Sikorsky S-45 "Future Trans-Oceanic" Clipper


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26 May 2006
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in 1939,Sikorsky designed a six engined large flying boat project for
Pan-American demond,it was called super flying boat.


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This is interesting...

The wing shape of the flying boat in the 3-view is different
compared with the one in the artists impresssion.
In : Lindbergh's Dream Plane -plane facts Air International July 1986
no Sikorsky designation is mentioned for his 6 engined contender.

The artist drawing is also published in:
The worlds Civil Marine Aircraft- John Stroud-Putnam World Aeronautical Lib.1975
with the S-45 label.
From the text: A drawing was released on 22 June 1938 showed the Sikorsky S-45
North Atlantic project as a very large aerodynamically-clean high-wing cantilever
monoplane with six engines.

I wonder if the flying boat in the Flight 3 view was the S-45.
Mmm, I'd bet the artist impression was a very superficial impression. Air International in its article on the PanAm competition (or it was in the Letters setion of the subsequent issue ?) expressed its doubts on the same picture, expressely relating to the feasibility of the wing... All they ha to do was consulting the archive (of a competitor... )
Or a typical reconstruction from a single photo, I could have made
the same mistakes and I did in other cases !
But the drawing from Flight International just says "Large transocean
flying boat of the same type as proposed by Igor Sikorsy", it doesn't say
that it is the S-45. ???
'Winged S' - I.Sikorsky and 'Giants in the Sky' - B.Gunston
are both showing the same artist impression but no
type number is given...
Thus so far , only J.Stroud is mentioning the S-45 typenumber
in his book...
A seemingly off-topic question: where has the Sikorsky aircraft archive ended up ? In the today Sikorsky company ? Is it accessible ?
I have been researching this period and the issue of the large pre-war flying boat designs.

The artists picture is quite interesting because there are some very vague hints that designers were considering retractable hulls (ie the reverse of the Blackburn ideas).

There is very little real evidence to site as yet but the combination of the artists picture and the hint of this design approach is a possibility, in a very general sense.

I have no idea if it applied to this design in practice.


Some additional published information on the Sikorsky S-45:

The actual design of this aircraft actually started before the design of the S-44 (XPBS-1) was initiated. The S-45 design was iterated many times between 1938 and 1940.

A drawing dated March 15, 1938, depicts the S-45 as having a wing span of 236 feet, a one step hull, a length of 155.5 feet, a height of 25.75, and a three fin tail with a horizontal surface 43 feet wide. The aircraft was designed to carry 100 passengers or a payload of 25,000 pounds, with a range of 5,000 miles and a speed of 200 mph. Perhaps in a "wishful thinking" the drawing of the S-45 showed the aircraft with Pan American markings.

Source: Pember, Harry E.; Sikorsky VS-44 Flying Boat; Flying Machine Press; Stratford, CN, 06497; 1998; p55
This must be the true S-45 flying boat Gannet..

Any hope for a view of the illustration ?

This model of a Sikorsky 4-engined flying boat was shown in Classic Aircraft Vol.1, published by
Flying Machine Press (got it from lark, thank you !), but without any further info.
Anybody who can identify it and give some more information ?


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That's the final design for the S-45 "Future Trans-Oceanic Flying Boat". I had never seen such a clear picture of it before. Thanks!
But at the S-45 reference that Hesham gave us it shows a six engined and triple tailed flying boat. On what basis do we assume the design shown in this post is a final design of the S-45? (Don't get me wrong, I believe Stargazer is on the right track, but perhaps there is more supporting evidence)
Judging from details like size of cockpit and windows always is very doubtful. And that this one is
4-engined, the other 6-engined may be just based on the fact, that more powerful engines
were available then. But if the origin of those two designs were the same, then I think there were
some essential changes with the requirements, as this one seems to be considerably smaller, than
the 6-engined type.
Jos Heyman said:
But at the S-45 reference that Hesham gave us it shows a six engined and triple tailed flying boat. On what basis do we assume the design shown in this post is a final design of the S-45? (Don't get me wrong, I believe Stargazer is on the right track, but perhaps there is more supporting evidence)

Jos, on a former computer that crashed, I used to have a picture scanned from a magazine (probably some old Airpower) which clearly identified the same model as the S-45, that's why...
From the book; Сикорский_Политехника 2003


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hesham said:
From the book; Сикорский_Политехника 2003

That's the book I got the S-30 from I think. So you see, you had that reference already.
1939 Flight International


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