Planes with canards can't spin?
JJ Johnson
maker of some homebuilt aircraft. (Long EZ or something similar.)
Anyway, he says that it's impossible to spin a canard-type aircraft and that it
can actually climb at 800fpm while in a full stall.
Comments anyone? Or better yet.....an explaination from one of you aeronautical
engineer types.
Thanks!
JJ Johnson D-18218
Virginia Beach
Dave
it do so...
IIRC, canard designs are planned and built so that the canard "stalls" at a lower
angle of attack than the main wing. Loss of lift on the canard lowers the nose
which picks up airspeed and reduces angle of attack on the main wing. There are
documented incidents in the NTSB files of canards fliers who managed to get their
birds into deep stalls while doing flight testing with aft CG (the canard was too
big=too much lift ability, or they had gap seals on the canard=too much lift
ability). Keep in mind.. Any airfoil can stall. You can design and engineer a
combination of them together to be resistant to stalling as a whole, but you can
still stall. And if you can stall, you can spin.
Not an engineer, just read a lot,
Dave
mike regish
pullup where the inertia might carry the nose high enough to stall the
main wing. I've heard of the deep stall, but nobody has explained how
they happen.
mike regish
PP-ASEL
k8...@pop3.concentric.net
productive...
Anyway, those statements are garbage...
Denny
Ron Natalie
mike regish wrote:
>
> I've always wondered if you could stall a canard design with a quick
> pullup where the inertia might carry the nose high enough to stall the
> main wing. I've heard of the deep stall, but nobody has explained how
> they happen.
>
There was one that got flipped by wake turbulance. Otherwise, it seems
to be caused by out of limits CG.
Marc J. Zeitlin
>
> I've always wondered if you could stall a canard design with a quick
> pullup where the inertia might carry the nose high enough to stall the
> main wing.
Yes. While canard aircraft (the Rutan derivatives, at any rate) are
designed to be stall/spin resistant, any plane can be made to have an
accelerated stall. However, the basis for the stalll resistant design
is to protect against stall/spin accidents on approach, where the speed
is relatively constant and the problem comes with too tight turns.
I've ridden in a Long-Eze with the stick pulled back full. We had full
roll authority, full directional control, could turn as required, and
the throttle setting determined the descent/climb rate. At idle, we
decended about 600 - 800 ft./min. At full throttle, we were climbing at
600 ft./min. - mind you, this is with the stick pulled back all the way,
with the nose of the plane bobbing slightly as the canard stalled and
unstalled in what's called pitch-bucking. There's no anxiety at all,
and even in a 30 degree - 45 degree bank, the plane would not drop it's
nose or spin.
> ...... I've heard of the deep stall, but nobody has explained how they happen.
They happen when the CG is too far back, and the nose rises far enough
to allow the main wing to stall. If the nose isn't dropped quickly
enough, the stall locks in on both the main and canard wings, and many
times no amount of control movement or engine changes will unlock it.
The plane descends at a very flat attitude at a very high AOA, with
decent rates in the 4000 - 6000 ft./min. range. There have been a few
deep stalls of Velocities, and one of a COZY/AeroCanard, all attributed
to CG problems, canard incidence angle problems, or removal of lower
winglets.
Nat Puffer did extensive testing with a movable 135 lb. weight in the
COZY MKIV to test deep stalls. In the current MKIV configuration, the
only way to instigate a deep stall was to have the CG 2" behind the
rearmost approved position. The only way to get out of the deep stall,
once locked in, was to move the weight to it's fowardmost position to
get the nose to drop.
--
Marc J. Zeitlin email: marc_z...@agilent.com
Marc J. Zeitlin
> Anyway, those statements are garbage...
> JJ Johnson wrote:
> > Anyway, he says that it's impossible to spin a canard-type aircraft and that it
> > can actually climb at 800fpm while in a full stall.
While in theory it's possible to spin a Rutan derivative canard
aircraft, I've never heard of it being done, either on purpose or by
accident. I've already posted a message stating that the aircraft can
most definitely climb at a substantial rate while holding the stick full
back.
So, your claim that these statements are garbage is misleading, at best.
Newps
>
> > > Anyway, he says that it's impossible to spin a canard-type aircraft and that it
> > > can actually climb at 800fpm while in a full stall.
