[Flightgear-devel] OFFLINE: YASim flaps flap
WY OFFLINE Induced drag is a function of the vortices surrounding the wing. Those vortices vary in strength with lift, not angle of attack. Since you There is nothing non-intuitive about it. Don't think in terms of angle of attack. Priceless. :-) Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] YASim flaps flap
Tony Peden wrote: Induced drag is a function of the vortices surrounding the wing. Those vortices vary in strength with lift, not angle of attack. Not so. The induced drag of an aircraft in high-speed cruise is much lower than an aircraft in level flight at stall speed. The lift in Anderson defines induced drag as the drag created by the presence of downwash - which arguably is very much related to wingtip vortices. You can *visualize* the physical generation of induced drag by picturing the lift vector tilting backwards - again, according to Anderson. Probably both of you are right in a sense. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft
Stoenworks aviation is in St. Louis Park. That's where I used to lie. Jon Not that it matters, but I meant that's where I used to *live* . Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft
No mention of Beech anywhere. Beech is now a division of Raytheon. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Inconsitent naming in src/FDM/JSBSim
Compilation stops with: JSBSim.cpp file not found. File is JSBSim.cxx Rainer No, there is a file called JSBSim.cxx that is used by FlightGear. The file JSBSim.cpp is used only to test JSBSim in a standalone mode. This file has recently been removed from the FlightGear tree. Try updating your FlightGear code: cvs update -dP If this does not work, write back right away. Could be Curt needs to do something more in CVS. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Bye bye, yellow and blue glider
Note the second: the windows are not transparent, yet, because there's nothing to see inside. The blue is just a placeholder. Can you add a texture that looks like brown kraft paper that's marked Remove before flight? ;-) Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Bye bye, yellow and blue glider
Note the second: the windows are not transparent, yet, because there's nothing to see inside. The blue is just a placeholder. Looks like a great start. Thanks! Screen shots? How can you guys tell how it looks? Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Wind confusion.
BTW, it's good to see that people have started experimenting with various combinations of wind and FDM's. There are interesting differences in ground handling between various models. Speaking of ground handling, all aircraft have the tendency to slowly float sideways, even with zero wind, brakes applied and engine(s) stopped. What's up with that? Ground handling - and *very* especially handling in a *stopped* condition - is an acknowledged bitch to model by everyone who endeavors to model it. NASA, X- Plane author Austin **??** (can't recall his last noame at present), myself, etc. We have ground handling pretty much figured out, but the quirks of modeling a vehicle at rest are still being worked out. For us particularly (JSBSim developers) there have been other issues to tackle for this current FlightGear release - both technical and home life. This has given me, at least, some time to think about it and I am going to try something I've had on my mind for a few weeks as a potential solution. But it will still be a short while until I can try it out. We acknowledge, though, that it does not work perfectly now and that this is an important problem to solve. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Crash when KMYF not KSFO
Question: Who's responsibility is it (or should it be) to set the runway elevation inside of FGInterface? JSBSIm does fine on its own by using a runway elevation (or scenery elevation, or whatever) of zero - assuming sea level operations only, for now. JSBSim defaults to sea level in standalone mode. We have to default somewhere. If FlightGear wants us to follow them to somewhere and fly from there, how else can we get the runway/scenery elevation except from FlightGear?? It's a two-way street; FlightGear has to tell us about the world it is simulating (the scene it is showing and where in the world it is). We can do the rest. Maybe I am unclear on what you are saying that FlightGear does and doesn't do. Am I missing the point (I haven't had my morning coffee, yet, so maybe I am)? Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] JSBsim C310 crashes the sim on gear retrac
BERNDT, JON S. (JON) (JSC-EX) (LM) writes: Where in the code is the gear position (i.e. relative to retracted or extended) calculated and managed? Curt. The gear forces and moments are calculated in individual instances of FGLGear. The ground reactions as a whole are managed in FGGroundReactions. What code determines whether the gear is retracted or extended or in some intermediate state? It's in FGLGear that the determination is made as to whether the gear is up or down. For aero purposes, there is an intermediate state that is determined by an instance of FGKinemat - an FCS class. Look at the c310 config file. It instantiates an instance of FGKinemat fot he gear. That isntance takes the gear position lever as input (I believe) and calculates gear in-transit position). There should be a belly contact point defined in case the gear is up and ground contact occurs. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Another documentation correction
