Talk:V-tail/Archive 1

Archive 1

Inventor?

Did Rudlicki invent the V-tail, or did Clyde Vernon Cessna? 59.167.55.80 07:37, 6 May 2007 (UTC)Dave

pelikan tail?

Has anyone heard of the idea of moving the vee halves to either side of a lifting body? Is that a distinct idea? Please comment at Wikipedia:Articles for deletion/Pelikan tail. Potatoswatter (talk) 23:38, 4 May 2008 (UTC)

Inversion

Does an inverted V tail have particular advantages, or is it just about lifting the tail boom higher on these small drones? Andy Dingley (talk) 11:27, 14 August 2008 (UTC)

The inverted V-tail hasn't just been used on drones, see Ultraflight Lazair for example. There probably should be some discussion here on the advantages of the inverted V-tail, if a suitable reference can be found. In most applications it seems to be mounted inverted to use the tips as landing gear (as in the Lazair) or to keep a pusher prop off the ground. - Ahunt (talk) 11:37, 14 August 2008 (UTC)

Interesting one - I haven't seen an analysis but suspect an inverted v-tail actually has a small drag and control authority disadvantage compared to a conventional v-tail - it's located closer to the wing's trailing edge turbulence and eddies resulting from such airflow interacting with the fuselage. Also, it would be further away from the propwash - especially in slow flight at high angles of attack - so is likely to have less control effectiveness. I'll have a poke around and see if there's any deeper analysis. Ozzielinden (talk) 14:08, 14 August 2008 (UTC)

A long time ago I had read a note by the Lazair's designer, Dale Kramer, claiming that the inverted V-tail was the most efficient tail for about a half a dozen reasons. I will try to see if I can find the article. In the case of the Lazair, which is a highwing aircraft the tail is actually in pretty clean air at cruise speed. I do know that when I flew Lazairs, that as you entered ground effect the inverted V-tail created a nose-down pitching moment that prevented over-flaring and the risk of a stall near the ground. Of course it could also cause you to pitch into the ground, but the effect was not pronounced and at a 35 mph approach speed, not a problem. - Ahunt (talk) 15:08, 14 August 2008 (UTC)

Dubious Claim for Drag Advantage

There is a statement made in the "advantages" section that a V tail is inherently less draggy and lighter than a conventional tail arrangement. Given that 99% of the world's aircraft DONT use V tails, this is a statement that requires some justification, unless one is prepared to assume that every major aircraft manufacturer in the world is stubbornly, stupidly, using a less efficient configuration.... (Personally, I think it's an untrue assertion) MadScot (talk) 21:40, 8 January 2009 (UTC)

It has been claimed that less drag is "trivially mundane" becauise there is 2/3 the tail hence 2/3 the drag. This is incorrect, because it assumes that each of the two surfaces ona V tail would be the same size as ona conventional tail. But in fact in order to get the same stabilising effect you need to make the V tail surfaces larger, and if you do the maths you'll find that in fact they get larger by ... 50%. So, two surfaces, overall 50% bigger, or 3 surfaces the original size = same drag/weight, to the first order. i want to see an actual reference to back up the unsupported claim in the article, and I'm putting back the tag. MadScot (talk) 00:14, 9 January 2009 (UTC)

"Dubious" claim for Drag Advantage; continued

The question of drag is very interesting - I've been toying with the idea to build a model to simulate the drag from a V-Tail compared to a conventional T-Tail as this issue is less than clear-cut. In my view, the surface drag should indeed be similar, however, I suspect the induced drag, the vortice drag (from more surfaces connecting to the fuselage and creating interesting airflow interactions) and, most significantly, the aerofoil-tip drag (caused by wingtip vortices) will be grater in a T-Tail compared to V-Tail, simply due to the larger number of surfaces.

I don't have the appropriate software to efficiently model complex airflows (unless someone knows of an easy way to tweak Mathematica...) so if anyone's an aerodynamics student with access to a wind tunnel modeller, I'd be happy to help! Ozzielinden (talk) 19:21, 1 February 2009 (UTC)

According to my old textbook (*Aircraft Design: A Conceptual Approach, 3ed.* by Daniel P. Raymer, 1999, p. 78) the V-tail does require approximately the same wetted area as a comparable T-tail, but still manifests reduced total drag from reduced interference drag, due to fewer intersecting surfaces; the net effect on weight is unclear, but the complexity of control & stability increases (inverted V-tails, such as on the Predator, actually have stability advantages, although the control complexity is not reduced). Sketch051 (talk) 21:07, 2 November 2010 (UTC)

"Dubious" claim for Drag Advantage; continued AGAIN

I've come across an interesting claim: "Control response of V-tail equivalent to conventional tail of 40% greater area" on two websites Aviation-History.com and Pilotfrient.com No sources and I can't seem to find anything substantiating those claims; anyone seen/heard this before? Is it out of the old (1960s) marketing for the Bonanza? OzLind (talk) 11:52, 5 September 2013 (UTC)

Yaw -> roll?

