X-Plane is a flight simulator for personal computers produced by Laminar Research. It runs on iPhone, Linux, Mac or Windows-based PCs. 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.
Blade-element theory attempts to improve on this by individually evaluating the parts that constitute an aircraft. 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.)
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 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.