Sikorsky models and designations

[Maveric]

...a Sikorsky S.28 from 1919...

 

[Maveric]

...and a project without number (Source for all:Сикорский Политехника 2003).

 

[Jos Heyman]

Some interesting finds by Maveric: the S-28, S-63 and this transport aircraft.
The data I had so far said:
"The S-28 designation was first used in June 1919 for a heavy bomber design for the White army of Kolchak.
The designation was again used in November 1919 for a multiseater biplane with a span of app. 40 m and three engines of 700hp. There were two versions of the project:
· Option "A" - two engines placed on the lower wing, the third in the nose or the back of the nacelle fuselage; and
· Option "B" - two engines placed on the lower wing, third on the upper wing, tailplane had a different form of fastening."
This drawing, dated 22 April (or is it July) 1919 does not nicely fit.
As far as the S-63 is concerned, this is what I had so far:
"Also known as S-62B, the S-63 referred to a S-62 fitted with a S-58 rotor system."
The picture does not look like that at all.
Finally, the 4 engined transport looks very late 1940s to me - this was the time Sikorsky was seriously working on helicopters, so why a transport diversion?
Just some thoughts...

 

[Stargazer]

Some interesting finds by Maveric: the S-28, S-63 and this transport aircraft.
The data I had so far said:
"The S-28 designation was first used in June 1919 for a heavy bomber design for the White army of Kolchak.
The designation was again used in November 1919 for a multiseater biplane with a span of app. 40 m and three engines of 700hp. There were two versions of the project:
· Option "A" - two engines placed on the lower wing, the third in the nose or the back of the nacelle fuselage; and
· Option "B" - two engines placed on the lower wing, third on the upper wing, tailplane had a different form of fastening."
This drawing, dated 22 April (or is it July) 1919 does not nicely fit.
As far as the S-63 is concerned, this is what I had so far:
"Also known as S-62B, the S-63 referred to a S-62 fitted with a S-58 rotor system."
The picture does not look like that at all.
Finally, the 4 engined transport looks very late 1940s to me - this was the time Sikorsky was seriously working on helicopters, so why a transport diversion?
Just some thoughts...

I agree with Jos. The would-be "S-63" looks nowhere near what the S-62B was supposed to be. If anything, the design looks more like an S-64/S-65 derivative.

 

[Stargazer]

Two pics of the flying crane depicted above, one being the same image but in much higher quality and in color (pictures #1 and #2).
The project is said to be dated circa 1970 and is described as an HLH proposal. It looks like a further development of the S-64B, also attached (pictures #3 to #6).
An alternative HLH proposal (undated) is also added for comparison (picture #7).

 

[Stargazer]

The Sikorsky DS-103 design was also very similar to the HLH but probably a bit earlier. It is described as a missile-carrier flying crane.

 

[Maveric]

...my source :-[

 

[Stargazer]

Wow. Sorry Maveric, I wasn't doubting you, just questioning your source! So it would seem the S-63 designator was used twice...

Seems like an interesting book. Where did you get it from?

 

[Maveric]

Stargazer2006 see your PM!

 

[Jos Heyman]

Seems we still have much to discover on this (and other) topic. Thanks Maveric.

 

[Stargazer]

Recent evidence provided by Maveric seems to point to a very different allocation of Sikorsky's S-46 to S-48 designations. This leads to the following modified list:

• S-46 = VS-300 and VS-300A
• S-47 = VS-316A (R-4, HNS)
• S-48 = VS-327 (R-5, HO2S)

Same source (attached image) also clearly gives the V-tailed flying crane project as the S-63.

Considering the overall quality and reliability of the source, I'm strongly inclined to believe that the above is correct.

In that case, the following designations would remain a follows:

• S-49 = VS-316B (R-6, HOS)
• S-50 = uncompleted project
• S-51 = H-5, HO3S-1, etc.

 

[Stargazer]

After giving the "S-63" matter a closer look, the matter seems more complicated than it seems.
Other sources suggest the HLH contender was the S-73, not the S-63. This seems coherent with the fact that it is a development of the S-64 and should therefore be a later project with later (not preceding) designation. Besides, other artwork of the very same project is dated 1970.

Still, the seemingly "final" Sikorsky HLH shows a very different shape. So either the first configuration (based on the DS-103 design) was S-63 and the final version were S-73, or they were all S-73 and S-63 was the S-62B as has previously been said.

 

[Jos Heyman]

Based on data I have (which may well have been from this forum ) the S-50 was c[/size]onnected with VS-327. It was a 1943 design study for a small two seat helicopter but, apart from a wooden mock-up, was not built.

