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H. Roxbee Cox Flying Wing Seaplane

hesham

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Hi,

British designer H. Roxbee Cox proposed this 6-engined flying wing seaplane
just before WWII,with an unlimited take-off run and the 100% lift efficiency
of a flying wing, the SEAPLANE deserves another examination with modern
technologies.
 

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Jemiba

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" .with an unlimited take-off run.."
That's an argument, often heard in favour of flying boats. But it should always be kept in mind,
that this runway ist very rarely really smooth. And, as the experience with the Saro SR. A/1
had shown, cleaning such a runaway of dangerous debris is much more difficult, than for a
runway at shore.
Not to be misunderstood, I'm a fan of flying boats, but I think, we have to accept, that this type
of aircraft will be used today only for specialised tasks, like firefighting.
But then, it still could succeed, I think ! ;)
 

blackkite

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Unknown flying wing boat design

Hi! Anyone please identify this 70 ton flying wing boat design in 1937. I find it in Koku Asahi magazine in1943.
The text is not clear to read. The designers are Dr.Rockspee? and Mr.L.P.coom?
 

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Nik

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Re: Unknown flying wing boat design

Phew, that's a clean design ! Give wave impact forces, I'd worry about pitch authority. I'm surprised by the lack of wing-tip floats, though, and those props look as if they'd be wave-cutting. I'd suppose the air-inlets are above the wing...


By analogy with other low-wing designs, I'd be concerned about ground effect. I'd suspect this beast would be able to throttle back and cruise as a 'WIG'. Down-side is getting down onto the water before the zone marker buoys loom ahead...
 

blackkite

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Re: Unknown flying wing boat design

Hi! Many thanks for detail and sharp technical consideration.
 

Retrofit

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Re: Unknown flying wing boat design

In the magazine "Aircraft Engineering" dated Feb. 1945, A.R.Weyl described this project as dated 1937, and designed by M. Roxbee Cox and L.P. Coombes. Lateral floats are retractable.
 

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blackkite

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Re: Unknown flying wing boat design

Wow thanks!! My post include side view. ;)
 

Stargazer2006

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Re: Unknown flying wing boat design

A British design, presumably.
 

Grey Havoc

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Re: Unknown flying wing boat design

Stargazer2006 said:
A British design, presumably.
Perhaps for a pre-war Japanese requirement?
 

blackkite

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Re: Unknown flying wing boat design

Kawanishi?
 

Retrofit

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Re: Unknown flying wing boat design

Here-after the data of Lawrence Percival Coombes:
Souces: http://www.austehc.unimelb.edu.au/guides/coom/COOMS006.htm
1899 : Born Madras, India
1915 : Began course in engineering at City and Guilds Institute.
1917-1918 : With RNAS No.10 Naval Squadron and RAF 210 Squadron as Pilot of Sopwith Camels in France. Awarded DFC.
1918 : Freeman of the City of London for war services
1919 : Barnstorming on BE2Es with Kingsford Smith
1920 : London BSc, Degree in Engineering with 1st Class Honours from City and Guilds Engineering College
1920-1924 : With C.A. Parsons and Co., Newcastle-on-Tyne. Apprenticeship and Research Department.
1924-1925 : Royal Aircraft Establishment, Aerodynamics Department (in wind tunnels).
1925-1930 : Marine Aircraft Experimental Establishment, Felixstowe. First scientific officer under Maurice Wright then H.M.Garner.
1926 : 6 April. Married to Annie Marie Lee (Nancy).
1928 : 2 September, daughter Shirley Ruth born.
1930-1938 : RAE. In charge of Seaplane Tank.
1932 : 15 February, daughter Josephine born.
1938 : Travelled to Australia to establish the Aeronautical Research Laboratories, a Division under the Council for Scientific and Industrial Research. First Chief Superintendent.
1943 : Appointed agent for the Overseas Corporation (Aust) Pty.Ltd.
1945 : Elected Fellow of the Royal Aeronautical Society.
1946 : Inaugural meeting of the Commonwealth Advisory Aeronautical Research Council in London (of which LPC a member).
1949 : ARL transferred to the Research and Development Branch of the Department of Supply, becoming one of the Defence Science Laboratories.
1953 : Chairman of the Melbourne Branch of the Royal Aeronautical Society on its formation in 1953. Eventually became President of the Australian Division of the Society.
: Elected Fellow of the Institute of Aeronautical Sciences.
: Elected Fellow of the City and Guilds Institute.
1964 : Retired as Chief Superintendant of ARL
: Awarded the honour of Commander of the Most Excellent Order of the British Empire.
1965-1972 : Christ Church involvement
1968 : Awarded the Kernot Medal by University of Melbourne
1975 : 19 March, Awarded the degree of Doctor of Engineering, Honoris Causa, by Monash University.
: Foundation Fellow of Australian Academy of Technological Sciences.
1988 : Died, 3 June.

In the concerned period 1930-1938, he was working at the RAE, seaplane research dept.

