Chinook & other tandem rotors discussions
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Msuldo,
Ages ago when I started this thread, I never expected to read something like you have written, dropping in from such a height would seem like a certain one way ticket, was it just massive bulk bodywork that saved you and your pal.
thank you for that short but very gripping piece of your flying history.
Peter R-B
VfrpilotPB
Ages ago when I started this thread, I never expected to read something like you have written, dropping in from such a height would seem like a certain one way ticket, was it just massive bulk bodywork that saved you and your pal.
thank you for that short but very gripping piece of your flying history.
Peter R-B
VfrpilotPB
AAAAHHH Belvedere !
Stable because Raoul Hafner ,the designer didn't believe in power operated controls,although they were fitted after a few flights,one engine at each end because it was born as a piston design but modified for turboshafts when they first arrived on the scene in the mid fifties ,able to fly at AUW on one engine (with an auto doubling of power if one failed) but never intended for the RAF who got the short straw when the original customer ..the RN cancelled in favour of the Wessex ,hence the lack of cabin windows,the stalky front landing gear,and the overall fuselage dimensions.
Mind you Belvedere Mk 2 would have beaten the Chinook hands down if Bristol's had been allowed to build it.Aft mounted Gnome engines(3 or 4),rear ramp,four blade rotor system ,cabin plug option for civil use, but cancelled because the short sighted government didnt see any use for large helicopters once they withdrew from east of Suez.
Hindsight is a wonderful thing !
Stable because Raoul Hafner ,the designer didn't believe in power operated controls,although they were fitted after a few flights,one engine at each end because it was born as a piston design but modified for turboshafts when they first arrived on the scene in the mid fifties ,able to fly at AUW on one engine (with an auto doubling of power if one failed) but never intended for the RAF who got the short straw when the original customer ..the RN cancelled in favour of the Wessex ,hence the lack of cabin windows,the stalky front landing gear,and the overall fuselage dimensions.
Mind you Belvedere Mk 2 would have beaten the Chinook hands down if Bristol's had been allowed to build it.Aft mounted Gnome engines(3 or 4),rear ramp,four blade rotor system ,cabin plug option for civil use, but cancelled because the short sighted government didnt see any use for large helicopters once they withdrew from east of Suez.
Hindsight is a wonderful thing !
Last edited by heli1; 2nd Aug 2011 at 08:35. Reason: spelling
Three or four engines.....long ladder to get into the cabin....narrow as a sausage....oh yeah right it would have beat the Chinook! Even the RAF is celebrating thirty years of flying the Chinook.
Some of us are celebrating 44-45 years of flying Chinooks....and in the future there shall be Kids celebrating 90 years.
We should also recall the Wessex was originally designed by Sikorsky and some variants are still flying in commercial service today fifty plus years later.
Some of us are celebrating 44-45 years of flying Chinooks....and in the future there shall be Kids celebrating 90 years.
We should also recall the Wessex was originally designed by Sikorsky and some variants are still flying in commercial service today fifty plus years later.
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Belvedere vs Chinook
The Chinook is a great aircraft even with all of it's warts and blemishes. The Belvedere did enter production and service in the RAF. My interest is their aerodynatics. Why does one reqiures supplimental stability controls and the other doesn't. Is it pilot training or a fix to the airframe?
I would like to understand the tandem rotor helicopter not cause an argument between rotorheads.
I would like to understand the tandem rotor helicopter not cause an argument between rotorheads.
Designers learned as they went....the "A" model Chinook had a very sharp end to the Aft Pylon and was quite sensitive in Yaw. The subsequent models had a squared off end to the Aft Pylon which provided the equal of about 37 feet more fin or some such number....and was much more stable in Yaw. The A and B models had dual channel three axis SAS systems.
Starting with the "C" model the aircraft were equipped with an additional Pitch SAS system.
The earlier Piasecki CH-21 has no SAS but did have stabilizing fins on the Aft Pylon.
The H-25 or HUP had neighter SAS or Fins..
Starting with the "C" model the aircraft were equipped with an additional Pitch SAS system.
The earlier Piasecki CH-21 has no SAS but did have stabilizing fins on the Aft Pylon.
The H-25 or HUP had neighter SAS or Fins..