Alex Perry wrote: Think of it this way: a YASim aircraft will be as close to the real airplane as the real one is to any other aircraft of the same general class. That's good enough for me. And in a lot of situations (military aircraft in particular), this is as good as we're going to get anyway. There isn't any public performance data for these beasts. How about this ? JSB will be exact for every situation that is known and flight tested, but may have odd and/or unrealistic behavior outside normal flight. (Shhht, don't let Jon hear this!) Ha! Actually, when we get around to it, we do want to be plausible off-nominal, too. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] 0.7.9pre2
The only thing preventing FlightGear from compiling on FreeBSD is the missing gcvt function. Jon and I discussed it some yesterday and I sent him a fix that places the definition in FGJSBBase.h. Hopefully that has made it to him. I know it may be too late now to get it into 0.7.9 though. Mike: Can you send me the fix one more time, please? ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] 0.7.9pre2
On Wed, 2002-02-13 at 09:05, [EMAIL PROTECTED] wrote: The only thing preventing FlightGear from compiling on FreeBSD is the missing gcvt function. Jon and I discussed it some yesterday and I sent him a fix that places the definition in FGJSBBase.h. Hopefully that has made it to him. I know it may be too late now to get it into 0.7.9 though. Mike: Can you send me the fix one more time, please? Sure. I've re-sent the patch. So hopefully this time it'll get to you. Where is it? Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
re: [Flightgear-devel] [BUG] JSBSim: sudden plane crashes
Melchior FRANZ writes: This can reliably be reproduced as follows: Start the c310 (fgfs --aircraft=c310) and climb at, let's say, 1000 ft, then abruptly push the stick forward (pitch down; Elevator Cmd = 1). JSBout310.csv shows extreme and extremely alternating values for forces and acceleration. I believe that these are lingering problems with the propeller models. Is this still present with the newer JSBSim code/files? Strange. It's hard to picture why, when everything has been at equilibrium for a while, why the propeller should suddenly spin out of control. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] X-15 rumble sound
I'd really like to have a good XLR-99 rumble sound. Right now I don't recall there being any audio indication that the engine is burning. Is there? What is the maximum size (in bytes) that a sound clip should be? For a rocket I think attenuating the volume with throttle setting should be all that is needed. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] OT: Easy on the rudder there, Cowboy
There's politics at work here somewhere. The actual statement by the NTSB was actually fairly straightforward and plausible. But the fact that it was made at a podium in front of a room full of reporters pretty much guaranteed that the pilot error angle would be played up. Weird. So they pointed the training problem out. In front of a room full of reporters... I've seen several NTSB press conferences. They usually are in front of the press. I must be missing the point ... ? Are you saying the NTSB is slanting its analysis against Airbus for reason, or that the press is putting a spin on the story? I'll buy the latter. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] OT: Easy on the rudder there, Cowboy
What this doesn't address is why the tail of this particular airliner fell off while it was travelling at a comparatively modest speed. Anything over 250 kts would have been illegal at that altitude and would have been REALLY played up by the media. But the point is valid; the NTSB quizzed a bunch of pilots about Vne issues and discovered that most of them were clueless about the subject. Did they quiz the pilots about Vne? I thought I had read that the pilots they interviewed were incorrect in their assumptions about rudder limiting features, and that there did exist an opportunity to enter combinations of rudder movements (specifically a series of opposite rudder commands) that could cause structural failure in the rudder - even well below Vne. I read that the pilots were unaware of this. Probably so were the designers. One would think that, unlike a Bonanza, a modern commercial transport would limit the ability of the pilots to damage their own aircraft via structural filters and limiters. Airbus has had its share of problems with smart FCS, though. I still remember the video of that Airbus (A-300?) inaugural flight that plowed a section of forest when trying to takeoff after a low-speed pass over the runway, when the FCS insisted that the aircraft was landing and could not command the engines to takeoff thrust. Wasn't there also an angle to this story where a failed composite structure of the rudder was involved in a previous incident on the same aircraft, or that the failed part was actually an illegally repaired and used part? Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Building SimGear/FlightGear fails
Have you upgraded any cygwin packages recently? Curt. It used to be that when running aclocal in CygWin one had to do it like this: aclocal -I . I just updated to the very latest CygWin in all things. SimGear, at least, built easily using aclocal with NO arguments, i.e.: aclocal The whole build procedure I used is in a perl script (available in JSBSim CSV, called createfgfs.pl). The procedure is: aclocal automake -a autoconf 'CFLAGS= CXXFLAGS= ./configure --with-logging make install This works for me when building SimGear. Curiously, aclocal -I . was in the build procedure for plib, and that worked. I am going to try building FlightGear, now. The important point about all of this is that it could be that now FlightGear can be built with a stock CygWin - no reversion may now be necessary for various auto* tools. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] Nits
