Shetland Chinook legacy remembered
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Shetland Chinook legacy remembered
25 years ago today a Boeing Vertol (BV) 234 LR, G-BWFC, on contract to Shell, crashed 2.5 miles east of Sumburgh, Shetland Isles with the loss of 45 lives a catastrophic forward transmission failure which de-synchronised the twin rotors causing the blades to collide.
The Air Accidents Investigation Branch (AAIB) stated that the underlying causes were the inadequacy of a previously accepted test program and the failure of a stringent inspection programme.
Recommendations were:
BBC News - Shetland Chinook legacy remembered
25th anniversary of Chinook helicopter disaster which killed 45 men | Aberdeen and North | STV News
The event prompted workers begin to stand up for their rights for the first time. Their campaign eventually led to the helicopters being withdrawn.
The Air Accidents Investigation Branch (AAIB) stated that the underlying causes were the inadequacy of a previously accepted test program and the failure of a stringent inspection programme.
Recommendations were:
- Certification procedures be reviewed so that all modifications to vital components are adequately scrutinised and tested before approval and more closely monitored after their introduction into service.
- The Civil Aviation Authority should report on the progress that has been made towards the early incorporation of a specification for suitable condition monitoring systems into airworthiness requirements for helicopters and indicate the time scale and scope of likely developments.
- Requirements relating to the ADELT (Automatically Deployable Location Transmitter) equipment, including location, crashworthiness, protection and power supplied, be reviewed in the light of the accident. (The beacon did not operate due to impact damage to the aft part of the aircraft).
BBC News - Shetland Chinook legacy remembered
25th anniversary of Chinook helicopter disaster which killed 45 men | Aberdeen and North | STV News
The event prompted workers begin to stand up for their rights for the first time. Their campaign eventually led to the helicopters being withdrawn.
Certainly one of the worst crashes in civilian history and probably the second worst Chinook crash of all time after the loss of 46 souls aboard the US Army Chinook which crashed on September 11th 1982 near Mannheim, Germany.
The BIH disaster heralded the end of the type's UK commercial debut but, across the North Sea, Norway's Helikopter Service kept them running a while longer despite a number of in-flight engine failures the year after the BIH tragedy!
Despite several high profile indicents (some of them crew induced) the type remains an indispensable military asset.
The BIH disaster heralded the end of the type's UK commercial debut but, across the North Sea, Norway's Helikopter Service kept them running a while longer despite a number of in-flight engine failures the year after the BIH tragedy!
Despite several high profile indicents (some of them crew induced) the type remains an indispensable military asset.
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As the person who would have been in Fox Charlie's FO's seat had I not been on leave that week I feel there are a couple of points of accuracy to clear up regarding the report and findings of this event.
I have posted the real events on this forum before but can't find the post now - no doubt someone with better search skills will, but the statement " Certification procedures be reviewed so that all modifications to vital components are adequately scrutinised and tested before approval and more closely monitored after their introduction into service. " conveys a meaning at variance with the facts as I remember them. The inadequacies and flawed mods that led to the accident were actually imposed by the CAA themselves in the face of strenuous objections by Boeing and BIH's own engineers who had developed what they considered a sounder and more practical version but as ever the CAA knew better than the aircraft's builder and the world's hugely experienced leading operator of the type.
The problem of internal bolts in the gearbox losing their torque was certainly solved (though clumsily in engineering terms whilst incurring unnecessary cost and downtime) but included a very minor though as it turned out, critical change to the configuration of some washers which allowed salt crystals to lodge in the threads of a bolt, a corrosion pit developed, a crack propagated and the rest is history.
I was a new and junior FO on the fleet at the time but clearly recall the bafflement when the report was published as it bore little resemblance to the events we "knew" about. It was widely considerd a whitewash to cover the CAA's role in causing an unnecessary accident through unwarranted interference in matters that others understood better. Whether my recollection is entirely accurate I cannot say at this remove in time, and will hapily retract any inaccuracies that forumites can identify.
Although it had some flaws - with hindsight BAH should have specified the Boeing-offered mid-cabin emergency exits for instance (wouldn't have saved any lives in this event but would have made a big difference to acceptance of the type by the bears who generally disliked it, largely due to being used to every window being a pop-out as on the S61) the Chinook, which if not already the safest helicopter ever on the N Sea certainly had the potential to be so, was subjected to a concerted, vicious, inaccurate and sometimes hysterical smear campaign by the local "newspaper" which effectively prevented its use on the N Sea again.