SAS:
The H-25 or HUP had neither SAS or Fins..
HUP-1 had fins on the side of the aft cowling.
HUP-2 had no fins and a crude SAS.
HUP-3 had a more sophisticated SAS (that could, I've been told, autohover).
My dad flew the HUP-1 and -2. Said they weren't very pleasant to fly.
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SAS and FH1100,
Thanks for your input! The best information comes the guys who drove these machines. Please forgive my ignorance, I drove OV-1's while in the Army but escorted a few Chinooks into some bad places.
Thanks for your input! The best information comes the guys who drove these machines. Please forgive my ignorance, I drove OV-1's while in the Army but escorted a few Chinooks into some bad places.
Belvedere Development.
The turbine powered version bore no relation to the ship borne torpedo firing botch-up that the British Navy wanted. It was similar in appearance, though larger, and more importantly, earlier than the Chinook. I cannot find any drawings of it at the moment but the ones I have seen were very impressive.
However, shoveling money into the back pockets of benefit scroungers, illegal immigrants etc, had a far higher priority for public money so the project was scrapped.
The turbine powered version bore no relation to the ship borne torpedo firing botch-up that the British Navy wanted. It was similar in appearance, though larger, and more importantly, earlier than the Chinook. I cannot find any drawings of it at the moment but the ones I have seen were very impressive.
However, shoveling money into the back pockets of benefit scroungers, illegal immigrants etc, had a far higher priority for public money so the project was scrapped.
The Belvedere Mk.2 was nothing like the original version SAS less...it had a level undercarriage ,larger cabin and was very Chinook-looking ,even though the design predated the Boeing aircraft.No coincidence that after it was cancelled some top Bristol designers emigrated to Philadelphia ?!
The success of the Chinook since just shows what a world beater the Brits would have had if the government hadn't cancelled it ...
As for the S-58 the British conversion to twin turbine power turned a heavy poor payload aircraft into something that could fly OEI at max AUW.
The success of the Chinook since just shows what a world beater the Brits would have had if the government hadn't cancelled it ...
As for the S-58 the British conversion to twin turbine power turned a heavy poor payload aircraft into something that could fly OEI at max AUW.
Last edited by heli1; 3rd Aug 2011 at 12:03. Reason: correction
I was more familiar with the Army version....which in those days...helicopters were considered more in line with Jeeps and Trucks than aircraft.
The CH-34 had "ASE" , and auto pilot system with a Barometric Altitude hold feature....which did not find its way to the Huey or Chinook. It is no surprise the HUP was far better equipped than the H-25.
As in most helicopter designs of the US Military....there are many different models of the same aircraft.
From the US Army Aviation Museum at Fort Rucker, Alabama.....
The CH-34 had "ASE" , and auto pilot system with a Barometric Altitude hold feature....which did not find its way to the Huey or Chinook. It is no surprise the HUP was far better equipped than the H-25.
As in most helicopter designs of the US Military....there are many different models of the same aircraft.
From the US Army Aviation Museum at Fort Rucker, Alabama.....
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This may be of interest, picture taken from the RAF news, showing Belvedere picking up a crashed Lightning. The Lightening crashed after the Pilot ejected, after an undercarriage failure. BAC wanted it back for examination, as it was by the sea, and the tide was coming in.
Aircraft was flown by Flt.Lt Youngs, and Flt.Lt. (Bunny) Austin, with me as crewman. After we managed to get it back, we found it was full of sand, and seawater, so was way over the 6000lbs hook weight.
Aircraft was flown by Flt.Lt Youngs, and Flt.Lt. (Bunny) Austin, with me as crewman. After we managed to get it back, we found it was full of sand, and seawater, so was way over the 6000lbs hook weight.
Chief Bottle Washer
There never seemed too much concern about what was slung under a helicopter back then: and always a short strop, too 
Bristol Belvedere XG 456 of 66 Squadron - based at Seletar, Singapore - recovers Westland Wessex XS 117 of 845 Naval Air Squadron.
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Bet that was a fun load to fly Dave....Not! Just as well it was more dense than anticipated.