No airplane climbs in a stall. That's what stall means....not flying.
(Not counting fighters with more thrust than weight, their not planes
either when going straight up.) If you stall the main wing in a canard
then you most likely are really screwed. It may not recover. Good
article in Flying this month about canards and why they have been
relegated to the dustbin of history.
HLAviation
>it
>can actually climb at 800fpm while in a full stall.
>
>aeronautical
>engineer types.
>
Yes and no. There is a caveat here and that is the canard must be properly
designed built and rigged. The deal with a canard id that the canard is rigged
to stall before the main wing there by dropping the nose and blah blah
blah..therefore the main foil negets a chance to stall. When properly executed
in construction, this works perfectly. However, if incorectly done, these
little craft have a propensity for going directly into a flat spin. Not a lot
of fun if you're the test pilot. Best thing I found was to get rid of the
canopy and climb out on the nose and hope it breaks over. If yoiu can't
recover by 1500' seperate yourself from the plane and pull the chute.
Marc J. Zeitlin
>
> >
> > > > Anyway, he says that it's impossible to spin a canard-type aircraft and that it
> > > > can actually climb at 800fpm while in a full stall.
>
Read up on your aerodynamics. "Stall" means that the wing's lift curve
slope no longer increases with increasing AOA, and starts decreasing
with increasing AOA. The wing does NOT stop flying or producing lift;
it just produces less of it as the AOA increases. If you put enough
power in an aircraft, it will be able to climb with the front wing
stalled (and I'm not talking Thrust/Weight ratios higher than one).
In a canard aircraft, the front wing is small and it being stalled does
not substantially impact the total lift produced, so it is trivial for
the airplane to climb with the front wing stalled. As I've stated, I've
ridden in a L.E. that climbed while the canard was stalled.
> ........ Good
> article in Flying this month about canards and why they have been
> relegated to the dustbin of history.
This is just plain silly. There are over 2000 L.E.'s, V.E.'s, Cozy's
and other canards flying, and more are being built all the time. There
are over 500 Cozy MKIV's under construction as we speak. Canards
haven't caught on for certified GA aircraft for a number of reasons,
mostly having to do with the conservativism of the industry and the
difficulty of adding flaps to lower landing speeds, but the "dustbin of
history" is hardly where canards will end up.
Roy Smith
> Canards [...] the difficulty of adding flaps to lower landing speeds
Why is it difficult to add flaps to a Canard?
--
Roy Smith <r...@popmail.med.nyu.edu>
CP-ASEL-IA, CFI-ASE-IA
George R. Patterson III
mike regish wrote:
>
> I've always wondered if you could stall a canard design with a quick
> pullup where the inertia might carry the nose high enough to stall the
> main wing.
Yes. A friend of mine died when he managed to stall one on final. He had
about an hour in the plane, with no dual, and he had lots of time in a
V-tail Bonanza. When the canard stalled, it appears that he reacted by
pulling back sharply on the yoke about the time it started flying again.
The nose went up sharply, and he got a second stall that put the plane
pretty much straight down. That happened at about 800' AGL, and he went
into a parking lot.
George Patterson, N3162Q.
Charles K. Scott
mike regish <mre...@mediaone.net> writes:
> I've always wondered if you could stall a canard design with a quick
> pullup where the inertia might carry the nose high enough to stall the
> main wing. I've heard of the deep stall, but nobody has explained how
> they happen.
Deep stalls aren't limited to pusher canards, but the only recent
experiences with the phenomina have been with Velocities and under test
conditions with the Cozy. No Vari EZ's or Long EZ's to my knowledge
have experienced it. As Mark and others have stated, the pusher canard
is designed so that the canard stalls prior to the main wing, under all
flight conditions. This being the case, the main wing does not
unstall, ever, it remains fully flying. Spins start when one wing
stalls and that wing drops and begins the rotation. If both wings
remain flying, by definition no spin can occur.
In the case of the deep stalled Velocity's, again as Mark pointed out,
a too far aft CG could cause a high enough angle of attack to be
developed such that the main wing does in fact stall. In one instance
it was the use of gap sealing tape on the canard which increased it's
effectiveness to the point where it exceeded any previously reached
angle of attack and stalled the main wing. It was a test to see how
effective sealing tape would be on the canard. The answer was, very.
