On Fri, 2003-09-05 at 08:01, James Turner wrote: > On Friday, September 5, 2003, at 03:12 pm, Martin Spott wrote: > > > 3.) I know, you should not employ the flaps at 200 kts .... > > But if you do so, the aircraft climbs like attached to a high > > speed elevator :-) > > I've been flying the Fokker 100 quite a bit, and I've noticed similar > instabilities. Roughly (I am not a pilot) > > - very rapid control response, especially on the roll axis). This > sometimes extends to a 'snap' condition where I command an aileron > reversal (okay, I just pull my joystick to the other side), and there > is a very prolonged period with no response (for example, 8 or 10 > seconds, usually continuing the previous roll command) until the roll > suddenly flips over. > > - a similar elevator effect to that martin described, when deploying > the flaps at high speeds > - very odd high pitch angle behavior ... I can't really describe it, > alas. It seems like way too much lift is getting developed at high > angles of attack, without a corresponding increase in drag to slow the > aircraft. > > Essentially, the aircraft flies pretty well (if a bit twitchy) > providing you stick to a 'good' flight regime, but handling > deteriorates exponentially when I go even moderately beyond it. I'm > aware that part of this may be running 'past the end of the data' in > JSBsim, but other models do not seem to have these problems. Can this > be alleviated by tuning the last data point for various coefficients, > which I assume is what JSBsim extrapolates from?
Just for the record, JSBSim never extrapolates a table and always holds last value. In practice, this can have as bad an effect as extrapolation, but at least we're not making up data as we go along. > > (I was about to say the 747 is much more forgiving of my 80-degree > banks, but of course, it uses YASim). > > Anyway, aside from the nit-picking, it's a lovely plane, at least until > we get an ERJ ;-) > James > > -- > There is a very fine line between 'hobby' and 'mental illness' > > > _______________________________________________ > Flightgear-devel mailing list > [EMAIL PROTECTED] > http://mail.flightgear.org/mailman/listinfo/flightgear-devel -- Tony Peden <[EMAIL PROTECTED]> _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