1) The runways at KEDW appear to have no texture - they are pure white. 2) The date at bottom left on the screen flickers between todays date and the 15th of February. Weird. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] SITREP
Jon S. Berndt writes: What a good looking baby boy! Congratulations. I hope everyone is doing well. We're two weeks from twin boys being born, ourselves. I still don't have two good boys names in hand ... How about Spit and Spat or maybe that should be FGSpit and FGSpat? wow with all these suggestions I ought to find a viable name in no time. :-) Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
re: [Flightgear-devel] Manifold pressure
The engine model is probably just sending out a scaled version of the throttle position -- we're still working on powerplant output variables. It shouldn't be too hard to make MP dependent on throttle position AND whether it is operating or not - plus with some small lag in there. Would that be better than what is there, now? Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Uninitialized variables
Flightgear bombs when JSB outputs data in CSV format with MSVC 6 (latest change to c172.xml r1.38). It appears that the coefficient kCLge 'Change_in_lift_due_to_ground_effect' has a value derived from FGPosition::hoverbmac which is unitialized. Fixed. Will be committed later this evening. hoverbmac and hoverbcg init'ed to 0.0 in the constructor. Tony, if this should be done differently go ahead and change it. Otherwise I'll commit it with other changes I am making, later this evening. but I think that every member variables should have a default value set in class constructor Very good point. I think we need to go back over our code and do a sanity check to see if we missed anything. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] B2 Cockpit VR view.
I guess it is all in the eye of the beholder. I see significant difference in the function and symbology of the different displays and less in the physical layout. Agreed. I was really pointing out the physical similarity in the layout and arrangement of the panel faces. The specific instruments and controls will be different, of course. For example, the manual Solid Rocket Booster sep switch is hardly noticable in the B2. ;-) In both cases there appears to be few places to hang fuzzy dice. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] B2 Cockpit VR view.
Fun link: http://www.airspacemag.com/asm/web/site/QTVR/b2.html Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Compiler Compliance and Coding Conventions (was:
I'm sorry, but you misunderstood the extremly big advantage of being multiplatform. Every compiler allows you to get away with some stuff and breaks with some other stuff. Using mutliple different compilers gives you code that doesn't brake anywhere. By using MSVC I found lots of bugs. Some of them were highly likely to brake the code for other compilers after a short while. This is especially the case for uninitalized variables. FGFS has lot's of place where you've got code like float foo[4]; and later code that uses foo w/o initalizing it first. This runs fine on That's a good p oint, as much as I hate to admit it. That brings up a point, Christian, could you try compiling the latest JSBSim and let me know what you find? Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Starting up flightgear.
soon. (I'm thinking specifically of the startup-onground sinking into the ground and spinning slowly bug in JSBSim Done, tested, and committed (at the default airport). Note that now the wind will push you around on the runway, but it can't be any worse that rocking like a boat when you are sitting still! Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] RFC: Keybinding Changes for Powerplant
Yes, yes, my comment was not intended as a slam. No offense taken, and I didn't see it as a slam. I just wanted to communicate that we have thought of many of those things. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] Re: JSBSim BUG?
Hi Jon,
It looks like the compiler has got something here:
../FGEngine.h, line 186: warning(1171): expression has no effect
void SetEngineNumber(int nn) {EngineNumber == nn;}
Yes, I have just noticed that but cannot figure out what the hell that's all
about. Am I missing something obvious?
[posted to the fgfs developer list]
Jon
___
Flightgear-devel mailing list
[EMAIL PROTECTED]
http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] ANN: Cessna 310 twin-prop
- Single-engine flight doesn't cause any yaw (I suspect a JSBSim bug here). What!? no yaw? ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Float -- Double
Probably you could indentify different precition needs and typedef them your own. E.g. jsbsim_float jasbsim_double and jsbsim_log_double. Then you only need to change one file (and there only 3 lines) to figure out what precition you want or need. for file in *.cpp, *.h, filtersjb/*.cpp, filtersjb/*.h do sed 's/flost/double/g' $file temp mv temp $file done I think that's about what I did. Easy as PI. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
