Talk:Ornithopter

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Hello, Many researchers works at the realization of a flapping wings design. The time devoted to this work does not make it possible to pass much time to explain this technic. The flapping flight with the human muscular power ( manned ) can be learned by visiting the principal sites of French forum : OVIRC and American forum : Ornithopter org.

Best regards.

Why is Icarus mentioned on this page as if he was a real person? All he is, as far as I know, is a character from Greek mythology. - J.Wallos (2/9/06)

Contents

[edit] =================

Dear J.Wallos, Daedalus and Icarus are a myth. Today people ( civilian and military ) is trying to make MAV. But since many years, some researchers are working on the manned. A design powered by a human acting system. If you want to know more, just click on the (laconic) sites up there. Glad to read you.

Georg.(2/12/06)

[edit] Manned ornithopter

An ornithopter is an aircraft that produces all the thrust and most of the lift by the flapping of it's wings alone. The Schmid aircraft only produced the thrust with a [relatively small] set of flapping wings. The lift was produced by a large set of fixed wings. Since the flapping wings were only used for propulsion, this aircraft can not be classified as a true ornithopter and further, this cannot be classified as the first successful flight of a manned ornithopter. These flights should be described factually for what they were....successful flights of a fixed wing aircraft that uses flapping wings instead of a propeller for propulsion. Making attention-getting false claims such as 'the first manned ornithopter' only serves to muddy the waters of history and obscure the true facts.


The reason Schmid's machine is classified as an "ornithopter" is as follows:

Real birds have a flapping front wing and a rear fixed wing. Whether you call it a tail, stabilizer, or whatever, the bird's tail does contribute a significant amount of lift. The body of a bird is shaped for producing lift also. As an ornithopter is an imitation of bird flight, I see no reason why the requirement not to use fixed lifting surfaces should be imposed.

You would be correct to point out that the fixed wing on Schmid's aircraft is much bigger than a bird's tail. However, that is just a quantitative matter. There is no logical dividing line between a bird that has 40% of its lifting surface fixed, versus Schmid's which has about 80% fixed. If a particular aircraft has 50 or 60% fixed, how would you classify that? If you draw a line anywhere, you create the ridiculous situation that two nearly identical aircraft will be differently categorized because of a 1% difference in wing surface allocation.

There is also the idea that an ornithopter must use the same surface to produce both lift and thrust. In Schmid's configuration the flappers could have been tilted to provide no lift, though more likely they did provide some lift, and really we have insufficient information to know for certain what percentage of total lift they did provide. Those of us who build ornithopters know that it is no special challenge for a flapper to produce both lift and thrust. One of the most successful and widely used flapper designs has a flat wing that is symmetrical about the horizontal plane and takes on a positive or negative camber in the up or down stroke due to aeroelastic properties. This basic flapper design produces lift just by virtue of having the correct angle relative to the motion of the aircraft. There is nothing difficult about producing both lift and thrust together, but Schmid's ornithopter does appear to have been designed to enhance the lift production of the flappers as evidenced by their cambered ribs evident in the photos.

There are a few ornithopters in which there is NO fixed wing (tandem flappers mostly) or in which the fixed wing produces a downforce instead of lift. Since neither of these configurations is met by real birds, I don't think we should insist that an ornithopter should be so constrained.


[edit] Manned ornithopter

Your comment is perfectly right. Groups of researchers are working in the field of instationery air flow. This aerodynamic allows the flapping wings to create lift and thrust. The result is not assured yet. "Will be a planetary event". Georg. 03/16/06

[edit] Intro

An ornithopter is an aircraft that flies by wing-flapping. Many examples exist in nature such as birds, bats, and insects. Man-made ornithopters are usually on the same scale as these flying creatures, though some overscale, manned ornithopters have also been built.

I'm sorry, but the definition of "aircraft" (it's a machine) excludes birds, bats and insects from the definition of an ornithopter. Then "man-made" also is strange, because all machines are man-made, aren't they? These three sentences need a little tweaking. PeepP 20:21, 18 March 2006 (UTC)


[edit] Dictionary

I'm not the author of " aircraft " . On the other hand, I am favourable to give an exact definition, in a world dictionary, to the object flying by flapping wings, built by the man. Best regards. Georg. 21 March 2006

[edit] appears to have held

"Alexander Lippisch appears to have held this point of view" < at the end of the second paragraph, in Ornithopter#Aerodynamics.