The accdent certainly brought about big safety changes throughout offshore operations as listed in the first post, but the tragedy of this accident was that it was totally preventable and should never have happeped.
Of all the types I've flown since, including other Boeing-built products, this is the one I'd go back to like a shot if the opportunity arose. Like most of its pilots I loved the BV234. But then BAH were the only people outside Boeing who really knew or understood it. The remaining three, BISN, BISP and BISR(?) still fly for Columbia helicopters where they have been intensively hauling timber in some of the most arduous conditions extant in the helicopter world ever since. Without significant accident afaik.
That's one impressive safety record, but then the mighty 234 was one hell of an impressive aircraft.
Its hard to believe that dark day was 25 years ago though.
And just for once it is not inappropriate to add RIP.
Because I knew some of them
I have posted the real events on this forum before but can't find the post now - no doubt someone with better search skills will, but the statement " Certification procedures be reviewed so that all modifications to vital components are adequately scrutinised and tested before approval and more closely monitored after their introduction into service. " conveys a meaning at variance with the facts as I remember them. The inadequacies and flawed mods that led to the accident were actually imposed by the CAA themselves in the face of strenuous objections by Boeing and BIH's own engineers who had developed what they considered a sounder and more practical version but as ever the CAA knew better than the aircraft's builder and the world's hugely experienced leading operator of the type.
The problem of internal bolts in the gearbox losing their torque was certainly solved (though clumsily in engineering terms whilst incurring unnecessary cost and downtime) but included a very minor though as it turned out, critical change to the configuration of some washers which allowed salt crystals to lodge in the threads of a bolt, a corrosion pit developed, a crack propagated and the rest is history.
I was a new and junior FO on the fleet at the time but clearly recall the bafflement when the report was published as it bore little resemblance to the events we "knew" about. It was widely considerd a whitewash to cover the CAA's role in causing an unnecessary accident through unwarranted interference in matters that others understood better. Whether my recollection is entirely accurate I cannot say at this remove in time, and will hapily retract any inaccuracies that forumites can identify.
Although it had some flaws - with hindsight BAH should have specified the Boeing-offered mid-cabin emergency exits for instance (wouldn't have saved any lives in this event but would have made a big difference to acceptance of the type by the bears who generally disliked it, largely due to being used to every window being a pop-out as on the S61) the Chinook, which if not already the safest helicopter ever on the N Sea certainly had the potential to be so, was subjected to a concerted, vicious, inaccurate and sometimes hysterical smear campaign by the local "newspaper" which effectively prevented its use on the N Sea again.
The accdent certainly brought about big safety changes throughout offshore operations as listed in the first post, but the tragedy of this accident was that it was totally preventable and should never have happeped.
Of all the types I've flown since, including other Boeing-built products, this is the one I'd go back to like a shot if the opportunity arose. Like most of its pilots I loved the BV234. But then BAH were the only people outside Boeing who really knew or understood it. The remaining three, BISN, BISP and BISR(?) still fly for Columbia helicopters where they have been intensively hauling timber in some of the most arduous conditions extant in the helicopter world ever since. Without significant accident afaik.
That's one impressive safety record, but then the mighty 234 was one hell of an impressive aircraft.
Its hard to believe that dark day was 25 years ago though.
And just for once it is not inappropriate to add RIP.
Because I knew some of them
Last edited by Agaricus bisporus; 5th Nov 2011 at 19:56.
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AB
You have mostly repeated the Boeing line. Boeing actually appealed the AAIB report and the judicial review through out their claims as unfounded.
Boeing's defence, that they were forced to do a modification, is disingenuous as in reality their original design wasn't suitable for a corrosive maritime design anyway and besides the mod was Boeing's and they fluffed it badly.
You have mostly repeated the Boeing line. Boeing actually appealed the AAIB report and the judicial review through out their claims as unfounded.
Boeing's defence, that they were forced to do a modification, is disingenuous as in reality their original design wasn't suitable for a corrosive maritime design anyway and besides the mod was Boeing's and they fluffed it badly.
BAH were the only people outside Boeing who really knew or understood it.
A small outfit called the US Army started flying the Chinook in the early 60's and had millions of fleet hours by the time BAH even saw a Chinook up close.