It seems to me that "side rudder" would introduce a roll-force in the "outwards" direction? One control surface goes down and introduces momentum to roll which is enhanced by the other control surface going up at the other side and also producing momentum in the same direction. Eh? —Preceding unsigned comment added by 83.251.57.154 (talk) 19:31, 7 September 2010 (UTC)

About Coanda-1910 and related work to "V"-Tail

Translation from the French article from 1935, "L'Aeronautique" page 333, Dans le domaine des recherches et expériences, l'ingénieur Herbemont s'est attaché à l'élude d'un empennage en V, évolution logique de l'empennage classique puisqu'il remplace les éléments composants à actions verticales et horizontales par leurs résultantes. Un empennage de ce type avait été proposé il ya deux ou trois ans par l'ingénieur polonais Rudlicki. Antérieurement, en 191 1, Coanda avait présenté au Concours militaire de Reims un empennage en X. - In the field of research and experimentation, engineer Herbemont focused on the study of a V-tail, a logical evolution of the classic empennage as it replaces the classic elements composing the vertical and horizontal actions by their resultant. A tail of this kind had been proposed two or three years ago by the Polish engineer Rudlicki. Previously, in 1911, Coanda presented at the Reims military contest a X tail. As well I add here a quote from Antoniu's monograph from 2010 "Henri Coandă and his technical work during 1906–1918". Bucharest: Editura Anima. ISBN 978-973-7729-61-3. Bristol-Coanda canard 1912 Faithful to his beliefs that a new design had to be based on new and advanced concepts, Henri Coanda completed in 1912 a very interesting project that included many innovation in the field. This was a monoplane provided with a wing place in tandem with the main wing (canard), a solution used generally today on all transport aircraft. Based on the type of cockpit, this could be build in two versions: two-seat or single-seat trainer. To reduce the looses and improve aerodynamics, he placed the engine inside the fuselage and the propeller behind the wing, but in front of the empennage placed in a "V" with a 90-degree openeing. The forward wing gave stability to the machine by increasing the lift generated by the main wing at low speeds, a fact proven by tests in the wind tunnel in the laboratories of his friend Eiffel. ....

In 1913, when the model was sent to Gustave Eiffel, Coanda gave up the cross-shaped empennage, using instead two planes placed at 90 degrees from each other, a modification also illustrated in the drawing. The drawing and diagram of measurements was published in the periodical atlas published by Gustave Eiffel: Nouvelles recherches sur la résistance de l'air et l'aviation (faites au laboratoriee d'Auteuil) [New Research Realting to Air Resistance and Aviation (Carried Out in the Auteuil Labs)], Paris, 1914. Page 124-125 from Antoniu's monograph.

File:Coanda-1912.jpg

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Next is a the picture with the aircraft with the "V" tail and the angles and measurements taken from the pages 115-117 in Eiffel's book entitled "Modele au 1/40 du monoplan Bristol". ( Sorry for the quality :( If you find it relevant I can try to get a better scanning. As well I don't know anything about the copyrights. ) As well a contemporary photograph in Flight magazine of the 1911 aircraft at Rheims. Please join the Talk:Coandă-1910 as well. --Lsorin (talk) 12:23, 11 January 2011 (UTC)

Thanks for the info here. It is not clear to me whether the V-tailed 1912 design was ever built of remained at a model stage. - Ahunt (talk) 12:55, 11 January 2011 (UTC)

(edit conflict) Related to this, I had a look at Rudlicki's patents out of interest and they seem to be about having only two angled control surfaces and the particular mechanism required to coperate them from a single control - which is the V-tail. Unfortunately my opinion on the patents is worthless within a wikipedia context except as a suggestion for investigation of sources on the topic, and patents themselves are primary documents which can only really be used for establishing that a patent exists or as subject for an external link. GraemeLeggett (talk) 13:02, 11 January 2011 (UTC)

Graeme: I agree on your patent points, that finding a patent only shows that the patent exists, not that the person filing invented it or that the patent was even upheld later. I think the Coanda 1912 might be worth mentioning as an early V-tail, but we need to sort out a bit more background to get the entry right. Did it fly or was it just a model? - Ahunt (talk) 13:06, 11 January 2011 (UTC)

Couldn't find anything in Flight for 1912. The angled cruciform 1911 machine did fly. GraemeLeggett (talk) 13:51, 11 January 2011 (UTC)

Thanks Graham, I added that in there, with your ref. - Ahunt (talk) 17:30, 11 January 2011 (UTC)

Additional aircraft.

Wouldnt the Lockheed-Martin YF-23 Blackwidow and FM RQ-4 Global Hawk also be considered V-tail aircraft. If so, this should also be added to the article. 67.172.179.96 (talk) 06:58, 9 February 2011 (UTC)

These are just examples, not an exhaustive list. You would find that at Category:V-tail aircraft. - Ahunt (talk) 12:50, 9 February 2011 (UTC)