On Wed, 2003-12-24 at 05:51, David Megginson wrote: > Cameron Moore wrote: > > > One question though. I mentioned trying to line up with a fuel tanker > > and how the delayed movement was throwing me off. My guess is that this > > behavior was due to slow control surface movements. My question is if > > JSBSim simulates control surface movement speeds (excluding the flaps > > which do) or is the control surface deflection always exactly equal to > > the control input? > > Hinge moments for control surfaces probably have something to do with it, > but remember also that you're flying a heavy, fast plane. Even if the plane > is very responsive to control input (which has more to do with aerodynamic > damping effects than control-surface response speed), you're not going to be > able to change the flight path on a dime. > > All other things being equal, a plane that flies twice as fast (say, because > of heavy wing-loading) needs twice as much time and four times as much space > to make a change in its flight path -- that's why a little Cessna or Piper > can start its landing flare over the runway itself, while a transport jet > has to start flaring at least a half mile back (pulling up the nose at the > last moment would only change the attitude in which the jet smashed into the > runway).
Airliners aren't that sluggish ... the flare is initiated below 50 ft AGL and that is definitely over the runway. > Jet fighters turn fast only by pulling ridiculously high G-forces, > and even then, they need a lot of time and space to turn around. > > I'm sure that inertia has a lot to do with it as well, but I don't know > enough about physics to describe those effects. Inertia is a player, but most aircraft do not have large roll moments of inertia .. the mass tends to be concentrated close to the roll axis. > > > All the best, > > > David > > > > > _______________________________________________ > 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
