PC/WI Improved Bristol Belvedere Helicopter.

WILDGEESE

Gone Fishin'
The Bristol Belvedere was hampered by a cabin that was way to small, width wise and with engines that where put at either end of the fuselage.

What if the money was available for development, plus sales optioned from the RAF/RN

What if the engines where set at the rear, CH-46/CH-47 style, with a fuselage shortened plus but widened to help with troop carrying capacity. Plus a lowered front set of wheels (which was a throwback to a RN spec, for carrying torpedo's)

How do you think this would perform compared to the Boeing Vertol CH-46 SeaKnight?

Could this be purchased instead of the S-58/Westland Wessex for the RN?

What sales do you think would be attained by the RAF/RN?

Would Australia/Canada/New Zealand be interested in buying this aircraft/

Regards filers

PS: HAPPY CHRISTMAS AND HAPPY NEW YEAR, TO EVERYONE ON THE FORUM, NO MATTER WHAT GOD YOU FOLLOW. GOD BLESS.
 
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Your question seems to be what if Bristol built a Sea Knight. So what's the difference between the British and American helicopter industry? There's two different governments. There's Raoul Hafner and Frank Piasecki. There's two companies, Bristol Helicopter and Piasecki/Vertol/Boeing. Piasecki built the YH-16 helicopter which was a dead ringer for the Belvedere, only roomier. It had tremendous potential, but the prototype failed when some instrument apparatus failure severed the propshaft and it crashed. Piasecki moved on to the Sea Knight, and to the Chinook. Bristol didn't move on, and Hafner took up yachting, to his regret. An interesting note is that the gummint insisted on a cartridge starter for the Belvedere's engines. They only caused two fatal crashes that I recall.

The big difference seems to be that a successful helicopter was derived from moving on, and doing it wrong till you get it right. Piasecki did, although some of his dreams and ambitions remained unfulfilled. Bristol, and Hafner had other things to do. They could have achieved success, but didn't want it bad enough, or couldn't see it or taste it enough to take a step forward. Well, the Westland name is still around, hyphenated.

I have to go check a noise on the roof.
 
The OP has a lot of good points, mostly answered by the second poster.
The engine buried in the forward fuselage was mainly an artifact of its evolution from the single-engined, single-rotor Sycamore.
Same excuse for the rear engine buried in the aft fuselage.
Equally silly is clustering all fuel and hydraulic lines in a tunnel under the fuselage. That merely perpetuates a long-standing RAF tradition that "Erks" are only happy working in the dark, in the rain, in cramped quarters, with obscure tools and waiting for spare parts.
Since they already had a synchronizing shaft, it makes little mechanical difference whether both engines were installed on top of the forward fuselage or aft fuselage.
Considering all the different varieties of Heath-Robinson (Rube Goldberg for Americans) tail fins, a single, larger aft pylon would improve yaw stability in cruise.
That cargo door is silly for even more reasons. It is even sillier than the rear door on the Canadian Bobcat APC! One film shows a squady hand-lifting his rucksack in because he does not want to climb that high with that heavy a load. Watching those (lightly-equipped) squadies jump out makes this old paratrooper's knees ache!
First, front undercarriage legs could have been half as long if that had followed Sikorsky's lead and tucked torpedoes into the undercarriage "armpit" ala. Sea King. That might require a single nose-wheel leg, like a Sikorsky S-53 or S-61R or S-92 or EH-101 or most of the Piasekis.
Odd that the Belvedere has a small hatch on the left, aft fuselage, but relegated the main cargo hatch so far forward and so high????
Rescue hoist is the only dxplanation for such an odd door configuration.
By his second design (Flying Banana) even Frank Piaseki figured out that the best place for a cargo door was the lowest point in the fuselage.
The saddest thing about Belvedere's door is that the RN perpetuated the problem when they bought Westland/Sikosky Sea King/Commandos to haul Royal Marine infantry.
By far the saddest thing is Bristol's inability to learn from their mistakes. Belvedre was little more than a prototype for a cargo helicopter, successive versions would have learned from earlier mistakes, just as Sikorsky, Boeing-Vertol-Piaseki, Kamov, etc. learned from their crude, early designs.
 