Also: 6-9 "The Hull-Less flying boat" Description and patent
Incomplete paper headed 'The Hull-less Flying Boat' by H. Roxbee Cox and LPC; Patent agreement with the Air Council dated 30 August 1937 with attached description dated 31 July 1937.
 

Grey Havoc

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Re: Unknown flying wing boat design

Interesting. So how did the design end up in wartime Japan?
 

blackkite

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Re: Unknown flying wing boat design

Kawanishi K-200?
Many thanks Retrofit!
 

jzichek

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Re: Unknown flying wing boat design


Found the patent for the design here:


http://worldwide.espacenet.com/publicationDetails/originalDocument?CC=GB&NR=499883A&KC=A&FT=D&date=19390131&DB=EPODOC&locale=en_EP


Maybe one of our Australian forum members could visit the Australian Science and Technology Heritage Centre at the University of Melbourne and review Mr. Coombes' papers, as listed by Retrofit above. Might have more information on the project and perhaps some other ones as well. Would make an interesting model, but I'm not sure how one would scale it without having more data. The shape of the engine nacelles might provide a clue - do you think the contours may indicate Merlins?


-Jared
 

Apophenia

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Re: Unknown flying wing boat design

jzichek said:
... The shape of the engine nacelles might provide a clue - do you think the contours may indicate Merlins?
In that timeframe, Rolls-Royce Kestrels would seem more probable. The contemporary Junkers Ju 86V7 and the first three Ju 86Z-3s ordered for SAA had 745hp Kestrel XVIs.
 

blackkite

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Re: Unknown flying wing boat design

Wow Jared! You made my day.Thanks a lot. Very progressive shape at the day.
 

jzichek

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Re: Unknown flying wing boat design

You're welcome, Blackkite; these patent databases are quite remarkable and useful.
 

hesham

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Hi,

here is the Roxbee flying wing project drawing with details.
 

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hesham

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Re: H. Roxbee Cox Flying Wing Seaplane & His Work

Hi,

https://www.flightglobal.com/pdfarchive/view/1940/1940%20-%201777.html
https://www.flightglobal.com/pdfarchive/view/1940/1940%20-%201778.html
https://www.flightglobal.com/pdfarchive/view/1940/1940%20-%201779.html
https://www.flightglobal.com/pdfarchive/view/1940/1940%20-%201780.html
 

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Schneiderman

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We should be a little careful referring to the various aircraft in this thread as designs or projects. Roxbee Cox and Coombes (both from the RAE) presented them simply as concepts to illustrate their contention that the future lay with flying-wing aircraft and, for large aircraft, with flying boats. Their patent, using an early flying-wing concept as the basis, covers retractable step and wingtips. The concepts shown by Hesham above come, as you can see, from Roxbee Cox's Wilbut Wright Memorial Lecture to the RAeS entitled LOOKING FORWARD: Prolegomena for a Detailed Study of the Future of British Civil Aviation and are just illustrative of possible future directions.
 

hesham

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Schneiderman said:
We should be a little careful referring to the various aircraft in this thread as designs or projects. Roxbee Cox and Coombes (both from the RAE) presented them simply as concepts to illustrate their contention that the future lay with flying-wing aircraft and, for large aircraft, with flying boats. Their patent, using an early flying-wing concept as the basis, covers retractable step and wingtips. The concepts shown by Hesham above come, as you can see, from Roxbee Cox's Wilbut Wright Memorial Lecture to the RAeS entitled LOOKING FORWARD: Prolegomena for a Detailed Study of the Future of British Civil Aviation and are just illustrative of possible future directions.
Of course those were a hypothetical designs,the article said that originally.
 

Schneiderman

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I'm not sure that hypothetical is quite the right term. They are just illustrations of how the authors suggest design styles could evolve in an attempt to reduce drag; moving towards a pure flying wing and embedded engines. Some of the posts here requesting more details seem to overlook this point.
As such I wonder whether this thread belongs in Early Aircraft Projects; firstly as they were never intended to be projects and secondly as they are visualisations of possible future (i.e.post war) trends.
 

riggerrob

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Jemiba said:
" .with an unlimited take-off run.."
................................

That advantage was relevant before WW2, before they built all those hard-surfaced runways that allowed land-planes to take over long-range routes (e.g. trans-Atlantic).
Then flying boats' only advantage was their ability to fly in ground effect until they burned off enough fuel to climb to cruising altitudes (e.g. 20,000 feet).

Ironically, we now see floatplanes dominating short-haul routes from Vancouver harbour to Victoria harbour to Seattle harbour, etc. This can save enormous amounts of time for businessmen commuting from the power towers of downtown Vancouver to the provincial legislature over-looking Victoria harbour. They barely need taxis because walking distances are only a block or three.
Floatplanes can service those short-haul routes cheaper because they have 1/10 as many moving parts as helicopters.

