User talk:Dolphin51

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Dear Dolphin51: I like the improvements on center of pressure and static margin. I have one question; why are you distinguishing between neutral point and center of pressure. on the center of pressure page you introduce neutral point but it is not obvious to the non-technical reader what it has to do with the previous discussion on center of pressure. It seems to be an orphaned section. I am an educated reader on the subject and I seem to be missing some subtlety that you are tyring to make.02:22, 3 December 2007 (UTC) —Preceding unsigned comment added by Mangogirl2 (talk • contribs)

Contents

[edit] static pressure

Thanks for your kind invite to have a look at this article as it evolves - I should warn you that I'm not a formally trained aeronautics engineer or fluid dynamicist - just a half-trained planetary radio-astronomer :-). So when faced with questions that need clear thinking on fluids fundamentals, I usually reach for my copy of Batchelor! (I've had an article sketched out in my sandbox entitled 'classical theory of lift', which was also meant to be based on Batchelor's discussion, but which has made little progress in the last year).

I'll try and drop by the article over the next few days. Bob aka Linuxlad 15:51, 4 December 2007 (UTC)

Dolphin51: Missile people use center of pressure as the stick fixed location (no elevator deflection) of the aero forces on the airframe for epsilon angle of attack. Thus, the center of pressure at zero angle of atttack is defined as a the location of the center of pressure for the resulting pressure field at finite but small angle of attack. The center of pressure cannot be located at an infinite distance since you take the limit. We speak of the center of pressure at very small angle of attack. You calucalte the center of pressue use tail volumes, etc. Saying the neutral point is the definition of static margin is a circular argument for the non-technical reader. It provides no physical explanation. It really has to do with the lift curve slopes and locations of the wing and tail. The aerodynamic prediction code aeroprediction produces a zero angle of attack center of pressure location. Since my explanation is not strictly correct why don't we delete the discussion of static margin and aerodynamic center related to stability. The aerodynamic center is orphaned also. Also we should get rid of the neutral point discussion.

Mangogirl2 (talk) 23:05, 4 December 2007 (UTC)


Thank you for leaving notes on my user page, about your posts on Static pressure, but you don't need to, because that page is already in my watchlist, so that I get notified automatically. Regards. Giuliopp (talk) 23:55, 11 December 2007 (UTC)

Dolphin51:I have trouble following your changes to static margin. I feel that if the cg is ahead of the neutral point this should be call positive static margin. Maybe this is a country difference. Please look at the following link for some slides that I think agree with me.http://ocw.mit.edu/NR/rdonlyres/Aeronautics-and-Astronautics/16-885JFall-2004/6B524E1F-39F5-4E57-9B0E-812B40A21CED/0/aircraft_murman.pdfMangogirl2 (talk) 20:30, 12 December 2007 (UTC)

Dolphin51: looks like you are on top of the issue. I will stay out of it. It does seem to be a cultural practice difference. I have worked with UK folks on the guidance issue to some degree and never notices the difference. In fact we cowrote documents together and I never noticed a problem. I know you know what you are talking about. I will have to rewrite my definition of center of pressure to make more sense to the layman. I just reading an internal document about air vehicle stability and they used center of pressure and static margin consistent with my original use but I believe it is a case of all of us knowing what we mean and the explanation is not strictly corrrect for the unintiated. I will have rewrite missile center of pressure to be more transparent.Mangogirl2 (talk) 15:31, 20 December 2007 (UTC) Here is a link that I believe matcher Mangogirl2's view of center of pressure of an entire vehicle. http://exploration.grc.nasa.gov/education/rocket/rktcp.htmlMangogirl2 (talk) 19:48, 21 December 2007 (UTC)

[edit] Your concerns regarding the Bernoulli's Principle article

Hello!

I understand your concerns regarding the section the tries to do away with BP as the main source behind lift. Explaining away one faulty explanation with one a little less faulty but still lacking explanation can certainly put a strain on one's sense of accuracy.

