9.JG52 Woelfel

I know it's difficult to say. At this point, I've shot so many landings it's becoming increasingly difficult for me to be objective in making my subjective assessments, so to speak. What I make it a point to do is perform intentionally rough landings - then view the response of the suspension on the recorded track. I am going to post a few more revisions in drop box for you to try out and perhaps I'll attach a txt. file that defines the alterations. They can be opened and edited with the downloadable program called Notebook++ so feel free to tweak away. The quest for optimal settings is time consuming to say the least since every adjustment has some affect on every other setting dynamically and must be balanced accordingly in the ideal case. This is the most recent set up I tried which has some pretty dramatic alterations that I made just to see what would happen. It's of particular interest because I never expected it to work very well at all, although it does appear to. I'd really like some feedback on it because this sort of thing is really best evaluated by multiple test pilots. As I mentioned I'm getting to the point where I've tested so many different set-ups that I'm not sure i trust my own opinion anymore! For this one I did my test landings with no flaps just to see how difficult it was to keep the aircraft rolling down the center of the runway. Here's what I changed: Every value with the word 'Damper' in it - main gear and tail wheel - has been reduced to 10% of the original value while everything else is set to the default values. If it is an improvement then the problem has been that the undercarriage was prevented from responding quickly enough. Originally it seemed that the opposite was the case, and that the side to side oscillation or resonance was caused by an under-damped set-up. I'm very curious to hear your opinions on this one. The changes are highlighted in red: tailGearYawDamperK = 3.0 tailGearAxleFricM0s = 190.0 tailGearAxleFricM0f = 15.0 tailGearAxleFricVs = 0.2 tailGearAxleFricVf = 3.0 tailGearStockLength = 0.1 tailGearSpringForceFactor = 5590000.0 tailGearSpringForceFactorRate = 1.5 tailGearStaticForce = 15000.0 tailGearReduceLength = 0.02 tailGearDirectDamperForceFactor = 2.0 tailGearBackDamperForceFactor = 9000.0 tailGearDamageLengthLim = 0.1 mainGearSpringForceFactor = 1.8e6 mainGearSpringForceFactorRate = 2.2 mainGearStaticForce = 8500.0 mainGearReduceLength = 0.05 mainGearDirectDamperForceFactor = 2000.0 mainGearBackDamperForceFactor = 4500.0 mainGearDamageLengthLim = 0.12

You're all very welcome. As I said, it still needs a lot of work and there are a few parameters whose meaning I could only guess at - although I didn't touch anything that could possibly have any effect whatsoever on anything other than the suspension. Just keep a copy of your original FMOptions.lua file. Of course, if you lose it, you can always replace it with the 'repair' function. Good luck. I hope it makes things a little easier.

Sure. I'm working in the dark to a degree and it's a work in progress, no doubt, but here is a link to the latest revision of the modded file. I hope it works for you. https://www.dropbox.com/sh/d4rj27860817trm/AAAQVSpTd-h3OEbQd2ber936a?dl=0

I've completed just under 400 landings in the K4 so far and if it had the suspension adjusted a little it could be much easier to land. Hopefully when it's updated it will have been tweaked a bit, but until then it's going to seem a bit over sensitive until you really get used to it. I suspect it wasn't quite so much so in reality but i haven't the credentials to say so one way or another. What i do know is that the minor adjustments I made to the FMOptions.lua that contain the undercarriage spring and dampener parameters really made a difference.

The tail wheel is sprung to stiffly and/or is insufficiently dampened and the effect is magnified by the fact those variables are poorly matched to the main wheels which also have badly adjusted springs and dampeners. When bouncing from one main wheel to the other, the bounces ought to gradually diminish and the plane should settle down. A couple of examples that stand out in my mind was when after landing on grass and coasting in a straight line until a point where i was doing less than 75mph, and touching the right brake to begin a sequence of right/left brake inputs. The right main wheel strut compressed and the plane broke up as it bounced from one wing to the other. It was ludicrous for a variety of reasons for example the brake could scarcely have had that much effect on grass as anyone who's ever run off the road on a street motorcycle can tell you. The main wheel spring fully compressed and the tail wheel lifted a foot off the ground from a single tap on the right brake. Anyway, I'm going to go into the FMOptions.lua file and see if I can make a few adjustments to the undercarriage variables.

I"m happy to say I've finally had a dozen or so consecutive landings without scraping a wing. In my case the keys to success were higher approach speeds, not being in a hurry to flare out - not really flaring it out at all actually- just letting it run out of speed, landing on the front wheels and pulling the stick back immediately. I then watched the replay track and what stood out in my mind was how the tail wheel would bounce the tail right off the ground from a mere crack in the tarmac long after the aircraft had touched down. I can't help but believe there are some adjustments to be made in the spring/dampener characteristics for both the main wheels and tail wheel. They're simply too eager to bounce and demand that every landing be nearly perfect to be successful. In the past I worked on a flight sim that had the very same problem with the 109. It had a great FM but the undercarriage prevented anyone from being able to land it consistently. Once the spring/dampening parameters were adjusted properly and in sync with the tail wheel so that the AC didn't bounce from main wheels to tail wheel and back as well as from main wheel to main wheel, it became far more manageable. It took a lot of work since testing was primarily subjective in nature and each adjustment impacted every other. I can't recall the exact number but I know I performed a few thousand test landings before we were satisfied the optimal settings had been nailed down to the sixth decimal place. The very same types of adjustments could be performed on the real thing and I'd have to believe they were, given how many crashes might consequently be avoided. It's probably worth looking into on this particular FM.