This happened out over the Atlantic and the test pilot was wearing a
chute. The airplane was coming down at a steady descent, absolutely
flat. Full throttle did not push the airplane fast enough to begin
flying again. The pilot opened the canopy and leaned out over the nose
as much as he dared but no change. He elected to ride it down to the
surface of the water as he really wasn't coming down that fast.
The airplane belly flopped into the sea just offshore and a helpful
boater who had observed the impact came over to help. The airplane
floated just like a boat and was towed to shore where the only damage
to occur to it happened with over enthusiastic helpers who pushed on
bendable parts while trying to get it onto the beach.
Velocity changed the strake profile and specified exacting CG
requirements and no further occurences have been reported with properly
designed canard type aircraft.
In article <38905831...@sensor.com>
Ron Natalie <r...@sensor.com> writes:
> There was one that got flipped by wake turbulance. Otherwise, it seems
> to be caused by out of limits CG.
In this particular case, the owner/builder deliberately modified the
gas tanks, adding space aft of the area allowed for increased tankage.
The kit manufacturer and several aircraft inspectors tried to persuade
the builder to not do this but he persisted. I'm not sure how many
hours he had in the airplane when the incident occured but it couldn't
have been very many. He got behind that commercial jet (actually
vectored there by ATC) that has extremely fierce vortex swirls and got
flipped upside down. His nose was high, the gas moved to the rear and
the main wing stalled while upside down. The engine quit because it
was carburated and carburators don't run at negative G's. He had no
chute so he was basically doomed to ride it in. The pilot was in radio
contact until impact which killed him, literally a victim of his own
obstinance.
In article <389068BC...@mcn.net>
Newps <ne...@mcn.net> writes:
> No airplane climbs in a stall. That's what stall means....not flying.
> (Not counting fighters with more thrust than weight, their not planes
> either when going straight up.) If you stall the main wing in a canard
> then you most likely are really screwed. It may not recover. Good
> article in Flying this month about canards and why they have been
> relegated to the dustbin of history.
Normally you'd be right except with the type of canard aircraft in
discussion there are actually two flying surfaces, the main wing and
the canard. The "stall" that was mentioned was of course the canard,
not the main wing. As Mark alread mentioned it is possible to fully
stall the canard and yet climb quite nicely. It's a matter of how much
power you use whether you descend, hold level or climb.
The flipside of canards is because the main wing never stalls, it also
isn't going as slow as it could go to land. The typical Long EZ and
Vari EZ is optimized for high speed cross country, not slow landing
speeds. They are around 70 to 80 mph over the fence. I only mention
this because an engine failure means a high speed touchdown and the
higher the speed you hit something the greater the severity of the
impact.
In article <20000127113853...@ng-cd1.aol.com>
hlavi...@aol.com (HLAviation) writes:
> >Anyway, he says that it's impossible to spin a canard-type aircraft and that
> >it
> >can actually climb at 800fpm while in a full stall.
> >
> >Comments anyone? Or better yet.....an explaination from one of you
> >aeronautical
> >engineer types.
> >
>
> Yes and no. There is a caveat here and that is the canard must be properly
> designed built and rigged. The deal with a canard id that the canard is rigged
> to stall before the main wing there by dropping the nose and blah blah
> blah..therefore the main foil negets a chance to stall. When properly executed
> in construction, this works perfectly. However, if incorectly done, these
> little craft have a propensity for going directly into a flat spin. Not a lot
> of fun if you're the test pilot. Best thing I found was to get rid of the
> canopy and climb out on the nose and hope it breaks over. If yoiu can't
> recover by 1500' seperate yourself from the plane and pull the chute.
So HLAviation, have you actually spun one of these airplanes or knew of
someone who did?
Thanks, Corky Scott
David Fielding
up the relationship between the canard and the wing that gives the
stall-resistance.
To really do the job right would probably require flaps on both surfaces, or
drooping of the canard elevators somehow, to increase effective AOA on both
canard and wing.
David Fielding
Systems Manager, Llewellyn & McKane
(570) 822-8181
----------
In article <roy-BD2B47.1...@netnews.nyu.edu>, Roy Smith
Steve Won
> stalls and that wing drops and begins the rotation. If both wings
> remain flying, by definition no spin can occur.
