Re: [Flightgear-devel] Aircraft included in base package
On Thursday 20 Jan 2005 20:10, David Megginson wrote: > On Thu, 20 Jan 2005 20:06:13 +, Dave Martin > > <[EMAIL PROTECTED]> wrote: > > Is there any way to get a compensated 'TAS' output to drive the ASI > > because I *think* the B1900D's ASI is compensated (but I must check) > > I'd be pretty incredibly surprised to see an ASI doing that. Some > ASIs do have a circular sliderule (or similar) around the edge to > calculate true airspeed, but all ASIs necessarily show indicated > airspeed because that's what has the most aerodynamic significance for > the plane (i.e. it's going to rotate, climb, approach, stall, etc. at > the same indicated airspeeds at 10,000 ft density altitude and at sea > level, even though the true airspeeds are significantly different). > > What is the density altitude is the TAS for the Beech 1900 specified > at? 25,000 ft? If so, then divide by about 1.5 to find out what > number you should see on the ASI. > > > All the best, > > > David I couldn't find any further info on the ASI being compensated and you're undoubtedly right so I will go with that. Thanks :-) Dave Martin ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thursday 20 January 2005 19:47, Jim Wilson wrote: > David Luff said: > > On 20/01/2005 at 10:55 Jon Berndt wrote: > > >> Ok wrong word. Let me just say that it seems to lack > > >> some magic. > > > > > >Setting up > > > > > >> the p51d in Yasim was not my original intention as Jon S. > > >> Berdnt was > > > > > >claiming > > > > > >> at the time I started the 3D that he had a nearly working > > >> JSBSim model. > > > > > > ... which I did. I thought. The more I looked at the > > > numbers for aero qualities that I > > >was getting from DATCOM, the more I realized something was > > > amiss. Also, at the time I > > >believe our engine capabilities were not what I thought > > > they were. Now we have a > > >turbocharged piston engine model. > > > > You should consider the turbocharging to be an alpha model > > though - we haven't applied it in anger yet. When you start > > on a P51 or Spitfire (or any other model) give me a heads up > > and I'll test/refine/debug the turbo/supercharging stuff in > > tandem with what you're doing. > > We'd be a lot further or at least I'd have accomplished more > along the lines of 3D modeling and enhancing > animation/rendering code if I hadn't spent so much time > working on something I know hardly anything about (flight > modeling). This isn't to take away at all from the great work > that folks have done with the FDM code. > > Is there any chance someone out there is interested in > focusing on improving the flight model definitions for the 3D > art that we already have? > > Best, > > Jim Heh! - I'd guess I'm already spending about 70-80% of my FG time on flight behaviour stuff and about 20-30% on modelling & texturing. It's a varying figure because sometimes I'll combine a flight test with looking at large scale geological features:) All my fdms are in a state of flux and are constantly being worked on but I wouldn't have any problem with other people working on them too. However, if someone were to change a value, that I knew to be correct, to a value that was incorrect, say the wing incidence for example, then I think the fdms would have to fork. I can't see how using an incorrect value for something can produce something that's accurate and instead I would put more effort into finding what's wrong in the guesswork stuff. The idea of forking fdms wouldn't bother me at all though - in fact I would welcome it and I think it would be interesting to compare different fdms for the same a/c. LeeE ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thu, 20 Jan 2005 20:06:13 +, Dave Martin <[EMAIL PROTECTED]> wrote: > Is there any way to get a compensated 'TAS' output to drive the ASI because I > *think* the B1900D's ASI is compensated (but I must check) I'd be pretty incredibly surprised to see an ASI doing that. Some ASIs do have a circular sliderule (or similar) around the edge to calculate true airspeed, but all ASIs necessarily show indicated airspeed because that's what has the most aerodynamic significance for the plane (i.e. it's going to rotate, climb, approach, stall, etc. at the same indicated airspeeds at 10,000 ft density altitude and at sea level, even though the true airspeeds are significantly different). What is the density altitude is the TAS for the Beech 1900 specified at? 25,000 ft? If so, then divide by about 1.5 to find out what number you should see on the ASI. All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thursday 20 Jan 2005 19:47, Jim Wilson wrote: > We'd be a lot further or at least I'd have accomplished more along the > lines of 3D modeling and enhancing animation/rendering code if I hadn't > spent so much time working on something I know hardly anything about > (flight modeling). This isn't to take away at all from the great work that > folks have done with the FDM code. > > Is there any chance someone out there is interested in focusing on > improving the flight model definitions for the 3D art that we already have? > > Best, > > Jim If you mean working with the figures in the definition files then yes, I'm having a fiddle here and there (mainly B1900D at the mo to get it flyable). Dave Martin. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thursday 20 Jan 2005 19:45, Curtis L. Olson wrote: > Dave Martin wrote: > >Aha! My mistake - it appears that the ASI in the b1900d is not pressure > >compensated. According to the GPS, the aircraft is achieving its expected > > GS of 270kts. > > > >Am I understanding that correctly? > > Yes, you have to input true airspeed into the cruise section, not > indicated airspeed. At high altitudes there is a significant > difference. :-) > > Curt. Is there any way to get a compensated 'TAS' output to drive the ASI because I *think* the B1900D's ASI is compensated (but I must check) Cheers Dave Martin. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thursday, 20 January 2005 03:57, David Megginson wrote: > You know, after reading some of the other comments, I'm starting to > like the idea of having just the c172p in the base package. You should try helping clueless windows users to install scenery files in the IRC channel sometime. A lot of them need help to extract, copy and paste. I'd say yes if FG had an automated way of installing aircraft but till then I don't like the idea too much. It's just an extra step that can potentially cause more hassles and confusion. Paul ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Aircraft included in base package
David Luff said: > > On 20/01/2005 at 10:55 Jon Berndt wrote: > > >> Ok wrong word. Let me just say that it seems to lack some magic. > >Setting up > >> the p51d in Yasim was not my original intention as Jon S. Berdnt was > >claiming > >> at the time I started the 3D that he had a nearly working JSBSim model. > > > > ... which I did. I thought. The more I looked at the numbers for aero > >qualities that I > >was getting from DATCOM, the more I realized something was amiss. Also, at > >the time I > >believe our engine capabilities were not what I thought they were. Now we > >have a > >turbocharged piston engine model. > > You should consider the turbocharging to be an alpha model though - we > haven't applied it in anger yet. When you start on a P51 or Spitfire (or > any other model) give me a heads up and I'll test/refine/debug the > turbo/supercharging stuff in tandem with what you're doing. > We'd be a lot further or at least I'd have accomplished more along the lines of 3D modeling and enhancing animation/rendering code if I hadn't spent so much time working on something I know hardly anything about (flight modeling). This isn't to take away at all from the great work that folks have done with the FDM code. Is there any chance someone out there is interested in focusing on improving the flight model definitions for the 3D art that we already have? Best, Jim ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
Dave Martin wrote: Aha! My mistake - it appears that the ASI in the b1900d is not pressure compensated. According to the GPS, the aircraft is achieving its expected GS of 270kts. Am I understanding that correctly? Yes, you have to input true airspeed into the cruise section, not indicated airspeed. At high altitudes there is a significant difference. :-) Curt. -- Curtis Olsonhttp://www.flightgear.org/~curt HumanFIRST Program http://www.humanfirst.umn.edu/ FlightGear Project http://www.flightgear.org Unique text:2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thursday 20 January 2005 16:45, Jim Wilson wrote: > Dave Martin said: > > On Thursday 20 Jan 2005 16:13, Jim Wilson wrote: > > > Dave Martin said: > > > > On Thursday 20 Jan 2005 14:42, Jim Wilson wrote: > > > > getting an aircraft working > > > > > > > > > is about 2 parts theory and 1 part voodoo (the part > > > > > that the basic formulas don't cover). > > > > > > > > "Any sufficiently advanced technology is > > > > indistinguishable from magic" - Sir Arthur C Clarke. > > > > > > Ok wrong word. Let me just say that it seems to lack some > > > magic. Setting up the p51d in Yasim was not my original > > > intention as Jon S. Berdnt was claiming at the time I > > > started the 3D that he had a nearly working JSBSim model. > > > Doing the yasim model was a juggling act that started with > > > geometric specifications, a couple software patch > > > submissions, and then an endless number of tweaks. The > > > "tweaks" were really comprimises that ended up producing > > > something that was sort of close to performance > > > specifications, but not really accurate in any respect. > > > > > > Best, > > > > > > Jim > > > > Thats litterally what I've just been doing with the B1900D > > FDM. > > > > The numbers in the FDM file don't all match up to the > > numbers in the POH but the FDM does now match with the > > *performance* figures in the POH - Which I hope is the right > > thing to aim for. > > The biggest tradeoffs seemed to be in trying to balance high > end performance, (e.g. altitude, speed) against having enough > drag to get reasonable behavior at lower power settings. It > seems pretty common for yasim models to glide too much > (excessive lift/insufficient drag) when cutting the power. > > Best, > > Jim I've hit that lift/drag issue on just about all the a/c I've done. The degree varies but I mostly put it down to me not being any sort of aerodynamicist. Sometimes I wish for a more dynamic standalone solver so I could tweak the settings and see the results straight away. The gui would be massive though, and I'm not sure how the results could be visualised - a bunch of converging curves perhaps... LeeE ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thursday 20 Jan 2005 18:01, Dave Martin wrote: > On Thursday 20 Jan 2005 17:37, Jim Wilson wrote: > > Yes, I'm aware of the theory behind fixing these issues, but from the > > beginning I was compensating for them and getting reasonable thrust > > numbers (I think you are thinking of Vivian with the spitfire). On the > > last round Andy made some code changes, but I got stuck with solver > > issues when trying to crank up a little more power. Also I did not > > mention that there are some subtle problems that affect handling the > > aircraft during takeoffs that come into play when