another side of the hobby that's rewarding

[Guest Zevious Zoquis]

I think the really important qualifier in everything I've been saying is getting missed here - "as long as the plane works properly."I don't doubt for a second that there exists in the world of FS devs a wildly varying degree of skill as regards flight dynamics. I also don't doubt for a second that you are very knowledgable in that regard (much much more so than myself I'm certain). I'm not a pilot nor am I an aeronautical engineer. My experience of flight consists of a couple trips to Toronto on a Boeing 727 and lots of time in front of my PC flying around in FS and various other sims. I rely to a large degree on folks like yourself and LAdamson and others with real experience to sort of clue me in to things. That's why your comment regarding Rob Young's work - "I am aware of Real Simulations work. I have had big nasty arguments with those people. They have ignored the laws of physics and struggled through a lengthy trial and error process to make airplanes spin above all else. They turn the MOI's upside down and inside out to get what they want. They think those of us who take a conventional aeronautical engineering approach are full of hooey. I think they are full of hooey"- peaked my interest so much. It sounded particularly adversarial. I don't doubt your contention regarding Rob ingnoring the laws of physics and messing with the MOI's and so forth. My only question is why should I care? I find Rob's work to be superb - all of R/A's planes are amongst the best flying and best functioning I've flown in the sim. Of course, that in itself doesn't really mean much given my lack of real knowledge. However, R/A's stuff is almost universally recognized as representing sort of a high water mark for flightsim addons as regards flight dynamics (amongst other qualities) - and that praise comes from individuals who I know to have - like yourself - a great deal of knowledge on the subject. So again, I'm curious...what is it you find to be wrong about the way RealAir's planes work in the sim? Becuase as I've been saying, it's only the end result I care about and if there's nothing specifically wrong with that, then concerns about the data that's used to get to that result move more into the realm of "personal obsession" rather than "meaningful issue."

[LAdamson 240]

However it's done................ I've flown the real SF260, and I sure like Rob's! :-hah Still my favorite FS plane of all time! But then I'm partial to sliding canopy's!L.Adamson

[LAdamson 240]

>>I have noticed that even with "major brand names" in the FS>aircraft business, some simple things need fixing. I forgot>the particular names but I downloaded a beautiful prop plane>the other day that was great except you could not set the>power correctly because the prop control simply did not work.>It took five minutes or less to adjust the max blade angle and>get that control working. Now the plane flies great.Here's one for you. If you can get a simulated C/S prop to do a good job of braking effect's, when pushed forward to fine pitch in the landing phase, it will be an accomplishment. More than not, most simulated C/S props act just like a fixed pitch when it comes to landing.L.Adamson

[Guest Tom Goodrick]

I have never flown an RA model. Someone set me up once for a confrontation with the RA folks. They sent me a copy of the FD files for the Cessna 172. I looked over those files and noted the bad MOI's. I have been complaining about bad mOI's in FS models for many years. The roll MOI is usually the smallest. The pitch MOI is about the same size but slightly larger. The yaw MOI is always the largest. MOI's are calculated by multiplying each mass chunk on the aircraft by the square of the radius to the axis in question. The fuselage does not contribute to the roll MOI but the wings do. The wings do not contribute to the pitch MOI but the fuselage does. Both wings and fuselage contribute to the yaw MOI. If you have these in roughly the proper magnitude, or in a correct proportion to each other but scaled up slightly using a common factor, as needed sometimes in FS9, you will get good results.The MOI's contribute to all "handling aspects" such as rolling into a turn, rotating on takeoff, flairing for landing and some more complex maneuvers such as descents from a steep bank, rolls, loops and spins (which was RA's claim to fame). In a sim as complex as FS9, you must have the basics in order to have any faith that the result will be "realistic". I said as much when reviewing the FD files for the RA C172 and within an hour had a blazing response from an RA representative. He claimed they had done many months of research working out the MOI's. But the fact is they did not have them close to the proper relationship. I have forgotten what they had wrong but it was very wrong and I told him so. They must work very hard on other aspects of the design. But getting the MOI's right is very easy. I published a way to do it several years ago. Microsoft offers a simplified formula that works very well giving nearly the same results I get.There are many esoteric aspects to FD work. But we should always start with the basic things we know like the geometry and the masses. Then after taking care of those loose ends we can get to the esoteric stuff.

[Guest Zevious Zoquis]

With all due respect, if you haven't flown any of R/A's planes, then I'm not particularly interested in your opinion of them. That's not a shot at you or anything, it's just reality. I don't have to have "faith" that the result will be realistic (in so far as I can judge realism given my limited r/w flying experience). I can just fly the planes in the sim and determine if they feel realistic to me. I've never looked in an FD cfg file at all. I don't care whats in there. The plane either flies right or it doesn't.

