Talk:Canard (aeronautics)

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Fake the duck[edit]

Strictly technically speaking, the Sukhoi-27 derivatives are NOT canards, because they also have tailpanes. In fact the russians themselves refer to these aircraft as having an "integrated tandem tri-plane" aerodynamics configuration instead. 82.131.210.162 16:48, 12 September 2007 (UTC)

Having tailplanes does not negate the canard aspect. Read the lead paragraph. AKRadeckiSpeaketh 16:54, 12 September 2007 (UTC)
An aircraft with a canard AND a tailplane is a "three surfaces" aircraft, not a canard. Plxdesi2 (talk) 20:52, 9 April 2013 (UTC)
I wonder whether term "canard" is really an adjective, as in "canard configuration" and "canard foreplane". In ordinary English a plain "canard" means a distraction or red herring (as in "flying a canard" to distract people from the truth), while ISTR that in French it often means an ill-conceived project or white elephant. Whether the term is ever authoritatively used for a three-surface foreplane is something I don't know, but unless it can be verified I would assume it has not. — Cheers, Steelpillow (Talk) 09:37, 15 April 2013 (UTC)

Piaggio P-180 should be removed from gallery[edit]

The P-180 does not have a canard because the front wing does not have any control surfaces on it. Piaggio specifically points this out on their website:

http://www.piaggioaero.com/en/products/aircraft/p180/efficienza.php

"The Avanti II's forward wing (which is not a canard because it has no control surfaces) " —Preceding unsigned comment added by Lindec (talkcontribs) 17:38, 20 January 2008 (UTC)

I object... A new section should be created, and exceptions should be placed there. The new section could be named, for example, "Aircraft not considered canard aircraft". For each entry, a short note describing why it's not a canard aircraft should be included. --Henrickson User talk | Contribs 21:43, 20 January 2008 (UTC)
I don't think either a special section or deleting the Avanti picture is required. If you read the article: non-moving surfaces are included as canards, so the Avanti's front surface is a canard by that definition. It is fine as it is. - Ahunt (talk) 22:22, 20 January 2008 (UTC)

References[edit]

This article is a great opinion essay, but is not of very much value as an encyclopedia article, because it does not cite references, with the sole exception of one general ref at the bottom. I have tagged each para to show where in-line citations are needed. Please do not remove these tags unless they are replaced with footnotes. - Ahunt (talk) 12:11, 8 February 2008 (UTC)

canard aerodynamics[edit]

What canards do is to create additional wing tip vortices which are forced towards the main wing due to the canard induced downwash. These vortices re-attach the flow of the main wing near the wing root and offer improved high alpha (high AoA) performance. A good citation of the issue is the book of Klaus Huenecke, Modern combat aircraft design.

As far as I know the canard existence does not increase the blade root drag. The total drag however could be increased due to the existence of the canards as...external elements.

georgepehli (talk) 10:07, 16 May 2008 (UTC)

Contradictions in the pro and con sections[edit]

With regard to the canards always/sometimes stalling before the main wings, and the main wings stalling/never stalling. I don't really know, I just noticed, and "must be designed to stall before the main wing" sounds like pure BS to me. Why must it be designed that way? By U.S. law? By some international agreement? Or is just because of good taste of the designer? ;-) --80.134.46.77 (talk) 14:05, 19 May 2008 (UTC)

It is actually mentioned in a couple of books that the canards should be deigned to stall before the main wings. This as far as I know there is no US Law for that (except if we assume that the canards are some kind of terrorists ;-) ). The actual reason is that the canards create pitching moments due to their lift. Therefore if the main wing is stalling and the canards produce lift then the plane gets a highly unstable attitude. This can cause dangerous stall/spin situations e.t.c. However this is not the case in combat aircrafts, since these planes are already designed to be unstable (or...artificially stable) in order to be more manuverable. Therefore I do not think that the comment about the stalling point applies in general. Maybe a special note is needed. georgepehli (talk) 21:40, 19 May 2008 (UTC)

Overuse of fact tags.[edit]

"This template is intended for specific passages which need citation. For articles or sections which have significant material lacking sources (rather than just specific short passages), there are other, more appropriate templates, such as {{unreferenced}}." Tagging every paragraph in the article adds nothing but clutter. Gigs (talk) 04:33, 5 August 2008 (UTC)

Fine, works for me. :P Gigs (talk) 04:42, 5 August 2008 (UTC)

Characteristics[edit]

I have restored a much-modified discussion of the characteristics of canard aircraft, and have added another reference. Hopefully none of the addition is contentious, so it should not need any inline cites. If any of it does not come up to scratch, it should be possible just to remove those bits rather than the entire discussion, which IMHO is sorely needed. -- Cheers, Steelpillow (Talk) 22:08, 5 September 2008 (UTC)Fixed-pitch canards

I would say at least some of that is quite contentious. For instance:

"In order to provide stability in pitch, a canard foreplane is trimmed to a higher angle of incidence than the main wing. This contrasts with the need to trim a conventional tailplane to a lower angle."

"Due to this high angle of incidence, a canard foreplane produces more lift per unit area than a conventional tail plane (i.e. it is more highly loaded). This allows both the canard and the main wing to be smaller, reducing overall drag and weight, and increasing performance."