  • He appears to have? To whom?
  • Someone should find a quote, and change this sentence to "In [YEAR] Alexander Lippisch held this point of view." or something more appropriate.

VdSV9•♫ 18:50, 10 July 2006 (UTC)

[edit] Comparision to helicopters

The use of the same surfaces for lift and propulsion has the fundamental advantages that drag-inducing structures are minimized while the volume of air acted on to produce thrust is maximized. [...] From general aerodynamic considerations, ornithopters appear to make more efficient use of power than rotating propeller or jet aircraft do.

Apparently, the same could be said about a helicopter. Could someopne enlighten me (and improve the article) by describing the pros and cons of an ornithopter versus a helicopter? And why an ornithopter might be favorable to a helicopter?

Can an ornithopter produce a vortex ring? --Klaws 06:52, 11 July 2006 (UTC)

A practical ornithopter has the potential to be far more manuverable. Consider how manuverable humming birds, flys, and other insects are, simply from flapping their wings. No machine ever created is as agile as that. Potentially they can be faster than helicopters as well if they combined aspects from fixed wing aircraft. I don't see why they can't fix their wings in place and use a jet engine when they want to achieve sustained high speed flight. Malamockq 06:39, 20 February 2007 (UTC)

[edit] JULY 8 2006 FLIGHT OF DELAURIER HYBRID AIRCRAFT

Regarding the July 8 2006 flight of the Delaurier ornithopter/fixed wing hybrid aircraft. It did not take off unaided, an auxiliary jet engine was mounted under the fuselage for the purpose of providing the thrust to accelerate to lift off speed in order to avoid using the flapping of the wings [thereby eliminating the severe heaving and pitching of the fuselage which has caused problems throughout the life of the aircraft]. This aircraft had auxiliary fixed wings installed sometime after 2001, it ceased to be an ornithopter and became a flapping/fixed wing hybrid aircraft instead. The July 8 2006 flight was made possible only by the use of these fixed wings and the jet engine [the jet engine is in addition to the gasoline engine which flaps the wings]. In other words, this flight was not the first sustained flight of a piloted ornithopter. This has not yet been done. This kind of sensationalist reporting in an online encyclopedia and in the media distorts the truth and will make it very difficult for future generations to find an accurate, unbiased record of ornithopter history.

[edit] Photo of ornithopter

The ornithopter shown in the title photograph appears quite crackpot in design and I believe it is inappropriate as the primary photograph in an article supposedly about the flight and development of working ornithopters. Perhaps it could go in a subsection, but I believe that something more plausible as a working machine should go at the top. My suggestions are Leonardo da Vinci's sketches, scale-model ornithopters shown in flight, or an image from fiction that shows a plausible machine (this could have the advantage of being obviously an ornithopter - many attempted models do not appear to be obviously flapping in still photos). Thoughts, anyone?--EDH 07:07, 3 October 2006 (UTC)

someone has recently changed the main photo to an animation of a model ornithopter in flight. Much more appropriate.--EDH 04:11, 30 October 2006 (UTC)

[edit] Recent changes

I just wanted to explain certain points in my recent edit.

First, I personally feel that "manned" ornithopter was a suitable choice of words, but another user felt strongly about using gender-neutral language. I didn't like to say "piloted" because I didn't want it to be confused with "remotely piloted" and that seemed awkward anyway. So I chose the phrase "person-carrying" instead.

Second, Yeti Hunter wanted to convey the idea that an unmanned ornithopter is a model or small-scale representation of a larger manned aircraft. I find this approach unacceptable, because an ornithopter is a model of a bird, not a model of a larger aircraft the way scale model airplanes are. In a few cases, an unmanned small ornithopter is built as a prototype for a proposed or subsequently built manned ornithopter, but that's really not the activity most of us are engaged in. Personally I have no interest in manned flight but I am keen on imitating bird flight more closely. I think most ornithopter builders are like me. I know there are a few who are working on manned projects but even they would agree that an ornithopter is based on bird flight and is not a scale model of anything other than a bird.