Heli 1, while it probably would have garnered a few orders, i am not convinced a Belvedere Mk2 would have done that well. Just as many other UK designed ac of the 60s didn't - many foreign air forces were already buying US or Soviet ac due to their lower costs and better availability, never mind the hidden cold war subsidues. Most CH 47s have been bought by the US Army, so do you really see them buying from us rather than US built...? Coupled with the fact that the RAF would probably only bought about 30 , the production line would have probably closed 1970 before we woke up to the real value of such beasts as we have now.
Heli 1, while it probably would have garnered a few orders, i am not convinced a Belvedere Mk2 would have done that well. Just as many other UK designed ac of the 60s didn't - many foreign air forces were already buying US or Soviet ac due to their lower costs and better availability, never mind the hidden cold war subsidues. Most CH 47s have been bought by the US Army, so do you really see them buying from us rather than US built...? Coupled with the fact that the RAF would probably only bought about 30 , the production line would have probably closed 1970 before we woke up to the real value of such beasts as we have now.
Tallsar.
Of course the US Army wouldn't have bought it.US politics would have seen to that ,even if it was twice as good,but when you look at UK purchases of Chinook since then,now close to entering three figures, and a few other possible overseas sales..Canada,Australia etc it would have been a decent run and justified the millions spent on Belvedere development.
Like many British projects,it was just ahead of its time.
Of course the US Army wouldn't have bought it.US politics would have seen to that ,even if it was twice as good,but when you look at UK purchases of Chinook since then,now close to entering three figures, and a few other possible overseas sales..Canada,Australia etc it would have been a decent run and justified the millions spent on Belvedere development.
Like many British projects,it was just ahead of its time.
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Heli one,
like the Spitfire, RR Merlin and more, then the Jet Engine, the turbine, the fully flying tail components, The Buccaneer, other supersonic designs, Concord/TSR2, to name just a few
if our politians had had brains then,.. the UK Inc would be in a good state now !
Peter R-B
like the Spitfire, RR Merlin and more, then the Jet Engine, the turbine, the fully flying tail components, The Buccaneer, other supersonic designs, Concord/TSR2, to name just a few
if our politians had had brains then,.. the UK Inc would be in a good state now !
Peter R-B
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Tall Star
Yes it was tense, as the pilots were not aware that it had been slung wings down, so I had to keep saying "you must get some more height", as the wings were in danger of clipping the ground. Trouble was they were using all available power.
Here is a picture of why it could never enter Naval service. Embarking on HSM Albion, en route to the far east.
Yes it was tense, as the pilots were not aware that it had been slung wings down, so I had to keep saying "you must get some more height", as the wings were in danger of clipping the ground. Trouble was they were using all available power.
Here is a picture of why it could never enter Naval service. Embarking on HSM Albion, en route to the far east.
Belvedere MK II
Heli One, you had written that the MK II would have 3-4 engines. It sounds as if the design was conceptual in nature. To exceed the performance of the CH-47A, which had 2 X T55-L7's at 2650shp each ( or to address beating the CH-53A which was on the scene as well with 2 X GE T-64-6B at 2650shp each ), it would have needed the four engines I suspect.
I certainly concur with your remark re the talent available. Sikorsky as well as Boeing were very lucky to sign up UK engineers, who were hard working, extremely talented and an asset of immense importance. And they certainly added a note of civility to our often loud and noisy design decision meetings.
As I believe SAS was getting at, however, the task facing Bristol in starting with the model 192 and coming up with a product that exceeded the built in capabilities of the 47A and 53A, was funding an an investment that probably wasn't justified by the total expected sales revenue ( whether the money came from Bristols or UK Gov't funds ).
Thanks,
John Dixson
I certainly concur with your remark re the talent available. Sikorsky as well as Boeing were very lucky to sign up UK engineers, who were hard working, extremely talented and an asset of immense importance. And they certainly added a note of civility to our often loud and noisy design decision meetings.
As I believe SAS was getting at, however, the task facing Bristol in starting with the model 192 and coming up with a product that exceeded the built in capabilities of the 47A and 53A, was funding an an investment that probably wasn't justified by the total expected sales revenue ( whether the money came from Bristols or UK Gov't funds ).
