll rate in the simulator will remain unchanged no matter how these sliders are set, fine control will be increased for smaller, partial deflections, since the flight controls will move less for a small-to-moderate stick deflection in the hardware joystick or yoke. This will give a nice, fine pitch control and slow, detailed roll control.

If, after changing the control response, the aircraft still does not fly as it should, read on.

The next level of control tuning is stability augmentation. If the plane still feels squirrelly or overly sensitive, go back to the Nullzone tab of the Joystick & Equipment window and try dragging the three sliders in the upper left of the window (labeled stability augmentation) all the way to the right.

This will cause X-Plane to automatically counteract any stick input to some degree, resisting rapid or large deflections in pitch, heading, and roll. Basically, it is like always having an autopilot on that smooths things out. This is obviously very fake, but in the absence of a perfect flight control system, g-load, and peripheral vision feedback, this can help smooth out the airplane&rsquo;s flight characteristics. Try flying with those sliders at various places, bearing in mind that full left should be most realistic (with no artificial stability added).

If, after doing all of the above, the aircraft still does not fly as it should, nothing more can be done within the simulator. It is now time to tweak the airplane model itself. In the real world, if a plane is pulling to one side or the other, a pilot will bend the little trim tab on the aileron one way or another. This bending of the aileron trim tab counteracts any imperfections in the shape of the airplane, the dynamics of the propwash, or the mass distribution inside the plane. The same thing can be done in X-Plane&mdash;you can bend a trim tab a bit one way or the other to make the plane fly true.

To do this, first exit X-Plane and open Plane Maker (found in the X-Plane installation folder, located by default on the Desktop). Go to the File menu and select Open. There, select the plane that is pulling left or right and load it using the Open button.

Then, go to the Standard menu and click Control Geometry. In this window, select the Trim & Speed tab. Look at the far right-hand column of controls in the top half of the screen, labeled trim tab adjust. This is a measure of how much the trim tabs are bent on each axis. The top control is the elevator, the middle the aileron, and the bottom the rudder (per the labels on the far left). A value of 0.000 in the trim tab adjust means that the trim tab is not bent at all. A value of 1.000 means the tab is bent so far that the control is fully deflected by the trim tab&mdash;this is way too far. Try bending the trim tab just a little bit&mdash;maybe set the value at 0.05 or at most 0.10. This would correspond to being enough force to deflect the controls 5% or 10%, respectively, due to the trim tab. A positive value corresponds to bending the trim tab up or right, depending on whether it is pitch, yaw, or roll. Thus, if the plane needs to roll right a bit more (or needs to stop rolling left), then enter a positive number for the aileron control. The same goes for the rudder: if the plane needs to pull right a bit more, enter a positive rudder trim tab adjust. If the plane needs to pull up a bit more, give it a positive elevator trim tab adjust. Tweak the trim tabs as needed, save the aircraft file (using Plane Maker&rsquo;s File menu), and exit Plane Maker. Then, open up X-Plane and try flying the plane again. It should noticeably pull one way or another based on how the trim tabs were bent. The trim tab controls may need to be tuned again to get the plane to fly as straight as is desired.

Setting Up a Copilot&rsquo;s Station
A copilot&rsquo;s station is a second computer networked to the main simulator, set to view a portion of the cockpit intended for the copilot. To use a copilot&rsquo;s station, you will first need two computers, each running their own copy of X-Plane. These need to be on the same network, or then need to be joined together with a single crossover Ethernet cable. The computers should form a simple LAN, configured as normal within Mac OS X or Windows, whatever the case may be.

You will need two copies of the aircraft file you intend to fly, both either created or modified using Plane Maker. The first copy of your aircraft should have the pilot-side instrument panel. If you are content with the default panel layout, any of the stock planes could be used.

With the first version (the pilot-side version) of the plane ready, simply make a copy of the entire airplane folder and add some suffix, such as &ldquo;_copilot&rdquo; to the end of the folder&rsquo;s name&mdash;for instance, if the aircraft you wanted to fly was in the folder &ldquo;Boeing 747&rdquo;, you might name the copilot-side version &ldquo;Boeing 747_copilot&rdquo;.

Next, open the copilot-side copy of the aircraft in Plane Maker and tweak the instrument panel (as described in the chapter &ldquo; Creating an Instrument Panel&rdquo; of the Plane Maker manual) as desired for the co-pilot&rsquo;s side of the craft. Save it when finished and close Plane Maker.

There should now be two copies of the same aircraft folder, where each aircraft file within has its own instrument panel. These folders should have names like &ldquo;Plane name&rdquo; and &ldquo;Plane name copilot&rdquo;. Both folders should be in the same place within your X-Plane directory.

