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US Navy XHP (Experimental Helicopter - Patrol) competition

Stargazer2006

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In early 1950, the following companies submitted these designs to a Navy specification calling for an HP class (Patrol) helicopter with ASW (anti-submarine warfare) capability, a brand new mission for the helicopter at the time. None was selected in the end (source: Spangenberg Index, April 1950).

  • Curtiss-Wright P-592
  • Gyrodyne 9 Helidyne
  • Hughes 212
  • Kellett KH-9
  • McDonnell 73/A/B/C/D
  • Pennsylvania Aircraft Syndicate (designation unknown)
  • Piasecki PD-22B
  • Piasecki PH-26/A Convertaplane
  • Sikorsky XHPS/-(A)/-( B )/-(C)
 

hesham

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And also may be it was Kellett KH-9;

http://www.google.com/patents?id=xElzAAAAEBAJ&pg=PA1&dq=kellett+helicopter&source=gbs_selected_pages&cad=1#v=onepage&q=kellett%20helicopter&f=true
 

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allysonca

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OK Pundits,

Here is another one or your thinking caps.

we have been commissioned to do a rotor system for this and trying to decide if this would have been a 3 blade hot cycle rotor like the XHCH-1 or a 5 blade conventional arrangement.

I'm leaning towards the former but a 2 blade tail rotor? Seems to be original.......

Ideas and thoughts welcome, and sorry..... not for sale or trade.
 

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hesham

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Hi Allysonca,

the designation is wrong,nothing called XHPS-1,can you tell us what the right
one ?.
 

allysonca

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I am unsure of the correct designation and the numbers I have stated are on the fuselage side so anyone's guess is as good as mine. I DO love these mysteries. There was a suggestion that this could be a Sikorsky, but I have my doubts.
 

hesham

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Hi Allysonca,

it's Sikorsky of course,and called XHPS-A,not -1,and logically it had a three blades,too
small to fitted with five blades.

https://www.secretprojects.co.uk/forum/index.php/topic,9868.msg91413.html#msg91413
 

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Looks like the grandfather to the S56/CH37.
 

Silencer1

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allysonca said:
I am unsure of the correct designation and the numbers I have stated are on the fuselage side so anyone's guess is as good as mine. I DO love these mysteries. There was a suggestion that this could be a Sikorsky, but I have my doubts.
Could the large waterdrop-shaped fairings on the wingtips have been nacelles for radial engines?
 

hesham

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Please change the title into; Sikorsky XHPS-A,and thanks.
 

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Silencer1 said:
allysonca said:
I am unsure of the correct designation and the numbers I have stated are on the fuselage side so anyone's guess is as good as mine. I DO love these mysteries. There was a suggestion that this could be a Sikorsky, but I have my doubts.
Could the large waterdrop-shaped fairings on the wingtips have been nacelles for radial engines?
Seems more likely they were floats to give some amphibious capability.

Edit: I'm wrong. Seems like they probably were radials, in the same tradition as the S-56 and XHRS.

https://www.sikorskyarchives.com/S+56%20HR2S-1H-37.php
 

Silencer1

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Perhaps, helicopter designation describes it's function: P for Partol - actually, antisubmarine warfare?
The sphere under fuselage belly could be radar or sonar, and the rear cabin has been intended for crewmembers, operating the search equipment. Just my guess.

Curiously, in the Sikorsky' list of S numbers there is no mention about XHPS.

P.S. What's orange model represents?
 

TomS

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Check the link Hesham gave. This project was indeed for a Patrol (ASW) helicopter.
 

Silencer1

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TomS said:
Check the link Hesham gave. This project was indeed for a Patrol (ASW) helicopter.
Thank you, TomS!
I read post at this link earlier, but without proper attention. :-\
 

hesham

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hesham said:
Hi Allysonca,

it's Sikorsky of course,and called XHPS-A,not -1,and logically it had a three blades,too
small to fitted with five blades.

https://www.secretprojects.co.uk/forum/index.php/topic,9868.msg91413.html#msg91413
Please Moderator,modify the title.
 

Jemiba

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I'd love to ! As soon, as there's a proof for the assumption, that it is a Sikorsky design ...
 

Silencer1

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Jemiba said:
I'd love to ! As soon, as there's a proof for the assumption, that it is a Sikorsky design ...
The inscription on the model could be a clue, but not a proof.
 

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hesham

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Jemiba said:
I'd love to ! As soon, as there's a proof for the assumption, that it is a Sikorsky design ...
Please look to this topic;

https://www.secretprojects.co.uk/forum/index.php/topic,9868.msg91413.html#msg91413
 

Jemiba

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Where's the proof, please ? ???

"XHPS" probably stands for Experimental (X), Helicopter (H),
Patrol (P) and maybe Shipborne (S). That would be valid for all contenders. That we
don't have an internal designation for the Sikorsky proposal, but only the short for the intended
role doesn't make things easier.
But I merged both topics, as it may give a better overview.
 

Silencer1

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Jemiba said:
"XHPS" probably stands for Experimental (X), Helicopter (H),
Patrol (P) and maybe Shipborne (S). That would be valid for all contenders. That we
don't have an internal designation for the Sikorsky proposal, but only the short for the intended
role doesn't make things easier.
But I merged both topics, as it may give a better overview.
My guess, that XHPS has been named according to US Navy' designation system,
eXperimental Helicopter Patrol, Sikorsky.
Compare this with US Navy HO2S and HO3S designations for Sikorsky R-5 helicopters.
Perhaps, taking in account model's inscription and some similarity to later Sikorsky helicopter - addition of "Sikorsky" to topic' name would be useful?
 

Jemiba

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May be right, for now, I removed "McDonnel" from the title, as this may lead to more
confusion. As long, as we don't have much stuff about any of those contenders, a thread
about the whole program may be ok, I think.
Few things are as persistent, as a wrong identification !

@ allysonca : Some more photos would be great ! ;)
 

Silencer1

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Jemiba said:
At least we can rule out with a good certainty the McDonnel entry for this competition:
Great addition to the topic, Jemiba!
And I now understand, where I previously seen similar model' interior - in McDonnell 73.
 

hesham

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My dear Jemiba,

from the book : US Military Aircraft Designations and Serials 1909-1979;

if it was for McDonnel,should be XHPH,and for Sikorsky was XHPS,the suffix "H"
was always given to McDonnell,not for Sikorsky.
 

Jemiba

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As I think, that we can regard Jim Keeshens "Secret US Proposals of the Cold War" as a reliable
source, we have an evidence on page 161 of that book. Not sure, that it is the same model, it's
without its main rotor, too, but still has its two-bladed tail rotor. Designation is given as Sikorsky XHSPA-1.

Silencer1 said:
P.S. What's orange model represents?
Shown on the other page, it's the DS 160
 

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Silencer1

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Thank you, Jemiba!

Jemiba said:
Designation is given as Sikorsky XHSPA-1.
The inscription on the model "XHPS-A". Perhaps, there is a typo in the book's text?
IMHO the "A" suffix could mark, that this have been one of the Sikorsky proposals for the competition and "B", "C" etc. versions have been also presented.

Silencer1 said:
Shown on the other page, it's the DS 160
Please, are there any other details? Manufacturer, helicopter's role?
 

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The XHPS-A / XHPS-B / XHPS-C designations are confirmed by the Spangenberg Index and 100% certainly Sikorsky. 3 different configurations proposed.
 

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Same timeframe : https://www.sikorskyarchives.com/S+56%20HR2S-1H-37.php
 

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Silencer1

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Looks, like there were no "S"-index has been allocated to Patrol Helicopter - as the list in Sikorsky' archives doesn't contain any mentions about this proposal.
Of course, it's possible, that some project just didn't reach the stage, when company "S"-index used in their designation.
Or, perhaps, this project started long line of S-56?

