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Old Oct 09, 2008, 01:36 PM
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Airboatflyingshp,

Thanks for your reply! I'm so sorry to hear about your struggles, I wish you all the best!

As for the Seagull, I can't resist your suggestion to ask half throttle; it would certainly be interesting to know what they are up to, Kuni and Mr. Thompson.

As I think I mentioned, I have the plan and I’d really like to find some time for a project like this (although I never seem to get around to actually doing it). Meanwhile, I keep finding myself re-visiting this thread from time to time…

Thanks again,

/ Dag
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Old Oct 15, 2008, 08:50 AM
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The plan is a bit of a challenge with some errrors on it and the layout doesnt help but it does give you a great aircraft and with modern elecs and motors it would be a stunner.
As for Kuni well the designers aware of the original plan erors and he has all the original data. ...Kuni is thinking a bit larger with a hand crafted contra motor and other full scale refinements!?
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Old Oct 15, 2008, 09:39 AM
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try this for inspiration http://www.maxxprod.com/mpi/mpi-266.html
and if I havent before http://www.rcgroups.com/forums/showt...5#post10734276
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Old Oct 17, 2008, 12:54 PM
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Hi here,

it's Kuni. I have a close connection to John Thompson, the original's plan designer. I also have collected all I could find here. Plan to draw up and build a 2,3m span version of this model, complete with contra-rotating motor, scale retracts, folding wings, tail hook...
At the moment we are in the design stage of motor and retracts. I think it will last until next spring we can present something. Plans will be drawn-up next year, building time following winter season.
The type has some strange points for a model built: the trunk or pylon must be built lightweight but strong, for the wing is cantilever and all loads go thru the trunk, who also needs to play with the motor loads. The retracts are the trickiest I ever have seen! A real challenge to copy them in model form... we will see if it works.

Best whishes,
Kuni
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Old Oct 18, 2008, 02:32 AM
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Wow!

Hi Kuni,

Thanks for the update, this sounds pretty mind-boggling - absolutely awesome!! What a challenge! You are a brave man!

Ehh, you never mentioned the variable incidence wing, flaps and slats (would that be possible even at this large scale?), but considering your ambition with this, I guess that goes without saying?

Also, may I guess that you are looking into improving the scale accuracy on the area around the cockpit and reducing the wing-area? It seems to me that this is slightly altered on John's plan previously discussed on this thread?

Finally, may I ask you what reference material you and John have on the Seagull? The only sources I have seen are "Supermarine Aircraft since 1914" (CF Andrews, E B Morgan), an article in Aeroplane Monthly (or possibly Fly Past)from the 90’s, and this thread... Do you have anything else?

Again, thanks for the update, and the best of luck with this fantastic project!

Cheers / Dag
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Old Oct 18, 2008, 04:23 AM
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Hi Dag,

hmm, some things are better hidden
I have thought about that wing incidence changing as well as the slats to be operated, but deceided against, as the benefits are not clear. Slats without that wing gear dosn't let the hull be sit horizontal in the air, and regards the incidence gear I don't know how to make it stiff enough for that rough field/water flying conditions. Keep in mind that the plane still must be light enough to fly!
I have the article from Aeroplane monthly 12/1976, an cutaway-drawing from J.H. Clark from 12/1947, the article from The Aeroplane 12/1947, an essay from John Thompson about this plane with some 3-views, a color reference also from John, an article from Aeroplane monthly 3/1987, and the capture from the supermarine book. This will be enough to redraw the cockpit section and the wing. The challenging parts are the wing folding hinge (who ever created such weird hinge angles and wing panel cutouts should be arrested!) and the retracts gear. If these are drawn up the rest is modellers work rather than 3D-CAD car engeneers work. My brother-in-law makes these parts for me.

Regards,
Kuni
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Old Oct 18, 2008, 01:53 PM
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Reference material

Kuni,

Well, I suppose only a aerodynamicist could properly calculate the "benefits", in terms of improved stall slow speed handling. But even then, think about the difficulties with testing the thing in a safe way - tilting the wing too much, and... well, the risk is that you'd soon need another prototype... :-( A wind tunnel would be usable ;-)

I checked my old magazines and found the article I was mentioning previously: FlyPast, August 1994, author Ken Wixey. It's a one and a half pages article with three quite interesting pictures (none of them shown on this thread or in the "Supermarine Aircraft since 1914”-book). I'd be happy to supply you with a copy, if you're interested!

I've now ordered the back issues of Aerplane Monthly (http://www.aeroplanemonthly.com/back/). However, I've no idea of how to get the 'The Aeroplane 12/1947', or John Thompson's essay... I do understand that you may not want to just upload a picture of the old article (I suppose this could have cost you some money), but do you know how I and/or other people could get my hands on John's essay?