In related news, Dornier just announced a partnership with Diamond to build 12-seater SeaStar flying boats.
 

steelpillow

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We should be a little careful referring to the various aircraft in this thread as designs or projects. ... Their patent, using an early flying-wing concept as the basis, covers retractable step and wingtips.
The caution is sound advice.
But I think the patent must have been a little more than that. It lists three specific claims: the fuselage-free configuration (which may or may not have a tail on twin booms) for a flying boat, the retractable step, and the design as depicted in the illustrations (including a swept leading edge to extend the bow forwards, retractable engines which can be raised for takeoff and landing, and retractable wingtip floats). Also, the numbers appended to some published images show that it had been studied with at least some attention to engineering design. I think I would call it a concept study comprising the two specific concept designs illustrated, as somehow I doubt they crunched any numbers for the biplane version.
Roxbee Cox rose to be Director of Scientific Research at the Ministry of Aircraft Production and as such he chaired the Tailless Aircraft Advisory Committee, which was stuffed with old friends of J.W. Dunne, father of the tailless swept wing. He also put Dunne himself, who had secretly returned to the fray, in touch with E.F. Relf of the National Physics Laboratory to get a 6ft span wind tunnel model made and tested, but that is another story.
 
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Schneiderman

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Lawrence Coombes had been an RNAS pilot in WW1 and involved in flying boat research at the RAE and MAEE since 1924. He was deeply involved in the water tank research prior to the Schneider Trophy contest in 1927, aiding Supermarine, Gloster and Short with float design, and travelled with the team to Venice. He left the UK in 1938 to take up a senior position in Australia with their Aeronautical Research Laboratory
 

Tony Williams

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I have always been intrigued by those twin-hulled Italian catamaran flying boats, and once thought of combining them with a swept-back flying wing, with podded engines on top of the centre section. That would permit gun turrets at the forward and aft ends of the hulls with very wide unrestricted arcs of fire.

However, an Italian aeronautical engineer told me that it was necessary to add tail booms to give the tailplane enough leverage to force the hulls to break contact with the water, which rather spoiled the idea...
 

steelpillow

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However, an Italian aeronautical engineer told me that it was necessary to add tail booms to give the tailplane enough leverage to force the hulls to break contact with the water, which rather spoiled the idea...
I wonder how true that can be. The Burgess-Dune tailless swept floatplanes in general had no problem in getting airborne. If you have a long hull then yes, forcing the stern down will take some doing. But if the "hull" is as short as a modest float or a wing, as in the Cox/Coombes design, it should be a lot easier.
 

Schneiderman

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That is where a good understanding of hydrodynamics comes in, balancing the shift in centre of hydrodynamic lift with the CG and aero centre. If you get the planing bottom and step design optimized the 'boat will take a nose-up attitude automatically as speed rises reducing the need for down leverage from the flight surfaces. In many early hull and float designs raising the nose often tended to go too far with the tail digging in.
 

Tony Williams

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However, an Italian aeronautical engineer told me that it was necessary to add tail booms to give the tailplane enough leverage to force the hulls to break contact with the water, which rather spoiled the idea...
I wonder how true that can be. The Burgess-Dune tailless swept floatplanes in general had no problem in getting airborne. If you have a long hull then yes, forcing the stern down will take some doing. But if the "hull" is as short as a modest float or a wing, as in the Cox/Coombes design, it should be a lot easier.
That sounds reasonable, but I suspect that the hydrodynamic performance of long hulls would be much better, especially in rough seas. On landing, very short hulls would surely be in greater danger of "tripping up" on waves, and in extreme circumstances even doing a forward somersault?
 

steelpillow

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That sounds reasonable, but I suspect that the hydrodynamic performance of long hulls would be much better, especially in rough seas. On landing, very short hulls would surely be in greater danger of "tripping up" on waves, and in extreme circumstances even doing a forward somersault?
The hydrodynamics depends on the slenderness ratio of the submerged section more than its absolute length. For a wide wing centre section such as the CC concept, the depth of water needed is very shallow and the craft readily acts like a "skimming dish" as it speeds up. In the vertical plane, the submerged part of hull is thus extremely slender.

One problem with this would be directional stability, and here the wingtip floats can play a part by being "toed-in" to act as differential drag stabilisers: Dunne even took out a provisional patent on that once.

And yes, there needs to be flotation well forward of the centre of gravity. Both Dunne and Burgess realised that the talless swept "arrow" wing was ideal because the central float was naturally right in the bow. This was balanced by the subsidiary floats which were forced back by the wing sweep as they moved outboard. Usefully, forcing an auxiliary float down into the water does not increase the volume submerged anything like as much as forcing the back of a long, big float or hull down similarly. Cox and Coombes (CC) were also well aware of all this, hence both their patent designs place the bow well forward, with the wing sweeping back and outward from behind it.
 

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Thanks for the info.

So a catamaran flying wing should have the twin hulls mostly forward of the CG, with relatively little of them extending behind the wing?
 

steelpillow

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So a catamaran flying wing should have the twin hulls mostly forward of the CG, with relatively little of them extending behind the wing?
Yes. If the plane sat level in the water it would leave the centre of buoyancy too far forwards. If you look at old photos, many flying boats therefore sit very nose-up in the water until they get up enough speed to start planing. The planing step is always just a little behind the CG. Note the very short section of movable "hull" behind the retractable step in the CC designs.
 
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