The FAA disagrees with you: a spin can only happen when both wings are
stalled, but one is stalled more than the other.
-------------------------------------------------------------------
Semper Fi PFC Steven H Won Weapons Company
"Ding" 2nd Batallion
PP-ASEL 24th Marines
Duct tape is like the Force, it has a Light side and a Dark side and it
holds the Universe together.
Piper News Reader
>
> > > Anyway, he says that it's impossible to spin a canard-type aircraft and that it
> > > can actually climb at 800fpm while in a full stall.
Isn't the definiton of a stall the state where the wing is no longer flying? Therefore
an 800 fpm climb while in a full stall is a bit optimistic, yes?
>
> I've already posted a message stating that the aircraft can
> most definitely climb at a substantial rate while holding the stick full
> back.
And the stick full back does not result in a stall :)
Phil T
------------------------------------------
Fly Right, Be Safe
PA24-260C N9312P
Marc J. Zeitlin
>
> "Marc J. Zeitlin" <marc_z...@agilent.com> wrote:
> > Canards [...] the difficulty of adding flaps to lower landing speeds
>
> Why is it difficult to add flaps to a Canard?
Flaps substantially change the moment coefficient of the wing they're
added to (when extended). If you add flaps to the main wing of a canard
aircraft, you substantially change the interaction between it and the
canard, which would have to be able to provide a lot more lift when the
flaps were deployed.
One could do this in a number of ways - one could add flaps to the
canard as well, and link them to the main wing flaps so that they extend
simultaneously. One could move the canard forward and backward, one
could enlarge the area of the canard in some manner, etc. These are all
very difficult. The Beech Starship had a canard that could sweep
forward and back in synchrony with the flaps on the main wings, but this
is clearly a difficult, expensive, and complicated proposition.
Charles K. Scott
Roy Smith <r...@popmail.med.nyu.edu> writes:
> "Marc J. Zeitlin" <marc_z...@agilent.com> wrote:
> > Canards [...] the difficulty of adding flaps to lower landing speeds
>
> Why is it difficult to add flaps to a Canard?
I think it has to do with the special relationship between the canard
and the main wing. The canard is designed to stall first so that the
main wing does not stall, ever. In order to do this properly, the
canard really can't be very large or it would be too effective. So if
you then put flaps on the main wing, two things would happen: 1. When
the flaps are lowered, the angle of attack will likely change; in most
cases, the nose drops. This would meant that the canard would have to
support more weight to bring the nose up. 2. With the main wing flying
slower, the canard will now stall and be unable to hold the nose up.
It's problematic to put flaps on the canard too because it's a very
small airfoil and is sized that way so that it stalls first, getting it
flapped properly so that it fits the now much more narrow window of
operation would be really tough.
The Starship has a canard that is either straight out or swept back
depending on airspeed and the main wing flaps, for this reason. Or at
least I thought that airplane had flaps.
Anyway, it sounds like it's very very hard to design the canard to work
in both regimes.
Corky Scott
Charles K. Scott
"Steve Won" <sw...@uiuc.edu> writes:
> The FAA disagrees with you: a spin can only happen when both wings are
> stalled, but one is stalled more than the other.
Ok. I'm not going to argue with the experts, it's pretty much what I
meant anyway.
Corky Scott
le...@homer.premrad.com
Exactly. When people discuss a canard-type design "climbing while stalled"
what they are actually describing is "climbing while the CANARD is stalled."
The canard is typically at a higher AOA than the main wing. Theory is that
the main wing cannot stall because the canard stalls first, so it lacks the
authority to raise the main wing's AOA to the point of stall.
9I know a couple of others said this in more detail, I thought I'd just
through a wuick summary out)
Steve
Steve Won
message news:86qapq$kam$1...@merrimack.Dartmouth.EDU...
I'm no expert, but that's what it said to say on my written test :)
k8...@pop3.concentric.net
web site, and I am a registered builder of a MkIV... Having said that, I will again say
that the the statements as initially reported here without a source being identified -
and the writer of the post asked for opinions - are aeronautical garbage... Now let us
discuss why I say that...