you start "tweaking". > > I vaguely remember a further problem with Yasim in connection with engine > > power, but it'll require getting my head back into it before I know for > > sure. > > > > Best, > > > > Jim > > I'm dealing with such problems in getting the b1900d to perform in the > cruise. > > Unfortunately, while it handles well in the circuit, the cruise speed is > stuck at 200kts @ 20,000ft (70 below POH) :-/ > > Dave Martin > Aha! My mistake - it appears that the ASI in the b1900d is not pressure compensated. According to the GPS, the aircraft is achieving its expected GS of 270kts. Am I understanding that correctly? Thanks Dave Martin ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thursday 20 Jan 2005 17:37, Jim Wilson wrote: > Yes, I'm aware of the theory behind fixing these issues, but from the > beginning I was compensating for them and getting reasonable thrust numbers > (I think you are thinking of Vivian with the spitfire). On the last round > Andy made some code changes, but I got stuck with solver issues when trying > to crank up a little more power. Also I did not mention that there are > some subtle problems that affect handling the aircraft during takeoffs that > come into play when you start "tweaking". I vaguely remember a further > problem with Yasim in connection with engine power, but it'll require > getting my head back into it before I know for sure. > > Best, > > Jim I'm dealing with such problems in getting the b1900d to perform in the cruise. Unfortunately, while it handles well in the circuit, the cruise speed is stuck at 200kts @ 20,000ft (70 below POH) :-/ Dave Martin ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Aircraft included in base package
On 20/01/2005 at 10:55 Jon Berndt wrote: >> Ok wrong word. Let me just say that it seems to lack some magic. >Setting up >> the p51d in Yasim was not my original intention as Jon S. Berdnt was >claiming >> at the time I started the 3D that he had a nearly working JSBSim model. > > ... which I did. I thought. The more I looked at the numbers for aero >qualities that I >was getting from DATCOM, the more I realized something was amiss. Also, at >the time I >believe our engine capabilities were not what I thought they were. Now we >have a >turbocharged piston engine model. You should consider the turbocharging to be an alpha model though - we haven't applied it in anger yet. When you start on a P51 or Spitfire (or any other model) give me a heads up and I'll test/refine/debug the turbo/supercharging stuff in tandem with what you're doing. Cheers - Dave This message has been checked for viruses but the contents of an attachment may still contain software viruses, which could damage your computer system: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
"Curtis L. Olson" said: > > > >The biggest tradeoffs seemed to be in trying to balance high end performance, > >(e.g. altitude, speed) against having enough drag to get reasonable behavior > >at lower power settings. It seems pretty common for yasim models to glide > >too > >much (excessive lift/insufficient drag) when cutting the power. > > > > > > Jim, > > I think this is more a factor of getting the right actual power output > from the engine. If the engine output is too low, you are going to get > up with a "slick" model that glides forever. If the engine output is > too high you are going to end up with a "draggy" model that slows down > too quickly. I remember you struggling with trying to model the complex > p51 engine gearing correctly in yasim and maybe that never came out > right and you ended up with a severely under powered model. > > If that is the case, yasim will reduce drag and make your wing lift > better so that you can still hit the performance numbers. > > For the Citation-II I felt like Yasim did a pretty good job. I haven't > really hit the validation end of it hard, but I was getting plausible > performance throughout the envelope. > > I think the big trick is to get the engine power output in the right > ball park, then everything else starts falling into place much better. > Yes, I'm aware of the theory behind fixing these issues, but from the beginning I was compensating for them and getting reasonable thrust numbers (I think you are thinking of Vivian with the spitfire). On the last round Andy made some code changes, but I got stuck with solver issues when trying to crank up a little more power. Also I did not mention that there are some subtle problems that affect handling the aircraft during takeoffs that come into play when you start "tweaking". I vaguely remember a further problem with Yasim in connection with engine power, but it'll require getting my head back into it before I know for sure. Best, Jim ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thu, 20 Jan 2005 14:42:40 -, Jim Wilson <[EMAIL PROTECTED]> wrote: > Probably I've got this wrong, but isn't the c-172 our most refined/realistic > flightmodel? My impression of yasim, from using it for the p51d, but not as > an aero engineer, is that getting an aircraft working is about 2 parts theory > and 1 part voodoo (the part that the basic formulas don't cover). Actually, I'd say that the two are roughly equal in realism: JSBSim can use real, measured flight coefficients when they exist (most of the time we have to make them up right now), but it is stuck at a high level of abstraction because it can apply its calculations only to the aircraft as a whole; YASim cannot use real coefficients, but since it handles each lifting surface separately, it works at a lower level of abstraction can handle various asymmetric situations much more believably (for example, JSBSim can model a stalled plane, but YASim can model a stalled *wing* with the other wing not stalled). After working a lot on and flown a lot with both models, I find the handling of the YASim pa28-161 more realistic than the handling of the c172p, though they're both good. All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
