Shin Meiwa “GS”


Donald McKelvy
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14 August 2009
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Shin Meiwa, now ShinMaywa, “GS” (for Giant Seaplane) from 1977. The GS was an amphibian airliner designed to carry 1,200-passengers on three decks. 344 passengers on its upper deck, 626 on the main deck, and 230 on the lower deck. Payload was estimated at 120 tons.

Designed for transoceanic service, the GS had a range of 3,500 nm. Cruising speed would be 486 knots at an altitude of 37,000 feet. The plane would take off in 3,800 feet at 92 knots and land in 1903 feet at 102 knots. The aircraft was designed to operate in Sea State 3 (maximum wave height at 5 feet).

Six advanced, high-bypass ratio turbofans of about 77,000 pounds of thrust would be needed to power this mammoth flying boat. For enhanced STOL capability, the engines would exhaust air over the wing's upper surface in a propulsive lift concept similar to the Boeing YF-15. To that end, engines would be mounted above and forward of the supercritical wing. An advantage of this arrangement is that the engines are out of spray range and thus safe from flameout due to excessive water ingestion.

Advanced turbofans, improved hull and supercritical wing designs, composite materials for weight savings and salt-water corrosion resistance, and water evacuation systems required by the GS were expected to take about six years to achieve.

Purchase price was expected to be $60 million in 1977 dollars.

General Characteristics

Length: 293.9 feet
Wingspan: 255.9 feet
Height: 71.3 feet
Width: 27.6 feet
Weight: 1.04 million pounds


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Mentioned in AviationWeek May, 1977, too :


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There's been a revival of interest in the concept of giant jet powered seaplanes (for the most part, for the carriage of cargo) in the last 12yrs or so.
The Shin Meiwa GS as seen in a thesis called THE USE OF SEAPLANES AS AN ADVANCED WEAPON SYSTEM, by Algeu Kreniski, September 1988:


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I can't find any information about this surprising giant flying boat project in Japanese sources. :-[
Hi! Shinmaywa GS and SS-X.


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Hi my dear hesham! Please visit Hiroshima(広島) and Miyajima(宮島)(Itsukushima(厳島 : another name of Miyajima)).


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is there any drawing to Shin Meiwa " MS" ?.
Wow! Thanks. GS, MS and SS-X. We had to find MS specification, SS-X specification and SS-X three side view drawing.


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Please see attached for SS-X specifications.



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Wow! Thanks a lot.
In 1977 Shin Meiwa had several ideas for it's STOL flying boat concept on the drawing board but none were ever built. They were the Shin Meiwa LA (Light Amphibian), a 40 passenger light amphibian for inter-island feeder service; the 400 passenger Shin Meiwa MA (Medium Amphibian); the Shin Meiwa MS (Medium Seaplane) a 300 passenger long range flying boat with its own beaching gear; and the gargantuan Shin Meiwa GS (Giant Seaplane) that has a passenger capacity of an astonishing twelve-hundred (1200) passangers seated on three decks! Unlike the Shin Meiwa LA and MA which were like the US-1 in design the Shin Meiwa MS and GS had it engines located in front of and above the wing like the USAF Boeing YC-14 to give STOL effect. In the end, none of the four designs got beyond the drawing boards.[1] Recently however, there has been a revival of interest in the GS concept.

Also during the late '70s, Shin Meiwa were working on a successor for the PS-1 ASW seaplane, however the program, along with further orders for the PS-1, was cancelled in September 1980. This was because land based aircraft (i.e. P-3C) seemed to had alleviated the need for more seaplanes for Anti-Submarine Warfare.

There were at least two PS-1 spin-offs. These (landplane) designs were Design #487 and Design #487C, part of a joint program of the 1970s with Grumman. Design #487 was aimed at a US Military STOL transport requirement, while Design #487C was a 90 seat commercial STOL airliner version aimed in particular at American Airlines.

LA wing tip shape looks like H7Y1's one?
According to MS 3-side view drawing, it's very hard to acommodate 300 passengers.


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Hi GS!
Any one please combine these drawings.

Edit: Done by Silencer1, parts removed here therefore
So our next question is "what is MA?"
This one? Too small? 400 passengers is mistake?,8242.msg72910.html#msg72910


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Oh!!! Thanks. Perfect. :D


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blackkite said:
Oh!!! Thanks. Perfect. :D

You are welcome!

Studying the comparison chart of Shin Meiwa projects, that you prepared, I wonder - what is the green giant hydroplane in the middle?


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royabulgaf said:
I did a bit of cypherin' based on the B-36 wingspan vs the KX-3. The wingspan is about 2.5 times the B-36s. Cubing this, I get a KX-3 volume of 16.625 times that of the B-36. Assuming similar construction methods and a B-36 gross weight of 130 tons, I get a weight of over 2000 tons. This is somewhat generous, as due to the square-cube law, construction would have to be sturdier. With a wing area of 443 sq meters, you get about .3 tons per square meter of wing loading. The KX-3 wing loading would be about six times as much. Am I missing something?

There is a sharp opinion about this 500ton flying boat like this.
Kawanishi GS's gross weight is 472ton.
Sorry for off topic.
Is this topic appropriate for some advertisements of Shin Meiwa company?
I could post some stuff here, which could be subject of interest to forum members.

I'd love to see it
Here they are:

Two leaflets - on US-2 search-resque amphibian and it's planned (on the moment of publication) fire-fighting version.
I didn't find any date on this booklet thought

I'm very impressed with the fact, that in our time large flying boats have been extensively used for life saving, sea rescue and fire fighting operations, then for military purposes.
Canadair, Shin Meiwa and Beriev boats have been a good example of this.


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Yes US-2 already saved many people under very bad weather. I also believe that US-2 water bomber and passenger transport type are very useful,too.

水タンク : water tank


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ShinMaywa Industries Ltd. Aircraft Division

'Aircraft Division Guide"
8 page booklet, date of publication about 2000-2010

Actually, these information, in the current state, could be found on the company's web-site:

There were a lot of videos, photos - and a story of company predecessor, Kawanishi.


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here is a more Info about LA,MA & MS.


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Unfortunately I am unable to currently scan an article regarding the Shin Meiwa LA which was published in the Airdata File section of Air International. This was in the November 1977 issue and mentions that a possible collaboration with Dornier could have been on the cards. This was to counter any clash with Dornier's own projects at that time, such as the DO 24/72A. It also mentions within the article that Shin Meiwa were looking at the possibility of utilising the fuselage of a Fokker F.27, presumable to speed up the development process and adding the necessary hull for waterborne operations. Power was to come from two turbofan engines producing around 8,000 lbs (3632 kg) of thrust with possible candidates being either the GE CF34 or the Hamilton Standard/NASA QFT55 which was a derivative of the Lycoming T55 turboshaft (which itself did spawn a turbofan engine in the shape of the ALF 502) , as fitted to the CH-47 et al. The QFT55 was to be a quiet fan demonstrator.
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Mainland China would love to have Shin - M. GS to service “their” islands in the South China Sea.

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