Perhaps that was the attitude that kept the Chinook from being a Commerical success under British management. What could the biggest operator of the Chinook possibly know as compared to a bunch folks experienced on 61's?
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A small outfit called the US Army started flying the Chinook in the early 60's and had millions of fleet hours by the time BAH even saw a Chinook up close.
Though Zalt's point about the offshore environment is important.
It only took 150 hours with the S-92 in the North Sea for the millions of hours experience of vespel splines on the H-60 to be shown to be irrelevant.
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B234
Just after the accident I was on the LHR-ADN flight and found myself sitting next to the CAA Test Pilot. I asked him how a helicopter with 5 gearboxes (3 of which are super-critical) could achieve UK certification just weeks after the publication of the Helicopter Airworthiness Report (HARP) by the same organisation. I didn't get an answer.
This report had been called for on the back of some serious mechanical failures and fatalities amongst the North Sea fleet and focussed, amongst other things, on the criticality of transmission components given the difficulties with creating redundancy within them. The HARP's authors' analysis was that 25 years ago helicopters were being designed using the principles that were applied to the Dakota. In other words the helicopter manufacturers were allowed to use old technology - 50 year-old technology and certification standards. I somehow think that the eye was taken off the ball somewhere along the line!
Seems to me that in the case of the 234 maybe some higher forces were at work. Could any of the 3 players (Shell, BA and Boeing) have applied pressure to the CAA? I wonder if there were any dissenting voices over allowing it on the civil register? I guess if there were then they must have felt justified after the Shetland accident although it has to be said that events since seem to have supported the notion that the 234 was, is, a reliable machine. I have yet to meet a Chinook/234 pilot who didn't love the beast completely.
G.
This report had been called for on the back of some serious mechanical failures and fatalities amongst the North Sea fleet and focussed, amongst other things, on the criticality of transmission components given the difficulties with creating redundancy within them. The HARP's authors' analysis was that 25 years ago helicopters were being designed using the principles that were applied to the Dakota. In other words the helicopter manufacturers were allowed to use old technology - 50 year-old technology and certification standards. I somehow think that the eye was taken off the ball somewhere along the line!
Seems to me that in the case of the 234 maybe some higher forces were at work. Could any of the 3 players (Shell, BA and Boeing) have applied pressure to the CAA? I wonder if there were any dissenting voices over allowing it on the civil register? I guess if there were then they must have felt justified after the Shetland accident although it has to be said that events since seem to have supported the notion that the 234 was, is, a reliable machine. I have yet to meet a Chinook/234 pilot who didn't love the beast completely.
G.
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The Norwegian "Oilies" eventually refused to fly in the BV234 because they didn't feel safe in it. Finally, the employee unions said no more and that effectively grounded the type as passenger transport in the North Sea oil industry.
There were other issues with the aircraft at the time. I watched one lift to the hover at Forus and leave its steerable rear u/c leg behind on the helipad. It was full of oil rig workers at the time, they were not impressed.
Control of another 234 was lost, following an engine problem in IMC. Again it was full of passenegers. That one came very close to total disaster.
I was offered a job on Super Puma the very same day, when the union decided that they would no longer require their members to fly in the type. Obviously, the demise of the 234 left a huge gap in the lift capacity of the company, which needed to be filled asap.
There were other issues with the aircraft at the time. I watched one lift to the hover at Forus and leave its steerable rear u/c leg behind on the helipad. It was full of oil rig workers at the time, they were not impressed.
Control of another 234 was lost, following an engine problem in IMC. Again it was full of passenegers. That one came very close to total disaster.
I was offered a job on Super Puma the very same day, when the union decided that they would no longer require their members to fly in the type. Obviously, the demise of the 234 left a huge gap in the lift capacity of the company, which needed to be filled asap.
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I'd forgotten that the HARP report came out before this accident.
The CAA have never made that report available online but there is an interesting article called 'The Price of Helicopter Safety' in the New Scientist of 27 Nov 1986 that suggests the research funding came after the Sumburgh disaster.
Geoffersincornwall said:
You mean a bit like the forces that were put on the regulators when the S-92 MGB failed its oil system certification test on 24 August 2002, weeks before the FAA were due to certify it?