Actually most canard aircraft use a completely different airfoil for the canard than the main wing (see The Incomplete Guide to Airfoil Usage - Canards) and these airfoils are selected specifically because the forward one doesn't have to operate at higher drag increased angles of attack in cruise just to stall first. Instead the airfoil selected for the canard will naturally stall at a lower angle of attack than the main wing airfoil and this may mean that the canard is actually set at a lower angle of incidence than the main wing in some cases.
I think the text needs some revisions and definitely needs inline citations to support it. - Ahunt (talk) 23:05, 5 September 2008 (UTC)
I endorse Ahunt's view that Steelpillow's additions need inline citations. Much of what Steelpillow has added looks like little more than popular but scientifically-incorrect views. For example, consider the leading sentence In order to provide stability in pitch, a canard foreplane is trimmed to a higher angle of incidence than the main wing. A canard foreplane may well be rigged at a higher angle of incidence than the main wing, and the converse for a conventional stabiliser, but this has NOTHING to do with Longitudinal static stability! There are various strategies available to aeronautical engineers to increase or decrease the static margin, but fiddling with the rigging incidence of the horizontal stabiliser or canard foreplane isn't one of them. (The rigging incidence is determined more by attempting to have the fixed stabiliser and moveable elevator colinear in cruise at a representative CG position.) If Steelpillow methodically looks for references for each of his additions with a view to finding a citation for each one, he (or she) will find many of his statements cannot be supported and so must be deleted. Dolphin51 (talk) 08:23, 6 September 2008 (UTC)
Fair enough, I should perhaps have qualified the statement about angle of incidence in some way or discussed angle of attack instead, but I was trying to keep the introduction simple and clear: the theory of canard design gets quite complicated quite quickly. I disagree with Dolphin51's idea that the relative angle of incidence has nothing to do with stability. I recall a prototype (forgotten its name) from the 1970's which for simplicity employed three identical wing pieces for left and right main and whole fore planes. To provide longitudinal static stability, the foreplane was rigged to a higher incidence than the main wing. Of course the center of gravity needs adjusting accordingly, but that is not the point being made here. And yes, many designs modify the canard aerofoil section for this reason among others - I also mention this later on, but perhaps it should be given more prominence. I suppose one's approach depends on whether one is considering how to fiddle the airfoil to stabilise a given planform, CG and incidence, or how to fiddle the planform, CG and incidence to accommodate a given aerofoil. Perhaps this is why there seem to be two competing strands of popular "folkore" - one that canards are inherently stable and safe, and the other that they are inherently vicious little brutes. The truth is far more complex. I have tried to touch on this issue in a non-contentious way, evidently without success. Perhaps some inline cites might be necessary if things get too heated, but I think it better to avoid contentious areas of opinion as far as possible and stick to well established principles to be found in the referenced literature (maybe I may not have done as well there as I thought either). Anyway, I thought the important thing was to get something up there for people to improve on - nobody is going to write a perfect and accessible overview of canard theory first time round! Go to it. -- Cheers, Steelpillow (Talk) 13:35, 6 September 2008 (UTC)

Hi Steelpillow. Thanks for the prompt reply. The Wikipedia approach is to begin with that information for which you have citations, and hope that other editors fill in the gaps with verifiable information of their own. The approach whereby one editor writes down what he believes to be true in the hope that other editors will find suitable citations is discouraged. WP:VERIFIABILITY contains the advice that The threshhold for inclusion in Wikipedia is verifiability, not truth. You have given as one of your references Mechanics of Flight by A.C. Kermode; but without quoting an edition number or chapter or verse. I have the eighth edition open in front of me. Admittedly this is now an elderly edition, but the Index does not mention the word canard. In Chapter 5, Level Flight there is a very brief mention of tail-less and tail-first aeroplanes, including a photograph of the experimental retractable fore-planes on the Dassault Mirage Milan, but little more. If you are planning to use Kermode as a source for your information it will be important to quote edition number, chapter etc. I suggest you delete all your information for which you can't provide an in-line citation, and then proceed to add information with citations. Regards. Dolphin51 (talk) 06:58, 7 September 2008 (UTC)

Verifiability is necessary, as you say. But that is not to say that sometning must be verified before it it written up. WP:POLICY states:
Editing policy
Improve pages wherever you can, and don't worry about leaving them imperfect. It is advisable to explain major changes.
and Wikipedia:Editing policy expands on this.Fixed-pitch canards
Your criticisms make it clear that some of my "facts" are questionable and that my attempts at netural POV were not very successful. My hope is merely that others will take the section from here and improve it, rather than delete it all wholesale.
As for citations and references, I'll delete Kermode. My memory must have let me down: I know I read most of that stuff somewhere, but my (very old) reference books are all in storage, and it may not be in any of them anyway. So unfortunately I cannot add sensible references at this point. (Instead, I have tried to include example aircraft which illustrate the point). Nevertheless, I think there should be enough non-contentious material to allow some sort of discussion to remain, and sooner or later someone with access to better references will come along.
Meanwhile, if you see a way to make improvements, please feel free to attack the section with vigor - you will not offend me. I'll see if I can think of some way to accommodate your technical POV, too. -- Cheers, Steelpillow (Talk) 10:22, 7 September 2008 (UTC)
Thanks Steelpillow. The history of Canard (aeronautics) shows that by 13 July 2008 the article had comprehensive information about the characteristics, advantages and disadvantages of tail-first configurations, but all of that information was unsourced. Every paragraph carried a "citation needed" tag. On 5 August 2008 there was a mini edit-war and all the unsourced information was finally deleted, leaving the article in the state you found it a week ago. Clearly, there are lots of views and ideas out there about canards, but none of us has been particularly successful in finding authoritative sources to support that information. I will do what I can to find authoritative sources and begin re-building the article over the coming week. Dolphin51 (talk) 01:23, 8 September 2008 (UTC)
Well, I am disappointed that you felt the whole thing had to go. But I'm not going to start another edit war. At least, I hope the structure I gave it was a better starting point than the previous one. Especially, the close coupled canard delta is an important canard configuration, given its prevalence among modern combat aircraft, so that discussion needs to come back eventually. -- Cheers, Steelpillow (Talk) 19:57, 8 September 2008 (UTC)

The concept of the so-called close coupled canard can be retained. I have Aircraft Design: A Conceptual Approach by Daniel P. Raymer (AIAA Education Series, New York, NY) and he distinguishes between the lift-canard and the control-canard. In WP, citations are everything. The control-canard mostly operates at zero lift coefficient and its role is to generate beneficial vortices and downwash onto the mainplane for the purpose of boundary layer control at high alpha. The control-canard is seen in high performance combat aircraft. The lift-canard mostly operates at a significant lift coefficient and is seen in low performance aircraft such as the Rutan Vari-Eze. Dolphin51 (talk) 23:12, 8 September 2008 (UTC)