I have however argued - on talk:Bernoulli's principle - that we should keep the section mostly intact. For my reasons for feeling this way, please see that page and continue the discussion there. And thank you for the heads up. :) --J-Star (talk) 12:33, 31 December 2007 (UTC)


[edit] Static Margin

dolphin51 -- Just read Static Margin. It is really good now. Good job. This has been an enjoyable experience in that it sharpened my understanding of somtehing I had gotten somewhat blase about. Thanks for challenging me. I have been roving the aerospace topics over the last year. So maybe we meet. I hope you have a good year in 2008. Mangogirl2 (talk) 04:47, 8 January 2008 (UTC)

[edit] Static Pressure

Looks really good now. Gman is really belaboring a point that needs no belaboring. Words mean what we choose them to mean. Ever instance I have ever seen in fluid dynamics agrees with you. Gman repeated point about dynamic pressure not being a real pressure is unwarranted. For an isentropic reduction in speed the stagnation pressure is the "static" pressure plus the dynamic pressure (as we all know). Dynamic pressure is as real as any thing else. Way to go.—Preceding unsigned comment added by Mangogirl2 (talk • contribs) 01:53, 16 January 2008 (UTC)

Ask Dolphin51 about my "unwarranted" claim on dynamic pressure: the current revision of static pressure says that "[total and dynamic pressure] are not pressures in the usual sense - they cannot be measured using [a] mercury column", i.e. dynamic pressure is not defined in terms of force onto an area, which is what I said. [Note: Dolphin51 is right about dynamic pressure but wrong about total or - better - stagnation pressure, which is indeed defined as the force per unit area in the fluid, at a stagnation point and can be measured with any Pitot tube]. Let's close the circle, anyway: dynamic pressure is clearly correlated to "static" and stagnation pressure, sometimes very simply by Bernoulli's equation (when applicable), sometimes not so simply (compressible flows) but it is always a quantity well distinct from the other two and with a different physical meaning (not force, but density square velocity). Is that warranted enough?
As for the static pressure article, I'll come back to it at a later date. Yours Gman (talk) 01:06, 17 January 2008 (UTC)

Gman has written (17 Jan 08) Dolphin51 is … wrong about total or - better - stagnation pressure, which is indeed defined as the force per unit area in the fluid, at a stagnation point and can be measured with any Pitot tube. I agree that total pressure and stagnation pressure are identical numerically in incompressible flow, and also in isentropic compressible flow. For that reason we regularly interchange them. However, the two are not synonymous. The concept of total pressure has meaning at every point in a fluid flow field. Stagnation pressure is simply the pressure (aka static pressure) at a stagnation point (and there may be no stagnation point in the flow field.)

I maintain that it is not possible to measure total pressure. When people want to know the total pressure along a streamline, or in the efflux from a reservoir, they can be ingenious and artificially create a stagnation point, usually by inserting a Pitot tube in the flow. They can then rely on the fact that stagnation pressure is numerically equal to total pressure and state confidently that the total pressure along the streamline is equal to the pressure measured using the Pitot tube.

In supersonic flow the stagnation pressure downstream of a shock is not equal to the total pressure upstream of the shock. As a consequence, a good deal more ingenuity is needed to compute the total pressure. In summary, total pressure is a mathematical concept and is not amenable to measurement, but stagnation pressure, being a pressure (aka static pressure) is readily amenable to measurement.