Jim Wilson wrote: Dave Martin said: On Thursday 20 Jan 2005 16:13, Jim Wilson wrote: Dave Martin said: On Thursday 20 Jan 2005 14:42, Jim Wilson wrote: getting an aircraft working is about 2 parts theory and 1 part voodoo (the part that the basic formulas don't cover). "Any sufficiently advanced technology is indistinguishable from magic" - Sir Arthur C Clarke. Ok wrong word. Let me just say that it seems to lack some magic. Setting up the p51d in Yasim was not my original intention as Jon S. Berdnt was claiming at the time I started the 3D that he had a nearly working JSBSim model. Doing the yasim model was a juggling act that started with geometric specifications, a couple software patch submissions, and then an endless number of tweaks. The "tweaks" were really comprimises that ended up producing something that was sort of close to performance specifications, but not really accurate in any respect. Best, Jim Thats litterally what I've just been doing with the B1900D FDM. The numbers in the FDM file don't all match up to the numbers in the POH but the FDM does now match with the *performance* figures in the POH - Which I hope is the right thing to aim for. The biggest tradeoffs seemed to be in trying to balance high end performance, (e.g. altitude, speed) against having enough drag to get reasonable behavior at lower power settings. It seems pretty common for yasim models to glide too much (excessive lift/insufficient drag) when cutting the power. Jim, I think this is more a factor of getting the right actual power output from the engine. If the engine output is too low, you are going to get up with a "slick" model that glides forever. If the engine output is too high you are going to end up with a "draggy" model that slows down too quickly. I remember you struggling with trying to model the complex p51 engine gearing correctly in yasim and maybe that never came out right and you ended up with a severely under powered model. If that is the case, yasim will reduce drag and make your wing lift better so that you can still hit the performance numbers. For the Citation-II I felt like Yasim did a pretty good job. I haven't really hit the validation end of it hard, but I was getting plausible performance throughout the envelope. I think the big trick is to get the engine power output in the right ball park, then everything else starts falling into place much better. Regards, Curt. -- Curtis Olsonhttp://www.flightgear.org/~curt HumanFIRST Program http://www.humanfirst.umn.edu/ FlightGear Project http://www.flightgear.org Unique text:2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Aircraft included in base package
> Ok wrong word. Let me just say that it seems to lack some magic. Setting up > the p51d in Yasim was not my original intention as Jon S. Berdnt was claiming > at the time I started the 3D that he had a nearly working JSBSim model. ... which I did. I thought. The more I looked at the numbers for aero qualities that I was getting from DATCOM, the more I realized something was amiss. Also, at the time I believe our engine capabilities were not what I thought they were. Now we have a turbocharged piston engine model. It's still something I want to return to, but priorities changed - some in response to address the changes needed to build a better P-51D. I apologize for my premature statements - I didn't know at the time that I would run into the hurdles that I encountered late in the process. Jon ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
Dave Martin said: > On Thursday 20 Jan 2005 16:13, Jim Wilson wrote: > > Dave Martin said: > > > On Thursday 20 Jan 2005 14:42, Jim Wilson wrote: > > > getting an aircraft working > > > > > > > is about 2 parts theory and 1 part voodoo (the part that the basic > > > > formulas don't cover). > > > > > > "Any sufficiently advanced technology is indistinguishable from magic" - > > > Sir Arthur C Clarke. > > > > Ok wrong word. Let me just say that it seems to lack some magic. Setting > > up the p51d in Yasim was not my original intention as Jon S. Berdnt was > > claiming at the time I started the 3D that he had a nearly working JSBSim > > model. Doing the yasim model was a juggling act that started with > > geometric specifications, a couple software patch submissions, and then an > > endless number of tweaks. The "tweaks" were really comprimises that ended > > up producing something that was sort of close to performance > > specifications, but not really accurate in any respect. > > > > Best, > > > > Jim > > Thats litterally what I've just been doing with the B1900D FDM. > > The numbers in the FDM file don't all match up to the numbers in the POH but > the FDM does now match with the *performance* figures in the POH - Which I > hope is the right thing to aim for. > The biggest tradeoffs seemed to be in trying to balance high end performance, (e.g. altitude, speed) against having enough drag to get reasonable behavior at lower power settings. It seems pretty common for yasim models to glide too much (excessive lift/insufficient drag) when cutting the power. Best, Jim ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thursday 20 Jan 2005 16:13, Jim Wilson wrote: > Dave Martin said: > > On Thursday 20 Jan 2005 14:42, Jim Wilson wrote: > > getting an aircraft working > > > > > is about 2 parts theory and 1 part voodoo (the part that the basic > > > formulas don't cover). > > > > "Any sufficiently advanced