Fluid dynamics as well?[edit]

This article is linked from the Sea_Shadow article. Could someone please explain how it applies to water vessels as well? Aar☢n BruceTalk/Contribs 21:20, 24 February 2009 (UTC)

I checked that - just a linking error I suspect, it isn't really the right place to send readers for more info, is it? - Ahunt (talk) 21:39, 24 February 2009 (UTC)
I think they meant to link to Hydrofoil. --McSly (talk) 22:53, 24 February 2009 (UTC)
Hydrofoil would make sense. Dolphin51 (talk) 01:44, 25 February 2009 (UTC)

Lifting-canard[edit]

On 4 April 2009, user 208.103.75.112 added three paragraphs under the sub-heading Lifting-canard. None of the additional information was supported by a reference or an in-line citation.

I believe most of this additional information reflects a popular understanding of lifting-canards, but unfortunately it contains a fair amount of hangar talk and it is not sufficiently accurate for Wikipedia. I will shortly give my reasons for believing it is not accurate.

I will delete the information added by 208.103.75.112. I have no obection to someone restoring some or all of that information, provided it is accurate and supported by a suitable in-line citation.

Here is my analysis of the additional information:

An added advantage of a lifting-canard is the prevention of stalls.
COMMENT: The canard configuration is not intrinsically immune to high-alpha stalls. It can be designed to be spin-resistant, but so too can the conventional aft-tail configuration. A poorly designed or operated canard aircraft can be just as vulnerable to the high-alpha stall as a conventional aircraft. In some respects, the canard configuration requires greater attention to detail to protect against poor low-speed handling characteristics. For example, the upwash from the vortices which trail behind the canard cause the angle-of-attack on the outboard regions of the main wing to be higher than it is on the inboard regions. This promotes wing-drop at high angle-of-attack and so necessitates special steps to guard against wing-tip stall.


In a conventional aft-tail design, it is possible for the pilot to place the aircraft in an attitude in which the main wing is no longer producing lift (most commonly by attempting to fly at too steep of an angle). This is a safety issue -- to recover, the pilot must "push forward" to dive and thus increase airspeed, which is both a counter-intuitive action and one which requires enough altitude from which to descend to recover enough airspeed for the main wing to begin flying again.
COMMENT: The editor’s objective here is unclear. In a canard aircraft the pilot must also push forward to increase airspeed. If pushing forward to avoid low-speed handling problems is counter-intuitive in an aft-tail aircraft, it is also counter-intuitive in a canard aircraft.


Many lifting-canard aircraft are designed such that the canard is set at a higher angle of attack than the main wing.
COMMENT: To achieve longitudinal static stability, I would say that all lifting-canard aircraft must operate with the canard at a higher angle-of-attack than the main wing. However, this is achieved by appropriately specifying the aft center-of-gravity position. CG position and fore-plane/tail-plane angle are tied together by the need for the aircraft to be balanced in pitch during flight. When the designer specifies one, the other follows automatically. It is a simple matter to specify CG position and then determine what fore-plane/tail-plane angle is needed to support that position. It would be much less practical to specify fore-plane/tail-plane angle and then determine what CG position is needed, because the result would most likely be an impractical loading case.


It will thus stall before the main wing, and the nose will drop back to a safe attitude.
COMMENT: In Aircraft Design: A Conceptual Approach, Daniel Raymer says: … a canard can be made to stall before the wing by making it a very high-spect-ratio surface. This prevents the pilot from stalling the wing, and is seen in several canarded homebuilt designs. (Page 56, fourth edition.) In this book, Raymer is identifying the way choice of aspect ratio is important in designing a canard aircraft with good low-speed handling characteristics. Raymer is fully aware that the canard configuration is not intrinsically spin-resistant, and must be designed carefully if it is to have good handling qualities.


If the pilot attempts to hold the nose up, a periodic (but generally safe) "nose bob" effect may occur.
COMMENT: Yes, in a well-designed and correctly operated canard, if airspeed is reduced slowly ( eg one knot per second) the aircraft will display a minimum steady-flight speed rather than a stall. Most aft-tail aircraft at forward CG position also display a minimum steady-flight speed rather than a stall when airspeed is reduced slowly. However, when the approach to the stall is accelerated (eg three to five knots per second) the result may be different, regardless of whether the aircraft has a fore-plane or a tail-plane!


In some aircraft, such as the Cozy MK IV, testing for this effect is part of the standard flight testing procedures.
COMMENT: What standard flight testing procedures does the editor have in mind?


However, this effect also requires a specific aircraft center-of-gravity (CofG) range, specified by the manufacturer/designer. Pilots must take care to ensure the aircraft is always within the specified range. Otherwise, under certain conditions, a main wing stall is possible.
COMMENT: All this is universally true. It is just as true for aft-tail aircraft as for canards, except that main-wing stall is usually not a problem for aft-tail aircraft.


In a lifting-canard, this often leads to a "deep stall" from which recovery is difficult or impossible to Fixed-pitch canardsachieve.
COMMENT: If it happens often there would not be many lifting-canard aircraft remaining! I think the expression deep stall used here is very different to the deep stall that troubles designers of T-tail jet aircraft.

Dolphin51 (talk) 02:45, 5 April 2009 (UTC)

D51: Good analysis. I agree that most of it is WP:OR or just plan apocryphal. I tagged it for refs and had it on my list to cut it all unless refs were cited within a few days. You saved me the work! - Ahunt (talk) 12:47, 5 April 2009 (UTC)

Alternatives[edit]

Fixed-pitch canards Chines and leading edge extensions are often used as alternatives, but the current article doesn't say much about this. Can somebody drag up some refs for the tradeoffs please? Hcobb (talk) 21:33, 1 August 2009 (UTC)

The GAO should have a report somewhere that states that canards would have more cost effective on the F-22 than LERXes, and how much using LERXes cost the US taxpayers. P: - BilCat (talk) 22:12, 1 August 2009 (UTC)

Restructuring[edit]

I'd like to do some significant restructuring:

  • Discuss lifting canards before control canards, since that was the historical development.
  • Add a third class for ride control, as in the B-1 Lancer.Fixed-pitch canards
  • Sub-divide the list of examples into the three classes.