It is meaningful to contemplate the total pressure in the flow in a nozzle or diffuser, but it is not meaningful to contemplate the stagnation pressure in a nozzle of diffuser because clearly there is no stagnation point in such a device. Dolphin51 (talk) 11:30, 20 January 2008 (UTC)

Ah, ok now it makes sense. I had forgotten about the subtle difference between total and stagnation pressure, which becomes evident in non-isoentropic flows. In light of that, I believe there's quite some work to do to Total pressure (aside from the static pressure controversy), if anyone wants to have a go at it. Giuliopp (talk) 22:33, 20 January 2008 (UTC)

Haven't heard much from you in a while.Mangogirl2 (talk) 01:48, 5 March 2008 (UTC)
Hi MG2. I thought you must be on vacation! I have left a message for you on your Talk page under Neutral Point. Dolphin51 (talk) 03:37, 5 March 2008 (UTC)

Dolphin51: I missed the Feb 7 note. Also, I ran out of things that I know enough to write about. Been busy with Science Fairs. Do they have them in your country? Mangogirl2 (talk) 03:25, 7 March 2008 (UTC)

Hi MG2. I don't know what a Science Fair is, so I guess we don't have them in Australia. In recent years "hands-on" science centres have become very popular, and with good reason. In my city we have Questacon, a dedicated hands-on science centre. See Questacon. It is mostly manned by volunteers. Is this anything like your Science Fair? Dolphin51 (talk) 10:48, 12 March 2008 (UTC)

Dolph51: There is a good description on Wikipedia under science fair I have changed my name to skimaniac. —Preceding unsigned comment added by Skimaniac (talk • contribs) 18:23, 13 March 2008 (UTC)

[edit] Load factor (aerodynamics)

I had to cut a major part out of Load factor (aerodynamics) because of copyright violations. Now the article has no introduction. If you have time, can you give it an introduction? Cheers, Kingturtle (talk) 13:22, 12 March 2008 (UTC)

Thanks Kingturtle. I have posted a reply on your User talk page. I have also initiated a discussion on the Talk:Load factor page. Dolphin51 (talk) 00:34, 13 March 2008 (UTC)

[edit] Vortex generator

Thanks for your recent edits to Vortex generator. Your info there looks pretty accurate and reasonable, but other than citing two FAR/air regs, you haven't provided any refs for the information. My own experience suggests that your info is right, but I don't have a ref to back it it. All factual edits in Wikipedia must be supported by references see WP:citing sources.

Lately Wikipedia has been under the gun in the general press for doing damage with unreferenced articles. For anyone who doesn't think it is important for Wikipedia to be scrupulously referenced, I suggest that you read this CBC article. A lack of references can cause real damage in some cases. Obviously your edit on vortex generators isn't going to get anyone labeled a terrorist, but refs are still needed! - Ahunt (talk) 11:13, 14 March 2008 (UTC)