I also removed the reference to DeLaurier's crash because it reflects badly on our field and DeLaurier specifically to include that information. I think it sufficiently conveys what happened to say that a 14 sec flight was made.—Preceding unsigned comment added by Chronister (talk • contribs) 18:33, 30 October 2006

According to the definition of an Ornithopter as I understand it, such a machine is an aircraft that achieves flight by the action of wing-flapping. That is, any size of machine that flies (or attempts to fly) in this manner. That's not to say that a small one is imitating a larger one or vice versa, it's still a machine with flapping wings. Clearly small-scale ornithopters have achieved success (often as a result of their resemblance to birds) and large, manned ornithopters have not. However I believe it is inappropriate to assign one type or size of machine greater legitimacy as an "ornithopter", and I certainly wasnt trying to imply anything like that.
Also, on the use of the word "manned", I am of the opinion that "person-carrying" and "flight with person on board" are far more awkward than either of the other options. If you really insist on a gender-neutral term, I see nothing awkward about "Piloted" and "Piloted flight". Cheers -Yeti Hunter.--ABVS 05:02, 31 October 2006 (UTC)


I hope you don't mind, I moved the Design Engineering article to the "external links". To me it seems DeLaurier's own report is the primary source and more suitable as a "reference". I also eliminated the "witnessed and confirmed" wording because no one is going to question DeLaurier's accomplishments. Also I feel it is unfair to earlier work. Lippisch and Schmid flights were certainly witnessed and confirmed in their time. I am actively searching for more documentation on these flights, but such information becomes scattered over time. It simply is not realistic to apply the same standard.


[edit] Schmid Flight

The article claims that 15 minute flights were performed in 1942. If that is hard to believe then you are correct. The proof is in the fact that 3 HP would not be enough to fly a hypothetical weightless aircraft with a 60 kg pilot, let alone the monster aircraft built by Schmid.

The minimum requirement is at least 15 HP for an ornithopter (or normal aircraft), and that is for level flight only, and presumes perfectly friction free moving parts etc.. The sums are easily done by even novice aero-engineers. ( HOWEVER, consider the less than 1 hp. used to fly the human-powered aircraft across the English Channel; the aircraft was powered ONLY by human power; the craft was designed by Dr. Paul MacCready. So, if less than one horsepower was used to fly a human with such success, then let us be ready to find some way to use ornithopting with less than the 15 h.p. you note.Joefaust (talk) 00:22, 31 January 2008 (UTC) )

The text I refer to is:

"Adalbert Schmid flew a motorized, manned ornithopter at Munich-Laim. It was driven by small flapping wings mounted at the sides of the fuselage, behind a larger fixed wing. Fitted with a 3 hp Sachs motorcycle engine, it made flights up to 15 minutes in duration. Schmid later constructed a 10 hp ornithopter based on the Grunau-Baby IIa sailplane, which was flown in 1947. The second aircraft had flapping outer wing panels."

Dear unsigned and undated, the reference in the article seems to be this page at ornithopter.org, and from there Schmid, Adalbert. Weltluftfahrt, volume 1, issue 9, March 1950, page 195. Schmid was clearly not a novice aero-engineer. It would be scientifically more useful to find out if it was done, and then to work out what happened, rather than to calculate impossibility and then deny that something happened. It is not clear whether the flight was manned, but what is interesting is that the machine apparently took off from the ground. If one could get hold of the quoted reference, it would help. --Seejyb 07:49, 22 January 2007 (UTC)
On another point of your calculations, it is mentioned in Vladimir Toporov's research notes (which I think this site links to; if not, a crude translation can be found at ornithopter.org) that the efficiency of ornithopters as opposed to fixed-wing prop-driven aircraft is markedly different. The ornithopter is significantly more efficient due to a) the fewer number of drag inducing structures, and b) the fact that the wings produce thrust, not drag, for half the flap cycle. That said, I do not have the actual calculations, but I think it is unwise to assume that such a calculation would be the same for a fixed wing craft.--ABVS 09:35, 22 January 2007 (UTC)

[edit] Use in fiction

Is there enough material in the vein of fiction to warrant mention, or is it just the Dune universe? —The preceding unsigned comment was added by 143.66.6.240 (talk • contribs).

There used to be more references, but I removed them, as they were largely bare-mention "There was an ornithopter in this book/movie/game". Ornithopters were pretty important and recurring in Dune, so I kept that one, but I'm not wedded to it. The key is that new things that are added shouldn't just be mere mentions of ornithopters. They need to feature prominently in the work. --Eyrian 18:51, 5 March 2007 (UTC)
Why is there no mention of Dune in the fiction section? –Gravinos (To each their own*      *as long as they leave me alone.) 00:10, 6 December 2007 (UTC)

[edit] Prevailing Culture?

"Perhaps because the prevailing culture favors fixed wing aircraft..."