As far as the S-63/S-73 dilemma is concerned, Stargazer's effort to place these on a time line was interesting. I know it is dangerous to do this, and I know that I have not seen the Russian publication, let alone know the expertise of the writer, but it would not be the first time that a designation, such as S-63 in this instance, has arisen from a typing error (the'6' and '7' are next to each other on the keyboard, as we all know) that has happily been perpetuated by others and finally becomes 'fact'. But, again, this is only a specualitve thought from my twisted mind.[size=10pt]

 

[Stargazer]

The S-50 has appeared as this project:

 

[Stargazer]

Here is a list of as-yet undesignated Sikorsky projects and prototypes which I have pics of (by no means exhaustive!):

Tests of parasol wings on biplane airframes:

• Curtiss Oriole fitted with Sikorsky UN-4 wing (Jul '25)
• Curtiss JN-4D fuselage with a Sikorsky-Gluhareff G-S-1 (UN-4) high-lift parasol wing (ATC Group 2-23) (Mar '27)
• Standard J-1 conversion with UN-4 parasol wing (May '27)
• SN-1 Standard J-1 conversion with UNW-9 parasol wing (Jun '27)
• Curtiss JN-4C fuselage fitted with Sikorsky wing
• Stearman C-3K (Siemens engine) fitted with UN-4 parasol wing; reverted to C-3B (Aug '28)

Flying boats:

• U.S. Navy XP2S-1 (1932)
• U.S. Navy XSS-1/SS-1/XSS-2 (1933)

Monoplanes:

• BLR-3 Long-range bomber project
• Four-engined commercial transport project
• SST supersonic transport studies

Rotorcraft & VTOL:

• patent for an Amphibion modified as a helicopter
• Sikorsky-Loewy Aerial Bus (1945)
• Tilt-rotor convertiplane proposal
• DS-160 large tandem-rotor crane transport
• UTV Universal Tactical Vehicle flying crane proposal
• fan-in-fuselage Shrouded Rotor attack proposal (SCAT)
• LAAV/UTTAS/Type A/commercial and other S-69 ABC derivative proposals
• HLH 23-ton helicopter proposal
• Tilt-rotor commercial transport project
• Navy X-Wing combat helicopter studies
• X-Wing fighter helicopter study
• HSR(High Speed Rotorcraft) tilt-rotor attack project
• VLCT (Very Large Civil Transport) project
• SH-X co-axial ASW proposal for Navy
• High Speed Rotorcraft design with inverted vee-tail (rigid and floating rotorhead variants)
• TRAC telescopic rotor and variable-diameter rotor studies
• VDTR military transport titl-rotor proposal
• YRAH-66AComanche developed with Boeing Helicopter for U.S. Army (LHX program)
• Cypher
• Dragon Warrior (Cypher II)
• Mariner
• ACA large transport helicopter
• UCAR studies
• X2 high-speed coaxial-rotor demonstrator
• X2 attack / utility assault / SAR proposals
• X2 VUAS unmanned proposal
• X2C Joint Heavy Lift (JHL) Crane proposal
• X2HSL High Speed Lifter Joint Heavy Lift (JHL) proposal ("CH-71")
• Reverse Velocity Rotor RIA (Runway Independent Aircraft)
• Co-axial crane-type transport project

Compounds:

• Large twin-turboprop compound helicopter study (1965)
• Stopped-rotor USAF jet fighter
• Tilt-engine Light Intra-theater (LIT) Transport transport study
• Fan-in-wing proposal based on Grumman Mohawk airframe with two jets
• DS-103 missile-carrier flying crane project
• T-tailed folding tilt-rotor SAR aircraft proposal
• Four-jet VTOL transport project with ten bypass lift engines in two nacelles
• DS-507 VDR compound aircraft design using flexible roll-up rotor (linked to S-65-300)
• CARA stowable-rotor proposal, with North American (1967)
• 100-passenger commercial compound study (various tail configurations)
• Twin-jet stowed rotor design with fan in tail

 

[hesham]

Hi,

S-15 was a light bomber floatplane,one aircraft was built.

S-1 & S-2 were not a helicopters,but was a historical biplanes.

http://www.sikorskyarchives.com/B%20Russian%20Years.php

 

[Stargazer]

Very interesting. But they made an obvious mistake on S-27 and S-28.
The French bomber design was the S-27.
The S-28 was Sikorsky's first (unbuilt) design after arriving in America (check this forum for both).

 

[Stargazer]

Anyone knows if someone still runs the Igor I. Sikorsky Historical Archives website, or if it's been abandoned?

I've tried to contact them to signal a mistake or two, but got an error message saying that the mailbox didn't respond/exist.

 

[Jemiba]

Sorry Ardavan, but those are drawings of the Convair Trans-Oceanic Flying Boat, NOT Sikorsky designs.

 

[Spook]

Sorry Ardavan, but those are drawings of the Convair Trans-Oceanic Flying Boat, NOT Sikorsky designs.

You are right Jembia.. My Mistake...Is there any way to remove them ?!

Regards,
AK

 

[Jemiba]

You are right Jembia.. My Mistake...Is there any way to remove them ?!

Regards,
AK

Why ? http://www.secretprojects.co.uk/forum/index.php/topic,17655.msg168291.html#msg168291

 

[Spook]

Thank you Sir !.. ... ;D

 

[gatoraptor]

Recent evidence provided by Maveric seems to point to a very different allocation of Sikorsky's S-46 to S-48 designations. This leads to the following modified list:

• S-46 = VS-300 and VS-300A
• S-47 = VS-316A (R-4, HNS)
• S-48 = VS-327 (R-5, HO2S)

Same source (attached image) also clearly gives the V-tailed flying crane project as the S-63.

Considering the overall quality and reliability of the source, I'm strongly inclined to believe that the above is correct.

In that case, the following designations would remain a follows:

• S-49 = VS-316B (R-6, HOS)
• S-50 = uncompleted project
• S-51 = H-5, HO3S-1, etc.

The February 2013 issue of the Sikorsky Archives News agrees with this listing of the S-46 through S-49, and they ought to know!

 

[fightingirish]

From Graham Warwick twitter feed

Graham Warwick ‏@TheWoracle 19. Feb.
@SikorskyAircrft CH-53K facts: 4 flight-test engineering development models are YCH-53Ks, model number is S-95, name to come at May rollout.

Link: https://twitter.com/TheWoracle/statuses/436184054082600960

 

[hesham]

Great find my dear Rolf.

 

[hesham]

From Le Fana 382,

here is a small Info about Sikorsky S-15.

 

[burunduk]

Dear friends!

In Aero Digest #4 1926 p.200 I've found an interesting advertisement of Sikorsky's amphibian aircraft.
The aeroplane is very similar to S-34, but is sufficiently smaller: please, look on characteristics below.

I can't identify the plane and don't know, was it really built or not. Although it would be strange to advertise non-built project, isn't it?

May be, somebody can clearify this?

 

[hesham]

That needs search my dear Burunduk.

 

[Maveric]

Airco
Aircraft Corp of America, New York NY; to be manufactured by Sikorsky Co for a consortium of NYC financiers and businessmen, including heads of May Co, Allied Chemical, and Gotham Hosiery.

1926 - Listed here only for interest value. Despite prominent advertising, there is no record of this consortium's aircraft being produced. Ads, along with attendant press releases about the Super Rhône-powered Airco Amphibian and Airco Super-Sport, soon faded from aviation publications. No connection with British Airco-de Havilland.

FROM AeroFiles

 

[burunduk]

Maveric, Hesham, thank you.

So, it seems, it's really an advertisement of the paper project, never realised later...

 

[fightingirish]

Here is a list of as-yet undesignated Sikorsky projects and prototypes which I have pics of (by no means exhaustive!):

Tests of parasol wings on biplane airframes:

• 
  [...]
  • UTV Universal Tactical Vehicle flying crane proposal
  [...]

Source: https://flic.kr/p/2afArys

 

[hesham]

So weird,

I think Sikorsky used two "DS" series in same time,for examples DS-103,DS-109 & DS-137 were appeared in early 1960s up to 1967,but you find DS-508 or S-67 was displayed in late 1960s also,so it is confused ,why ?!.

https://apps.dtic.mil/dtic/tr/fulltext/u2/651416.pdf

https://www.secretprojects.co.uk/threads/sikorsky-s-67-blackhawk.3712/page-3#post-247458

 

[flyhigh]

The Sikorsky helicopters designations you are quoting are not quite right.
Here is the correct allocation of the early US helicopters:

S-46: VS-300
S-47: VS-300A
S-48: VS-316A = R-4
S-49: VS-316B = R-6
S-50: VS-327 = R-5 to R-5E and HO2S
S-51: H-5F to H-5H and HO3S
S-52: H-18 and HO5S
S-53: XHJS-1
S-54: R-4 modified in sesqui-tandem configuration

Found this photo of the Sikorsky S-54, interesting configuration.

 

[dan_inbox]

In my files this photo has the title:
Sikorsky R-4 modified to test sesqui-rotor system with tail rotor pivots from vertical to horizontal position

 

[Grey Havoc]

S-56 *MOJAVE / °WESTMINSTER US Marines large ASW helicopter and *transport Army variant, also built by Westland° [HR2S]

https://twitter.com/x/status/1598262631252385792

View: https://twitter.com/clark_aviation/status/1598262631252385792?s=20&t=oTmpbp7Nojmu9lLN1DDhgg

 

[Kiltonge]

Any known reason why the Sea King was designated HSS-2 by the US Navy, suggesting that it was a variant of the HSS, instead of HS2S?

 

[hesham]

From this book,

the S-16 versions ?.

 

[Stargazer]

Any known reason why the Sea King was designated HSS-2 by the US Navy, suggesting that it was a variant of the HSS, instead of HS2S?

It has always been a mystery to me, but it might have had something to do with how difficult "HS2S-1" may have been to pronounce and remember!

 

[Kiltonge]

It has always been a mystery to me, but it might have had something to do with how difficult "HS2S-1" may have been to pronounce and remember!

Completely unintentionally found the answer in John Andrade's "US Military Aircraft Designations and Serials":

"it was procured as an HSS model for funding purposes".

Not the first and not the last!

 

[Stargazer]

The Sikorsky CH-53K King Stallion is also designated the S-95.
The Sikorsky/Boeing SB-1 Defiant is also designated the S-100.
The Sikorsky (Lockheed Martin) Raider-X (or RAIDER-X) is also designated the S-102.
The Sikorsky/Boeing Defiant-X is also designated the S-103.