Thanks for your note. It isn't a personal crusade of mine. In the past I have had text I had put into articles tagged for lacking sources. At first I found it annoying, because it was stuff that I "just knew", but then I had the official policies pointed out to me. The CBC article really just cemented the issue in my mind and I came around to the official policy way of editing Wikipedia - when adding substantive text (not just spell checking or fixing grammar and wikilinks). The main articles on this are: Wikipedia:Citing sources and Wikipedia:Original Research. Essentially things that we all "just know" from our own personal experience do not belong in an encyclopedia, because they are unverifiable.
As it says in the policy Wikipedia:Verifiability:
"The threshold for inclusion in Wikipedia is verifiability, not truth. "Verifiable" in this context means that readers should be able to check that material added to Wikipedia has already been published by a reliable source. Editors should provide a reliable source for quotations and for any material that is challenged or is likely to be challenged, or it may be removed." This is policy, not optional and not a personal crusade.
Adding fact tags where they are needed is also policy:
"The burden of evidence lies with the editor who adds or restores material. All quotations and any material challenged or likely to be challenged should be attributed to a reliable, published source using an inline citation.[1] The source should be cited clearly and precisely to enable readers to find the text that supports the article content in question.
"If no reliable, third-party sources can be found for an article topic, Wikipedia should not have an article on it.
"Any edit lacking a reliable source may be removed, but editors may object if you remove material without giving them a chance to provide references. If you want to request a source for an unsourced statement, consider moving it to the talk page. Alternatively, you may tag a sentence by adding the {{fact}} template, a section with {{unreferencedsection}}, or the article with {{refimprove}} or {{unreferenced}}. Use the edit summary to give an explanation of your edit. You may also leave a note on the talk page or an invisible HTML comment on the article page."
So policy actually says that each sentence should be fact tagged, but this is clearly overkill when several paras are added.
The use of the "ref improve" tag has not proven enough to motivate editors to add citations. There have been many articles "ref improve" tagged for over a year and not only are no refs added, but lots of new material has been put in without citations. Generally the use of "fact" tags seems to improve the chances of editors adding the references.
I spend a lot of my time on Wikipedia actually finding refs for other people's edits and "fact" tags actually help me know exactly what needs a source. They aid the collaborative process.
The fact tags also serve an important role for non-editing members of the public (including the media) who are reading an article. They show that the information is not referenced and therefore should at best be considered unreliable.
Despite the policy that says to just remove the information, I believe that "Fact" tagging is usually a better approach, especially in cases like the text you added where my own experience indicates that your info is probably correct, but I can't source it from the internet or my own fairly large collection of aeronautical books.
As you can see some people think that it shouldn't be fact tagged at all, but quickly removed:
"I can NOT emphasize this enough. There seems to be a terrible bias among some editors that some sort of random speculative 'I heard it somewhere' pseudo information is to be tagged with a 'needs a cite' tag. Wrong. It should be removed, aggressively, unless it can be sourced. This is true of all information, but it is particularly true of negative information about living persons.
–Jimmy Wales"
I didn't tag the first para, because in general the introductory para of most articles does not have a citation, although some do. In most cases it is a summary of the text to follow and rests on those refs. If the intro para has information that seems to make a claim of some fact, rather than a general overview, then it should have a citation as well. In the case of this article I judged it to a very general statement, although perhaps another editor might disagree and prefer it be properly footnoted.
I hope this explanation has been helpful. - Ahunt (talk) 13:47, 14 March 2008 (UTC)
Thanks for your comment on my talk page. I am guessing that all means that you don't have a reference for the text that you entered in the article and that it is all from personal experience? - Ahunt (talk) 15:02, 15 March 2008 (UTC)
To help out on this issue I found sufficient refs to back up the text and expand it somewhat. - Ahunt (talk) 16:17, 15 March 2008 (UTC)
Glad that was all helpful. The article is looking much better! I agree that using Busch's article which requires a free membership is not ideal. Wikipedia:EL#Sites_requiring_registration says these should be avoided for external links. Wikipedia:Citing_sources has nothing to say on the subject. I usually do avoid these sorts of refs, but Busch's article was too good a ref to pass up. Let's see if anyone objects! - Ahunt (talk) 12:17, 17 March 2008 (UTC)

[edit] Edit of 203.218.190.157 on Bernoulli's principle

Hi Dolphin51. It is very well possible that 203.218.190.157, who seems to be new to WP, did his removal of this example in good faith. The example is quite dubious, given all discussions about "misunderstandings" on lift. Crowsnest (talk) 11:38, 25 March 2008 (UTC)

Hi Crowsnest. I see that you and the special contributor have deleted the description of lift and Bernoulli's principle. You will notice that the text you deleted contained a reference:

When a stream of air flows past an airfoil, there are local changes in velocity round the airfoil, and consequently changes in static pressure, in accordance with Bernoulli’s Theorem. The distribution of pressure determines the lift, pitching moment and form drag of the airfoil, and the position of its centre of pressure.” Clancy, L.J., Aerodynamics , Section 5.5

This is a very, very powerful reference. Very powerful indeed. This book is very comprehensive in the field on aerodynamics, and its author L.J. Clancy is one of the doyens of aerodynamics, at least in Europe. In contrast, the Bernoulli Sceptics (you are one of these) never, never quote a reference of any kind when you do your work.

