trainee would require, adding in items to enhance the suspension of disbelief. Enclosures, projectors, even real aircraft components or nose sections are commonly incorporated in the drive to make the experience as 'real' as possible. Commercial aviation While general aviation pits are often put together for real pilots to train on, commercial aircraft pits are often purely for entertainment. Very few people who are not professional pilots ever have the opportunity to pilot a real airliner, but a realistic home simulator will provide a highly immersing experience. Commercial airliner pits offer a greater challenge to builders as there are more systems to model such as the autopilot, CDU/FMS, engine management, etc. Even the throttle quadrant is a complex piece of engineering compared to the simply replicated push/pull throttle used in the GA Cessna. However, a number of commercial suppliers exist supplying replica panels, controls, even complete cockpits to the community. Where these or 'real' components are not available or are out of budget builders will often fabricate components at home out of wood or similar easily worked materials. With most modern aircraft using "glass cockpit" displays it has become easier to create highly realistic panels. The displays on these panels can be driven by multi-head graphics cards, or networked PCs running dedicated software that can read from the simulator spreading the processing load. Interfaces for switches, knobs, and other elements needed can be purchased commercially or created by dismantling existing hardware such as keyboards or joysticks. Feedback from the PC to the panel, for example to light warning lamps or move a real instrument is more complex and normally completed through a commercial expansion board. Military aviation The third common genre for a simpit is the military pit. Like commercial pits, these sims are typically designed more for entertainment than training. Military-based pits are commonly based on a single aircraft, often the F-16, due to the availability of highly realistic simulation software (Falcon 4.0) of this aircraft. Software One of the first software requirements for a simpit is a suitable flight simulator to provide the graphics, sound and instrument outputs for the pit. To date, the majority of civilian simpits are built around Microsoft Flight Simulator, and most military pits use Falcon 4.0 as a base, but as of 2013 the Digital Combat Simulator series has spurred interest for the A-10 as well. X-Plane 11 is also a powerful software