Full back stick in a canard planform is not a stalled condition for either the canard
or (god forbid) the main wing... The canard wing has limited pitch control authority by
design...
With full back stick, at the moment the pitch angle of the airframe stops increasing
the main wing is definitely not stalled and has a lift coefficient in the range of 0.8
to 1.1, and at that exact moment the canard cannot raise the pitch angle of the
airframe any higher and has a coefficient of lift of about 1.3 (not zero)... Why?
Because the canard wing has simply entered the roll off portion of the L/D ratio and
the lift being generated by the canard exactly matches the weight applied by the
pitching moment of the main wing to the canard, thus the canard cannot increase the
pitch angle of the airframe (or itself) beyond that point... It is not stalled, it
simply cannot increase it's lift due to entering the roll over knee on the L/D ratio
and is hanging there... And, if the canard were aerodynamically stalled, i.e.
complete separation of attached airflow, and with the main wing still lifting the
airframe, the forward pitching moment would cause an immediate and dramatic dive
before reattachment of the airflow and recovery of canard lift... I urge you to read
the definitions and peruse the graphs of the stalled condition versus entering the roll
off, by Von Doenhof, or Hollman, et. al. for clarification of these points...
Now, unless you are flying machinery in the F15 class that have a thrust to weight
ratio greater than 1:1, or sitting on top of a Saturn rocket, there is no way that a
stalled wing can CLIMB... To claim that it does violates the laws of physics, a couple
of laws of aerodynamics, and my finely, honed sense of smell for aeronautical
garbage... A stalled wing cannot lift because when stalled the airflow has detached and
the lift generated is only the flat plate thrust value (there are some other forces
here, but we are keeping it simple)... Remember, the main wing of the canard planform
absolutely did not stall... The pitch authority of the control system is designed to
prevent that... The main wing is still lifting... This point will become important
further on, here... Stalled wings cannot climb!
Now Marc, since you ARE describing the behavior of any properly built and rigged Cozy,
what is actually going on...
First, we have a canard that is properly sized so that for any weight within the
allowable C of G range, and for any allowed, non-accellerated maneuver, the canard
reaches the roll off portion of the L/D ratio before the main wing does...
If the canard is sized too big you could pitch up far enough to stall the main wing...
Bad, bad, idea in a canard...
If the canard is too small you will never stall the main wing, but you also may not be
able to flare enough during the landing to avoid wiping out the nose wheel.... Bent
metal, torn fiberglass, not fun at all...
So, there we are with the canard lift exactly matching the pitching moment from the
main wing, and everything is in balance just like a see saw... If the canard angle of
attack increases even a tenth of a degree the lift rolls off several percent and the
nose drops slightly.. The lowered angle of attack of the canard by few tenths of a
degree causes the lift to slide back up the roll off curve by several percent and lift
the nose again... And we go gently bobbing along, as Marc points out...
Now, let us turn to the claim that a canard aircraft will climb while fully stalled...
Well, the main wing is NOT stalled, as discussed above... If it was, the ship would
pitch backwards onto its back (not good!)... And, the canard is not stalled or the ship
would pitch forward into a dive (may or may not be good, depending)...
Now trooops, what makes a plane climb? (all together)... POWER!!!
Of course... So, we take our beautiful Cozy and increase the power while bobbing along
with the stick full back and what will it do? CLIMB! As Marc correctly pointed out...
Mystery solved... Canards are indeed great airplanes...
OK, lastly the spin... very briefly... Canards don't spin, or do they?
Well, at least one heavily abused canard ship spun in, so they will spin if the main
wing is stalled...
What is a spin? A spin requires one wing to be stalled while the other is still
lifting in order to generate the rotation... But, we design canards so that the main
wing never, never, never, stalls...
So, are canards spin proof? Nope... Stall the main wing and they will spin... But,
follow Nat's and Marc's advice on the building and rigging of your beautiful Cozy, and
they are spin resistant, and perfectly safe...
How did I do, Marc?
Denny
To beat a dead horse now...
1. Stalled wings can climb? - Nope, Total Horse Pucky...
Canards are spin proof! - (depends upon word definitions)... Canards are spin
resistant, just don't stall the main wing...
