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Nick,
The Southern North Sea will be re-equipping with medium sized helicopters when some new contracts are issued by our clients.
Do you recommend the operators automatically go for the AB 139 as it is certified to the latest standards or go for the S76C+ because it is a well proven successful design?
g33
The Southern North Sea will be re-equipping with medium sized helicopters when some new contracts are issued by our clients.
Do you recommend the operators automatically go for the AB 139 as it is certified to the latest standards or go for the S76C+ because it is a well proven successful design?
g33
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g33,
Good question! I recommend that they know what they are buying. The TCDS for each will tell the story, and no Sikorsky person will offer to repaint the S-76 in 2004 paint and call it a brand new design.
As proof, please look to my old posts on this subject in previous threads, and you will see that I have pointed out that I believe AB-139 might be the next example of a true "new"design. This should make it very attractive.
I do not believe the EC 225 to be unsuitable at all, it is a good helicopter, as is the S-61. The record of these machines, and the S-76, make them excellent candidates for you or anyone else. Look to the total package, of course!
Just beware when a press release says "in compliance with the latest version of the JAR 29 standard from the new European Airworthiness Security Agency (EASA)." That statement started this thread, and I think it has been found to be an awful overstatement. I personally think it was promulgated to decieve, or at least hide the true state of the grandfathering. It tries to tell you and me that there is no grandfathering on the aircraft.
This does not make the EC 225 unfit, in my humble opinion, but it does make their press people (and their marketing guys too) out to be folks to watch carefully. Very carefully.
Good question! I recommend that they know what they are buying. The TCDS for each will tell the story, and no Sikorsky person will offer to repaint the S-76 in 2004 paint and call it a brand new design.
As proof, please look to my old posts on this subject in previous threads, and you will see that I have pointed out that I believe AB-139 might be the next example of a true "new"design. This should make it very attractive.
I do not believe the EC 225 to be unsuitable at all, it is a good helicopter, as is the S-61. The record of these machines, and the S-76, make them excellent candidates for you or anyone else. Look to the total package, of course!
Just beware when a press release says "in compliance with the latest version of the JAR 29 standard from the new European Airworthiness Security Agency (EASA)." That statement started this thread, and I think it has been found to be an awful overstatement. I personally think it was promulgated to decieve, or at least hide the true state of the grandfathering. It tries to tell you and me that there is no grandfathering on the aircraft.
This does not make the EC 225 unfit, in my humble opinion, but it does make their press people (and their marketing guys too) out to be folks to watch carefully. Very carefully.
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Nick,
I guess it all boils down to the question, do you want an evolutionary design or a revolutionary design? Grandfathering is not all bad, look at the 737. It is grandfathered up to the hilt but still a very effective and safe design.
As we all agree it is the client who will chose, not the operators. I wonder if they will do their homework?
I think lumping the EC 225 in with the S61 is a bit disingenuous. The EC 225's cabin is based on an old design, but the engines, drive train, rotors, avionics & AP are to the latest standard. Even if some parts of the EC 225 are grandfathered from the AS 332L2, decades separate the S61 and L2.
What we need is EC to provide an official spokesman and then you and their representative could wrestle in cyberspace!
How do you find time to do your day job as you seem to be fighting on several fronts (threads) and thats only on pprune!
g33
I guess it all boils down to the question, do you want an evolutionary design or a revolutionary design? Grandfathering is not all bad, look at the 737. It is grandfathered up to the hilt but still a very effective and safe design.
As we all agree it is the client who will chose, not the operators. I wonder if they will do their homework?
I think lumping the EC 225 in with the S61 is a bit disingenuous. The EC 225's cabin is based on an old design, but the engines, drive train, rotors, avionics & AP are to the latest standard. Even if some parts of the EC 225 are grandfathered from the AS 332L2, decades separate the S61 and L2.
What we need is EC to provide an official spokesman and then you and their representative could wrestle in cyberspace!
How do you find time to do your day job as you seem to be fighting on several fronts (threads) and thats only on pprune!
g33
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g33,
I really do try to be clear and ingenuous (as opposed to disingenuous!) The 225 is clearly a "newer" aircraft in many ways than an S-61, and those items that were updated are inclusive of that.
I do find it uncomfortable to be espousing and wouldn't really enjoy duking it out with an EC salesman (assuming HC is not one!) because I fear bending pprune over into a commercial vein. The technical comments I make are that, and I try to separate them from the opinions that I also hold.
I hope this thread is instructive for everyone, it was for me.
In any case, I always speak here as an individual, never as the spokesman for any company, and my thoughts here are strictly my own. Those who know me in person might vouch that I do try to call it as I see it, I think. For the record, I do not know of a bad helicopter - like sex, the worst one I ever experienced was pretty darn good!
I really do try to be clear and ingenuous (as opposed to disingenuous!) The 225 is clearly a "newer" aircraft in many ways than an S-61, and those items that were updated are inclusive of that.
I do find it uncomfortable to be espousing and wouldn't really enjoy duking it out with an EC salesman (assuming HC is not one!) because I fear bending pprune over into a commercial vein. The technical comments I make are that, and I try to separate them from the opinions that I also hold.
I hope this thread is instructive for everyone, it was for me.
