Mechanics of Elevator Trim. In Detail.

On Jun 12, 5:08 am, Tina wrote:
Yes, the time my son spent with canard aircraft brought out all sorts
of interesting information about canards and the history of trying to
scale up Rutan's original concept Beech Starship. The smaller true
canards like the Long-eze are pretty good aircraft. However there is
a reason why we don't see large (six plus passenger) true canards.
It's the relationship between CG, fuel load, payload and range.
Apparently in the scale up process there is a point where it is no
longer practical.
Ron Kelley

Hmm, how the XB-70 or this,
http://en.wikipedia.org/wiki/Boeing_Sonic_Cruiser

I think the aircraft business is extremely conservative.
KISS applies, also canards are difficult for the average
pilot to understand, (Hey man, you got that thar tail on
the wrong end :-).

Would it not also be true that passive stability is not as important
in larger modern airplanes? I would guess (again, I admit being
ignorant of the realities) that adding a 10% aerodynamically induced
increased load on bigger aircraft would be avoided for efficiency
reasons? It might be better to have enough fly by wire and computer
induced stability instead. I don't know enough about this stuff to
even find the back of an envelope, let alone do a calculation there.

Canards are NOT simple, I've designed quite a few,
and studied others, especially Rutan's.
I find they can be optimised for a given air speed
and are much better than the conventional lay-out.
The main problem is designing the stall.
Ken