Finally a couple of links to two pictures on the net, which has not been mentioned on this thread previously:
http://www.airwar.ru/enc/sea/seagull.html
http://news.webshots.com/photo/10117...7832yjkyezVzmu (the only color photograph I've seen of the Seagull)

Kindest regards,

Dag
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Old Oct 20, 2008, 09:37 AM
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Dag take a simpler sport model with a similar configuration and try the idea out on that. I know Kunies into the flash stuff but If I was able to play with one aspect of the design it would be the tilt wing the motors are available off the shelf now but the wing is something no ones played with yet
As for suitable donor designs ... K Kusomas T13 a free plan on this site in waterplanes or Leven by Alasdair Sutherland its was released as a free plan in RCMW mag july05 its by Alasdair Sutherland..published by Traplet...............a light but robust corrosion proof hinge fixed to the spar or center section sould surfice on a light test bed.......... even try a SPAD/blue foam mule.
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Old Oct 20, 2008, 10:34 AM
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Hi Air,

even a mule cannot tell you if the wing (section, flaps and slats) will do it on a larger and heavier model. It's too risky for me, and even the mechanics and servos will add too much weight. Just take a look at the retracts; they can weight up to a full kilo at the model size I prefer! Will have to take care here...

Dag: I will ask John if he allows me to copy you the things. If you would copy the FlyPast, August 1994-article, I would do the same with The Aeroplane 12/1947' one.

Regards,
Kuni
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Old Oct 22, 2008, 08:17 AM
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Quote:
Originally Posted by Kuni
Hi Air,

even a mule cannot tell you if the wing (section, flaps and slats) will do it on a larger and heavier model. It's too risky for me, and even the mechanics and servos will add too much weight. Just take a look at the retracts; they can weight up to a full kilo at the model size I prefer! Will have to take care here...

Dag: I will ask John if he allows me to copy you the things. If you would copy the FlyPast, August 1994-article, I would do the same with The Aeroplane 12/1947' one.

Regards,
Kuni
Hi Kuni I wasnt thinking of your pantechnical leviathan thats how the project came unstuck in the first place ...too many clever ideas in one plane.... they forgot they had to carry stuff inside like crew and passengers the cut away is evidence We mortals can only aspire to exploring a couple of aspects of this beastie. The rest we will have to be stand off.

Reputedly in slow flying observer mode this thing could follow the local steam locos along the tracks.
as for the folding wings and scale working UC operation .......... its scary on the full size and mind boggling on a model.
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Old Oct 22, 2008, 01:45 PM
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Kuni, I'd be happy to send you the article! Just please give me one or two days and you’ll have it in a PM.

Airboatflyingshp, thanks for the suggestions regarding proof-of-concept designs. I thought you were all scale-buffs here, so I am surprised that you didn't suggest building a Dumbo – standard configuration with motor in the front, no contra rotating props, no retracts, perfect test vehicle, but still scale!?

I do indeed understand Kuni’s decisions here. Complexity, weight and safety (flight tests) are difficult problems to manage (especially on such a large model, I suppose); they are probably all good reasons for having the wing fixed. And, after all, this aircraft is amazing even without those features!

But then again, I just can’t stop visualize the sight of a Seagull in scale landing configuration, slowly progressing on short final… You may call me a dreamer, that’s ok… Regardless, I still don’t want to regard this as an impossible thing to do. I mean, ust take a look at http://www.dcmodelshop.com/image/Cru...0maiden%20.wmv (this site also contains picture of the jack-screw mechanism).

Although this ends with a fairly hard landing, I don’t think the wing is to blame. Rather, it sounds and looks like an engine flameout and possibly a too weak undercarriage... These guys clearly don’t have to worry about floats that physically mangle the incidence mechanism. However, the speed and wing loading on this jet is of course much higher that it would be on a Seagull…

And when it comes to slats. I just saw http://www.bphobbies.com/view.asp?id...9&pid=C3001677 mentioned in another thread on this forum, with functional slats and flaps (although the flaps are clearly much more simple that it should be on the Seagull).

I'm not sure what I want to say with this... I guess I just wanted to share my inspiration...
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Old Oct 23, 2008, 08:46 AM
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This is a research and data thread as far as Im concerned so its all ways of generating usefull info and getting round problems.... I have scans of a large tornado jet model that uses a screw jack mechanism to swing its wings...they are usefull in this context as they offer a degree of built in fail safeness. LMA guys use them to back up there UC mechanism .... stripped down electrical screw drivers.

The key to choosing to alter wing incidence is in the flyingboats need to get of the wet stuff. Its been a bane of the real things you either pull yourself off SM55 prophanging stile or you need to float your boats wing at a greater ange of wing attack.
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Old Oct 28, 2008, 06:40 PM
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More Seagull documents...

Hi everyone,

Since we seem to agree that this is a research and data thread… I did some more surfing on this topic, and I feel like I’ve stumbled into some really good stuff that I just have to share with you guys.

