Implementing VNAV support in FlightGear: Difference between revisions

{{cquote| I don't think any aircraft AP supports vertical route navigation yet - and the route-manage itself only has partial support for editing waypoint altitude. There's no real obstacle - waypoints store an altitude (and speed), and the AP can read it, but nobody spent time making it work yet. Vertical modes (VNAV) also tend to depend more on fuel/load and engine performance data from the FMS, which is an area that's been lacking in FlightGear,  

{{cquote|I've seen the use of simple simulation within a simulation, where performance data is being calculated. It was not within JSBSim, however.

This is an interesting prospect. Nobody has ever done this, up to now. My initial reaction was pessimistic. However, the flight control components

within JSBSim are fairly capable, and you are permitted to define arbitrary functions. So, my guess at this time is, yes, you should be able to set up

JSBSim to calculate *some* performance data. It may be a lot of work, but it should be possible. <ref>{{cite web |url=http://sourceforge.net/p/jsbsim/feature-requests/29/?limit=10&page=1#8ce6 |title=JSBSim Issue#29: performance database/prediction   

{{cquote|Without being very familiar with the FG source code, the usual way to do this is to call the FDM. Isn't that sort of thing exactly what JSBSim is for? The distinction between a flight planner and a flight simulator is the bounds on the integrations. A simulator will integrate over a frame; a flight planner much longer.<ref>{{cite web |url=http://forum.flightgear.org/posting.php?mode=quote&f=6&p=51952