Professional and educational FlightGear users
FlightGear is used by dozens of organisations, companies and universities all over the world.
- Aeronautical Development Agency, Bangalore India. FlightGear is used as as the image generator for a flight simulation facility for piloted evaluation of ski-jump launch and arrested recovery of a fighter aircraft from an aircraft carrier.
- Veridian Engineering Division, Buffalo, NY. FlightGear is used for the scenery and out-the-window view for the Genesis 3000 flight simulator.
- MathWorks provides the Aerospace Blockset libraries for interfacing FlightGear to their Simulink software.
- NASA/Ames Human Centered System Lab - 737NG full scale cockpit simulator developed by LFS Technologies. FlightGear provides visuals for four large screen wrap around displays, improved turbo-fan math models, detailed fuel system models, and extendable network interface to cockpit displays and electronics. 
- FlightGear was used by Pragolet s.r.o. in a motion platform based flight simulator of light and ultra-light sports aircraft. 
- ATC Flight Simulator Company builds FAA approved flight simulators, that use FlightGear for the visuals.
- ActiveFly has a worldwide unique paragliding simulator. FlightGear is used to provide the visuals. "In order to make practicing with the ActiveFly Simulator as realistic as possible, the harness as well as the risers and brakes are suspended below a frame in such a way that they can be operated"
- Video (YouTube)
Todd Moyer of Aeronautical Radio, Incorporated (ARINC) used FlightGear as part of an effort to test and evaluate Flight Management Computer avionics and the corresponding ground systems. Certain capabilities of the Flight Management Computer are only available when airborne, which is determined by the FMC according to data it receives from GPS and INS sensors.
They wrote additional software that translates the NMEA output of FlightGear (including latitude, longitude, and altitude) into the ARINC 429 data words used by GPS and INS sensors. These data words are fed to the Flight Management Computer. the position information from FlightGear is realistic enough to convince the FMC that it is actually airborne, and allows ARINC to test entire `flights' with the avionics.
RWTH Aachen research simulator
The Institute of Aerospace Engineering at the RWTH Aachen is using FlightGear to drive the cockpit and the visuals of a general aviation simulator for training and research purpose. Micro Air Vehicles are being implemented by MATLAB/Simulink flight dynamics models; all I/O-related tasks, be they required by FDM, controls or instruments, are connected over network, using FlightGear native interfaces. 
- The University of Naples, Italy used Flightgaer in a six degrees of freedom (6dof) motion simulator, serving as a research and training tool.
- University of Illinois at Urbana Champaign. FlightGear is providing a platform for icing research for the Smart Icing Systems Project. 
- Simon Fraser University, British Columbia Canada. Portions of FlightGear were used in simulation to develop the needed control algorithms for an autonomous aerial vehicle.
- Iowa State University. A senior project intended to retrofit some older sim hardware with FlightGear based software.
- University of Minnesota - Human Factors Research Lab. FlightGear brings new life to an old Agwagon single seat, single engine simulator.
- The Intelligent Robotics Group at the University of Wales, Aberystwyth, UK is using FlightGear as part of their aerobot research to design aerial vehicles that can operate in the atmosphere of other planets.
- The Delft University of Technology, the Netherlands used FlightGear for their ICE project. Their goals was to design, test, and evaluate computational techniques that can be used in the development of intelligent situation-aware crew assistance systems. Using methods from artificial intelligence, ICE focused primarily on the data fusion, data processing and reasoning part of these systems. 
- FlightGear is being used as the basic framework to provide the UTC Challenger Center (and hopefully other centers in the future) a low cost virtual reality computer simulation in the University of Tennessee at Chattanooga. Our simulation is using flightgear and JSBSim, specifically the shuttle module, to develop a shuttle landing simulator. Currently, we are trying to get to the point of at least contributing instructions on how to interface our virtual reality hardware with Flightgear back to the OS community.
- Department of Aerospace Engineering at The Pennsylvania State University used FlightGear primarly for its graphics engine, in advanced research programs in the areas of flight control design, advanced rotorcraft flight dynamics modeling, and near real-time acoustics simulation.
- A team of Northeastern University (Boston, USA) engineering students has developed a system that allows a pilot to fly a simulated airplane in FlightGear, using nothing more than his or her brainwaves.
- The Aeronautical Engineering University of Argentina uses FlightGear to display the outside view of their simulator. Pictures can be seen at http://gsdv.com.ar/fotos/20110528/index.html.
- Arizona State University (USA) used a combination of engineering programmas (among which FlightGear) in its aerospace engineering program. The faculty shifted how they were teaching to put less focus on theory and more emphasis on simulation and visualization through the immediate use of engineering software. Students used those programms within MATLAB.
- The Malaysian Universiti Teknologi Malaysia uses FlightGear for several projects.
- French Aerospace Lab (ONERA) and University of Toulouse, France (2004). A thesis student Frédéric Dehais has used FlightGear and developed a cognitive counter-measures experimental environment (p.119 and following) to show the pilot/ATC scheme could be formalized and enhanced to avoid cognitive perturbation. Use of Atlas and Onera Messenger. Over 22 real-life pilots have been testing this environment. More at 
Home built applications
- Team Viper is building a 360 degrees roll and pitch simulator, that runs on FlightGear.
- John Wojnaroski's 747 cockpit is a long time project.