Article about twin-boom aircraft

[Tophe]

The TN-29T drawing in the other topic was a puzzle concerning definition (like the B-16H at the end of "The end of Forked Ghosts"): are there 2 or 3 "tail-tubes"? My opinion is rather 2 but one may prefer to count 3, including the pilot pod. According to me, this pod is carried by the tail, and is not carrying the tail...
But to avoid any problem , let us prefer the asymmetric TN-29U
Well, it is the same problem after all, the pod is above the fuselage but is still a different tube... Aspirin anybody?

[Tophe]

Defining a word to classify is always uneasy. Look at an example (doubled to belong to this twin-tail subject...): what is a T-tail? It seems easy: "the shape of a T" !!! Yes, but Arial T is not Times T... and that makes 2 very different P-82T T – as starting point, because in Russian T is written as well [size=8]T[/size] or m, in Greek it is slightly different, in Hebrew & Arabic the T-sound is written very differently, in Japanese & Nepali, T does not exist but Ta is very differently written, etc...

Dear JHM, what is the T-tail expert opinion?

[John Howling Mouse]

Tophe, only YOU could see entirely new aircraft design dynamics in the subtle intricacies of a mere font!!

Cool ideas, too.  May I please "borrow" the "Times" T-Tail details?  Would make a lot of sense for a floatplane or three or ten that I have in mind.

[Tophe]

Tophe, only YOU
Cool ideas

Well, thanks for believing I am the genius inventor of this Times-T-tail layout ^_^ , but I am not (unless today events are a dream of mine ):
- In a recent Trait d'Union (French Air Britain) magazine was presented a weird plane with such a tail, at very short distance of the wing). Alas I was not sure  to be allowed to present it without Copyright.
- My friend Paul found the source as AviMag 727 (April 1st 1978) more than 25 years ago, so no more Copyright ... This is the plane on the left below, with a Zwilling version of mine on the right, of course...  

The text said: "from French official archives, this fighter project dated 1939 was named Kolko ACA 5/2".
- The date April 1st of the magazine may be a problem for JMNs, frowning eyes , but not us what-ifers ...
- The Zwilling version of mine , dated April 1st 1940 , is named Kolko-Z, as a joke B) , because the designer was communist and kolkoz was the name for Soviet farms ...

[Tophe]

I have read at last the very nice article "Boeing Flying Wings of 1935" in Airpower 03/2005. Weird ! And I have smiled reading the final acknoledgments: to our dear Elmayerle himself , that explained to the author the external elevon principle & drawbacks... Thanks Evan to have helped this great article to come!

I have just a few remarks:
- the external-elevon principle was not only encountered on Skoda-Kauba prototypes of the early 1940s: mainly it was featured on the Soviet Kalinin K-7 of 1933, intended to carry 120 passengers, and crashed this year. There were such aft surfaces from the wing but also from the remaining tailplane and even vertical from the fin! See http://www.umt.fme.vutbr.cz/~ruja/modely/p...in/K-7/k7-2.jpg
- As a "tail" is defined by its distance from the centers of weight and lift, could these external aft elevons be called "tails"? The pretended flying-wing tail-less Boeing 306s would be twin-tails... (with 4 booms on the 306B&C, 6 booms on the 306A, 306, 306fb). No? I will not post pictures from the article, I own no Copyright, but I can draw Mustangs in the same way, to show the 'puzzle'...
As my favourites are twin-boomers, I will start without 4 nor 6 booms, simply with asymmetry and no elevon on the starboard side: FWg-51C-0: twin-tail or flying-wing? There is more balance on the double-pod FWg-51B-0. And without twin-pod, the FWg-51A-0 is even almost-classical.
I don't know what is a tail, as the last XP-56 prototype was called a tail-less with a rear fin...


With fins and rudders, there is still a puzzle for taxonomy: the TT-51C-4 has 2 separate tailplanes thus 2 tails somehow, but 4 tail-booms and 4 tail-fins... The TT-51B-3 has 2 tail-booms, 3 tail-fins... The TT-51A-1 has a single fin (and a single tailplane spar), less than a F-18 while having 2 tail-booms. Aspirin required...

