Hooray wrote: he kept refering me to the FMC perf section. so the aircraft would show me F1, F2 etc speeds on decent.
oh boy that was a mistake.
those are limitations in FG itself (and in its supported FDMs), not specific to the 777 - it is true, that we currently do not have any aircraft with a properly working FMS and performance database support.
The changes you saw, were mostly about the cockpit and avionics, more recently, the PFD and ND.
Overall, the 777 remains one of the most developed aircraft/airliners in FG, especially in comparison to hundreds of other aircraft.
But compared to airliners supported by FSX or X-Plane, we are still lacking in that department and do not provide a complete solution (yet).
And it is also not foreseeable when that will change, because it will require changes in the FDMs we're using or use of some 3rd party/proprietary performance database.
Otherwise, it is not currently feasible to come up with VNAV/LNAV modes that properly work for different aircraft.
The 3rd party approach is being used for TPPs data, but in the case of FDMs, we would need 100% accurate FDMs, too - so it would be better to directly use the FDM for computing a performance DB.
For a more detailed explanation, please see:
viewtopic.php?f=25&t=21104&p=192038&hilit=performance+vnav#p192038viewtopic.php?f=40&t=13777&p=140255&hilit=#p140255Finally, please understand that for over a decade, FlightGear had extremely poor support for any modern avionics (PFD, ND, CDU, FMC/FMS) - in particular in comparison to MSFS/FSX and the plethora of commercial addons - this has recently changed (well since 2.8 ), due to TheTom's Canvas system, which now makes it possible for everybody to easily create modern avionics like a PFD/ND or CDU, without having to be an expert C++ programmer with OpenGL/OSG experience - but supporting VNAV/LNAV still is tricky for other reasons, and currently not on anybody's agenda - it's not just something that can/should be tackled by a single aircraft developer, it requires lower-level changes in FlightGear's architecture and the way FDMs are used.
It really is a long-standing issue and has been discussed hundreds of times (as you'll see when you check out those links), but so far it's not a priority - but please do feel free to file a feature request:
http://code.google.com/p/flightgear-bug ... %20requestYou would need to be really familiar with FDM internals, airliner performance and have strong maths skills to solve this just for a single airliner.
Also, please keep in mind that there's nothing really wrong about FSX (or X-Plane) - and some of the more established commercial addons are of excellent quality, developed by teams with dozens of fulltime programmers who could often consult back with ATPL holders and type-rated pilots, but also freely use all sorts of data and documentation, we do not typically have this sort of expertise and support available here - which is why some things may takes a while to mature unfortunately... If you should have any expertise/documentation to contribute, I suggest to get in touch with Hyde, who will surely appreciate such feedback and resources!