Any objections or other comments? -- Cheers, Steelpillow (Talk) 12:33, 14 August 2009 (UTC)

Historically the key problem with this article has been uncited and speculatory text, so I would say as long as you have refs then by all means do so! - Ahunt (talk) 19:07, 14 August 2009 (UTC)
Is linking to an existing article good enough, if that article already has a decent bibliography? I do not intend to add any information that is not already present on Wikipedia. In fact, all but the phrase "Active vibration damping" is already in this article. -- Cheers, Steelpillow (Talk) 20:14, 16 August 2009 (UTC)
Each article really needs its own footnoting. It doesn't help readers if the refs are elsewhere, as they can't assess the accuracy of the article and also the refs may be removed from the other article or even the article deleted! You can cheat a bit and copy refs over, however. - Ahunt (talk) 22:18, 16 August 2009 (UTC)
OK I had a go - durned login session timed out and logged it as an IP edit. The B-1 Lancer article does not cite a specific reference for active vibration damping, but it is a well-enough known feature that it is surely covered in the docs given as general references - none of which I have, so I can't copy one across as a specific ref here. Hope it's acceptable to just link the Lancer article as my "reference". -- Cheers, Steelpillow (Talk) 21:12, 19 August 2009 (UTC)

Fixed-pitch canards[edit]

How should we classify fixed-pitch canards, as on the Atlas Cheetah, IAI Kfir and so on? Their direct contributions to stability and overall lift are negligible, so they are not true lifting-canards. Nor do they have any movable surface for conventional pitch control, so they are not control-canards as described here. And they are certainly not active vibration dampers. Their function is more akin to leading-edge slats, to direct air downwards over the wing when flying at high angle-of-attack, reducing turbulence and hence leading to improved lift and drag. For the time being I have classified them as control-canards, on the basis that many movable control-canards also act in this way, while lifting canards generally do not. Or, do fixed-pitch canards really represent a fourth class of canard? -- Cheers, Steelpillow (Talk) 11:44, 23 August 2009 (UTC)

I suggest fixed-pitch canards deserve their own paragraph, and their own explanation modelled on Steelpillow's summary above. Dolphin51 (talk) 12:28, 23 August 2009 (UTC)
I agree - they are more like remotely installed leading edge devices! - Ahunt (talk) 12:29, 23 August 2009 (UTC)
How much can we say without formal references? In the absence of such for an appropriate descriptor or technical appraisal, can we call them "fixed-pitch canards"? I'm thinking to tile the subsection as such, and be careful to avoid a formal descriptor in the text, along the lines of "Canard planes of fixed pitch are used by some aircraft. The canards surfaces deflect air ...". It seems unreasonable to avoid describing a visible design feature because we don't yet have any references (see WP:IAR and related policies), but will the citation police agree? -- Cheers, Steelpillow (Talk) 13:13, 23 August 2009 (UTC)

Let's invent less and use the actual industry terms like "close-coupled canards". Canards do exactly three things.

  • Some shift center of pressure by acting as tiny wings.
  • Some are close-coupled with the main wings to massage the airflow.

and

  • Some use some or all of their surfaces as driven control surfaces for moving some or all of the aircraft.

Hcobb (talk) 14:54, 23 August 2009 (UTC)

Now there's a perfect example of the citation police problem. Last September I added a section on close-coupled canards, only to have it reverted by ardent citationists because I didn't have a reference to hand. Do you have one? That would be wonderful. -- Cheers, Steelpillow (Talk) 15:45, 23 August 2009 (UTC)
"Many current aircraft designs for future air-superiority fighters incorporate close-coupled canards. This relatively new configuration has been developed, principally, through wind tunnel testing that indicates a favorable aerodynamic interaction between the canard and wing at high incidence. The favorable interaction creates a high total lift capability and reduced trimmed drag, leading to important gains in combat effectiveness." http://www.sageaction.com/aircraft_testing1.htm#JetAircraft
Of course The Force gave up on canards when they went all stealth, but the Europeans never venture out where hostile radars might illuminate them, so they don't care. Hcobb (talk) 13:45, 25 August 2009 (UTC)

OK I've done my best. The division of the examples into control and close-coupled types may need attention, especially as some types such as the Dassault Rafale are described as "active close-coupled", meaning that they act as control-canards during normal flight and as close-coupled typed at high a-o-a, so really need to go in both lists. For some types, I have no idea whether they fit in either or both categories, but have made educated guesses. -- Cheers, Steelpillow (Talk) 19:15, 25 August 2009 (UTC)

Concorde[edit]

Concorde has small strakes on the forward fuselage, whose purpose (IIRC) is to reduce buffet at high a-o-a by stabilising the small vortices shed by the fuselage. I'm not sure if they also act as close-coupled canards; Concorde relies on larger wing-generated vortices to direct the airflow at high a-o-a, however stabilising the fuselage vortices does help stabilise the wing vortices too. Do they really count as canards anyway, or are they just too small? -- Cheers, Steelpillow (Talk) 19:26, 25 August 2009 (UTC)

I suggest Concorde's strakes are vortex generators rather than canards. They are in the same class as the strake on some engine nacelles such as on Boeing 737 with CFM56 engine, visible here. Dolphin51 (talk) 22:44, 25 August 2009 (UTC)
User:Dolphin51: I think you may well be right about that. In which case perhaps they should be mentioned in this article for sake of completeness with a link to Vortex generator. - Ahunt (talk) 22:46, 25 August 2009 (UTC)

http://books.google.com/books?id=bs9EbQ6pdRQC&pg=PA25&lpg=PA25 "are there to reduce side slip" Hcobb (talk) 23:12, 25 August 2009 (UTC)