The Putnams book on Bristol Aircraft shows that several improved Belvederes were proposed. When Bristol merged with Westland they were further refined it into the WG.11 in preference to Westland's Westminster (and the Fairey Rotodyne) but HMG bought the Chinook instead.

According to the book the original Bristol Type 173 was to have been fitted with a pair of Bristol Janus turboshafts. Unfortunately the Company had to abandon the project due to lack of resources and the Leonidas Major had to be used instead.

I think the Janus is one of the great might have beens of postwar British aviation as it would have given the helicopter designers a turboshaft engine in the Gnome class 5-10 years before the real DH Gnome became available. The 1950s Whirlwinds would have been better with an equivalent of the Gnome instead of the Leonidas Major. Similarly the Wessex HAS Mk 1 and Belvedere would have been better with a Gnome equivalent instead of the Napier Gazelle.

However, until recently I thought the RR Clyde was one of the great might have beens and I was corrected about that, so maybe I have overrated the potential of the Janus too.
 
I think the Janus is one of the great might have beens of postwar British aviation as it would have given the helicopter designers a turboshaft engine in the Gnome class 5-10 years before the real DH Gnome became available. The 1950s Whirlwinds would have been better with an equivalent of the Gnome instead of the Leonidas Major. Similarly the Wessex HAS Mk 1 and Belvedere would have been better with a Gnome equivalent instead of the Napier Gazelle.

However, until recently I thought the RR Clyde was one of the great might have beens and I was corrected about that, so maybe I have overrated the potential of the Janus too.
Not convinced there - the Janus is (so far as I can tell) a 500 HP engine - see https://www.flightglobal.com/pdfarchive/view/1949/1949 - 1549.html . The Gnome and Leonides Major are both ~1,000 HP engines - and the UK already had a 1,000 HP turboshaft in the form of the Armstrong-Siddeley Mamba which was already flying on the Balliol prototypes in 1948.
 
Not convinced there - the Janus is (so far as I can tell) a 500 HP engine - see https://www.flightglobal.com/pdfarchive/view/1949/1949%20-%201549.html . The Gnome and Leonides Major are both ~1,000 HP engines - and the UK already had a 1,000 HP turboshaft in the form of the Armstrong-Siddeley Mamba which was already flying on the Balliol prototypes in 1948.

I'm not sure any more either, which is why I put in the caveats.

IIRC Janus started at 1,000shp and was then cut down to 500hp, but AFAIK could have grown back upto 1,000hp or higher. Again AFAIK the GE T-58 which DH/BS/RR built as the Gnome began at 500 shp but was developed to produce around 2,000shp. I assumed that the Janus had similar growth potential out of wishful thinking more than anything else.

Leonidas Major was very unreliable. The 72 of 130 Whirlwind HAS 7 were lost in crashes. It was so bad that the type had to be grounded and the AS Gannets remained in service for longer than planned.

IIRC another 1,000hp turboprop that was around in the late 1940s was the RR Dart. However, I don't know if RR had any plans to adapt it for helicopter use or if AS planned a turbo-shaft version of Mamba. For all I know both engines could have been adapted, but both companies were probably fully occupied with their other projects, e.g. RR getting the Avon to work.

But, I do know that AS was working on a turbo-shaft in the late 1950s in the same class as the Gnome called the AS.181. Bristol Helicopters was converting two incomplete Sycamore airframes into prototypes of a machine similar to the Gnome-Whirlwind and had designed a twin-AS.181 version similar to the Gnome-Wessex.

However, the AS.181 was terminated in favour of the Gnome when Armstrong-Siddeley, De Havilland and Bristol Aero Engines merged to become Bristol Siddeley Engines. Similarly the turbine powered developments of the Sycamore died when Bristol Helicopters was taken over by Westland.
 
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