The threshold for inclusion in Wikipedia is verifiability, not truth. See WP:Verifiability. Whether your deletion is true or not is of secondary importance. Verifiability is paramount and I have provided the reference to Clancy's words on the matter. What do you have to say about verifiability of your point of view? If you have a reference, please reveal what it is. If you don't, please immediately re-instate the text you have deleted.

It is not sufficient to say "see the discussions on lift". There is a lot of material on the Talk:Lift page. I don't intent to wade through it to find what you have in mind, or to find a reference for you. Dolphin51 (talk) 11:51, 25 March 2008 (UTC)

Hi Dolphin51. You are right. My apologies for reverting your restore. Best regards, Crowsnest (talk) 11:58, 25 March 2008 (UTC)
Hi again Crowsnest. Thanks for your latest message. I started a new topic in Talk:Bernoulli's principle to highlight the problem. Thank you also for restoring the deleted text. When I saw that it had been restored I went back into my new Talk article and deleted references to "Crowsnest". Happy editing! Dolphin51 (talk) 12:20, 25 March 2008 (UTC)
Sorry for calling this example dubious. I am just overly triggered by anything related to lift force and Bernoulli's principle, due to the section "A common misconception about wings", which is all about different ways how to determine or how not to determine lift force, and has nothing to do with Bernoulli's principle. Crowsnest (talk) 12:51, 25 March 2008 (UTC)

Troll?

Is it possible that Rcgldr/203.218.190.157 is a troll? Based on this entry:

  • No, I've visited that web site, but had no plans to quote anything from that website, although that site does include text about static ports, a real world example that differences in air stream velocity don't produce lift. Rcgldr (talk) 21:18, 1 April 2008 (UTC)

I'm beginning to have my suspicions... ComputerGeezer (talk) 22:50, 1 April 2008 (UTC)

Hi ComputerGeezer. I don't think he is a troll. I think his enthusiasm for participating on matters of aviation greatly exceeds his expertise. So far his efforts have been harmless because he has not edited the main article, only the Talk page. He only started contributing to Wikipedia on 31 March, and everything he has contributed has been on the Bernoulli Talk page. He displays a high degree of self-confidence but his writings don't warrant that self-confidence. He mostly writes nonsense. I am about to comment on his latest contribution. Best regards. Dolphin51 (talk) 11:03, 2 April 2008 (UTC)

Ok, I'll sit on my editing fingers for a while. (I think you're right, it's just that the last one moved from misunderstanding into silliness and made me start considering alternative explanations.) ComputerGeezer (talk) 14:08, 2 April 2008 (UTC)

[edit] 1999 South Dakota Learjet crash

Hi. Thanks for your message and its "heads up". Maybe one day Wikipedia will include an Automated Edit Warning System that features a "LINK UP!" alert... Sardanaphalus (talk) 12:12, 30 March 2008 (UTC)

PS The way in which creatures such as dolphins move so rapidly through water with such seemingly work-defying ease is one of those natural wonders I'm particularly impressed by. Thanks for the reminder on your userpage.

[edit] thanks: wing Warping

I added references explicitly. Since I had linked to the Wright Brothers Page and to the wing warping page that had references to authoritative sources, i thought I didn't have to insert them in the section I added. The Wright Bros page talks extensively about the lack of realization of the need for aircraft control before the Wrights. The other big contribution of the Wrights was the wind tunnel for scale model testing. Saltysailor (talk) 02:35, 9 May 2008 (UTC)

[edit] AfD nomination of Laurence Clancy

I have nominated Laurence Clancy, an article you created, for deletion. I do not feel that this article satisfies Wikipedia's criteria for inclusion, and have explained why at Wikipedia:Articles for deletion/Laurence Clancy. Your opinions on the matter are welcome at that same discussion page; also, you are welcome to edit the article to address these concerns. Thank you for your time. Do you want to opt out of receiving this notice? RolandR (talk) 12:44, 11 May 2008 (UTC)

Sorry to hear that the article on L.J. Clancy has been deleted. Crowsnest (talk) 08:40, 19 May 2008 (UTC)

[edit] Talk:Spin (flight)

I have never flown an aircraft as Pilot In Command but I grew up on a airport and had AvGas in my blood for most of my younger years. I just never went as far as to get flight training. Therefore, I'm surprised that you, as a trained pilot, disputed the validity of the term "flat spin". Before taking this as another personal attack, please read on.