Thanks,
John Dixson
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Hel1 - i think you missed my point. In the 60s, the RAF only ever had a requirement for 15 Chinnook. It was not the late 70s that some cash was found to buy the 33 to meet a new BAOR task ... And then reluctantly. In other words, there simply was not a requirement for enough Uk built ac for our own services to sustain profitable production. Why would Australia and Canada then buy an overly expensive Belvedere 2 compared with the small number of more cost effective CH47s they would have found cheaper and more supportable. Had the RAF and the Army had the vision to want a lot more in the first place, then maybe a sustainable and cheaper product could have been made. Forget not that with the Defence budget as always under great pressure, all the money in that era was going on Polaris, TSR2 and the reequiping of BAOR with hundreds of tanks etc. You would have found very few voices supporting spending precious R&D money on a large helicopter...and thats in the military staffs, not the government.
Hmmm Tallsar...since when in the 1960-1970s did we ever base military orders on sustainable production ? I'll leave others to produce a list !
Instead I will comment on the proposed Type 191/193 naval variant ,which as the Belvedere picture on Albion shows ,was overly ambitious .However it was sized for the larger HMS Eagle class carrier lifts.As the picture shows there was a novel way of fitting the rotor blades if removed but the 191 had blade folding ,using chinese scaffolding I think to stow the rear set! Certainly I wouldnt have wanted to be working on them on deck in a sea state 5!
Three 191s were virtually completed when the contract was cancelled ,with a vee tail unit (fitted the lift better) and a Wasp type heavy duty landing gear.None were fitted with the intended Leonides Major piston engines and instead were used as Gazelle turbine engine and transmission test rigs for the Belvedere.One eventually ended up in the pit at Ternhill.
The similar Type 193 for the Canadian Navy was cancelled before any were completed and reallocated to the RAF order.Canada went for the CH-124 Sea King instead.
I admit that the whole 191-192 programme was financially a disaster,with all the investment lost , but in terms of keeping the UK at the head of the technology game and independent of foreign powers it was successful. Sadly its demise saw the breakup of a very good design and engineering team and although some of the specialism went to Yeovil to work on Lynx and future projects (including tilt rotors and tilt wings) the tandem rotor expertise withered away.
Instead I will comment on the proposed Type 191/193 naval variant ,which as the Belvedere picture on Albion shows ,was overly ambitious .However it was sized for the larger HMS Eagle class carrier lifts.As the picture shows there was a novel way of fitting the rotor blades if removed but the 191 had blade folding ,using chinese scaffolding I think to stow the rear set! Certainly I wouldnt have wanted to be working on them on deck in a sea state 5!
Three 191s were virtually completed when the contract was cancelled ,with a vee tail unit (fitted the lift better) and a Wasp type heavy duty landing gear.None were fitted with the intended Leonides Major piston engines and instead were used as Gazelle turbine engine and transmission test rigs for the Belvedere.One eventually ended up in the pit at Ternhill.
The similar Type 193 for the Canadian Navy was cancelled before any were completed and reallocated to the RAF order.Canada went for the CH-124 Sea King instead.
I admit that the whole 191-192 programme was financially a disaster,with all the investment lost , but in terms of keeping the UK at the head of the technology game and independent of foreign powers it was successful. Sadly its demise saw the breakup of a very good design and engineering team and although some of the specialism went to Yeovil to work on Lynx and future projects (including tilt rotors and tilt wings) the tandem rotor expertise withered away.
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The Belvedere had a very interesting starter system for each engine. Their lordships of the Air Council decreed that the aircraft should be independent in the field, of any external starter aids, so the BTH cartridge initiated Avpin system was fitted.
The only trouble was, the Avpin tank was above the cartridge breech, so if there was a seal leak over night, Avpin would fill the cartridge chamber.
The result of this, was that when you went to do the first start in the morning, the whole thing would explode.
The fix for this was to armour plate the co-pilots seat, the rear engine was no problem, as you had enough time to evacuate.
The only trouble was, the Avpin tank was above the cartridge breech, so if there was a seal leak over night, Avpin would fill the cartridge chamber.
The result of this, was that when you went to do the first start in the morning, the whole thing would explode.
The fix for this was to armour plate the co-pilots seat, the rear engine was no problem, as you had enough time to evacuate.