As mentioned above, Boeing appealed against the AIB report leading to an unprecedented independent legal review before the report was issued, held in public:
1989 | 3841 | Flight Archive
AB should note that Boeing were trying, unsuccessfully, to put blame onto BIH...
Unlike the Wells public inquiry in Newfoundland after the Cougar S-92 accident, the Chinook review was able to examine all aspects of the accident investigation and aircraft certification (Well's Terms of Reference gagged him form these aspects), and confirmed the thoroughness of the AIB's work.
There was also a Fatal Accident Inquiry held in a court in Scotland too.
The CAA have never made that report available online but there is an interesting article called 'The Price of Helicopter Safety' in the New Scientist of 27 Nov 1986 that suggests the research funding came after the Sumburgh disaster.
Geoffersincornwall said:
Seems to me that in the case of the 234 maybe some higher forces were at work. Could any of the 3 players (Shell, BA and Boeing) have applied pressure to the CAA?
As mentioned above, Boeing appealed against the AIB report leading to an unprecedented independent legal review before the report was issued, held in public:
1989 | 3841 | Flight Archive
AB should note that Boeing were trying, unsuccessfully, to put blame onto BIH...
Unlike the Wells public inquiry in Newfoundland after the Cougar S-92 accident, the Chinook review was able to examine all aspects of the accident investigation and aircraft certification (Well's Terms of Reference gagged him form these aspects), and confirmed the thoroughness of the AIB's work.
There was also a Fatal Accident Inquiry held in a court in Scotland too.
Last edited by squib66; 7th Nov 2011 at 17:57. Reason: Correction AAIB was still the AIB at the time plus extra web link
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Zalt, I am "repeating" no one's line. That was the position as known in the company at the time.
Boeing were "forced" to do a mod? ie told what to do by the CAA against their better judgnent and contrary to established engneering practice when the pevious less intrusive mod was working perfectly. I don't see your point. I can't see how disingenuousness comes into it - or how it relates to your alleged and baseless accusation of unsuitability. How was it unsuitable? I wasn't aware of serious environmental probs before this, are you?
SASless. Oh dear, You imagine I've never heard of the US Army, do you? How patronising. Perhaps the BV234 not being a CH47 has something to do with it (though sharing a great deal of commonality) and this isn't a thread about CH47s.
Perhaps the fact that when the high-time CH47 was overtaken by a two year old fleet of BV234s it was on its nth rebuild and 25years old - with only 3000hrs. The US Army don't do intensive flying like N Sea ops. By the time of the accident the BAH fleet had several times the hours of the next highest in the US inventory. So yes, I think BAH knew a bit more than them about intensive and offshore Chinook ops. Don't you?
Your knowledge of the commercial success (not to mention management attitudes - where did that spiteful little gem come from?) of the 234 is obviously lacking too, it was wiping the floor with the competition - Bristows were terrified of it because they couldn't compete. It needed high intensity high volume routes to work and the Brent provided that, its market was limited but in the right place it was commercially unbeatable.
On what grounds do you imply that pressure was put on the CAA to certificate it? That suggests the CAA were reluctant to do so. Why? What did they know? Please provide us with evidence to support that - so far - baseless allegation. But I won't khold my breath.
The Noggies didn't operate theirs in anything like the same intensive way that BAH did, and the unions stopped them because they (wah! wah" wah") "didn't like it". Poor flowers! Materials technology, gearbox design and manufacturing techniques had made quantum leaps since the early 30s (there had been a world war in between) which is the baseline for the Dakota so I can't see that point is valid. The S61 was of similar - maybe a little earlier - baseline than the CH47 and I don't hear questions over their gearboxes, The Puma had fundamental design faults producing hideous MGB problems for years - but then there are no questions over the safety or reliabilty of Chinook gearboxes are there, apart from a philosophical one of being 3 critical instead of 2? Not a huge difference, is it? Some helicopters have five or six rotor blades, some have two. Could that be said to make the 214 three times safer than a Chinook then? Of course not.
And if there were failures in certification, if authorities took their eye off the ball (for which there is no evidence afaik) then whose fault was that, which was the main point of my post anyway.
Squib, I wasn't aware that Boeing had tried to blame BAH; interesting. Got any links for that? - thanks. But then what else would you expect US liability lawyers to do? That would be just be a normal damage limitation exercise wouldn't it?