Over the last couple of years, I have seen a great deal of accurate and useful information disputed or even excised from Wikipedia by know-nothing buttinskis who have nothing better to do with their time than peruse Wikipedia for unreferenced statements to dispute. Those who believe that Wikipedia should err on the side of exclusion have won-out over those of us who believe that it should err on the side of inclusion. Your suggestion that the term "flat spin" should be removed--a term that is used in countles books, manuals, official accident reports and published scientific research--made you look like one of the above. The last thing I expected was to find out that you have experience in aviation.

So, my question to you now is, as a trained pilot, why do you think "flat spin" is a colloquialism? Is there a school of thought, that I'm unaware of, that says "a spin is a spin, there is no 'flat spin'"? —Preceding unsigned comment added by Rsduhamel on June 5, 2008.

Hi again Rsduhamel! Thanks for explaining your viewpoint. It gives me the opportunity to explain mine. As a pilot, flying instructor and aeronautical engineer I have carried out a lot of spins and read quite a few books on the subject. I am very respectful of all spins, including those regarded as steep spins (alpha less than 45 degrees). It is not only flat spins (alpha more than 45 degrees) that are potentially hazardous. Flying instructors regularly demonstrate to their students the way their airplane spins, and also the recovery procedure. They don’t demonstrate steep and flat spins. In my (general aviation) experience, single-engine airplanes have one spin mode only. It is not possible to choose whether to put these airplanes into a steep spin or a flat spin. It is only possible to put them into a spin and then accept whatever angle of attack is the result. I have in front of me the excellent book Aerodynamics for Naval Aviators by H.H. Hurt Jr. It contains comprehensive information about spins. The terms flat spin and steep spin are not used anywhere in the book. Every reference is about spins in general without regard to whether the angle of attack is less than, or greater than, 45 degrees. In my experience, professional aviation books talk inclusively about spins without attempting to differentiate them into steep and flat spins. The av8n web site is generally very good, but it does misuse the notion of the “flat spin”. NASA distinguishes between steep and flat by arbitrarily using an angle of attack of 45 degrees. NASA does not claim there is a significant change in the character of spins at the 45 degree point. I intend to use the comment facility on the av8n web site and draw the misuse of "flat spin" to the attention of the authors.
As Spin (flight) exists at present it contains a number of anomalies. Here are a few of them.

[edit] Under Steep spin it says:

  • A steep spin can be initiated by applying rudder while beginning a stall. (No citation provided.) This is the initiation procedure for spins in general, not just steep spins. This sentence would be fine if the word steep is deleted.
  • Recovery from a steep spin is usually accomplished by neutralizing the ailerons and applying rudder opposite to the direction of yaw. (No citation provided.) This is a general recovery procedure applicable to spins in general, not just steep spins. This sentence would be fine if the word steep is deleted.

[edit] Under Flat spin it says:

  • if an aircraft is not rated for flat spins, it is unlikely that the pilot will be able to recover from a flat spin. Some airplanes are rated for spins, and some are not rated for spins. Airplanes are not rated for different types of spin. The sentence implies that the pilot will be able to recover from a steep spin, even if it is not approved for spinning – very dangerous implication - a young pilot might try a steep spin in an aircraft not rated for spins! This sentence would be fine if the word flat is deleted.
  • A flat spin can be deliberately initiated by the pilot and, if conducted in an aircraft approved for the maneuver, is quite recoverable. This is true of all spins, including steep spins. This sentence would be fine if the word flat is deleted.
  • Recovery from a flat spin caused by the C.G being too far aft is usually not possible using the flight controls. If the CG is too far aft any spin is usually not recoverable. This is true of spins in general, including steep spins. This sentence would be fine if the word flat is deleted.

