I wrote: > > -----Original Message----- > > From: AJ MacLeod [mailto:[email protected]] > > Sent: 29 June 2011 12:51 > > To: FlightGear developers discussions > > Subject: Re: [Flightgear-devel] A couple of random oddities > > > > On Wed, 29 Jun 2011 10:39:55 +0100 > > Vivian Meazza wrote: > > > > > > * English Electric Lightning: I believe the plane should be able to > > reach > > > > Mach 2 around 36.000 ft in level flight - even in a descending > > pattern, I > > > > was never able to reach above Mach 1.7 - is there a problem with the > > FDM? > > > The author is inactive at the moment. Perhaps he can be persuaded to > > give > > > this fine model a bit of a work-over. > > > > The author is a bit too active, which sadly doesn't leave any time for > > Flightgear :-( The instruments I'll try and fix myself, but do any > JSBSim > > experts have any ideas on what might have changed the behaviour of the > FDM > > model? It worked OK "before"... though I have no idea when that > changed. > > > > Cheers, > > > > Good to see that you're busy in RL, but not too busy to ignore FG > completely. I've just pushed Ron's update to the JSBSim config. It needs > quite a bit of up-elevator trim to maintain the cruise at 36000 ft, so > there > might be something else not quite right, but it will do M2.0 at 36000 ft. >
Further research indicates that the F1A, modeled here was NOT capable of M2.0 at 36000ft. M1.9 seem more likely. Moreover, due to structural and stability problems the F1A was operationally limited to M1.7 or approximately 700KIAS. We have pushed a small change in Mach drag to model this better. Ron will look at the Mach stability issue a bit later. Vivian ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2d-c2 _______________________________________________ Flightgear-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/flightgear-devel
