On Tue, 26 Feb 2002 11:19:13 -0600 (CST), "Curtis L. Olson" <[EMAIL PROTECTED]> wrote in message <[EMAIL PROTECTED]>:
> David Megginson writes: > > I haven't added a tab object to the 3-D model yet, but I'd like to > > understand more about how it actually works first (ditto for > > elevator and rudder trim). > > > > >From the pilot's point of view, I think, the elevator trim tab > > controls the amount of pressure required to hold an elevator > > position on the yoke -- you just turn the wheel with your right hand > > until you don't have to pull or push the yoke with the left hand (or > > vice-versa in the co-pilot's seat). I don't think that the trim tab > > changes the range of the elevator movement per se, as much as it > > changes the lift of the elevator surface in the airstream (i.e. > > neutral position is different), but I could be totally confused. > > > > In JSBSim, we're just summing up the trim and elevator and clamping > > to the elevator range -- I don't know if that's right, but it > > doesn't seem to bother most people. We cannot do real trimming > > without force-feedback controllers (that can hold a non-neutral > > position). > > Right, when you move the trim tab, it changes the 'neutral' position > of the elevator which is why you then don't need pressure to hold the > position. The key thing though is that the elevator does move when > the trim changes. I think you could think of it as an alternate input > to the elevator control. ..another mental model of this, is "servo rudder". Here you have a trim tab size rudder, controlling the rudder (etc for the pre-hydraulic big irons), yawing the plane. -- ..med vennlig hilsen = with Kind Regards from Arnt... ;-) Scenarios always come in sets of three: best case, worst case, and just in case. _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
