In article ,
Steve Hix wrote:

In article
,
Alan Baker wrote:

In article ,
Steve Hix wrote:

In article
,
Alan Baker wrote:

Pusher or puller doesn't affect pitch forces. What affects pitch forces
is the length of the moment arm between the centre of mass and the
thrust line.

Or center of drag vs thrust line?

The problem with that is "centre of drag" changes.

And, as it does, so would pitch resultants.

Better to take all the separate moments for the various components about
the centre of mass.

Which will change as airspeed/AOA/etc. change, right?

No. The centre of mass *never* changes (in the context of this
discussion.


Come to think on it, the total moments of drag don't care about any
masses, just the shape(s) of the aircraft exterior.

You have to take moments about something that isn't going to shift,
Steve. Centre of mass.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg