On the other hand if you compare landing speed for landing speed it

is hard

to beat a conventional airplane with Fowler flaps. Not easy to put

Fowler flaps on a Rutan canard. To get the same landing speed a
canard needs a lot more

wing area and that is a lot more drag at high speeds.

Paul Lamar

Or go to a 3 lifting surface a/c which supposedly has the best of

both

worlds.  Vance what do you think about these 3 wing a/c?

Jarrett Johnson

Matt Prather wrote:

Note, migrated topic...

I like idea of the Peterson STOL 182:

http://www.260se.com/index.html

Or the Piaggio (though it looks like a caricature of a catfish) P180:

http://www.piaggioamerica.com/

I think flaps can be put on a canard - I think the Starship has them.

To

utilize
the extra lift coeficient of the main wing, the canard has to have

something

that either increases its moment, or further increase its lift

coeficient.

 The
Starship has a swinging canard, I believe with an interlock to the flap
system.
If the flaps are out, the canard swings forward.  Movement of either one
of the
mechanisms without the other also moving would likely be unsafe (at

least

at low airspeeds).  It has been on my long time todo list to build a
flying model
with swing canard and flaps.  Maybe I'll finally get to it.

Fowler flaps are not a Rutan kind of thing though.  Too many moving
parts, or something like that.  That's probably why we haven'tseen them
on a canard.  Keep in mind that the original Varieze didn't have

ailerons...

Nobody besides Rutan has really designed a modern canard.
Regards,

Matt-
--

Paul Lamar

I wondered how long I could go biting my tongue. and since I was sort of
invited in
I will give my call on this argument. The EZ's and their variations are very
fine
aircraft, but a canard does not represent the optimum cure all airframe by
any
means. I thnk it was almost 15 years ago that I made the statement that you
will probably never see Mr Rutan ever use a canard as the primary pitch
control again, and I think that pronouncement has held true. With a canard,
 you must never never work the main wing to it's maximum capability, because
if the canard does not stall first you will lose control of the aicraft. The
limited pitch authority of this configuration generally will prevent the
classic stall spin situation, but that did not come free. This is even more
pronounced
with the Tandem configurations, if you are too slow, low, you cannot flare.
Putting flaps on a canard usually involves variable geometry canards or
other
aerodynamic tricks. I also do not believe that three surface is the best of
both
worlds, more like the reverse of that, A typical three surface configuration
is
primarily a conventional configuration, with the added front surface moving
the center of lift so you can move the main spar out of the cabin.
Aerodynamically
it is much like a very extreme reverse stagger unequal biplane.

With the exception of the Voyager, no canard has set any major speed or
efficiency record in any class,. Sailplanes are a strong test of efficiency,
and the canard sailplane was not a good call.
Vance

 
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