[LAdamson 240]

When your creations have been applauded world wide; by pilots, simmers, and other FD designers.................then perhaps you'll have the right for confrontations. But all I see, is that you're arguing "air", when all I see is a form of manipulated electrons!I don't care if RA's use of MOI's is voodoo, or black magic. The results for the types of aircraft done by RealAir is rather amazing.Do yourself a favor and get the Marchetti SF260. You might be flabbergasted yourself, and start tweaking those electrons, just as they do at X-Plane too!....L.Adamson

[mnmon 0]

I won't get into the RA question; I haven't used any of their planes either. However, I will back up Tom in this debate. As a physicist one of the first things that caught my eye in the cfg file was the MOI's. And the reason they caught my eye is that when I started using a new plane I would discover aspects of the flight model that weren't right. These varied from stall characteristics, turn rates, low speed flight, cruise pitch, etc. you name it. Well, the bottom line that I've found is that fullly 90% of those payware planes out there have messed up MOI's. Once I fixed those, many of the problems certainly improved, if not disappeared. My starting this thread was just to point out that the MOI's are a start, but now I've also discovered that the entire Weight & Balance has to be correct also. The really GREAT part of this is that this parallels exactly my real world flying experience: ignore W&B at your peril. L & Z: just a quick question: when you get a new plane how do you evalute its flight characteristics? I'm asking because if all one does is T/O; climb; level flight; approach and land; then there are many planes out there that perform adequately. However, just push the envelope a bit and you'll soon discover their limitations. I always take a new plane up with about an 80% load and do the following: power on/off stalls, full flaps stalls, slow flight configuration, steep turns, short/soft field T/O techniques, high speed cruise looking for hands off stability after proper trimming, and finally I hand fly an IFR approach. Most of these are things taught at the basic private pilot license level. NEVER turn on that autopilot! If the plane can't be hand flown 100%, then something is messed up in the FDE. The amazing part is the MSFS can give a very realistic simulation of ALL aspects of the flight envelope with a properly designed plane. Mike

[Guest PARADISE]

This reminds me of the engineering students vs the pilots when I was in flight school. The engineering students would go to great lenghts to explain how this and that effected such and such. To which the pilots would just shrug their shoulders and ask, " Does it fly? If so, then get in and lets go "John M

[mnmon 0]

Ahh.. but the real question for the flight SIM is does it fly CORRECTLY ?? Mike

[Dirk98 354]

>> I won't get into the RA question; I haven't used any of>their planes either. However, I will back up Tom in this>debate. As a physicist one of the first things that caught my>eye in the cfg file was the MOI's.You don't know how badly their (MS) 3D-freedom code is convoluted (can anyone remind MS's original name for the flight dynamics code please). What if you hit the right spot with a seemingly wrong number in the config? The result sometimes can be much better than the numbers you deem right from your past studies. RA planes can be a good illustration to that. Their FD feels very credible with a few unique spin features. And c'mon guys, why would you want to discuss something you didn't code (I mean FS) and even haven't tried (I mean RA's planes)?

[Guest PARADISE]

> Ahh.. but the real question for the flight SIM is does it>fly CORRECTLY ??>>> MikeAgreed,.....for a flight sim. However, that's why in real life we have pilots......to make them fly correctly.:-hah John M

[LAdamson 240]

> L & Z: just a quick question: when you get a new plane how>do you evalute its flight characteristics? Would this be sim or real..........as I do both. :7 Been in the experimental/kitplane/homebuilt "hobby" for many years.but, since I've installed them.............I check those auto-pilots too! :-hah Note: Before backing up anybody ---- try a RealAir! :)L.Adamsonedit: just had to throw in a "steep turn" pic. Un-painted Van's RV "kitbuilt" over Lake Powell in the vicinity of Rainbow Bridge.Notice - aileron is now neutral.http://forums.avsim.net/user_files/169305.jpg

[LAdamson 240]

> Ahh.. but the real question for the flight SIM is does it>fly CORRECTLY ??>Well,I did do some serious "spin" and slip testing between the revised Piper Cub files offered in this thread, and the RealAir Scout. Don't have the RealAir Decathlon installed on this cpu.For starters, the new Piper certainly has an improved takeoff roll. For whatever reason the default suffers from computeritis, in which some days it's functional, and other days just a continuous ground loop, no matter what you do!What I didn't see is any real drift to the left on climbout, but then I have not flown a real Cub, to see just how it really is. The closest fabric taildragger that I've flown is a Maule.Slips............ The RealAir products are always good at this, as you can aim for a point, and stay there with plenty of rudder. The revised "Cub" does quite well here too! For these test's I used full realism settings as well as the settings recommended in the "readme".Spins........... Stall the aircraft from straight and level, then pull yoke full back as well as full right or left rudder. I'm not using any aileron here, but you actually can, as suggested in the Cessna POH's, as well as the fact that it's done for airshow routines. Both airplanes drop a wing rather quickly and break into the spin. The RealAir spins are quite consistant with the nose remaining below the horizon. Some fully developed spins in the Scout require active anti-spin control such as full opposite rudder, and other times, just releasing the controls will recover from the rotation.From the revised "Cub", I got some good looking spins, but at other times it was a tumbling action, or the nose would constantly bob above and below the horizon. The readme says to apply full rudder to remain in the spin. When released, the aircraft would recover from it's rotation.I performed both spins to the right, and to the left. It's about the same either direction, with both airplanes.L.Adamson

[ejoiner 21]

I'd highly encourage you to work on some freeware planes where the authors are great at visual presentation but this whole flight dynamics area remains a mystery. I suspect many would welcome the help.This applies to PAYware as well. I for one, would love to see a new FDE for the Alphasim AT-6. That sucker is way too docile for what that airplane really is. (a beast). Eric

[Guest Zevious Zoquis]

Here's me in the Deke going into a very low altitude spin. I call this one "Kissing Terra Firma" :Dhttp://members.shaw.ca/ZevSpace5/Kissing_Terra_Firma.wmv