2015-11-01

For our November “Community Choice” Project of the Month, we selected FlightGear, a multi-platform flight simulator. The FlightGear team shared their thoughts about the project’s history, purpose, and direction.

SourceForge (SF): Tell me about the FlightGear project please.
FlightGear team: FlightGear is an open-source flight simulator. It supports a variety of popular platforms (Windows, Mac, Linux, etc.) and is developed by skilled volunteers from around the world. Source code for the entire project is available and licensed under the GNU General Public License. The goal of the FlightGear project is to create a sophisticated and open flight simulator framework for use in research or academic environments, pilot training, as an industry engineering tool, for DIY-ers to pursue their favorite interesting flight simulation idea, and last but certainly not least as a fun, realistic, and challenging desktop flight simulator. We are developing a sophisticated, open simulation framework that can be expanded and improved upon by anyone interested in contributing.

SF: What made you start this?
FlightGear team: The FlightGear project started as an idea that was proposed by one member of a strong community of flight simulator enthusiasts assembled around the old rec.aviation.simulators newsgroup. As this community had already developed many additions and infrastructure for the proprietary flight simulators of the day, the idea was to break free of the shackles of the closed source world and the inability to effectuate any real change within the software, and to develop the world’s first open source flight simulator. A team quickly crystallized around this idea and, in the middle of 1996, the FlightGear community and project was born.

SF: Has the original vision been achieved?
FlightGear team: Yes, though there is always further development we want to make. As we’re about to release V3.6, we have a large group of people from all over the world using the simulator and a vibrant community contributing content, such as aircraft an scenery that build on the Open Source nature of the project.

SF: Who can benefit the most from your project?
FlightGear team: Everybody who is interested in flight simulation, including real life pilots, scientific users, or just-for-fun flyers.

SF: What core need does FlightGear fulfill?
FlightGear team: The dream to be able to fly has probably been people’s dream ever since the beginning of history. FlightGear gives the ability to fly almost any aircraft at any time and any place at zero cost, at least virtually.

SF: What’s the best way to get the most out of using FlightGear?
FlightGear team: Start flying with our default aircraft, the Cessna 172 , it’s a great and accurate model of the most popular trainer aircraft in the world. FlightGear gives a great simulated experience while learning the program and how to fly in real life.

SF: What has your project team done to help build and nurture your community?
FlightGear team: The early decision to use XML for almost all the data files has made it easy for non-coders to contribute to the simulator in a wide variety of ways. We’ve also got an active forum, and a monthly newsletter. Some of us also meet in person at FSweekend, the world largest international flight simulator event. We also recently started to have regular video chats.

SF: Have you all found that more frequent releases helps build up your community of users?
FlightGear team: Absolutely, since we have been releasing on a regular schedule our user base has increased significantly. I also have the impression that our code gets more stable because we gather more feedback.

SF: What was the first big thing that happened for your project?
FlightGear team: We prefer not to think in terms of first or biggest but one great experience was being contacted by a commercial flight-simulator company (ATC Flight Sim). One phone call evolved into a long-term relationship that culminated in a FlightGear-based flight simulator with FAA Level 3 FTD Certification.

SF: What helped make that happen?
FlightGear team: An FAA certified flight simulator needs to be complete; however, to get to that point, many people contributed a whole lot of effort on a lot of different fronts.

SF: What was the net result for that event?
FlightGear team: Much of the work required to get over the finish line for FAA certification fed back into the Open Source core of FlightGear, so there was a net benefit for everyone involved.

SF: What is the next big thing for FlightGear?
FlightGear team: A new user interface – our existing plib-based interface is showing its age. In the last year we introduced a web-based interface and we are currently adding a Qt based UI. We’re also planning to use HLA/RTI, which will allow FlightGear to integrate with distributed simulation environments (important for industrial applications) and make better use of multi-core processors.

SF: How long do you think that will take?
FlightGear team: Probably years.

SF: Do you have the resources you need to make that happen?
FlightGear team: In many ways our project is fortunate in that the only resource required is coding time; it’s easy for coders to find an area to make major changes without needing too much coordination. However, more coders are always needed! Many of the core coders have been working on the project for 10+ years, during which time we’ve grown up, got married and had kids and don’t quite have the time to spend a week of holiday on a code-fest as they once did. However, there is a steady influx of new developers who add a fresh perspective and outside experience to the group.

SF: If you had it to do over again, what would you do differently for FlightGear?
FlightGear team: Defining a multi-threaded client-server architecture from the beginning would make a big difference today but, of course, that wasn’t a priority back then.

SF: Why?
FlightGear team: Currently we don’t take good advantage of multi-core CPUs.

SF: Any reason you can’t do that now?
FlightGear team: We can and will, switching to HLA/RIT will give us that, but it’s going to be a long and tricky process.

SF: Is there anything else we should know?
FlightGear team: The FlightGear project is very grateful for all the services and support SourceForge has provided to us (and all the other Open Source projects) over the years.

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