This statement sounds a bit put-upon to me, and I don't really see what it adds to an otherwise good article. Would anyone object to my either removing or re-writing it? --ConfuciusOrnis 20:18, 16 April 2007 (UTC)

Not remove, but I agree that it should be rewritten. As it stands it sounds a bit like ornithopter fanboys complaining that they're not taken seriously. Perhaps if a reliable source could be found asserting something of the sort (something like "flapping wing craft have long been ridiculed in aviation circles since the success of fixed wing craft") we could include that. Not sure how to word it though.--Yeti Hunter 00:41, 27 October 2007 (UTC)

[edit] Merger proposed (Tim-bird)

The following discussion is archived. Please do not modify it. Subsequent comments should be made in a new section.

The result was: Merge --B. Wolterding 16:08, 26 October 2007 (UTC)

I propose to merge the content of Tim-bird into here, since the notability of that article has been questioned. While the product "Tim-bird" as such exists, there are not many secondary sources about it, so the short article might be best merged here.

Please add your comments below. Proposed as part of the Notability wikiproject. --B. Wolterding 11:36, 19 October 2007 (UTC)

The context of the Tim-Bird page is a little thin and lacking in references, but if the term "tim bird" refers to generic bird-like toy ornithopters, then it probably merits a one-line reference in the Ornithopter article (eg "toy ornithopters resembling birds, known as tim-birds, have been popular since whatever year"). If however it's a brand name, AFD.--Yeti Hunter 07:23, 21 October 2007 (UTC)
I think that there's a place for descriptions of the various toy (model) ornithopters. Whether they go an a separate page or are included in the Ornithopter entry I'll leave that to someone else. There are more than one make of these other than Tim-Bird, as I had one of another make when I was a kid, back in the 1970s - I think it may have been Airfix. Ian Dunster 09:37, 21 October 2007 (UTC)
So "Tim-Bird" is a brand name? --Yeti Hunter 04:08, 22 October 2007 (UTC)
I don't know - I've never heard it called a 'Tim-bird' but I live in the UK and it may be either a brand name or a local name for the toy somewhere else. Ian Dunster 08:45, 22 October 2007 (UTC)
I'll merge it in. Feel free to edit it as needed. A redirect seems to be warranted in any case. --B. Wolterding 16:04, 26 October 2007 (UTC)
The above discussion is preserved as an archive. Please do not modify it. Subsequent comments should be made in a new section.


[edit] Recent developments

First 4 paragraphs provide unreferenced information. Links to Sage Grouse, Gossamer Albatross, Smithsonian Institution, SRI International, Reciprocating Chemical Muscle, pterosaur, Quetzalcoatlus northropi, Robert C. Michelson do not provide reference to recent developments of ornithopters or ornithopter technology. If proper references can be provided, it would help organize this section chronologically. If there are no supportive references, perhaps the information should not be included. I'm wondering for example about the idea that someone might accomplish something in the future that might be applied in this context should be included. Rogerfgay 13:11, 24 October 2007 (UTC)

[edit] Efficiency

(Copied from the Science desk:) Unfortunately, the efficiency section is not very accurate. Ornithocopters are not efficient for high-speed flight, as the wing-section required for lift is miniscule already. At supersonic speeds, I believe flight would be impossible for an ornithocopter. Current aircraft are more efficient for their mass and speed than birds are. Comfort has nothing to do with why we don't build ornithocopters, otherwise why wouldn't our reconnaissance drones have flapping wings? It is in fact a "failing" of biology to evolve a species to occupy a high-speed, high-mass, high-altitude niche, because to do so would require some kind of rotary muscle that does not exist in any animal we know of. The phenomenon is similar to why our ships use propellers instead of flippers. In this case, engineering firmly wins out, as many sea animals can compete with the weight and speed of our ships. SamuelRiv (talk) 18:31, 21 November 2007 (UTC)

[edit] Aerodynamics section

"As demonstrated by birds, flapping wings offer potential advantages in maneuverability and energy savings compared with fixed-wing aircraft." — This directly implies the possiblity that birds could have developed engines over the course of evolution. ¶ dorftrottel ¶ talk ¶ 20:32, December 5, 2007

Why was most of the old aerodynamics section deleted, and what's this implication that ornithopters are more efficient than propellers about? There perpetually seems to be a lot of bad information in this section, and nobody is citing their references. SamuelRiv (talk) 19:02, 6 February 2008 (UTC)