Canards and stability[edit]

Hi,

This topic is being discussed here. I'd be grateful if you could help us reach a consensus. — Cheers, Steelpillow (Talk) 18:53, 19 May 2012 (UTC)

I have read the debate and left my comment. (My diff.) Dolphin (t) 12:57, 20 May 2012 (UTC)

Moved and getting urgent[edit]

Hi again,

The discussion has now moved to Talk:Stabilizer (aircraft) and is rapidly turning into an edit war. Please help reach consensus! — Cheers, Steelpillow (Talk) 14:28, 3 June 2012 (UTC)

Unlike a conventional tailplane[edit]

"in order to achieve longitudinal stability a canard surface is trimmed to increase lift as speed increases. This equates to a negative coefficient for trim drag." - GraemeLeggett These two sentences don't make any sense. They may have made sense in some context, but that context is not represented here. "Unlike a conventional tailplane" is an oxymoron. A canard is a conventional fore plane, not an unconventional tailplane. "Tail" planes go on tails.

"in order to achieve longitudinal stability a canard surface is trimmed to increase lift as speed increases", again this statement makes no sense in itself. If you can explain what it means, knock yourself out, but don't put it in this article just because you found the words written down somewhere.--Stodieck (talk) 07:16, 28 May 2012 (UTC)

No, "Unlike a conventional tailplane" is not an oxymoron, it is a tautology. Clancy may be showing his age, but the sentence makes perfect sense to me as it is. By all means find a clearer and more detailed way of making the point about achieving stability and negative trim drag, or even come up with a more current reference. But for now this one meets Wikipedia's standards. And no, you should be able to tell that the words are not lifted direct from Clancy because there are no quotation marks, so I have no idea what might have given you that idea. But don't just delete what you don't understand. — Cheers, Steelpillow (Talk) 19:51, 28 May 2012 (UTC)
In following this discussion I have to add the the offending para makes perfect sense to me as well and the ref seems reliable and acceptable to Wikipedia. - Ahunt (talk) 20:01, 28 May 2012 (UTC)


Sorry, no matter how a canard is trimmed it doesn't produce longitudinal stability. Nor does the trim of tail plane.. I understand the situation quite well. The statement was removed because it is not properly cited and not verifiable. I have no way of reading the original text and the original text is not quoted. The sentences do not contribute to the article, and they are not needed. And no, a canard is not a type of tail plane anymore than a duck is a type of truck. --Stodieck (talk) 20:21, 28 May 2012 (UTC)

Doesn't this all only apply to lifting canards at best? Hcobb (talk) 21:21, 28 May 2012 (UTC)

Clarify[edit]

The General Characteristics are both negative and makes me wonder why this design was used for the Eurofighter Typhoon. There must be something good about it. The Eurofighter Typhoon article seems quite impressed with the design even the handling. QuentinUK (talk) 14:35, 4 December 2012 (UTC)

Added a pair of advantages to that section, but it really does depend on the type of canard. Hcobb (talk) 16:46, 4 December 2012 (UTC)
Historically it has been hard to find adequate references for this article, so it has become biased towards whatever points could be referenced. IMHO that has not made for a well-balanced article, but I live in hope (grin). — Cheers, Steelpillow (Talk) 21:12, 4 December 2012 (UTC)

Putting canards on the outside of aircraft is exactly like filling the aircraft with lifting gases. It's a solution that's been in search of the right problem since the earliest days of aviation. Every generation or so a new batch of bright young engineers pop up uneducated in the problems faced the last time this was tried and they do it for a while until they learn better. The most recent replacement for the canard is the chine. I suspect that the next time canards are replaced it will be with airframe morphing. Hcobb (talk) 00:39, 5 December 2012 (UTC)

What, you'd put them on the inside? ;) — Preceding unsigned comment added by Steelpillow (talkcontribs)

Remarks 14 april[edit]

Canard has two meanings : canard configuration and canard surface. I propose "canard aircraft" (or canard design) for the concept, and "canard" alone for the foreplane.

Better to avoid the expression "canard wing", to prevent confusion with (main) wing. So, in the text, canard alone means the foreplane, and wing means the main wing.

In "General characteristics", the second paragraph "However a canard design tends to be etc..." applies ONLY to the VariEze model 31, fitted with elevons onto the canard (Ref : Nasa TM 88354). As this concept was inefficient, it was soon discarded. So the generalized comment has to be modified or deleted. Plxdesi2 (talk) 20:18, 14 April 2013 (UTC)

Active vibration damping types[edit]

May those tiny surfaces be called "canard" surfaces ? it rather look like a special kind of vortex generators. Do you agree ?Plxdesi2 (talk) 16:18, 17 April 2013 (UTC)