"Marc J. Zeitlin" wrote:
> k8...@pop3.concentric.net wrote:
>
> > Anyway, those statements are garbage...
>
> > JJ Johnson wrote:
>
> > > Anyway, he says that it's impossible to spin a canard-type aircraft and that it
> > > can actually climb at 800fpm while in a full stall.
>
> While in theory it's possible to spin a Rutan derivative canard
> aircraft, I've never heard of it being done, either on purpose or by
> accident. I've already posted a message stating that the aircraft can
> most definitely climb at a substantial rate while holding the stick full
> back.
>
> So, your claim that these statements are garbage is misleading, at best.
>
mike regish
(EZ, Cozy, etc.) but could excess inside rudder stall the inside wing in
a turn? I have a hang glider (EZ Riser) that has tip rudders that seem
to act more like air brakes for turning. Do the EZ's work the same way
and if so, does that present a possibility of a stall/spin entry?
Great thread. I've always been intrigued by the canard pushers.
mike regish
PP-ASEL
Miklisdan
>productive...
>
What do you do with YOUR time?
Julius Lancer
>So I'm watching "Sport Aviation" on SpeedVision and they're interviewing the
>maker of some homebuilt aircraft. (Long EZ or something similar.)
>
>can actually climb at 800fpm while in a full stall.
The definition of a stall is that the plane is not producing lift. It is
impossible to climb in a stall unless the engine produces more thrust than the
weight of a plane (eg F-16).
I suspect that putting most any canard in a steep bank would coax a stall
that could produce a spin.
John - N8086N
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Marc J. Zeitlin
>
> Marc, I have the utmost respect for your knowledge of Cozy's, and I am a reader of your
> web site,
Hey, you don't have to butter me up :-).
> ..... and I am a registered builder of a MkIV...
Great! You should join the mailing list.
> Full back stick in a canard planform is not a stalled condition for either the canard
> or (god forbid) the main wing... The canard wing has limited pitch control authority by
> design...
Partially agree. The main wing is certainly not stalled, but the canard
is stalling and unstalling in the "pitch buck" rythym - about one half
to one HZ, depending upon CG position, IIRC.
> the main wing is definitely not stalled and has a lift coefficient in the range of 0.8
> to 1.1, and at that exact moment the canard cannot raise the pitch angle of the
> airframe any higher and has a coefficient of lift of about 1.3 (not zero)...
Agreed.
> Because the canard wing has simply entered the roll off portion of the L/D ratio....
I understand and agree with your arguments, but you're referring to the
Lift Coefficient/AOA curve here, not the L/D curve. The L/D curve is
totally immaterial to the subject at hand.
> ..... And, if the canard were aerodynamically stalled, i.e.
> complete separation of attached airflow,....
Here's part of the problem - "stall" does not imply "complete seperation
of attached airflow. "Stall" onset is where the CL/AOA curve peaks -
the airflow is still partially attached, and the wing is still producing
lift - close to the maximum amount it can, actually.
> ..... and with the main wing still lifting the
> airframe, the forward pitching moment would cause an immediate and dramatic dive
> before reattachment of the airflow and recovery of canard lift...
Only if the canard got well above the stall AOA - in a normal pitch
buck, the nose drops about 3 degrees when the canard stalls, so the nose
bobs up and down about 3 degrees every second or so as the canard stalls
and unstalls.
> .... I urge you to read
> the definitions and peruse the graphs of the stalled condition versus entering the roll
> off, by Von Doenhof, or Hollman, et. al. for clarification of these points...
Yeah, well, I think that a B.S. and M.S. in Aeronautical Engineering
from M.I.T. covered that reasonably well, unless aerodynamics has
changed a lot in the past 20 years. I've got a pretty good
understanding of what's going on here, I think, and I've read both VD
and Hollman.
> ..... A stalled wing cannot lift because when stalled the airflow has detached and
> the lift generated is only the flat plate thrust value (there are some other forces
> here, but we are keeping it simple)... Remember, the main wing of the canard planform
> absolutely did not stall... The pitch authority of the control system is designed to
> prevent that... The main wing is still lifting... This point will become important
> further on, here... Stalled wings cannot climb!