technology is indistinguishable from magic" - > > Sir Arthur C Clarke. > > Ok wrong word. Let me just say that it seems to lack some magic. Setting > up the p51d in Yasim was not my original intention as Jon S. Berdnt was > claiming at the time I started the 3D that he had a nearly working JSBSim > model. Doing the yasim model was a juggling act that started with > geometric specifications, a couple software patch submissions, and then an > endless number of tweaks. The "tweaks" were really comprimises that ended > up producing something that was sort of close to performance > specifications, but not really accurate in any respect. > > Best, > > Jim Thats litterally what I've just been doing with the B1900D FDM. The numbers in the FDM file don't all match up to the numbers in the POH but the FDM does now match with the *performance* figures in the POH - Which I hope is the right thing to aim for. Dave Martin ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
Dave Martin said: > On Thursday 20 Jan 2005 14:42, Jim Wilson wrote: > getting an aircraft working > > is about 2 parts theory and 1 part voodoo (the part that the basic formulas > > don't cover). > > > > "Any sufficiently advanced technology is indistinguishable from magic" - Sir > Arthur C Clarke. > Ok wrong word. Let me just say that it seems to lack some magic. Setting up the p51d in Yasim was not my original intention as Jon S. Berdnt was claiming at the time I started the 3D that he had a nearly working JSBSim model. Doing the yasim model was a juggling act that started with geometric specifications, a couple software patch submissions, and then an endless number of tweaks. The "tweaks" were really comprimises that ended up producing something that was sort of close to performance specifications, but not really accurate in any respect. Best, Jim ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thursday 20 Jan 2005 14:42, Jim Wilson wrote: getting an aircraft working > is about 2 parts theory and 1 part voodoo (the part that the basic formulas > don't cover). > > Best, > > Jim "Any sufficiently advanced technology is indistinguishable from magic" - Sir Arthur C Clarke. Dave Martin ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
David Megginson said: > On Wed, 19 Jan 2005 21:38:49 -0600, Curtis L. Olson > <[EMAIL PROTECTED]> wrote: > > > I would tend to agree with you with one exception. The default C-172 is > > very functional, but it is not our best model. A nice thing about > > including multiple aircraft is you can see some different nice things > > that can be done with FG aircraft. I think before we go with only 1 > > aircraft in the base package, we should really spiff up the C-172 > > externals and internals. Suspention animation, shadows, lights, and a > > much better 3d cockpit. If we go with only one aircraft, it should be > > really nice all around, and show off what we can do in FG. > > That sounds reasonable. For my own part, I'll see if I have time to > do more work on the Cherokee/Warrior, which would be a reasonable > alternative starter plane (as would any other trainer, such as the > Cessna 150/152, Beech Musketeer, or even Diamond Katana, if anyone is > interested in building one of those). The J3 Cub is probably the most > famous trainer in history, but the tailwheel ground handling is too > hard for most new users to manage. > Probably I've got this wrong, but isn't the c-172 our most refined/realistic flightmodel? My impression of yasim, from using it for the p51d, but not as an aero engineer, is that getting an aircraft working is about 2 parts theory and 1 part voodoo (the part that the basic formulas don't cover). Best, Jim ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Wed, 19 Jan 2005 21:38:49 -0600, Curtis L. Olson <[EMAIL PROTECTED]> wrote: > I would tend to agree with you with one exception. The default C-172 is > very functional, but it is not our best model. A nice thing about > including multiple aircraft is you can see some different nice things > that can be done with FG aircraft. I think before we go with only 1 > aircraft in the base package, we should really spiff up the C-172 > externals and internals. Suspention animation, shadows, lights, and a > much better 3d cockpit. If we go with only one aircraft, it should be > really nice all around, and show off what we can do in FG. That sounds reasonable. For my own part, I'll see if I have time to do more work on the Cherokee/Warrior, which would be a reasonable alternative starter plane (as would any other trainer, such as the Cessna 150/152, Beech Musketeer, or even Diamond Katana, if anyone is interested in building one of those). The J3 Cub is probably the most famous trainer in history, but the tailwheel ground handling is too hard for most new users to manage. All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
David Megginson wrote: You know, after reading some of the other comments, I'm starting to like the idea of having just the c172p in the base package. In combination with this change, I'd like us to start thinking about changing the starting airport to Palo Alto (KPAO) rather than KSFO. It's more in proportion with the C-172, and with a few buildings, etc., we could have it looking quite nice. A few minutes after taking off from there and flying in a straight line, a new user will pass over KSFO, which will be more exciting to look at from the air, and then San Francisco, adding a nice sense of discovery. David, I would tend to agree with you with one exception. The default C-172 is very functional, but it is not our best model. A nice thing about including multiple aircraft is you can see some different nice things that can be done with FG aircraft. I think