I wasn't doubting the thoroughness of the AAIB investigation, it is just that the information on which they based the background - ie the engineering events - differ fundamentally from those (as far as I'm concerned) that were universally understood by those right up close to the event at the time. However nothing alters the fact that pre the second mod the first one - the loctite solution - had worked perfectly and the problem gave ever sign of being solved. Completely. It didn't take long for catastrophic results to occur as a direct result of the second mod that, given the success of the first, was an unnecessary answer to a problem that no longer existed.
Boeing were "forced" to do a mod? ie told what to do by the CAA against their better judgnent and contrary to established engneering practice when the pevious less intrusive mod was working perfectly. I don't see your point. I can't see how disingenuousness comes into it - or how it relates to your alleged and baseless accusation of unsuitability. How was it unsuitable? I wasn't aware of serious environmental probs before this, are you?
SASless. Oh dear, You imagine I've never heard of the US Army, do you? How patronising. Perhaps the BV234 not being a CH47 has something to do with it (though sharing a great deal of commonality) and this isn't a thread about CH47s.
Perhaps the fact that when the high-time CH47 was overtaken by a two year old fleet of BV234s it was on its nth rebuild and 25years old - with only 3000hrs. The US Army don't do intensive flying like N Sea ops. By the time of the accident the BAH fleet had several times the hours of the next highest in the US inventory. So yes, I think BAH knew a bit more than them about intensive and offshore Chinook ops. Don't you?
Your knowledge of the commercial success (not to mention management attitudes - where did that spiteful little gem come from?) of the 234 is obviously lacking too, it was wiping the floor with the competition - Bristows were terrified of it because they couldn't compete. It needed high intensity high volume routes to work and the Brent provided that, its market was limited but in the right place it was commercially unbeatable.
On what grounds do you imply that pressure was put on the CAA to certificate it? That suggests the CAA were reluctant to do so. Why? What did they know? Please provide us with evidence to support that - so far - baseless allegation. But I won't khold my breath.
The Noggies didn't operate theirs in anything like the same intensive way that BAH did, and the unions stopped them because they (wah! wah" wah") "didn't like it". Poor flowers! Materials technology, gearbox design and manufacturing techniques had made quantum leaps since the early 30s (there had been a world war in between) which is the baseline for the Dakota so I can't see that point is valid. The S61 was of similar - maybe a little earlier - baseline than the CH47 and I don't hear questions over their gearboxes, The Puma had fundamental design faults producing hideous MGB problems for years - but then there are no questions over the safety or reliabilty of Chinook gearboxes are there, apart from a philosophical one of being 3 critical instead of 2? Not a huge difference, is it? Some helicopters have five or six rotor blades, some have two. Could that be said to make the 214 three times safer than a Chinook then? Of course not.
And if there were failures in certification, if authorities took their eye off the ball (for which there is no evidence afaik) then whose fault was that, which was the main point of my post anyway.
Squib, I wasn't aware that Boeing had tried to blame BAH; interesting. Got any links for that? - thanks. But then what else would you expect US liability lawyers to do? That would be just be a normal damage limitation exercise wouldn't it?
I wasn't doubting the thoroughness of the AAIB investigation, it is just that the information on which they based the background - ie the engineering events - differ fundamentally from those (as far as I'm concerned) that were universally understood by those right up close to the event at the time. However nothing alters the fact that pre the second mod the first one - the loctite solution - had worked perfectly and the problem gave ever sign of being solved. Completely. It didn't take long for catastrophic results to occur as a direct result of the second mod that, given the success of the first, was an unnecessary answer to a problem that no longer existed.
Last edited by Agaricus bisporus; 6th Nov 2011 at 15:39.
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BP see the first column of the link above. Note that at that time BAH was BIH.
With respect, you do seem to be challenging the AAIB's conclusions!
The recommendations are clear, Boeing (and other OEMs) should better test such modifications.
So why did Bristow not buy the BV234 if it was such a good thing? Alan Bristow said in 1978 he had rejected the BV234 for both economic and safety reasons:
1978 | 1682 | Flight Archive
Remember that Shell only wanted the BV234 in order to cut out transfer operations from Sumburgh, which were exceptionally expensive due to exorbitant landing fees.
With respect, you do seem to be challenging the AAIB's conclusions!
The recommendations are clear, Boeing (and other OEMs) should better test such modifications.