Simply copy that entire aircraft folder from one of the computers over to the other, putting the aircraft folder in the same directory (relative to the X-Plane installation directory) on the second computer. For example, the folder location might be X-Plane 10/Aircraft/Boeing 747/ on the pilot&rsquo;s computer and X-Plane 10/Aircraft/Boeing 747_copilot/ on the copilot&rsquo;s computer.

With that done, open X-Plane on each computer, move the mouse to the top of the screen, click on the Settings menu, and select Net Connections. In the Net Connections dialog box, go to the &ldquo;External Vis&rdquo; tab. From here, the procedure for the pilot&rsquo;s and copilot&rsquo;s machines differ.

On the pilot&rsquo;s machine, check one of the boxes labeled IP of extra visual/cockpit (this is master machine) and enter the IP address of the copilot&rsquo;s machine.

Now, on the copilot&rsquo;s computer, check the box labeled IP of master machine (this is extra cockpit) and enter the IP address of the pilot&rsquo;s computer. In the lower left, click on the &ldquo;folder name suffix&rdquo; text box and enter &ldquo;_copilot&rdquo; (or whatever suffix you decided on previously). After that, no matter what aircraft is opened on the pilot&rsquo;s machine, this computer will add &ldquo;_copilot&rdquo; to the name of the aircraft folder that it needs to open.

Next, on the pilot&rsquo;s (and thus &ldquo;master&rdquo;) computer, open the pilot version of the aircraft file you are using. If everything is set up correctly, the pilot&rsquo;s machine will send all the appropriate data to the copilot&rsquo;s machine, the copilot&rsquo;s machine will get the message. The copilot&rsquo;s machine will then apply the suffix &ldquo;_copilot&rdquo; to the name of the aircraft folder, and it will open the copilot&rsquo;s version of the aircraft cockpit on the copilot&rsquo;s machine.

Configuring a Multi-Monitor Simulator
There are a number of different ways in which a multi-display simulator can be used. You might want many displays linked together to form a super wide cockpit view, or you might want one display for your cockpit and others for external visuals.

There are two general ways of configuring multiple monitors. You can either have your monitors all connected to one computer, running one copy of X-Plane, or you can have multiple different computers all networked together, each one with its own monitor and its own copy of X-Plane.

In general, using multiple displays on one computer will be more restrictive regarding the ways in which you can configure the simulator. Networking many computers together will be more flexible, but it will also be much more expensive.

Driving Multiple Displays from One Computer
Multiple displays can be used with one computer in three ways. You can either:
 * configure plug two monitors into your graphics card (if it supports multiple monitors) and configure the monitors as entirely separate in your operating system;
 * purchase a video splitter like the Matrox TripleHead2Go, plug your monitors into that, and configure all your monitors as a single, super-large display in your operating system; or
 * using a technology like AMD&rsquo;s Eyefinity (included with the Radeon 5xxx and later series video cards), plug your multiple monitors directly into your video card and configure them in the operating system like a single, super-large display.

If your multiple monitors are configured as a single large display in your operating system, all you need to do to have X-Plane fill the screen with a single large window is to check the run at full screen box in the Rendering Options dialog box. If, on the other hand, your monitors are configured in the operating system as separate displays, your best option is to have a regular, windowed version of X-Plane which you manually resize to fill as much of your display as possible. If you want to use your secondary monitor as an instructor operator station, refer to the section &ldquo; sec:use_ios&rdquo; of Chapter.

Networking Multiple Computers for Multiple Displays
To set up a multi-computer simulator, each of the computers you want to use must first be linked together over a network. X-Plane should then be launched on each computer. On each computer, open the Settings menu and click Net Connections. In this dialog box, select the &ldquo;External Vis&rdquo; tab. Here, the steps differ between the &ldquo;master&rdquo; machine (the computer which is hooked up to all your flight controls) and the other computers. On the master machine, you need to check as many of the IP of extra visual/cockpit boxes as you have extra computers, then enter the IP addresses of each of the other computers. On the computers used as other displays, however, you need only check one box labeled IP of master machine and enter the master machine&rsquo;s IP address. Note that in no case should you need to change the port number from 49,000.

How should these extra displays be configured? Let&rsquo;s assume we are to use four computers and four monitors: one cockpit and three external visuals (a common setup). On each of the three computers used for external visuals, we first need to open the Rendering Options dialog box from the Settings menu. There, we will enter a lateral field of view of 45 &deg; for each of them. Enter a lateral offset for networked scenery of - 45 &deg; for the left screen, 0 &deg; for the center screen, and 45 &deg; for the right screen, with no vertical offset on all screens. This will simply yield a 135 &deg; (45 x 3) field of view. If this is drawn out on paper, it becomes apparent that the 45 &deg; offsets on the left and right screens will cause them to perfectly sync up with the center screen.