before we go with only 1 aircraft in the base package, we should really spiff up the C-172 externals and internals. Suspention animation, shadows, lights, and a much better 3d cockpit. If we go with only one aircraft, it should be really nice all around, and show off what we can do in FG. Regards, Curt. -- Curtis Olsonhttp://www.flightgear.org/~curt HumanFIRST Program http://www.humanfirst.umn.edu/ FlightGear Project http://www.flightgear.org Unique text:2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Wed, 19 Jan 2005 20:57:13 -0500 David Megginson wrote: > > In combination with this change, I'd like us to start thinking about > changing the starting airport to Palo Alto (KPAO) rather than KSFO. > It's more in proportion with the C-172, and with a few buildings, > etc., we could have it looking quite nice. A few minutes after taking > off from there and flying in a straight line, a new user will pass > over KSFO, which will be more exciting to look at from the air, and > then San Francisco, adding a nice sense of discovery. I agree with this, except I might suggest KSQL instead of KPAO, for three minor reasons. One is that we have a set of new user docs, designed to teach the basics of flight and flying the circuit in the c172, that come with the release; they presume that you started at KSQL. The second is that KSQL is closer to KSFO, and the Oracle buildings and Dunbarton bridge are very nearby, so there's quicker aesthetic gratification. Finally, KSQL and KPAO both need work as far as their taxiway layouts are concerned; but KSQL's will come from TaxiDrawers more quickly because KPAO's main apron area is circular and enclosed by a circular taxiway. -c -- Chris Metzler [EMAIL PROTECTED] (remove "snip-me." to email) "As a child I understood how to give; I have forgotten this grace since I have become civilized." - Chief Luther Standing Bear pgp5wcIvQw7ld.pgp Description: PGP signature ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Thursday 20 Jan 2005 01:57, David Megginson wrote: > In combination with this change, I'd like us to start thinking about > changing the starting airport to Palo Alto (KPAO) rather than KSFO. > It's more in proportion with the C-172, and with a few buildings, > etc., we could have it looking quite nice. A few minutes after taking > off from there and flying in a straight line, a new user will pass > over KSFO, which will be more exciting to look at from the air, and > then San Francisco, adding a nice sense of discovery. > > > All the best, > > > David Sounds like a great idea :-) Dave Martin ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Wed, 19 Jan 2005 10:53:33 -0500, Josh Babcock <[EMAIL PROTECTED]> wrote: > I'd like to see a golden age or WWII multi engine, but I guess the DC3 isn't > ready for prime time yet. I'm also *cough* working on a B29, but I haven't > touched it in months. I was in the middle of getting a Yasim config working, > after which I intended to put it out as an dev release. You know, after reading some of the other comments, I'm starting to like the idea of having just the c172p in the base package. In combination with this change, I'd like us to start thinking about changing the starting airport to Palo Alto (KPAO) rather than KSFO. It's more in proportion with the C-172, and with a few buildings, etc., we could have it looking quite nice. A few minutes after taking off from there and flying in a straight line, a new user will pass over KSFO, which will be more exciting to look at from the air, and then San Francisco, adding a nice sense of discovery. All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
Curtis L. Olson wrote: I know we can debate this endlessly so I hesitate to even bring this up, but are there any particular aircraft that absolutely, positively, must be in the base package. Now that we have a separate aircraft download page, there's no need to include every aircraft in the base distribution. I went through our list and tried to come up with a variety of aircraft that represents some of the major aircraft types as well as includes examples from many of our major aircraft designers. Here's the list I came up with. It's still probably too long. If you suggest a different aircraft, you have to tell me why it's better than two aircraft on my list so I can reduce the size of my list. So here's what I have ... 737 - large commercial jet. Reasonably well done. Flies pretty well. Nice 2d panel with some simple glass elements. A-10 - A gorgeous external 3d model by Lee with nice flight dynamics and really well done gear animation. bo105 - I could say a lot of nice things, but why bother, it's our only helicopter so it has to be included anyway. c172, c172-le, c172p, c172r, c172x - I don't have the energy to sort out the dependencies so throw it all in. c310, c310u3a - light twin, again I think there are cross dependencies so just include them both for now. dhc2 - Our only sea plane, a cool aircraft, nicely done 3d cockpit, flies well. f16 - A nicely done high performance military jet. j3cub - Another nicely done aircraft, simple, easy to fly. Hunter - A classic/early jet. Well done. 3d cockpit, european representation. p51d - A classic WWII fighter ... also well done. Full 3d cockpit. ufo - handy for debugging. wrightFlyer1903 - First successful powered flyer. So what did I miss and why should I replace something on my list with it? Regards, Curt. I'd like to see a golden age or WWII multi engine, but I guess the DC3 isn't ready for prime time yet. I'm also *cough* working on a B29, but I haven't touched it in months. I was in the middle of getting a Yasim config working, after which I intended to put it out as an dev release. Josh ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Aircraft included in base package