So why did Bristow not buy the BV234 if it was such a good thing? Alan Bristow said in 1978 he had rejected the BV234 for both economic and safety reasons:
1978 | 1682 | Flight Archive
Remember that Shell only wanted the BV234 in order to cut out transfer operations from Sumburgh, which were exceptionally expensive due to exorbitant landing fees.
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Please read my post more carefully. I asked the CAA TP point blank how come the Chinook was certified in the face of the HARP report findings and received in return a blank stare. Now, you can read that in a number of ways so hence my speculation. Not allegation, just speculation. You can make of it what you will but please don't ignore one of the most important documents ever produced on the state of our industry from a technical point of view.
I haven't read the HARP report in quite a while but my recollection is that the comment about the Dakota was theirs not mine.
G.
PS - Have just searched the web for half and hour looking for a copy of the Helicopter Airworthiness Review Panel (HARP) report of 1984 otherwise know as CAP 491, but cannot find a copy either to read or buy. Has anyone got one in their library that they can scan and make available please.
I haven't read the HARP report in quite a while but my recollection is that the comment about the Dakota was theirs not mine.
G.
PS - Have just searched the web for half and hour looking for a copy of the Helicopter Airworthiness Review Panel (HARP) report of 1984 otherwise know as CAP 491, but cannot find a copy either to read or buy. Has anyone got one in their library that they can scan and make available please.
Last edited by Geoffersincornwall; 6th Nov 2011 at 18:26.
AB,
Again....you just do not know what you are saying...
I suppose my Army Flight Records are all a fabrication then....and my first hand experience on the aircraft...along with my North Sea experience bar me from having a basis upon which to draw my obervations.
We flew the machines approaching two hundred hours per month under combat conditions....maintained them in the open....and carried loads much more stressful than did the BAH aircraft.
The Army does not operate a system of maintenance as do Civilian Operators and the aircraft do not accrue the airframe hours per individual airframe...but when one has 500 of the things....and over Ten Years experience operating them....there is a corporate knowledge that transcends a fleet operation of a mere handful.
The 234 is different from the CH-47 in exactly the same way the 61N and Sea King differ....only by degrees.
What did not change was the usual British institutional arrogance towards accepting advice from anyone else no matter how qualified the source.
That reluctance is of historical record, noted, and well known. The sayingis "Teach a Brit today....and he will tell you how to do it tomorrow!" That has never changed.
It also appears alive and well within your posts.
Again....you just do not know what you are saying...
The US Army don't do intensive flying like N Sea ops. By the time of the accident the BAH fleet had several times the hours of the next highest in the US inventory. So yes, I think BAH knew a bit more than them about intensive and offshore Chinook ops. Don't you?
We flew the machines approaching two hundred hours per month under combat conditions....maintained them in the open....and carried loads much more stressful than did the BAH aircraft.
The Army does not operate a system of maintenance as do Civilian Operators and the aircraft do not accrue the airframe hours per individual airframe...but when one has 500 of the things....and over Ten Years experience operating them....there is a corporate knowledge that transcends a fleet operation of a mere handful.
The 234 is different from the CH-47 in exactly the same way the 61N and Sea King differ....only by degrees.
What did not change was the usual British institutional arrogance towards accepting advice from anyone else no matter how qualified the source.
That reluctance is of historical record, noted, and well known. The sayingis "Teach a Brit today....and he will tell you how to do it tomorrow!" That has never changed.
It also appears alive and well within your posts.
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AB
You are correct, Bristow was terrified of the BV234, just not commercially.
Bristow actually had 5x BV234 ordered but contractual negotiations with Boeing broke down over penalties Bristow wanted for any shortfalls in performance. There was also an internal memo generated by the Operations Department looking at the implications of a ditching. This scared the heck out of Senior Management and combined with the contractual issues above, the order was cancelled.
Instead, the company went on to be involved in the development of the AS332L with Aerospatiale as it was then.
You are correct, Bristow was terrified of the BV234, just not commercially.
Bristow actually had 5x BV234 ordered but contractual negotiations with Boeing broke down over penalties Bristow wanted for any shortfalls in performance. There was also an internal memo generated by the Operations Department looking at the implications of a ditching. This scared the heck out of Senior Management and combined with the contractual issues above, the order was cancelled.
Instead, the company went on to be involved in the development of the AS332L with Aerospatiale as it was then.