You're confusing a number of aerodynamic issues here. As stated before,
a stalled wing most definitely DOES produce lift - the CL does NOT drop
to zero as the wing stalls or continues on past the stall AOA. Also, a
flat plate works just fine as a wing - it's just got crappy drag numbers
and a low maximum CL. Also as stated before, just because an airfoil is
stalled does NOT mean that the flow has completely detached, and while
you are correct that the main wing is NOT stalled, you are incorrect in
claiming that the canard isn't.
You also may want to read some reviews of the Glasair "Glastar" 2-place
aircraft. IIRC, at full throttle and with the wing stalled, this
aircraft can climb, with a thrust/weight ratio well under 1:1 (it's got
an O-320 in the most common configuration). This is a "conventional"
aircraft, not a canard.
> ......... the canard
> reaches the roll off portion of the L/D ratio before the main wing does...
Again, it's the CL/AOA curve, not the L/D curve.
> If the canard is sized too big you could pitch up far enough to stall the main wing...
> Bad, bad, idea in a canard...
Agreed.
> If the canard is too small you will never stall the main wing, but you also may not be
> able to flare enough during the landing to avoid wiping out the nose wheel.... Bent
> metal, torn fiberglass, not fun at all...
Agreed.
> ... And, the canard is not stalled or the ship
> would pitch forward into a dive (may or may not be good, depending)...
Here's where you're mistaken, as explained before.
> How did I do, Marc?
C- .
> To beat a dead horse now...
> 1. Stalled wings can climb? - Nope, Total Horse Pucky...
Shown to be incorrect.
> Canards are spin proof! - (depends upon word definitions)... Canards are spin
> resistant, just don't stall the main wing...
Agreed.
Timothy M. Metzinger
<dfi...@epix.net> writes:
>Flaps on the main wing would change its effective angle of attack, and foul
>up the relationship between the canard and the wing that gives the
>stall-resistance.
>
>To really do the job right would probably require flaps on both surfaces, or
>drooping of the canard elevators somehow, to increase effective AOA on both
>canard and wing.
>
Didn't the Starship have some sort of arrangement with flaps on the main wing,
and piviting of the canard?
Timothy Metzinger
Commercial Pilot - ASEL - IA AOPA Project Pilot Mentor
DOD # 1854 '82 Virago 750 - "Siobhan"
Cessnas, Tampicos, Tobagos, and Trinidads at FDK
Marc J. Zeitlin
>
> I don't know how the rudder or yaw control works on a canard type pusher
> (EZ, Cozy, etc.) but could excess inside rudder stall the inside wing in
> a turn?
Probably, but less so than on conventional planes. However, as has been
stated before, the main wing is far enough away from a stall even when
the canard is stalled (or pitch bucking) so that you'd have to be in a
VERY steep turn before you'd stall the inside main wing. It's probably
doable, but I've never heard of anyone have it happen to them. It's
pretty obvious when you're in this condition - the nose is very high,
and it's bobbing up and down. Shallow turns (20 deg. - 30 deg. ? ) are
safe, but I don't know that anyone would really crank it over, even by
accident. Also, at those speeds, you don't have a lot of aileron
authority - it's pretty mushy.
> ... I have a hang glider (EZ Riser) that has tip rudders that seem
> to act more like air brakes for turning. Do the EZ's work the same way...
There is a drag component on the wingtip rudders - that's why the EZ
type aircraft have rudders that only hinge outward - if they hinged
inward, the drag component would be counteracting the lift component for
moment generation. Both rudders can be deployed independently and act
as drag brakes if so desired.
> and if so, does that present a possibility of a stall/spin entry?
See above - it's less likely than on conventional aircraft due to the
relationship between the canard and the main.
> Great thread. I've always been intrigued by the canard pushers.
As well you should be :-).
Jerry Kurata
a "deep stall" is in relation to a getting the nose of a T-tailed aircraft
so high that the wing blanks out the airflow to the tail. So the tail
stalls because of lack of airflow and the plane is locked into a nose high
attitude with no elevator control to push the nose over.
Jerry
George R Patterson
Same deal with a canard. If you can manage to stall out both the canard
and the main wing, the aircraft stays in a nose-high attitude, and you
can't get it out. As many people have pointed out, this seems to be
impossible to do in most canard airplanes.
George Patterson, N3162Q.