From there, the monitors need to physically be moved around the &ldquo;cockpit&rdquo; (that is, where a user will sit when flying the simulator) in a semi-circle describing a 135 &deg; field of view. If this is not done, then the horizon will not appear straight as the craft pitches and rolls, caused by the &ldquo;fisheye lens&rdquo; effect. If a 135 &deg; field of view is described in a flat plane or in an arc of monitors that describe less than 135 &deg; of arc, fisheye distortion will result, apparent as a horizon that seems to bend and distort between monitors.

Lining Up the Horizon (Without Vertical Offsets)
Now, sometimes people sit on the ground and see the horizon does not line up, so they enter vertical offsets on some of the display machines only in order to get the horizons to line up. They quickly become confused when everything breaks down as they pitch and especially roll. If vertical offsets are used, they must be used on all networked machines in your simulator, unless you have one monitor physically above another. If some but not all of your computers have vertical offsets, things start getting messed up. What often happens is that a user will fly with a cockpit in the center screen, which shifts the center of that screen as far as scenery is concerned to be around 75% of the way up the monitor; this is done in order to leave room for the instruments. The external visuals, on the other hand, have screen centers in the center of the monitor, since they do not have to reserve space for the instrument panel. In this case, you need to do the following:
 * 1) Open Plane Maker from the X-Plane installation directory.
 * 2) Click on the File menu, then click Open Aircraft.
 * 3) Navigate to the aircraft you wish to fly and open it.
 * 4) Click on the Standard menu, then click Viewpoint.
 * 5) In the Viewpoint dialog box, go to the View tab.
 * 6) Set the view center Y, panel view i.e., the y coordinate of the center of the screen when in the panel view) to be one-half the height of your monitor in pixels (assuming you run X-Plane in full screen mode). For instance, if your monitor has a resolution of 1920 x 1080 pixels, you would enter 540 here
 * 7) Close the Viewpoint dialog box, either by pressing Enter or by clicking an X in the corner of the window.
 * 8) Open the File menu and click Save As ( not Save, since you do not want to overwrite the original file).
 * 9) Type in a name for this copy of the aircraft file (for instance, &ldquo;Triple Monitor [ aircraft name]&rdquo;) and press Save.
 * 10) Close Plane Maker.

Now, when you load the new copy of the aircraft up in X-Plane, the screen center will be just where you like it.

Correcting for Monitor Bezels
Let&rsquo;s imagine that you have three networked computers for additional visuals to form a wrap-around cockpit. Each computer might have a 45 &deg; lateral field of view as set in the Rendering Options). You would enter a lateral offset for networked scenery of - 45 &deg; for the left visual, 0 &deg; for the front visual, and 45 &deg; for the right visual, as discussed above. If each display has a field of view of 45 &deg;, these images will blend together seamlessly if you don&rsquo;t consider the width of the displays&rsquo;bezels (the frame around each monitor). If you cannot set up the monitors to run their effective image all the way to the edge (as you can with some, even though you wouldn&rsquo;t be able to see the part under the border), you might instead try a field of view of maybe 43 &deg; based on whatever fraction of the monitor is visible. Vertical and roll offsets, of course, are the up/down and tilt equivalents of the lateral offset.

Note: While the view offsets do indicate how much to the left or right or up or down each view is looking, people make the same mistake over and over: they run a center view with a cockpit in the center screen, and external visuals on the left and right&mdash;which is fine&mdash;but they notice that the horizon in the center (cockpit) screen does not line up with the horizons on either side. The reason for this is that the center-point of the screen where the horizon rests in a level flight attitude is up near the top of the screen in the cockpit view (to make room for the instrument panel) and the center of the screen for the external visuals (which do not need room at the bottom for the instrument panel). Often, people will incorrectly lower the vertical offset of the center panel (with the cockpit).

This results in countless problems with the views not lining up. The way to correct this is to do as in the &ldquo; sec:line_up&rdquo; section above and change the screen center for your aircraft; only then will the horizon always line up across all the visuals. In other words, the only time a vertical offset should be used is if there is one monitor on top of another.

Using Other Special Viewing Controls
The lateral field of view setting, located in the Rendering Options window, will change the way X-Plane displays the view of the outside world. Higher settings will allow more of the terrain to be viewed at any one time, but will reduce performance. Higher settings will also increase the &ldquo;fish eye&rdquo; effect of the simulator. The default value is 45 &deg; per display, which generally gives good performance and a natural view. Note, of course, that changing the field of view of a monitor in a multi-display setup will require you to re-evaluate your lateral offset values as well.

Now, suppose you are using multiple monitors, some for external visuals and others for cockpit displays. You may notice that when views are changed within X-Plane, the change propagates to all the visuals. To stop this from occurring, you can select the radio button labeled lock to panel view near the bottom right of the Rendering Options dialog box. Selecting this will cause the display to always show the forward-with-cockpit view.