On 12 Sep 2004 at 8:51, Jon Berndt wrote: > In the case of the JSBSim C172, we approximate the modeling of P-factor (which tends > to > yaw and slightly roll the aircraft left), we model gyroscopic effects, torque on the > airframe from the prop beating against the air. We do not yet model the slipstream > effects > of the propwash on the aerosurfaces. > > We have had pilots tell us that the left yaw/roll at takeoff is modeled very well, > and > some (usually newbies) tell us it is surprising. The fact is, the effect is real, and > those of us who have flown an aircraft like a c172 can tell you they have > experienced it. > Some simulators (perhaps MSFS, X-Plane, whatever) may model the effect differently, > either > more or less completely. I don't know. The *magnitude* of the effect may be > overstated. Or > understated. It depends on who you ask. > > So, the question can be raised: what are you basing your comparison on? I missed > part of > the earlier conversation. Are you a pilot of small aircraft? Are you comparing with > other > sims? Or, would you simply like the effect to be gone? The P-factor effect can be > mitigated by reducing the P_FACTOR setting in the config file to a smaller number , > say 5 > instead of 10.
Jon, as I explained earlier, I started simming (and I'm no real pilot) somewhere 15, 16 years ago. Sublogic's FS-II. You may know this one had very little to do with "real life flying" but I think it was the best of what one could get at the time. This even was true for the later MS Flightsim, which I tried with version 5. From the late 90's I went onto ProPilot and Fly, I believe Fly was the first one I experienced, which could model torque effects. It was switchable however and on lotsa occasions I simply don't switch it on. Now since I started with FG, I experienced lotsa control problems (on most a/c btw) which made it almost impossible to fly decently around. Part of those were the yaw and torque effects built in, but I'm still convinced it wasn't that alone. I did some tests with the similar a/c in Fly, also a 172 model with torque effects switched on and it was completely different. I don't have pedals here, not even a decent yoke, so I fly either from the keyboard or from the flightstick I have, which suits me fine most of the time. Flying FG from the keyboard is impossible, flying it from the stick is OK as soon as the plane has stabilized after some time. When I take off, I need all efforts on the stick to get it decently up at a decent rate, decent climb speed and straight heading. Therefore I usually engage AP after t/o, which gives me time to handle radio's, nav's etc. Once stable (even when still climbing) I can easily turn off the AP again now (that's what I found with the new version, I never tried it with 0.9.5) and fly it on the stick. No problem with that. I still don't know what causes it to go bezerk straight after I got airborne and the fact that once I get at say 1000' AGL, around cruisespeed, I can switch the AP off and fly it with 1 finger, so to speak, makes it even more stupid. Anyway, it starts to get interesting again. I was getting to the point where I thought "just trash this junk, it's no fun and I still have PP and Fly" and I'm glad I didn't. Louis _______________________________________________ Flightgear-users mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-users 2f585eeea02e2c79d7b1d8c4963bae2d