Chris Metzler wrote: > > p51d - A classic WWII fighter ... also well done. Full 3d cockpit. > > Just out of curiosity, what remains to be done with the Spitfire? If > it's in production, are there any reasons to favor it over the P-51, > or vice versa? > Nothing major remains to be done, although, as with the P51d, it still uses a legacy engine configuration. I will be restoring the creases some time soon, and will include instrument lighting when I get around to it. Eventually, I would like to provide an emergency boost facility. The Seafire still needs a working arrester hook. The only advantage I can think of is that you get 2 models for the price of one, otherwise they are very similar. You might find the Spitfire slightly easier to fly. On the other hand the P51d is a long standing feature of FlightGear, and this should be recognized. Regards, Vivian ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Tue, 18 Jan 2005 20:57:48 -0600 Curtis L. Olson wrote: > > 737 - large commercial jet. Reasonably well done. Flies pretty well. > Nice 2d panel with some simple glass elements. I like the 737 -- I've probably spent as much time with it as I have with the c172. I'm sure it's giving me bad habits; but it's fun. It has a couple of issues I think need to be resolved before it should go in the base package, IMHO. The most important is that when you run it from the command line, you get the huge "Beta" warning message telling you that it may not fly as expected and should be used for development purposes only. If that's not its status in FlightGear, the message should go; if that *is* its status, then it shouldn't be included. A casual user would find that message unsettling, IMHO. The second -- it's had a contrail submodel added to it, and I don't think the project is done. The contrails don't start until 7k feet, and they look OK at altitude. But they continue on as you descend through 7k feet and all the way to landing. When they're created at the engines, they have forward momentum, and their deceleration is less than what the aircraft experiences while braking on the runway. The result is that when you land, as you brake, your contrails go shooting forward past you and pile up on the runway ahead of you. This continues until you stop decelerating. The third -- I don't know when this happened, I can't find it from browsing the CVS logs, but right now the localizer arrow is hardwired to NAV1 and the DME is hardwired to NAV2, meaning anyone coming in on a localizer/DME has to have both radios set to the localizer and can't use a second navaid. This doesn't seem right to me, and I'm pretty sure it wasn't like this at one time. I haven't submitted a patch because I'm not sure about this and wanted others' input. So, I guess this is a request for that input. > c172, c172-le, c172p, c172r, c172x - I don't have the energy to sort > out the dependencies so throw it all in. I hope someone who does understand the dependencies and can sort it all out will. This has confused me in the past, so I guarantee there will be users who get confused. > p51d - A classic WWII fighter ... also well done. Full 3d cockpit. Just out of curiosity, what remains to be done with the Spitfire? If it's in production, are there any reasons to favor it over the P-51, or vice versa? -c -- Chris Metzler [EMAIL PROTECTED] (remove "snip-me." to email) "As a child I understood how to give; I have forgotten this grace since I have become civilized." - Chief Luther Standing Bear pgpSArqOZwMUd.pgp Description: PGP signature ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
"Jim Wilson" wrote: > [...] It would be very nice to have a civilian c310 (maybe > we should just repaint the u3a and call it a c310b?). To my knowledge there _is_ a civilian C310, at least there used to be one - no idea if it's still present, Martin. -- Unix _IS_ user friendly - it's just selective about who its friends are ! -- ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Wed, 19 Jan 2005 14:07:22 -, Jim Wilson <[EMAIL PROTECTED]> wrote: > Also I think I would have considered cutting the c310, even though it > is the only light twin. The u3a cockpit was my very first 3D project and it > really isn't too spiffy. It would be very nice to have a civilian c310 (maybe > we should just repaint the u3a and call it a c310b?). Gotta keep in mind that > we are still releasing the aircraft and it really doesn't pay to have a very > large base package. In any case, I'll work on untangling the cross > dependencies in the c310* folders. The C310 is of great historical importance for FlightGear -- when I started work on developing its flight model in JSBSim, we had no support at all for multi-engine aircraft, and it prompted a lot of significant architectural changes to both JSBSim and FlightGear. I think I might agree with Jim, though, that even though we should have a light twin modelled, neither of our C-310 models has seen enough TLC to justify throwing it at end-users. Perhaps leaving it out of the base package will spur one of us to put more work into it or to develop alternative light piston twin, like the Beech Baron, Piper Seneca, Piper Aztec, Cessna 340, etc. If we do include it, I also agree with Jim that it should be in civilian livery, not US military. I have no trouble with warbirds appearing in military livery, but there's no point going out of our way to show dual-use civilian/military planes that way, at least not in the default base package. All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