[Tophe]

Other related puzzle, that I mentioned in 1993: could the ends of a curved boom be counted as 2 booms?
See below:
- the TT-51B-2 has clearly 2 tail booms
- the TT-51B-U has one tail-boom with 2 parts, like 2 booms
- the TT-51B-? could have (depending on what is below the tailplane): 1 U-boom or 2 separate booms...

Uneasy puzzle once more.

[Tophe]

Definition issue too:
Probably I should have explained in the 'Forked Ghosts' 2nd or 3rd volume why I cancelled the layout-classification of the first book. The main point had been to separate twin-fuselages from wing booms beside a central pod (holding the crew and/or motorization). This was doomed as a clear twin-fuselage may have a tiny central motorization pod. See the possible Blohm und Voss P.123B below. I was still not what-ifing enough in 2000, I have been cured (here, thanks! ) in 2003 I guess...

[Tophe]

In my book "The end of Forked Ghosts", I had included as twin-boomers the PP-3838 and P-38DF (below, top), while the very close puzzles PZ-3838, PL-3838, P-38DZ (below, bottom) may be not twin-boomers:

PZ-3838: no tailplane nor fin, just tandem wings, so this is a complex flying wing, tail-less, without twin-tail-booms...
PL-3838 & P-38DZ: no distant tailplane nor fin, just located over the wing, these are simple flying wings, tail-less, without twin-tail-booms...

[Tophe]

The inline encyclopaedia Wikipedia brought a new definition to my collection:
"Twin-boom: twin-boom aircraft have their tailplanes and vertical stabilisers mounted on the tail of either two fuselages or on two booms fixed to either both sides of the single fuselage, the wings or the engines nacelles."
In "The end of Forked Ghosts" (free book of mine, downloadable at http://cmeunier.chez-alice.fr/Free_EoFG_MV.htm ), this could have been the 15th definition for Twin-boom, with the following classification according to my main map:

(A:yes, B:no) C:yes?, D:yes, E:yes,
F:no, G:yes?, H:no, I:yes, J:no
This is a new combination that was missing in my collection.

Anyway, I still prefer my own definition, as I disagree for case I, having 4 booms and not 2 according to me. Moreover, I disagree about the wording tailplanes AND stabilisers, judging OR would be necessary. Including the Polikarpov twin-boom 1943 (not a flying-wing according to me) rather than the Rutan Voyager (triplex boom according to me).
And I disagree about excluding the asymmetrical case with 1 boom + 1 fuselage (Rutan Boomerang).
And about requiring laterality ("sides") excluding for instance the Boeing 368.3 Pretzel.
And about forgetting the twin-boom drill, crane, wrecker, spray, lift, buoy, electronic-box etc (twin-boom is not at all dedicated only to aircraft machines)

This is simply one more definition, interesting while imperfect and arbitrary as the other ones.

[Tophe]

I disagree about the wording tailplanes AND stabilisers, judging OR would be necessary.

Detail below:

 COLOURS:
Green: agreement
Red: disagreement
Yellow: qualitative agreement / quantitative disagreement

[Tophe]

On the site http://en.wikipedia.org/wiki/Twin-boom I have added today a Discussion ( http://en.wikipedia.org/wiki/Talk:Twin_boom ). Other opinions/definitions are welcome...

[Brian da Basher]

Hi Tophe. I don't know if you're following this story or not, but Steve Fosset took off this morning from Florida in his quest to fly solo around the world and then back across the Atlantic, to complete the flight by landing in London. Here's a link to the homepage: Global Flyer Homepage

I've also attached a pic for you as well. I saw this and couldn't help thinking of my friend with a love for twin-tails!

Brian da Basher

[Tophe]

Thanks Brian for these news that I did not know at all. One more record for twin-boomers surpassing all other aircraft, that makes me smile... (As far as I am concerned, I am not proud trying to be the best in the World, but I know this is the goal of life for many people. I simply look at them, and if they pilot twin-boomers, or build twin-boomers, I smile with sympathy...)

[Brian da Basher]

I'm glad to make you smile, Tophe! Here's another pic that may add to your joy.

Brian da Basher

[Tophe]

As French TV did not mention the result of the Global Flyer flight, I have checked again the site, and smiled: twin-boom success...
Just a question: what is the definition of the longest flight ever? Satellites, or the inhabited Mir, or the winged Shuttle had turned around the Earth so many times  before coming down and land ... Yes, but they were not twin-boomers