Sikorsky S-61 prototypes, projects and license builds

[TsrJoe]

Sikorsky S.61 with BS. Gnome turboshaft engines

 

[riggerrob]

Sikorsky S.61 with BS. Gnome turboshaft engines

Rolls-Royce Gnome is a license-built version of the General Electric T-58-8F turbo-shaft engine that is standard on Sikorsky S-61.

 

[Apophenia]

Sikorsky S.61 with BS. Gnome turboshaft engines

Interesting to see the S.61R depicted.

 

[Kiltonge]

Avweek article, 21 Dec 1964 about the S-61R's evaluation and eventual rejection by the German army.

Modifications over the baseline S-61R included fixed undercarriage, increased tail rotor diameter and elliptical tips to main blades.

Pressure was apparently applied by US Army Europe to align with their use of Huey / Chinook / Mohawk rather than adopt a different, relatively unproven, type with a different air mobility doctrine.

 

[uk 75]

In the early 1960s BEA received some Sikorsky S61s. I have seen references to a licence built Westland version of this helicopter (Westland Winchester?). This might have been used by the RAF and RN.

 

[BlackBat242]

In the early 1960s BEA received some Sikorsky S61s. I have seen references to a licence built Westland version of this helicopter (Westland Winchester?). This might have been used by the RAF and RN.

Well, Westland did produce 182 S61 Sea Kings for the RN and RAF from 1966-and enough for multiple foreign militaries to total over 340 airframes.

[2.0] Westland Sea King Family

 

[uk 75]

The Seaking was a SH3 derivative.

 

[Stargazer]

The Seaking was a SH3 derivative.

And what was the SH-3, if not an S-61 version?!

 

[uk 75]

So an S61 is the same helicopter as an SH3. Okay I cant be bothered

 

[NOMISYRRUC]

I was 75% through writing this when @uk 75 uploaed Post 5.

The Seaking was a SH3 derivative.

Sea King was the USN's service name for the SH-3 and S-61 was Sikorsky's designation for it. S-61L & S-61N were Sikorsky's designations for the civil versions.

According to this website BEA Helicopters operated two (later one) S-61Ns on its service from Cornwall to the Scilly Isles from 1st May 1964. They initially flew from Lands End and from 1st September 1964 a purpose-built heliport at Penzance.

First Helicopter to Scilly Isles | On this Day | Penwith Local History Group | Penzance, Cornwall, UK

First Helicopter to Scilly Isles, 'On this Day', Penwith Local History Group, Penzance, Cornwall, UK

www.penwithlocalhistorygroup.co.uk

 

[uk 75]

Okay so I got the designations wrong (big calamity).
What I was trying to discuss is the Westland Winchester which offered the passenger helo to the RAF/RN.

 

[Arjen]

I have seen references to a licence built Westland version of this helicopter (Westland Winchester?). This might have been used by the RAF and RN.

Which references, please?
The first time Westland laid hands on any S-61/H-3 was in <edit>1967 1966</edit> - this from Putnam Westland by Derek N James.
BEA started S-61 operations in 1963.

 

[uk 75]

A drawing and entry in an Ian Allan softback book from the early 60s on helicopters. I have been trying to find my copy without success so hoped someone knew more about it.

 

[Arjen]

Ian Allan softback book

Would that be abc Helicopters by JWR Taylor? My copy has an introduction from 1960. It has an entry, with drawing, about the Westland WS-61 Wiltshire.
<edit> proper scan attached
<edit2> Move to different forum section?

 

[EwenS]

I think that the answer to this puzzle lies in the commercial licencing arrangements between Sikorsky & Westland.

AIUI in 1959 Westland acquired a licence to manufacture and develop the "short fuselage" military S-61B version of the S-61 that became the HSS-2/SH-3 Sea King which first flew in March 1959. This was an extension of their existing licencing agreement. Every Sea King Westland subsequently manufactured was based on that basic airframe. However it was 1965 before they got the opportunity to pitch it to the RN, and the prototype RN version and 3 pre-production aircraft were built in the USA with the first arriving in the UK in Oct 1966. The first Westland built HAS.1 then flew in May 1969.

Sikorsky then developed the S-61L/N variants for the commercial market with a fuselage some 4ft 3in longer than the S-61B/SH-3 version and capable of carrying 30 passengers. The S-61L version made its first flight in Nov 1961 according to the Sikorsky Archives, having been designed in 1961, followed by the amphibious S-61N in Aug 1962.

Westland never, AFAIK, built any of the civil S-61L/N version.

I note from Arjen's last post that Westland expected to fly the civil WS-61 Wiltshire in Nov 1960, a whole year before the S-61L made its first flight. So was it to be based on the "short fuselage" version, for which it already held a licence?

Maybe Westland later hoped to get a licence for the civil S-61L/N. Perhaps that would have become the Winchester?

When it comes to Augusta in Italy, they licence built military S-61 variants based on the SH-3 and the S-61R, as well as a civil variant of the S-61N with a shortened fuselage (The AS-61N-1 Silver).

 

[BlackBat242]

Maybe Westland later hoped to get a licence for the civil S-61L/N. Perhaps that would have become the Westminster?

