X-Plane (simulator)

X-Plane is a flight simulator for personal computers produced by Laminar Research. It runs on iOS, Palm's WebOS, Linux, Mac, or Windows. X-Plane is packaged with other software to build and customize aircraft and scenery, offering a complete flight simulation environment. X-Plane also has a plugin architecture that allows users to create their own modules, extending the functionality of the software by letting users create their own worlds or replicas of places on earth to create ultimate realism. It comes with five scenery disks, and one with scenery and the actual simulator.

Flight model
X-Plane differentiates itself by implementing an aerodynamic model known as blade element theory. Traditionally, flight simulators try to emulate the real-world performance of an aircraft by using lookup tables to find previously-known aerodynamic forces such as lift or drag, which vary with flight condition. These simulators do a good job of simulating the flight characteristics of the aircraft they were designed to simulate (those with previously-known aerodynamic data), but are not useful in design work, and do not predict the performance of aircraft when the actual figures are not available.

Blade-element theory is one method of improving on this. It is a way of modeling the forces and moments on an aircraft by individually evaluating the parts that constitute it. Blade-element theory and other computational aerodynamic models can be used to compute aerodynamic forces in real time or to pre-compute aerodynamic forces of a new design for later use in a traditional lookup table type of simulator.

With Blade-element theory, a wing, for example, may be made up of many sections (1 to 4 is typical), and each section is further divided into as many as 10 separate sections, then the lift and drag of each section is calculated, and the resulting effect is applied to the whole aircraft. When this process is applied to each component, the simulated aircraft will fly virtually like its real counterpart does. This approach allows users to design aircraft on their computer quickly and easily, as the simulator engine will show immediately how an aircraft with a particular design might perform in the real world.

X-Plane is capable of modeling fairly complex aircraft designs, including helicopters, rockets, rotor craft and tilt-rotor craft. Famous real world aircraft modeled in X-Plane include the V-22 Osprey, the Harrier Jump Jet, the NASA Space Shuttle, and Scaled Composites SpaceShipOne.

Blade element theory does have its shortcomings, as it can sometimes be difficult to design an aircraft that performs precisely like the real-world aircraft. However, as the flight model is refined, the simulator can better resemble real-world performance (as well as the aircraft's quirks and design flaws.)

Extensibility
Users are encouraged to design their own aircraft, and design software is included with the program. This has created an active community of users who use the simulator for a variety of purposes. Since designing an aircraft is relatively simple and the flight model can help predict performance of real-world aircraft, several aircraft companies use X-Plane in their design process. The CarterCopter uses X-Plane for flight training and research. X-Plane also contributed to the design of the Atlantica blended wing body aircraft.

Through the plugin interface, users can create external modules that extend the X-Plane interface, flight model, or create new features. One such feature is the Xsquawkbox plugin, which allows X-Plane users to fly on a worldwide shared air traffic control simulation network. Other work has been done in the area of improving X-Plane's flight model and even replacing entire facets of X-Plane's operation. Scaled Composites, for example, used the X-Plane rendering engine on top of their own simulator while designing and testing SpaceShipOne.

X-Plane is also capable of communicating with other applications via UDP. Through a relatively simple interface, third party developers can control the simulator and extract data regarding the simulation state. Companies like Scaled Composites have used this tool in order to use X-Plane as a rendering engine for their in-house simulators.

The maps and scenery are also fully editable. While no tool is provided to edit the 3D mesh objects, there are tutorials for using the third party 3D modeler AC3D. Once built, editing landscape elevation and 3D object placement is easily accomplished with the scenery editor. In fact, much of the world's detail, including detail in airports, such as ramps, buildings, and taxiways, is provided by the end-users. Users can also subscribe to a mailing list, receiving regular updates of the airport and navaid database.

Map imagery and aircraft paint can be created and modified with any paint program capable of manipulating PNG images. Additionally, Laminar Research has released a 7 DVD "Global Scenery Package" containing imagery of a much higher quality than the default information. This package covers close to 85% of the Earth's surface. The release of X-Plane 9 (Jan 2008) has introduced much improved areas of high ground relief (in particular, mountains) and a plethora of other improvements.

FAA certification
X-Plane is also used in non-motion and full-motion flight simulators for flight training. Some of these implementations have been certified by the FAA for authorized flight instruction such as Flight Level Aviation and Simtrain.

Community
The community for X-Plane has evolved rapidly over the last few years. A major factor in community growth has been thanks to the iPhone and iPad releases of X-Plane, as well as the closing of ACES studios, which produced Microsoft Flight Simulator. The two dedicated community sites for X-Plane are X-Pilot and X-Plane.org, where many tips, downloads, and development information for X-Plane can be found.

X-Plane v1

 * - Released in 1994

X-Plane v1 was a Macintosh-only product and was originally designed to simulate the Piper Archer.

X-Plane v2

 * - Released in 1996

This version was released for Microsoft Windows for first time.

X-Plane v3

 * - Released in 1997

This version ceased to require 256-color mode when working under Windows. Also introduced World-Maker and Weather-Briefer

X-Plane v4

 * - Released in 1998

This version introduced textured graphics and ability to use hardware acceleration with the help of the cross-platform graphics library OpenGL. Also in World-Maker you can now make photo-real terrain textures and you can create the Statue of Liberty, Empire State Building, Sears Tower, World Trade Center that was destroyed as part of September 11 attacks, and airport buildings.

X-Plane v5

 * - Released in 1999

This version introduced various things. Version 5.32 added the Airbus aircraft to the X-Plane CD. Version 5.6 introduced the United Airlines Boeing 747-400.

X-Plane v6

 * - Released in 2001

In this version, the aircraft bitmaps were replaced by paints. Version 6.10 fully supported Mac OS X, as well as Mac OS 9, and all current Windows OS but Mac OS 8.6 or earlier were no longer supported.

X-Plane v7

 * - Released in 2003

This version changed to a new game engine and a new .png texture format, as well as changing the icon.

X-Plane v8

 * - Released in 2004

This version can read the .dsf scenery format. Version 8.20 added a new .obj format that supports animation. Version 8.40 was fully compatible with Intel Macs. This is the first X-Plane version that released on DVD.

X-Plane v9

 * - Released in 2007

Version 9 of the X-Plane series is a major update from the previous versions. It includes:
 * Better Memory management.
 * Shader support: Users with high-end computers can see rippled shadows and reflections on water.
 * Installer: the installer automatically downloads and installs updated modules over the Internet.

X-Plane v10
Version 10 of the X-Plane series is set to go on sale around 2011, containing numerous new features and enhancements, including Integration of Open Street Map or improved ATC.

Compatibility
X-Plane is available for Windows, Linux, and the Macintosh. The Macintosh version is a Universal Binary, running on both PowerPC and Intel Macs. There are also cut-down versions for iOS and the Palm Pre.