In article ,
wrote:

On Fri, 31 Oct 2008 12:09:27 -0700, Alan Baker
wrote:


The one thing not quite right is that there is no important difference
between tractor vs. pusher configurations with respect to directional
stability.

Like some of the early rocket designers (e.g. Goddard), you are falling
into the fallacy that somehow pulling is more stable than pushing. This
is not so.
Pusher or tractor makes virtually no difference, but the vast
majority of pilon mounted engines ARE pushers - and the pilon mounted
engine does have that nasty quirk.

Yup, but that's because the pylon (note spelling) places the thrust line
far above the centre of mass, creating a long moment arm.

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