Questions and questions :cool:
 

hesham

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Jemiba said:
As I think, that we can regard Jim Keeshens "Secret US Proposals of the Cold War" as a reliable
source, we have an evidence on page 161 of that book. Not sure, that it is the same model, it's
without its main rotor, too, but still has its two-bladed tail rotor. Designation is given as Sikorsky XHSPA-1.

Silencer1 said:
P.S. What's orange model represents?
Shown on the other page, it's the DS 160
My dear Jemiba,

I have this book,but it's not a reliable source,the Spangenberg Index is certainly a proof,
and in the Model they wrote XHPS-A,and the caption is wrong.
 

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I would agree with Sikorsky.
I know that its no reliable indication and relies on gut feeling but design has elements that look fitting for Sikorsky.
The lack of an S- number might be a little puzzling though if this proposal was serious enough for small scale presentation models.
 

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ModelClassRoleProgramDate
Piasecki PD-22BHPASWXHP 04 1950
Piasecki PH-26/A ConvertaplaneHPASWXHP 04 1950
Piasecki PD-22BHPASWXHP 04 1950
Curtiss-Wright P-592HPASWXHP 04 1950
United Helicopters HillerHPASWXHP nd
Kellett KH-9HPASWXHP 04 1950
Sikorsky XHPS/-A/-B/-C HPASWXHP 04 1950
Hughes 212 / HAC 212HPASWXHP 04 1950
Gyrodyne 9 HelidyneHPASWXHPnd
McDonnell Model 73A/B/C HPASWXHP04 1950
Bell D-104/A (XHPL)HPASWXHPnd

These are all taken from the Spangenberg Index and definitely contenders to XHP. The Sikorsky identification is definitive! The model has XHPS-A written on it - we know XHPS-A was Sikorsky - we also know XHPS has to be Sikorsky according to the US Navy designation system. Lastly, it looks a lot like a larger Sikorsky helicopter of the same era.

With regard to the question of number of blades - it seems likely that -A was a conventional helicopter, with -B and -C being more exotic.
 

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hesham said:
from the book : US Military Aircraft Designations and Serials 1909-1979;

if it was for McDonnel,should be XHPH,and for Sikorsky was XHPS,the suffix "H"
was always given to McDonnell,not for Sikorsky.
That's right my dear Paul,

and as I explained before,the McDonnell was taken suffix "H",and the suffix "S" was
given to Sikorsky.
 

allysonca

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Sorry to have missed all of the fun and thanks for having relabeled the topic. I was offline for over a couple of weeks on business. The model is, in fact, Keeshans via McLaughlin and it has a Sikorsky stand BUT that to me is not an indicator as these things have a way of being switched, but as I had suggested I was not sure on the maker. Remembering that I've been collecting for well over 50 years there are those mysteries that do pop up.

I am still wondering on the blade config and wish we had pictures.....
 

overscan

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So - the brochure is at NARA, so anyone who lives nearby can in theory register to go visit and copy the brochure.

"Proposal" Files for Airplanes, Helicopters and Missiles 1934-1961
RG 72 (Bureau/Dept of Aeronautics)
UD 1048
ID 163451
Sec Class: C
NAII 631 74/63/04 to 75/9/07
1 to 676 Containers
ACC NN3-72-86-4

Box 122 Sikorsky XHPS/-A/-B/-c HP ASW XHP 04 1950
Box 123 Sikorsky XHPS/-A/-B/-C HP ASW XHP 04 1950
 

hesham

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allysonca said:
Sorry to have missed all of the fun and thanks for having relabeled the topic. I was offline for over a couple of weeks on business. The model is, in fact, Keeshans via McLaughlin and it has a Sikorsky stand BUT that to me is not an indicator as these things have a way of being switched, but as I had suggested I was not sure on the maker. Remembering that I've been collecting for well over 50 years there are those mysteries that do pop up.

I am still wondering on the blade config and wish we had pictures.....
Hi Allysonca,

I think a three blades is very suitable.
 
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