Jones (U.S. Bombers, Aero, 1974) calls them canards or, to be precise, "canard" vanes (his quote marks). Googling "B1 lancer canard" gets me just under 800,000 hits. They are not vortex generators and do not serve any direct aerodynamic purpose in the usual way, but are active surfaces which apply a variable lift force to counteract mechanical forces in the forward fuselage during turbulence, providing a smoother ride and so reducing fatigue on both the crew and the airframe. They do happen to be rather small, I guess to ensure that their destabilising effect remains insignificant at all times. — Cheers, Steelpillow (Talk) 18:39, 17 April 2013 (UTC)
In WP : "Rockwell included small triangular fin control surfaces or vanes near the nose on the B-1. The B-1's Structural Mode Control System rotates the vanes automatically to counteract turbulence and smooth out the ride." WP do not call them "canards".
If these surfaces provide a smoother ride in turbulence, are they "destabilising" ? it seems they do not act as canard pitch control surfaces, just see their surfaces ! but they act on the local flow in order to modify the lift of the long-nose fuselage. So, it seems that they act as a local flow control device (like VG, fences, vortilons), a lot more sophisticated but not as canard (lift or control) surfaces, subject of this article. Plxdesi2 (talk) 15:13, 18 April 2013 (UTC)
These fin control surfaces act on the lift as well as canards : ok, they are canard surfaces. VG (on Rutan canards), or VG on wings act on the lift too (increasing the max lift) ; are the VG called "canard surfaces" or "wings" ? Plxdesi2 (talk) 15:37, 18 April 2013 (UTC)
On the Viggen, one of the canard surface's main functions is as a vortex generator. I guess that like many things, the design options vary continuously from one function to another - the point at which one says, "this has now changed function. It was a VG but is now a canard (or vice versa)" is pretty arbitrary. The Lancer is a bit different in that most small surfaces are intended to change the aerodynamic performance of the aircraft in some way but the Lancer's canard vanes are not - their purpose is to change the structural forces in the forward fuselage - so one cannot compare them directly with the way those other surfaces are named. WP may not call them canards, but Jones does. So we should accept that - unless someone finds a more authoritative reference saying that Jones is wrong to do so. For example there are many definitions of a "canard"; if the most authoritative ones conflict with Jones' usage, that would make him less authoritative. Many of these questions seem to boil down to, "So what exactly is the definition of a canard?" I am not sure we have universal agreement on that. I don't know if that helps, I'm beginning to confuse myself now. — Cheers, Steelpillow (Talk) 20:24, 18 April 2013 (UTC)
The Viggen canard is a true lifting surface, because of his area and position relative to the wing. His secondary trim role (elevators) and vortex effect on the wing lift are also a lift function. So it's first a lift-canard surface.

"but (the small fins) are active surfaces which apply a variable lift force to counteract mechanical forces in the forward fuselage during turbulence"

I think, according to their areas, that these small fins do not apply any significant lift forces but modify the flow (the "2 alpha flow") around the Lancer long nose, in order to smooth the variations of the own fuselage (destabilising) lift in turbulent conditions. Imo, they act as VG do, in modifying a local flow condition. Being controlled, are they control pitch surfaces ? If we consider that the fuselage is a lifting surface, yes, they have a role in fuse lift. Accordingly, we have to consider the B1-B as a three-surface aircraft. If we do not agree with that, we consider the fuse lift is not significant, so the small fins are neither lift nor control (canard) surfaces. Generally (except wing bodies), fuses are not considered as lifting surfaces (although higly destabilising). Anyway I agree that the final answer is not easy ; I would like to consider these devices not as canards but as minor features "looking like small canard" acting on fuselage lift. Plxdesi2 (talk) 08:32, 19 April 2013 (UTC)
I do not know if you are right about the vanes modifying the airflow. But the key point is that their intended action is confined to the forward fuselage and not like a VG which is intended to affect the gross aerodynamic behaviour of the aircraft (e.g. by delaying the stall). So I see it as definitely not a 3-surface design or a VG. Their control function is similarly local, so they are not flight control surfaces in the usual sense either. Are they canard surfaces? That depends on what we mean by a "canard". If we mean "tail-first" then these vanes are not canards, if we mean "forward horizontal(-ish) plane significantly smaller than the main lifting surface" then they are, or if we mean something in between then we must turn to authoritative references to decide for us. That's where Jones is so far the only voice mentioning canards in the present context (though like so many authors, he does not define "canard"). — Cheers, Steelpillow (Talk) 09:38, 19 April 2013 (UTC)
Postscript: I seem to recall reading that the vanes were originally supposed to be larger, but had to be shrunk in order to stop them interfering with (destabilising) the overall aerodynamics. But never trust my memory. — Cheers, Steelpillow (Talk) 09:42, 19 April 2013 (UTC)
Are these small fins "forward horizontal (-ish) planes " ? forward, sure ; but "horizontal-ish", being 35° down angled surfaces, possibly yes/no. Amazingly too, Jones called the Curtiss XP-55, with 0.10 S canard area, lifting about 0.15 weight, "not a true canard", and these tiny 0.003 S (or 0.015 Stail) "canards vanes" (with S the wing area). Ok for "vanes", that is their function (deflecting/modifying only the local fuselage flow, as your postscript adds). "Forward vanes" would be more neutral than "canard vanes" that would be interpreted in this article as wing surfaces.
"As placed in front of the plane and acting on the lift, these surfaces are often described as "canard surfaces"." Is "often" meaning Jones only or others too ? Plxdesi2 (talk) 13:26, 19 April 2013 (UTC)
The talk about "Concorde" is consistent with VG / strake fonction, controlled or not. Concorde "petites ailettes" (small wings) serve as VG at high AoA, to increase the directional stability (there was a lack of yaw stability beyond 18° AoA). In Les avions de Transport modernes et futurs, André Peyrat-Armandy, Teknea. Plxdesi2 (talk) 13:47, 19 April 2013 (UTC)
Flight "B-1 Roll-out" in 1974 refers to them as "canard fins for ride control". GraemeLeggett (talk) 14:53, 19 April 2013 (UTC)

Canard foreplane stability[edit]

(talk moved from Stabilizer)

"This can be achieved with a combination of factors, including:

  • 1 by making the lift slope of the foreplane less than the lift slope of the main wing[16];
  • 2 by giving the foreplane a smaller lever arm about the center of gravity than the main wing;
  • 3 by making the lift coefficient slope of the foreplane less than that of the main wing etc..."