I understand your frustration at seeing Wiki editors deleting information they disagree with. However, be aware of this guidance: WP:BeBold
Best regards. Dolphin51 (talk) 03:39, 6 June 2008 (UTC)

[edit] More on flat spins

Okay, you subscribe to a school of thought that says "a spin is a spin". Your arguments have merit and my first impression is to agree. If you can cite independent research that agrees with your point of view then, by all means, put it in the article. However, even if the overwhelming scientific consensus is that all spins are varying degrees of the same event, the term "flat spin" should not be removed from the article. "Flat spin" means something to many people. Many pilots use the term, NTSB investigators use the term, NASA has defined the term. The article should then explain why many people differentiate between steep spins and flat spins and why the differentiation is not scientifically useful. That will educate people rather that leaving them high and dry if they want to learn what a flat spin is. In fact, if you had said something to the effect of "There is debate as to whether the term 'flat spin' is scientifically useful. The term 'unrecoverable spin' is often preferred (or whatever you would say).", I would have had no problem. But, then, I wouldn't have been prompted to do some research and add to the article.

As far as NASAs definition being arbitrary is concerned, it certainly is. Nothing new about that in science. If a tropical cyclone has sustained winds speeds of at least 74 MPH (and it's in the Atlantic or eastern Pacific Oceans), it's officially a hurricane. If the winds are less, it's a tropical storm or tropical depression. There is no significant change in the storm's characteristics at 74 MPH. But it is universally accepted as the dividing line between a tropical storm and a hurricane. The NASA definition of a flat spin seems unlikely to coincide with the point where a spin becomes unrecoverable. That would need to be covered in the article.

As far as the guideline WP:BeBold. Great idea but often abused. In my observation this abuse has often led to the people with the strongest opinions controlling the content. I have cut my editing back, perhaps, 80 percent. This is mainly because I spent too much time fighting to keep material from being deleted (mine as well as other's). So, the next time someone wants to delete the article about Dmitri Maksutov, because inventing an important type of telescope isn't notable enough to to warrant an article in Wikipedia, more power to them (That was someone else's article, not mine, I just saved it). Rsduhamel (talk) 05:30, 6 June 2008 (UTC)

Hi again Rsduhamel! I believe we have found common ground and are in complete agreement. Your analogy tropical cyclones and 74 MPH is brilliant. It hits the nail on the head perfectly.
I agree that "flat spin" is used widely, but in a subjective manner. The av8n web site exposes the NASA research very well. If I do some editing on Spin (flight) in the near future I will cite the NASA research - it shows what flat spins are, and what they are not.
If you look at sites such as Stall (flight), Static pressure, Position error, Longitudinal static stability and Bernoulli's principle you will see that I have cited the excellent book Aerodynamics by L.J. Clancy. I wrote a biographical article about Laurence Clancy and posted it on Wikipedia. Unfortunately others thought he was not notable enough, even though he was the author of an excellent book cited often in Wikipedia (probably only be me, unfortunately). The end result was my article was deleted and there is no longer any trace of it on Wikipedia. (See above in my User talk page and you will see a bit of the deletion activity.) I was disappointed that I was unable to save my article, but I guess them's the rules on Wikipedia. I think I have got over it.
Best regards, and happy editing! Dolphin51 (talk) 01:48, 7 June 2008 (UTC)

[edit] Thanks

Thanks for your input at Talk:Siphon! Third-party reviews help in these debates.--Yannick (talk) 13:53, 8 June 2008 (UTC)