Most of us have been looking years for a real successor to FSX/FS9. I never found one that looked as promising as Outerra; X-plane seemed to fill the void, but Austin Meyer's latest Xplane 10 disappoints for reasons Karamich mentioned earlier. Demand is for a more immersive, convincing world, on a global scale.
I agree with NAX: it all comes down to the essential
physics of flight and
variables for aircraft system modelling, environment/weather, communication/navigation, that are relevant for flightsimming:
- SDK for multiplayer development (to give room for "FSInn"-like modules)
- impact of weather on flight dynamics: wind/turbulence, temperature (icing, hot-and-high), pressure.
- visualisation of weather: realistic, gradual visibility transition (fog), variety in precipitation (intensity, rain/hail/snow), 3D clouds, cloud layering.
The team behind Active Sky 2012 might be of help here. They know exactly what the limitations are of FSX regarding weather. AS2012 sets the benchmark with its weather engine for FSX. The Active Sky series has evolved into the definite weather engine for FSX and now also incorporates superb textures. Real Environment eXtreme, aka REX, is famous for its weather and environment textures but REX's weather engine lags behind AS2012 - realistic flight dynamics model: you already got a decent one with JSBSim and as mentioned already by others, there are more decent models around. Quality world immersion, on a global scale, to go with one of these models, is what we are looking for! Outerrra does this better than any before!
- and finally, a good data protocol interface, like FSUIPC for FSX or Python Interface for X-plane, for third party software developers to linkup their software modules with all the internal variables of the Outerra world.
Development of complicated aircraft system modelling you could leave to flightsim legends as A2A (with Accu-Sim) , PMDG, Level-D. I really hope they join the Outerra fanclub and adapt/improve their products. What they need is the variables (flight model related, temps, pressures, weights, fuel, oil, voltages, etc. ) to base their models on. Than they can make their systems as complicated as they like. I myself would approach A2A and ask what variables they would like to see, apart from what FSX provides, to succesfully simulate all systems on an aircraft.
HD scenery development (regions/airports), simulation of ATC communications and AI Traffic should be left to addon developers, as long as they can work from some sort of SDK and an interface like FSUIPC or PythonInterface.
I love and know FSX but am no programmer, so forgive me if some of the above does not make sense.
PS SibWings (Andrej) could lead the way for other developers by showcasing his beautiful O-1 Bird Dog. If he can make it work in Outerra, so could others!