Please notice :
1 et 3 are the same, 2 is wrong : this is a parameter upon balancing considerations, not a stabilisation one. Plxdesi2 (talk) 14:22, 17 April 2013 (UTC)

No.
  • 1 and 3 are the same only if the wing and canard are of the same surface. Increasing the CL of a small canard and large wing by (say) 0.5 will yield a different change in the vertical force values.
  • 2 is about CG position. Increasing the canard lift by 2 Newtons and the wing lift by 4 Newtons will not have the same effect depending on their position relative to the center of gravity. This is usually represented by the notion of tail volume coefficient (Vt in our article, Vh in Phillips).
Balancing (trim) and static stability are both affected together by lever arm distances.
Have a look at equation 4.3.30 in Phillips 2010 (2nd ed) and you will see that there are many more terms than the two lift coefficient slopes that can make for a negative pitch moment coefficient slope... I am not saying we should list them all but only concentrating on the lift slopes only is a step in the wrong direction. Ariadacapo (talk) 16:22, 17 April 2013 (UTC)
about 1 and 3 : as "lift slope" means "lift coefficient slope" (dCl/da), what is the difference ?
about 2 : the lever arm of the canard is one of many parameters affecting the trim. If you decrease this distance without modifying anything else, you increase the wing loading of the canard, and his Lift coef too : as a result the lift slope of the canard is (or may be, it depends of the airfoil) lower : that is the same that 1 and 3. Just a remark, if the canard lever arm is lower than the wing one, the aircraft is no longer a canard, but a tandem.
Another possibility, different from (1-2-3) is to decrease the aspect ratio of the canard (see Hoerner/Lift, page 11-30, aspect ratio), with more lift induced drag and possibly a higher angle stall than the wing.
A stabilisation parameter is the power effect. In case of canard pusher propeller : "the power-induced flow clean up of the wing trailing edge" (Nasa TP 2382, VariEze) increases the wing lift slope. Conversely, a propeller located ahead of the canard (increasing the lift slope of the canard) has a strong destabilising effect (Tandem aircraft PAT-1, Nasa TM 88354).
Rutan solution is high aspect ratio canard, higher Lift coefficient (the wing loading of the canard is between 1.6 to 2 times the wing one) AND a canard airfoil the lift slope of wich is non linear (nearly flat) between 14° and 24° (Nasa TP 2382, VariEze).
The lift slope differential seems to be the main stabilisation parameter. Plxdesi2 (talk) 20:12, 17 April 2013 (UTC)

Clarification of statement?[edit]

Currently the article says: "However, the foreplane downwash effect on the wing lift distribution is unfavorable for the canard concept, so the difference in overall induced drag is actually not obvious, and depends on the details of the configuration"

Does this statement hold true for all distributions of the canard and main lift surface? I'm thinking of designs where the two are for instance set low and high respectively on the fuselage (Rutan Quickie, B.39 Libellula)? Does the sentence need clarification or qualification? GraemeLeggett (talk) 07:30, 21 April 2013 (UTC)

With a high-set main wing and a low-set canard, any downwash effect is likely to be minimal or insignificant. Conversely, where a lifting-canard is close-coupled, the downwash at high angles of attack can be the main reason for having it at all, because the downwash is primarily a vortex which re-energises the wing airflow to improve lift and delay the stall, as on the Saab 37 Viggen. So there is definitely some clarification to be done. Can I suggest modifying the sentence to, "However, in normal flight the downwash from the foreplane can affect the main wing lift distribution unfavorably, so the difference in overall induced drag depends on the details of the configuration and may not be obvious." — Cheers, Steelpillow (Talk) 11:16, 21 April 2013 (UTC)
That sounds about right. Couldn't see Rutan, or the masters of designing and building an aircraft in a few weeks getting caught out on obvious wing interference effects. GraemeLeggett (talk) 13:57, 21 April 2013 (UTC)
"With a high-set main wing and a low-set canard, any downwash effect is likely to be minimal or insignificant."
Anyway their respective vertical position, downwash effects of lifting foreplanes are significant  : one need a vertical gap equivalent to the span to avoid any deflexion effect (as for the ground effect). In Nasa TP 2382, the VariEze canard foreplane was tested in high (normal) and low position, without significant differences : "the canard in the low position had little effect on lift, pitching moment and trimmed drag.". At high AoA, the low canard deflexion effect on high wing may induce "most interference" [1].
About Viggen or close-coupled canards, the primary effect of canard downwash is to reduce the AoA and the lift of the main wing behind, preventing the stall of the central part of the wing, but conversely increasing the AoA of the flow outboard of the canard tip (with a local upwash peak just at the canard tip level, then an upwash decrease towards the tip). So the saw-tooth leading edge discontinuity, often present at mid span (Viggen, Gripen), inducing vortex at hig AoA to prevent the stall of the outboard section of the wing (same function as DLE - Drooped Leading Edge - on general aircraft (Lancair, Cirrus). The total lift increase comes from the upwash effect of the wing on the canard and from the canard positive pitch moment avoiding the negative wing flaps angle (and not mainly from canard vortices on main wing) : "Upwash from the main wing provides favorable (interference) flow conditions such the CL max of the canard was increased by 40 %". Nasa TM 88354.
This wash discontinuity, varying with global AoA and yaw angle is a very design problem ; lower loaded small canards (control ones with negative static stability)) are less problematic for this reason. Tandem configurations avoid the deflexion and lift distribution discontinuities, but have problems of their own, low rear wing lift, trim sensiblity to controls, strong power effect (if front propeller) on stability... Miles and Rutan tandem aircraft were not continued, the worse stability problems being with the tractor tandem configuration (Piper PAT-1, ref. Nasa TM 88354). Plxdesi2 (talk) 09:20, 22 April 2013 (UTC)

X-29A is a 3-surface[edit]

Discussion moved to Talk:Three_surface_aircraft

Etymology[edit]

I am very dubious about the cited etymology. For starters, there are two contradictory claims: the claim that the term was applied to the 14bis (cites Villard's Contact and a second claiming that it first used for the Fabre Hydravion (a more likely duck because it is a floatplane). The cite for this is the totally unreliable autobiography of Gabriel Voisin. I've scrabbled round contemporary sources and can find no use of the term before it is applied to the Voisin 1911 machine, again a floatplane. This suggests that Canard was a name given to this type, & later applied to othet types. I don't have Contact: I do have Villard's book on the Gordon Bennett books & although it's pretty good it's not without errors.TheLongTone (talk) 23:12, 5 April 2014 (UTC)

