On 07/03/2007 02:45 PM, Berndt, Jon S wrote: > A positive elevator angular deflection (about the +Y > axis) makes the trailing edge of the elevator move down, resulting in a > negative pitching moment. > > Likewise, a positive rotation of the rudder about the Z axis (positive > downward, with Y positive out the right wing and X positive foward) > results in the trailing edge moving left, resulting in a negative yawing > moment.
You can't argue that FG does both of these things correctly in accordance with that rule. It follows one convention for yaw, and the opposite convention for pitch. If you don't believe me, use the browse-internal-properties popup, and check the properties against cockpit control deflections and/or control surface deflections. I try to align all my conventions with the _pilot's_ point of view. The pilot is not looking at the rudder deflection. The pilot thinks that a positive deflection of the cockpit yaw control is whatever produces a positive yaw-wise motion of _the whole aircraft_. Likewise a positive deflection of the cockpit pitch control should produce a positive pitch change of _the whole aircraft_. Let's be clear: I am distinguishing: a) semantics of the cockpit control, versus b) semantics of the cockpit indicator, versus c) motion of the control surface, versus d) motion of the whole aircraft. I claim that (a) agrees with (d) by definition, and that (b) ought to agree with (a) and (d) ... and if that sometimes leaves (c) in disagreement, that's how the cookie crumbles. Since FG is already inconsistent, my suggestion certainly doesn't make anything worse. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