"Curtis L. Olson" said: > I know we can debate this endlessly so I hesitate to even bring this up, > but are there any particular aircraft that absolutely, positively, must > be in the base package. Now that we have a separate aircraft download > page, there's no need to include every aircraft in the base distribution. > > I went through our list and tried to come up with a variety of aircraft > that represents some of the major aircraft types as well as includes > examples from many of our major aircraft designers. Here's the list I > came up with. It's still probably too long. If you suggest a different > aircraft, you have to tell me why it's better than two aircraft on my > list so I can reduce the size of my list. > > So here's what I have ... > > 737 - large commercial jet. Reasonably well done. Flies pretty well. > Nice 2d panel with some simple glass elements. > A-10 - A gorgeous external 3d model by Lee with nice flight dynamics and > really well done gear animation. > bo105 - I could say a lot of nice things, but why bother, it's our only > helicopter so it has to be included anyway. > c172, c172-le, c172p, c172r, c172x - I don't have the energy to sort out > the dependencies so throw it all in. > c310, c310u3a - light twin, again I think there are cross dependencies > so just include them both for now. > dhc2 - Our only sea plane, a cool aircraft, nicely done 3d cockpit, > flies well. > f16 - A nicely done high performance military jet. > j3cub - Another nicely done aircraft, simple, easy to fly. > Hunter - A classic/early jet. Well done. 3d cockpit, european > representation. > p51d - A classic WWII fighter ... also well done. Full 3d cockpit. > ufo - handy for debugging. > wrightFlyer1903 - First successful powered flyer. > > So what did I miss and why should I replace something on my list with it? > It is too late for this, but just wanted to suggest (for next time) that both Curt's list and David's follow up both sounded great. I hope that we only included the c172p and I'd strongly favor cutting a military jet, adding the piper. Also I think I would have considered cutting the c310, even though it is the only light twin. The u3a cockpit was my very first 3D project and it really isn't too spiffy. It would be very nice to have a civilian c310 (maybe we should just repaint the u3a and call it a c310b?). Gotta keep in mind that we are still releasing the aircraft and it really doesn't pay to have a very large base package. In any case, I'll work on untangling the cross dependencies in the c310* folders. Oh yeah, and the ufo, even though it is small, is more fun on the website than in the base package. If someone needs it for debugging they are probably going to download it. Best, Jim ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
David Megginson wrote: > I just realized that the list didn't include any helicopter. Quoting Curt: > > bo105 - I could say a lot of nice things, but why bother, it's our > > only helicopter so it has to be included anyway. Martin. -- Unix _IS_ user friendly - it's just selective about who its friends are ! -- ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
David Megginson wrote: I just realized that the list didn't include any helicopter. Good point. Erik ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Wed, 19 Jan 2005 10:02:20 +0100, Erik Hofman <[EMAIL PROTECTED]> wrote: > Now that we have an aircraft download page I think that should be all > that gets included. I just realized that the list didn't include any helicopter. All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
David Megginson wrote: On Tue, 18 Jan 2005 20:57:48 -0600, Curtis L. Olson <[EMAIL PROTECTED]> wrote: c172, c172-le, c172p, c172r, c172x - I don't have the energy to sort out the dependencies so throw it all in. We should try to sort them out and include just the C172p by default -- in any case, you should be able to remove the c172-le, c172r and c172x without any damage (I think that all the dependencies are downwards on c172). Since that's three removed, it might be worth including a Cherokee (pa28-161), since it is the other common entry-level trainer at flight schools, and that way we'd have most student pilots covered. I think I agree with this. Lot's of aircraft depend on the availability of the C172 so that one should be included. The pa28 is the next most popular GA aircraft, so I would include that one also. Now that we have an aircraft download page I think that should be all that gets included. Erik ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Aircraft included in base package
> > c172, c172-le, c172p, c172r, c172x - I don't have the energy to sort > > out the dependencies so throw it all in. The C-172X is purely a development model It should definitely NOT be released. Jon ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Aircraft included in base package
On Tue, 18 Jan 2005 20:57:48 -0600, Curtis L. Olson <[EMAIL PROTECTED]> wrote: > c172, c172-le, c172p, c172r, c172x - I don't have the energy to sort out > the dependencies so throw it all in. We should try to sort them out and include just the C172p by default -- in any case, you should be able to remove the c172-le, c172r and c172x without any damage (I think that all the dependencies are downwards on c172). Since that's three removed, it might be worth including a Cherokee (pa28-161), since it is the other common entry-level trainer at flight schools, and that way we'd have most student pilots covered. Do we have a glider that's well enough along to include? That seems to be one big gap on the list (I'd remove one of the military jets to make room, if you have to). It might also be nice to include the Sopwith Camel so that we have WW I biplane. All the best, and thanks for putting together the list, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
