TS-136 USN Amphibious Utility Helicopter (alternatives to Kaman SH-2 Seasprite)

[hesham]

From Spangenberg files,

In 1956 the USN issued a high demanding specification for a
fast amphibious utility helicopter,the contenders were Kaman,
Bell,Sikorsky,Vertol and Hiller.
The contenders were;


Kaman K-19 (single-engined) & K-20 (twin-engined)
Hiller Model-1070
Bell D-226 & D-227
Sikorsky S-62
Vertol V.80,V.81 & V.82

The winner was Kaman K-20 and built as Seasprite helicpter.

 

[hesham]

By the way,


this competition was called TS-136.


http://www.dtic.mil/dtic/tr/fulltext/u2/a058197.pdf

 

[hesham]

From Ailes 30/7/1960,

here is a Model for Kaman Seasprite,but I suspect if it was K-19 single engined Project or K-20 ?.

 

[TomS]

According to the last post you made in this thread, the K-19 was a Synchrocopter, meaning two interleaved counter-rotating props. So this model with a top and tail rotor is clearly the K-20.

 

[hesham]

From AW 1965,

if that was Kaman K-20's Model,can we imagine the single engined
K-19,how it look like ?.

 

[hesham]

From anther report from, Michigan University,

here is a small Info about Kaman K-19,it had a two-rotor
configuration.

 

[TomS]

From AW 1965,

if that was Kaman K-20's Model,can we imagine the single engined
K-19,how it look like ?.

Not very likely. Remember, they K-19 is described as a synchrocopter, so two intermeshed top rotors. That would lead to a different fuselage shape.

I suspect this may have been an internal designation for some relative of the Kaman H-43 Huskie/HOK. Interesting paragraph from a site focusing on the Huskie: https://www.ragay.nl/kaman-htk-hok-huk/hok-design-development-test

15 Feb 1957 marks the start of the HU2K-1 aerodynamic investigation program. Not related to the history written in these website pages, however, the start of the development of a new Kaman helicopter is mentioned here to show the Kaman Corp. efforts for system's innovations and performance. It was for a single main and tail rotor configuration aircraft which was proposed and also submitted in the event that the proposed HOK-3N synchropter configuration might prove to be limited in order to satisfy future NAVY requirements. The HU2K-1 was proposed with a Navy funded GE T-58 engine program, which was expected to satisfy future NAVY helicopter turbine engine requirements (comment by Mr. A.D. Rita)

So this proposed K-19 synchropter might be the same or similar to the HOK-3N, which I believe the same site also refers to as the K-600-3N. In essence, a turbine Huskie/HOK with the engine moved out of the cabin, freeing up a good deal of internal volume.

Proposal for the Kaman K-600-3N turbine powered utility helicopter for the US Navy.

The installation of the lighter, higher powered turbine engine provides significant increases over the established performance of the HOK-1. The greatly enlarged internal cabin space made available by the “external” mounting of the engine, in combination with the substantial power margin, provides a service helicopter of unique capabilities.

The proposed K-600-3N was an advanced helicopter which will :

-- exploit the extensive growth potential of the HUK-1 with a minimum of design, development, testing and tooling.

-- provide a gas turbine powered utility helicopter for fleet service use in the shortest possible time.

-- utilize a substantial percentage of the logistic support already established for the HUK-1.

-- have a fuselage completely devoted to useful load but which retains the over-all size compactness of the HUK-1.

-- be comprised of components that are either already service tested or whose principles have been developed and refined by this Corporation.

(Kaman Report R-150, dated 02 May 1957) for drawing click here

 

[Kiltonge]

The implication, that I've just confirmed from JAWA 1967-68, is that the early Seasprite utility models ( up to UH-2C ) were capable of water landings as they had a sealed flotation hull. A Kaman rescue-kit retrofit program added a cabin-door ramp to help haul survivors into the cabin when seaborne.

This flotation capability may have been lost with the later LAMPS versions.

 

[Scott Kenny]

The implication, that I've just confirmed from JAWA 1967-68, is that the early Seasprite utility models ( up to UH-2C ) were capable of water landings as they had a sealed flotation hull. A Kaman rescue-kit retrofit program added a cabin-door ramp to help haul survivors into the cabin when seaborne.

This flotation capability may have been lost with the later LAMPS versions.

And arguably for good reason. Takes more pull to get out of the water, and there's the threat of waves catching the rotors in relatively mild weather.

 

[Arjen]

From Spangenberg files,

In 1956 the USN issued a high demanding specification for a
fast amphibious utility helicopter,the contenders were Kaman,
Bell,Sikorsky,Vertol and Hiller.
The contenders were;


Kaman K-19 (single-engined) & K-20 (twin-engined)
Hiller Model-1070
Bell D-226 & D-227
Sikorsky S-62
Vertol V.80,V.81 & V.82

The winner was Kaman K-20 and built as Seasprite helicpter.

The Seasprite was not a twin-engined helicopter from the start.

Kaman H-2A and H-2B variants had a single General Electric T58 engine.
H-2C/D/E/F variants all had two T58 engines.
SH-2G had two General Electric T700 engines.
All images from wiki.