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As the Bv234 was almost as wide as it was long and had the stability of a barge the implications of a ditching were that it would be almost impossible to overturn, thus it did not even need loatation gear. The Puma especially is notoriously unstable on the water and the failure of one float - a frequent, even common event, would very likely result in a capsize of most other, if not all other N Sea types. What on earth do you mean - I don't understand.
If you are referring to the lack of emergency exits in the cabin I have already addressed that matter. An option was available had Mr Bristow wished to take it up. "Negotiations broke down---shortfalls in performance" Er, what shortfalls in performance? I don't recall any. Surely not Bristows asking too much and then demanding guarantees? That just sounds to me like Bristow Bluster. I can understand that Bristow who knew first-hand how fickle helos can be was reluctant to put that many people into one machine lest there was a disaster, a suggestion published elsewhere. He was astute enough to see that so many bodied would make unacceptable PR, but that is a value judgement. My bet is he knew the 234 to have a limited market routes wise and that 2 companies chasing very few contracts would result in a profitless pissing contest and airframes being underused. The capital outlay and lack of obvious resale markets probably made this an opportunity to walk past, but being Bristow he couldn't and wouldn't say that so he came out with some bluster to cover it. As it turned out the 4 machines did pretty much fill the niche, and very profitably too. But I bet there wasn't room for 5 more. And from then on he missed no opportunity to snipe and slag it off because he couldn't compete in any other way.
It is indeed curious how contrary people can be on this forum against the presented evidence. It is confidently assumed that the CAA dishonstly colluded with industry to certificate an aircraft that is implied, with no shred of evidence to support the claim - that they somehow "knew" to be unsuitable/unsafe. (I'm curious, how could anyone know that, and if they did, how come it wasn't/isn't public/industry knowledge?) The dishonesty of the CAA is taken as read yet the suggestion that an AAIB report might not be completely accurate (when it is repeating a line given it by the "dishonest" CAA) is scoffed at. Why is one unquestionably honest and the other unquestionably not? Implications that an aircraft was thought fundamentally unsafe are made repeatedly with no shred of evidence to support it, despite other operational types having horrendous problems and no complaints of CAA collusion or unsuitability there. SASless apparently thinks that 3000 hrs accrued in short bursts of 200hrs per month over 25 years somehow says more about a machine's durability than three times that accrued in six, and confuses the corporate knowledge of 500 low hours airframes with the specific experience of three times the hours at high intensity which is the subject we are actually discussing. The inconvenient fact that Boeing themselves were the engineering authority throughout all of this is conveniently forgotten. Or perhaps they know nothing compared to the US Army too...
SASless, in reality most of the world would name a quite different English-speaking nation from the description you gave...And that's a fact.
So there you have it. A sound, safe transport helicopter that for some reason even helicopter experts love to rubbish without good reason or evidence while ignoring far more serious shortfalls on its competitors. Poor Chinook, it deserves better.
If you are referring to the lack of emergency exits in the cabin I have already addressed that matter. An option was available had Mr Bristow wished to take it up. "Negotiations broke down---shortfalls in performance" Er, what shortfalls in performance? I don't recall any. Surely not Bristows asking too much and then demanding guarantees? That just sounds to me like Bristow Bluster. I can understand that Bristow who knew first-hand how fickle helos can be was reluctant to put that many people into one machine lest there was a disaster, a suggestion published elsewhere. He was astute enough to see that so many bodied would make unacceptable PR, but that is a value judgement. My bet is he knew the 234 to have a limited market routes wise and that 2 companies chasing very few contracts would result in a profitless pissing contest and airframes being underused. The capital outlay and lack of obvious resale markets probably made this an opportunity to walk past, but being Bristow he couldn't and wouldn't say that so he came out with some bluster to cover it. As it turned out the 4 machines did pretty much fill the niche, and very profitably too. But I bet there wasn't room for 5 more. And from then on he missed no opportunity to snipe and slag it off because he couldn't compete in any other way.
