Taking to the skies with FlightGear

An interview with Curtis Olson, one of FlightGear's original founders and current project coordinators.

with Christopher von Eitzen

FlightGear is an open source flight simulator that can run on Windows, Mac OS X, Linux and other operating systems. The project saw its first release in 1997 and has been actively under development ever since, with the most recent release, version 2.6.0, arriving in February of this year.

Where did the project start and where does it expect to be in the future? The H spoke to Curtis Olson to find out.

The H: How long have you been with the project and what's your current position?

Olson – one of the original founders of FlightGear – develops unmanned aerial drones when he's not working on the project

Curtis Olson: I am one of the original founders of the project and initially (for the first few years) was the primary developer. These days I would call myself the project coordinator, because many other great developers have stepped up to the plate in the past few years to bring their unique skills and perspective and help share the bulk of the workload.

The H: How did you get started with FlightGear?

CO: We started FlightGear in 1996 – sort of on a whim – how hard could it be to write a flight simulator? By the time we discovered how young and naive we were, we had quite a few things working so we just kept ploughing forward. :-)

The H: What do you do for a day job when you're not working on the project? What have you done in the past?

CO: Right now I am working with a small technology company headquartered in Alaska called Airborne Technologies. Right now we are primarily focused on developing a small UAS (Unmanned Aerial System, sometimes referred to as a "drone"). I have always had a love of airplanes since my earliest memories and I was fascinated by computers starting with the first one I saw. "Aerial robotics" is a challenging way to combine some of my lifelong interests and force me to learn about and develop areas where I am weaker (like hardware and electronics).

A Grumman A-6 Intruder in FlightGear 2.6
Source: FlightGear When the idea for FlightGear was first hatched in 1996, I was working as a Unix system administrator for GE Medical Systems and dabbling with FS5 in my spare time. After a short stint at GE, I took a position at the University of Minnesota Mechanical Engineering department and participated in a number of projects centred around a large research driving simulator we built. The simulator facility included a real car, 6 projectors forming a 200+ degree wraparound visual system, high-end audio, vibration generators, and a small range of motion base. The facility continues to be used for "human factors" research. During my time at the University of Minnesota I also helped the Aerospace Engineering department with several UAV-related research projects.

The H: What do you think of commercial flight simulators like Microsoft Flight Simulator or Flight, or X-Plane?

CO: I don't spend a lot of time looking at other flight simulators, but when I do see them I am always impressed with the graphical effects and the scenery modelling.

The MPMap utility shows aircraft and runways on a world map
Source: FlightGear

The H: Other than being open source, what in your view sets the FlightGear project apart from them?

CO: FlightGear is open source and I believe this is the key distinction. It is our open-source nature that leads us to all the great things about FlightGear. (Forgive me if I lump all the "other commercial simulators" together and compare FlightGear against them generally – not all the comparisons work for every commercial simulator).

FlightGear is being actively and enthusiastically developed by people all over the planet – we are developing at the core code level, working on new graphics effects, developing new aircraft models and improving our existing ones, and developing and enhancing our scenery and our scenery tools. We don't have to worry about some large company discontinuing the product for business reasons, and we don't have worry about one person getting hit by the proverbial bus.

FlightGear uses open APIs and standard XML files for all of its configuration files. You don't need to compile code to create a custom instrument panel or gauge.

FlightGear includes a powerful scripting engine that has access to all the internal data values of the sim. For the geeks out there, you can model and script all kinds of interesting things without needing to compile any code. For instance, in one project I modelled a precision aircraft carrier auto-land system for our F-14. The auto-land system correctly accounted for carrier motion and wind. I did everything using FlightGear's built in scripting language. Other developers model specific instrument behaviour, build interactive tutorials, create clever and sophisticated 3D animations, and even model entire flight stability and control systems using our script engine.