The Westminster was a wholly different project, from before the S61 licensing.

uk 75 was asking about a "Westland Winchester" - which I have not seen anything on anywhere.

Westland Westminster 1958​

Large transport helicopter for up to 40 passengers with single main 5-blade rotor and gearbox from Sikorsky S-56 (CH- Mohave), tailwheel u/c, tubular frame fuselage structure with metal cladding for passenger role or open frame for utility/crane role. Powered by two 2920shp Napier Eland E220 turboshafts. Two built. Prot. G-APLE FF.

First flown on 15 June 1958, two prototypes were built before the project was cancelled. The Westminster was powered by twin Napier Eland turbines developing 2610kW with a single engine performance and could carry up to fifty-one troops or four Jeeps. The Westminster could cruise at 184kph, had a range of 330km and a gross weight of 16345kg. The project was cancelled in 1959.

Technical data for "Westminster"
Crew: 2, passengers: 45
engine: 2 x Napier Eland E.229A turboshaft, rated at 2090kW
rotor diameter: 21.95m, length: 27.4m
take-off weight: 14965kg, empty weight: 10125kg
max speed: 241km/h, cruising speed: 184km/h
hovering ceiling, IGE: 2750m,
range: 330km

 

[EwenS]

The Westminster was a wholly different project, from before the S61 licensing.

uk 75 was asking about a "Westland Winchester" - which I have not seen anything on anywhere.

Westland Westminster 1958​

Large transport helicopter for up to 40 passengers with single main 5-blade rotor and gearbox from Sikorsky S-56 (CH- Mohave), tailwheel u/c, tubular frame fuselage structure with metal cladding for passenger role or open frame for utility/crane role. Powered by two 2920shp Napier Eland E220 turboshafts. Two built. Prot. G-APLE FF.

First flown on 15 June 1958, two prototypes were built before the project was cancelled. The Westminster was powered by twin Napier Eland turbines developing 2610kW with a single engine performance and could carry up to fifty-one troops or four Jeeps. The Westminster could cruise at 184kph, had a range of 330km and a gross weight of 16345kg. The project was cancelled in 1959.

Technical data for "Westminster"
Crew: 2, passengers: 45
engine: 2 x Napier Eland E.229A turboshaft, rated at 2090kW
rotor diameter: 21.95m, length: 27.4m
take-off weight: 14965kg, empty weight: 10125kg
max speed: 241km/h, cruising speed: 184km/h
hovering ceiling, IGE: 2750m,
range: 330km

View attachment 732490

View attachment 732491

View attachment 732494

View attachment 732497

Yes. Got my names confused. Now corrected.

 

[Hood]

With hindsight it is odd that Westland never attempted to licence-build the S-61N given the North Sea oil boom.
Against that, we have to remember that the civil Wessex Mk.60 had been proposed in 1959 but didn't actually fly until July 1965 following an order from BHL earlier that year. Only 20 were ever built and two bad crashes ended the type's commercial career in 1981.

Given that the image Arjen posted from abc Helicopters is clearly a naval SH-3 derivative, perhaps this indicates where Westland's true aims lay, rather than the commercial market.

 

[Stargazer]

Would that be abc Helicopters by JWR Taylor? My copy has an introduction from 1960. It has an entry, with drawing, about the Westland WS-61 Wiltshire.
<edit> proper scan attached
<edit2> Move to different forum section?

Cool. I strongly suggest to rename the topic as "Westland WS-61 Wiltshire".and to move it to the Postwar Secret Projects section.

 

[EwenS]

With hindsight it is odd that Westland never attempted to licence-build the S-61N given the North Sea oil boom.
Against that, we have to remember that the civil Wessex Mk.60 had been proposed in 1959 but didn't actually fly until July 1965 following an order from BHL earlier that year. Only 20 were ever built and two bad crashes ended the type's commercial career in 1981.

Given that the image Arjen posted from abc Helicopters is clearly a naval SH-3 derivative, perhaps this indicates where Westland's true aims lay, rather than the commercial market.

The entire production run for the S-61N amounted to c120 airframes (I've seen 119 & 123 quoted) for use worldwide and North Sea use only began in 1965/66 with a handful of airframes. The North Sea boom really began in the mid-1970s when Westland was busy knocking out Sea Kings for the RN.

In the mid-1970s AIUI Bristows had most (11 of 12) of the North Sea contracts (from UK?) and had 18 S-61N on the fleet.

So maybe from a commercial perspective it didn't make sense.

 

[CJGibson]

No mention of a Winchester in the recent Westland Helicopters book, in the index anyway.

British International, Bristow and British Caledonian Helicopters used S-61Ns for North Sea operations, with the latter also using them for the Heathrow/Gatwick shuttle in the mid-1980s. I think Westland were punting their W30 for the offshore support role, which might explain why they didn't work on a Anglicised S-61N (was probably cheaper to buy the standard S-61N as well).

I have fond memories of them, slow, but much more comfortable than the Super Pumas/Tigers.

Chris

 

[uk 75]

Oops Wiltshire not Winchester. I did put a ? after it in my first post. Thanks Arjen. Age and dimness apologies on my part.