Agreed. Kenneth Munson's potted history of Fabre's 1910 aircraft in "Flying Boats and Seaplanes: Since 1910", Blandford (1971), refers to it throughout as "the Hydravion" (his italics). OTOH Almond's compilation of Getty images for "Aviation: The Early Years" (Ullmann 2011 Edition) Page 170, names it "Canard". Almond's text is very thin, and mostly but not always accurate. And I just had a look through the Flight archive. Throughout 1910 at least, Flight refers to the "Fabre Hydro-Aeroplane" with no associated mention of "Canard". The term does not appear in the context of aircraft until 1911, where it appears many times, from February on, reporting on the original "Voisin Canard" tail-first floatplane and (I suspect) other similar Voisin aircraft. Later, from September, Flight reports on the similarly-named "Blériot Canard" tail-first monoplane.[1] The first use in the general context of the configuration is on 11 October 1911, Page 895, where we read of two Morane all-metal monoplanes under construction, "One of them is modelled on ... torpedo-like lines and the other is a canard."(Flight's italics).[2]. Insofar as the 14-bis is mentioned in my sources, e,g, Angelucci and Matricardi's Sampson Low Guide, there is no mention of the name "Canard". All this would support a rewrite along the lines of:
The name "Canard" (Duck) was given to several early French aircraft of tail-first configuration, especially the Voisin Canard floatplane and Blériot Canard monoplane of 1911.[refs as above] By the Autumn of 1911 the term was being used to describe the tail-first configuration itself [ref as above].
I do not think that Voisin and Almond are reliable enough to support the Fabre story. The 14-bis claim is certainly not sufficiently supported. It's a shame that every source seems to have its inaccuracies, makes life difficult when information is scarce. — Cheers, Steelpillow (Talk) 12:36, 6 April 2014 (UTC)
The only use of canard in Flight during 1910 uses the word in the sense of "hoax". The OED cite is interesting: its from Horatio Barber's 1916 book on aircrat...Barber is notable for his canard Valkyrie monoplanes, but these were certainly not described at the time as canards. It's entirely possible that the description was used of the 14bis, but as a term for configuration it seems to date from 1911. It's the reliable cite combined with the removal of an existing one that is the problem.TheLongTone (talk) 12:55, 6 April 2014 (UTC)
Ah, I found Villard at Google Books, this URL might work for you:[3]. Page 37 contains the relevant material. He does claim that the 14-bis was called a canard, but then he also claims that its layout was "unconventional" and "backward". I find this last remark to be the judgement of hindsight. At the time there was no convention yet established, nor even a sustained flight in Europe, and moreover people like Voisin would follow the Wright pattern of tail-first: one could argue that tail-first was at that time the convention. He also claims it was unstable, but I seem to recall reading the opposite elsewhere - certainly, it had adequate rear vertical surface and steep dihedral which would suggest excess stability if anything. More scanning of Villard's work leaves me dissatisfied. The entire history of early British aviation prior to some international race or other ca. 1912 onward, is given a single paragraph, only two of Cody's achievements get a mention and the likes of Dunne, Blackburn and the Short Brothers get none. That chapter seems very American-centric, though I cannot access a great deal. The Table of Contents too seems American-centric, considering the widespread international activity at that time - and when I see that the book is copyright of the Smithsonian, I wonder whether there is a lesson in that. It does not look promising as an RS on European aviation, no doubt others who find what they want in it will disagree. — Cheers, Steelpillow (Talk) 15:48, 6 April 2014 (UTC)
Cheers, but the google books access runs out before I get to page 38...what you quote is hardly encouraging. I'll go and give l'Aerophile a closer read, see if there's anything about naming the voisin thing.TheLongTone (talk) 18:10, 6 April 2014 (UTC)

The canard wing was neither invented nor used for the first time by the Wright brothers[edit]

The plane built by Hiram Maxim and tested in 1894 had a clear front canard wing for pitch control (see, http://www.ctie.monash.edu.au/hargrave/images/maxim_1894_side_elev_1000.jpg ). I do not understand why the Wikipedia article about the canard wing starts with the Wright brothers. — Preceding unsigned comment added by 70.83.160.80 (talk) 23:11, 2 June 2014 (UTC)

Well spotted. I have added a paragraph. One cannot comment on the Maxim machine's flight characteristics, as it never flew freely. — Cheers, Steelpillow (Talk) 08:41, 3 June 2014 (UTC)

Foreplane stabilizing ?[edit]

In the article : "A canard foreplane may be used as a horizontal stabiliser, whether stability is achieved statically[16][17][18] or artificially (fly-by-wire).[19]"
The three attached quotes (16-17-18) use the term "stabilizer" in lieu of foreplane or canard, without saying that the canard is a stabilizing surface, so are invalid quotes. Using foreplane to control pitch (as a horizontal stabiliser does) is a control function, not a pitch stability matter.Plxdesi2 (talk) 19:36, 7 June 2014 (UTC)

No. The article says "as a horizontal stabilizer" and the quotes use the term "stabilizer". Your comment about "stabilizing" is not relevant and the references are just fine. — Cheers, Steelpillow (Talk) 21:21, 7 June 2014 (UTC)

In the article : "Nevertheless, a canard stabilizer may be added to an otherwise unstable design to obtain overall static pitch stability.[23] = Garrison quote
This sentence means that the wing is destabilizing and the canard is added to get stability, so the canard is stabilizing. This is wrong; a canard is always a destabilizing surface (see Fundametals of Flight, Shevell, : "in case of canard, the wing IS the stabilizer.") and others (in "Stabilizer" article). Second, the quote of Garrison does not say that the canard is stabilizing; he just says that the canard is necessary to the balance ("the aircraft would tip over forard if some balancing force were not provided."). There is no matter of stability here, so the quote has no value. Plxdesi2 (talk) 19:04, 7 June 2014 (UTC)

No. A wing on its own is indeed unstable and a canard may indeed added to give stability. What a thing is called is what it is called, why it is put there is why it is put there, how it works is how it works, and Wikipedia has to respect that. — Cheers, Steelpillow (Talk) 21:21, 7 June 2014 (UTC)
    • ^ Daroll Stinton, The design of the aeroplane, Arrangement of surfaces, P. 153