On Monday 08 October 2007 02:17, dave perry wrote: > The SenecaII wing rock with light turbulence appears to result from a > very exaggerated adverse aileron yaw. > So I did the same experiment with > the c172p and pa28-140
I agree that they both exhibit unrealistically bad handing characteristics. The 182 and 182rg were also quite nasty, until I brutally hacked the configuration to reduce it. One slight quibble: I'm not sure I would characterize all of the problem as adverse yaw. In addition to whatever adverse yaw problems there were, I noticed an excessive amount of slip-roll coupling. That is, any slip (due to ailerons or rudder or otherwise) produced a tremendous amount of rolling moment. This is a recipe for some bad Dutch Roll behavior, which is pretty much what I observed. We agree that aileron deflection was an easy way to set off this bad behavior, but I'm not sure that adverse yaw is the whole story. Somebody needs to look at all the parameters from top to bottom. > which both use the kap140. I don't think that's the primary issue ... although there might be a /secondary/ issue with the kap140 being more vulnerable to bad handling characteristics than some other autopilots are; I don't know. I recommend fixing the flight dynamics first, and only then looking to see what secondary issues might exist. Other oddity in the flight dynamics is: much too much rolling moment due to changes in engine power setting. I would have tried to fix this, but I didn't see any parameter to control this in the configuration file. I know there is some irreducible rotational drag from the propeller, and this rightly belongs in the engine/prop configuration ... but there are other things such as asymmetric wing-root incidence that are used to counteract it ... I didn't do an exhaustive search, but I didn't see that anywhere. There are many other oddities, such as fuel never being consumed from fuel tanks, effective mixture not being sensitive to altitude, EGT reading high and insensitive to mixture, etc. etc. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