It is indeed curious how contrary people can be on this forum against the presented evidence. It is confidently assumed that the CAA dishonstly colluded with industry to certificate an aircraft that is implied, with no shred of evidence to support the claim - that they somehow "knew" to be unsuitable/unsafe. (I'm curious, how could anyone know that, and if they did, how come it wasn't/isn't public/industry knowledge?) The dishonesty of the CAA is taken as read yet the suggestion that an AAIB report might not be completely accurate (when it is repeating a line given it by the "dishonest" CAA) is scoffed at. Why is one unquestionably honest and the other unquestionably not? Implications that an aircraft was thought fundamentally unsafe are made repeatedly with no shred of evidence to support it, despite other operational types having horrendous problems and no complaints of CAA collusion or unsuitability there. SASless apparently thinks that 3000 hrs accrued in short bursts of 200hrs per month over 25 years somehow says more about a machine's durability than three times that accrued in six, and confuses the corporate knowledge of 500 low hours airframes with the specific experience of three times the hours at high intensity which is the subject we are actually discussing. The inconvenient fact that Boeing themselves were the engineering authority throughout all of this is conveniently forgotten. Or perhaps they know nothing compared to the US Army too...
SASless, in reality most of the world would name a quite different English-speaking nation from the description you gave...And that's a fact.
So there you have it. A sound, safe transport helicopter that for some reason even helicopter experts love to rubbish without good reason or evidence while ignoring far more serious shortfalls on its competitors. Poor Chinook, it deserves better.
Last edited by Agaricus bisporus; 8th Nov 2011 at 10:22.
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As the Bv234 was almost as wide as it was long and had the stability of a barge the implications of a ditching were that it would be almost impossible to overturn, thus it did not even need floatation gear.
It is indeed curious how contrary people can be on this forum against the presented evidence
...of a bypass valve.
The report highlights a series of shortcomings in the operation and maintenance of the helicopter. It says that a
number of screws on other actuators were grossly undertorqued and that the operator, British Airways Helicopters, had failed effectively to investigate or resolve similar occurrences before the accident.
A damaged rear cargo ramp seal had allowed water into the ditched helicopter, which capsized about 80min after ditching.
Pre-flight flight control
The report highlights a series of shortcomings in the operation and maintenance of the helicopter. It says that a
number of screws on other actuators were grossly undertorqued and that the operator, British Airways Helicopters, had failed effectively to investigate or resolve similar occurrences before the accident.
A damaged rear cargo ramp seal had allowed water into the ditched helicopter, which capsized about 80min after ditching.
Pre-flight flight control
The Chinook was a horrible aircraft to be a passenger in. It was uncomfortable and despite the large cabin, the relatively small, high windows made it feel cramped and many of the passengers, who were scared of flying in many helicopters, were even more scared by the Chinook. My bag being ruined by a large hydraulic leak into the baggage compartment was the last straw and afterwards I always flew fixed wing to Sumburgh and then in an S61 rather than the Chinook
AB
I am not arguing with you about the performance of the BV234 either in normal operations or in the event of a ditching, I am relating the events of 1979-80.
The performance issues which led to BHL cancelling the BV234 order related to contractual performance, not actual aircraft performance.
Bristow wanted added penalty clauses for what was then a very expensive aircraft. The clauses related to aircraft availability to the customer. BHL wanted to be compensated if the customers (Shell and BP) declined to pay a portion of the standing charges due to aircraft being unserviceable. Offers of consignment spare parts failed to satisfy Bristow enough to prevent cancellation in 1980.
It was also decided that 2x 332Ls would offer greater flexibility at a cheaper cost to the oil companies than contracting 1x BV234 which, if unserviceable required significant backup capacity to transport 44 passengers.
I am not arguing with you about the performance of the BV234 either in normal operations or in the event of a ditching, I am relating the events of 1979-80.
The performance issues which led to BHL cancelling the BV234 order related to contractual performance, not actual aircraft performance.
Bristow wanted added penalty clauses for what was then a very expensive aircraft. The clauses related to aircraft availability to the customer. BHL wanted to be compensated if the customers (Shell and BP) declined to pay a portion of the standing charges due to aircraft being unserviceable. Offers of consignment spare parts failed to satisfy Bristow enough to prevent cancellation in 1980.
It was also decided that 2x 332Ls would offer greater flexibility at a cheaper cost to the oil companies than contracting 1x BV234 which, if unserviceable required significant backup capacity to transport 44 passengers.
Poor Chinook, it deserves better.
The military Chinooks are scheduled to be in service till close to 2050 or some unimaginable time....and folks skip over all of this.
She's a wonderful Bird....has always been...and always shall be!
To know her is to love her!