Just reached 25 hours into the test flight period. Rock solid.
Now to get the 1 rotor mounted and vetted for the beta prototype.
On the ground it is 16 deg. F under the inversion.
Up at 7000 feet it is 36 deg. Almost tolerable.
Chris Cosman
Congratulations Chris. It is a real cute airplane.
Paul Lamar
Great airplane!: Regarding the V tail, I guess the most popular use
of this
arrangement was in a Beechcraft airplane (Bonanza?) the upside down
version,
with the V not as a Vee, but as an A, may have the advantage of inducing
roll in the right sense, while the V tail induces roll in the
opposite sense
of turn.
I've always wanted considering an airplane with a Canard
configuration (Tail
first as in the 14 bis by Santos Dumont, the Curtiss Ascender and the
North
American B-70 Walkyrie) that offers additional lift, while the usual
arrangement of tail in the rear part of airplane produces no lift, or
even a
force down.
It was supposed that this arrangement has the added advantage of the
canard
surface stalling first, then blocking the main wing approaching an
stalling
incidence, as it usually has a higher incidence or angle of attack
than the
main wing, but some discuss this, and a recent article in Flying,
October
2012, about an accident in a Rutan Canard that lost suddenly power
because
of a broken propeller, that ended in the pilot killed, seems having been
worsened by the pilot pulling back the stick, instead of pushing it
down to
gain airspeed and attempt some emergency landing, the Canard entered
a flat
stall and precipitated to the ground at high speed, but in a flat
attitude.
There's an old article in Flight International, entitled: "Canards,
design
with care", (Free and open access in their website) dealing with the
subject
of foreplanes, and a very old article in the french "Aviation magazine",
about the Saab Viggen, points that the best arrangement in canard
airplanes
would be a tail unit placed in an upper position respect to the main
wing,
it can be in the upper section of fuselaje, or immediately after the
pilot's
cabin, and the wing placed in a low position, in the inferior rear
part of
fuselage.
Don't know much about the Piaggio canard private transport airplane,
besides
that they sold few, and are or were buying back those still flying in
order
not to continue having a legal obligation to maintain an stock of spare
parts for repairs.
The concept of a Canard surface of the A or inverted Vee type, placed
in the
upper part of the airplane, with a wing surface in the inferior part
always
looked to me as interesting, and if somebody has the computing power and
software to make a simulation of the flight characteristics of an
airplane
arranged this way, I'll greatly appreciate knowing any results, or
simply
having comments, oppinions or discussions on the subject.
t.
Thank you for your kind attention.
Have a nice week, best regards, salut +
Jose Gros-Aymerich
Madrid, Spain.
Here's my comments:
The Piaggio Avanti is not a canard. The fore-wing provides lift and
enables
the carry-through structure of the main wing to pass aft of the
passenger
compartment. The fore-wing does not control pitch; it has a
conventional
tail for that. Keep in mind that the Avanit has about as much main wing
area as a Cessna 172.
The Beech Starship is the orphan that is being bought back. It was
almost
100 mph slower than the Avanti on vastly more power. Beech mangled
the 85%
scale prototype up with a bulldozer in front of Rutan's Mojave hangar;
presumably they were upset with the program.
Canards have the built in weakness that the fore-plane must stall first.
This means that it must be more heavily loaded than the main wing, which
also means that the main wing never operates at it's ideal angle of
attack
for lift at slow speeds, which means it must be much larger to achieve
acceptable landing speeds, or land dangerously fast. The Starship
incorporated a huge top surface reflex (ski-jump shape) to help kill the
pitching moment at high speed (read: drag) otherwise the forward canard
would have needed to be enlarged to control pitch at cruise (more
drag) As
it was, I think the canard had a row of vortex generators. All of this
extra wing must be dragged along in cruise, which is why, hp per hp, any
given canard design will never be as fast and never land as slow as
equally
well designed conventional aircraft.
http://gravityloss.wordpress.com/2009/12/04/starship-vs-avanti/
That being said, there IS a regime where canard aircraft operate more
efficiently (key word), but that tends to be a slower speed, like 1.3 x
stall speed (if I recall correctly). And on a looks basis only, I've
always
been enamored by the Q-200.
Back to rotaries...
Chris Cosman
Good work and well put Chris. I learned a lot more about canards.
The Money spent on engineering school was not wasted :)
I am going to have to come up there and visit you guys when
you get a 1 rotor. We should have stopped on the way back from
the SCCA run offs in Elkhart Lake.
Paul Lamar
Thanks Paul. Just a "contact-intelligence" from hanging out with my
genius
father over the years. See, homeschooling does work. :)
We may put together a cross country down to Flabob later this year.
We'll
call if we do.
Chris Cosman
When you have a father like your father it certainly does.
Paul Lamar
I am deeply involved with canards. The involvement started about the
time Rutan released the Veriviggen(long before the VERI EZE). I can say
that his aircraft will not go into a flat stall or spin If several
conditions are met.
1. CG MUST be in the range that he requires.
2. Building the airframe MUST meet plans specifications.
After all he tested his prototypes at all CG's and attitudes
before releasing the plans.
3. The most common reason for problems with Rutan aircraft is putting a
larger engine than plans specs. moving the CG aft. There have been
several incidents of flat stall for this reason.
Not every one is a good builder and planes have been unsafe because of
poor construction, poor airfoil contour and even the airfoils not being
in the correct position on the fuselage.
4. Like all aircraft compromises were made for the intended use.
Because of this the canard as usually designed is not a slow landing
plane,but it sure goes fast for the horsepower.
chris smale
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