First of all, I discovered http://www.flightglobal.com/pdfarchive/default.aspx. This is a goldmine for anyone remotely interested in aviation. You get quite a few hits searching for well chosen search words… Most notably (there are more Seagull-stuff, but these seem to be the main articles):

Variable Incidence – Ancient Device is Super-modern Form... (April 1946)
http://www.flightglobal.com/pdfarchi...0-%200797.html

High Performance Amphibian (May 1947)
http://www.flightglobal.com/pdfarchi...0-%200655.html

Advanced Amphibian – Structural and Aerodynamic Features… (December 1947)
http://www.flightglobal.com/pdfarchi...0-%202115.html

High Performance Amphibian (November 1948)
http://www.flightglobal.com/pdfarchi...0-%201938.html

Secondly, I dug up a couple of interesting titles of some research papers and documents regarding S.12/40 and S.14/44 (the Air Ministry Specifications for the Seagull): Apparently you can order copies of these, although it seems that this could potentially be a bit expensive… Hmm, I need to look more into this… Also, I suppose most of them will be rather scientific in their nature… Anyways, please be aware that I am not claiming that this is an exhaustive list of Seagull-stuff.

Installation of A.S.V.X in S 12/40 aircraft (1942-1944)
http://www.nationalarchives.gov.uk/c...&CATID=1313386

Supermarine S.12/40 amphibian flying boat: tank (1942)
http://www.nationalarchives.gov.uk/c...&CATID=4931956

Calculated response of S 12/40 aircraft in roll (1943)
http://www.nationalarchives.gov.uk/c...932793&CATLN=6

Supermarine S.12/40 aircraft: wind tunnel tests (1943)
http://www.nationalarchives.gov.uk/c...932018&CATLN=6

Supermarine S.12/40 aircraft: further wind tunnel tests (1944)
http://www.nationalarchives.gov.uk/c...932119&CATLN=6

Appendix "A" Schedule of Airframe Equipment: for Supermarine S14/44 (1945)
http://www.nationalarchives.gov.uk/c...&CATID=4135449

S.14/44: Amphibian Bomber Recce. (1945)
http://www.nationalarchives.gov.uk/c...&CATID=-581687

Supermarine S.14/44 aircraft: wind tunnel tests (1946)
http://www.nationalarchives.gov.uk/c...932302&CATLN=6

Vickers-Supermarine S14/44 flying boat: electrical system (1946)
http://www.nationalarchives.gov.uk/c...935189&CATLN=6

Vickers-Armstrong Seagull S14/44 aircraft: stability and controllability (1943-1951)
http://www.nationalarchives.gov.uk/c...&CATID=3919906

There are also several other papers that may possibly discuss the Seagull further, although the titles are more “anonymous”, e.g.:

Monoplane with full span slats and a variable incidence wing: flight tests
http://www.nationalarchives.gov.uk/c...932370&CATLN=6

Finally, I previously suggested building a Supermarine Dumbo for testing the wing/lift devices. Another scale alternative seems to be the
Miles M.18, apparently used by Supermarine for testing the Seagull’s lift devices: http://www.jaapteeuwen.com/ww2aircra...ILES%20M18.htm

Rolling characteristics of high lift M.18 aircraft
http://www.nationalarchives.gov.uk/c...932969&CATLN=6

Happy reading!
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Old Nov 25, 2008, 10:13 PM
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Going to the FlightGlobal site, search under Supermarine 322 ( the Dumbo ) There are some mechanism photos for the variable incidence wing that may be relavant.

DJM
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Old Jul 24, 2009, 03:31 AM
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Seagull - why the arrangement?

The Supermarine 'Dumbo' was designed to try the adjustable wing incidence arrangement - which, as long as the angle was kept at 10 degress or less, had many advantages compared to a more normal wing, specially if there are span restrictions (both aircraft were deigned for onboard use - thus high-lift devices were desirable complications).

Especially the slats led to that the aircraft need to land at big angles of attack, to be of any use.

Eric 'Winkle' Brown writes about both aircraft in his well-known book "Wings of the Weird & the Wonderful II", as he was the world's most experienced test pilot during WW II, spoke fluent German & belonged to the Royal Navy - later he worked as test pilot in the US, seconded by the RN.

As is noticeable, with high angles the flying boat suffered lack of fin area, thus the different experiments with fins.

Folding wings were originally a feature, but was dropped when the planned use onboard carriers was dropped, thus second version didn't have folding wings!

That's all,

Tord,
Göteborg,
Sweden



Quote:
Originally Posted by hpfolland
Kuni,

Well, I suppose only a aerodynamicist could properly calculate the "benefits", in terms of improved stall slow speed handling. But even then, think about the difficulties with testing the thing in a safe way - tilting the wing too much, and... well, the risk is that you'd soon need another prototype... :-( A wind tunnel would be usable ;-)


Kindest regards,

Dag
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