In any case, I always speak here as an individual, never as the spokesman for any company, and my thoughts here are strictly my own. Those who know me in person might vouch that I do try to call it as I see it, I think. For the record, I do not know of a bad helicopter - like sex, the worst one I ever experienced was pretty darn good!
Apropos the discussion about the cost of operating a 'modern designed' helicopter, at least one Major Oil Company is at present attempting to design a mathematical model to cost the effect on safety of the certification state of the aircraft. This model examines accident/incident records and attempts to predict which ones might have been prevented if a helicopter had been certificate to each of the latest standards.
Such models are, by definition, difficult to apply as the Heinrich Pyramid indicates for every one major accident there are:
Each accident is also a sum of its constituent parts - some of which have been in play even before the aircraft takes off. Breaking the cause-and-effect chain at any link will of course prevent an accident - except in the case of a catastrophic failure (which might be seen as as (a predictable) failure of the certification system; interestingly, Vibration Health Monitoring is perceived as the device to prevent such catastrophic failures - even by some of the major manufacturers.)
It is clear that the examination of incidents/accidents also has to take account the perceived benefit of:
What is the bottom line for this exercise? When the unacceptable cost of a fatal accident rises above the cost of the application of some or all of the mitigating factors - the investment is worthwhile. (Which has been pointed out by others might be conditioned by society in the operational theatre.)
However, it is clear that the operational requirement is the first test for the customer - for it is that which will produce the short list of qualifying aircraft. In the case of the Southern North Sea, the AB139 might just be slightly too large and the competition could be narrowed to the S76 and the EC155. If that is the case it would be a pity as the certification basis and the installed power of the AB139 would have put it into a different class (but perhaps the sums will work out).
Such models are, by definition, difficult to apply as the Heinrich Pyramid indicates for every one major accident there are:
- three to five less significant accidents
- seven to 10 incidents; and
- several hundred unreported occurrences
Each accident is also a sum of its constituent parts - some of which have been in play even before the aircraft takes off. Breaking the cause-and-effect chain at any link will of course prevent an accident - except in the case of a catastrophic failure (which might be seen as as (a predictable) failure of the certification system; interestingly, Vibration Health Monitoring is perceived as the device to prevent such catastrophic failures - even by some of the major manufacturers.)
It is clear that the examination of incidents/accidents also has to take account the perceived benefit of:
- the regulatory regime (regulatory oversight, qualification of the pilots, compliance with ICAO SARPs, performance requirements, SOPs etc);
- application of Safety Management Systems;
- quality based maintenance systems;
- Helicopter Operational Monitoring Procedures (HOMP)
- the addition of Vibration (VHM) and Usage (UMS) monitoring systems;
- the number of engines;
- the number of pilots;
- additional operational equipment such as ACAS, EGPWS etc.
- crashworthiness above the certification standard; and
- survival equipment
What is the bottom line for this exercise? When the unacceptable cost of a fatal accident rises above the cost of the application of some or all of the mitigating factors - the investment is worthwhile. (Which has been pointed out by others might be conditioned by society in the operational theatre.)
However, it is clear that the operational requirement is the first test for the customer - for it is that which will produce the short list of qualifying aircraft. In the case of the Southern North Sea, the AB139 might just be slightly too large and the competition could be narrowed to the S76 and the EC155. If that is the case it would be a pity as the certification basis and the installed power of the AB139 would have put it into a different class (but perhaps the sums will work out).
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Jiml,
Your post is exactly on, the recording and understanding the pyramid of events that fortell an accident are one important (perhaps the most important) means of improving safety. Stats show that about 65 to 75% of all accidents are crew error in one form or another, and this will virtually zero that.
Regarding AB-139, the particular characteristics of that machine are not necessarily due to the regulations. Its extemely high OEI peformance is a design trait seleced by Agusta to meet a market segment's needs. I do think the awsome power margins will play havoc with its payload-range capabilities, because the extra power means much more fuel flow while in twin engine flight. It is up to the customers to decide what to buy, of course.
One switch that has not helped them is that the newest interpretations of JAR Ops has accepted small exposure windows on takeoff and landing, as long as the statistic probability of an engine failure is very small. For the S-92 we tossed out the -6 engine from the design because we thought the older JAR Ops would be in effect, calling for absolutely rock solid engine failure performance from rigs and small heliports. With the much smaller -6 engines, we would not have a very good rig OEI gross weight. We spent millions on the promise that JAR Ops would require hard OEI from rigs.
As ppruners might remember, I have advocated for the new softer OEI interpretations of JAR Ops (in spite of having poised the S-92 to meet it!) because it is actually correct, and less onerous on the operator. Thus the AB-139 might be over-powered for rig missions. Over-powered only in the way that extra power takes away some commercial advantage by absorbing some payload/range.
Your post is exactly on, the recording and understanding the pyramid of events that fortell an accident are one important (perhaps the most important) means of improving safety. Stats show that about 65 to 75% of all accidents are crew error in one form or another, and this will virtually zero that.
Regarding AB-139, the particular characteristics of that machine are not necessarily due to the regulations. Its extemely high OEI peformance is a design trait seleced by Agusta to meet a market segment's needs. I do think the awsome power margins will play havoc with its payload-range capabilities, because the extra power means much more fuel flow while in twin engine flight. It is up to the customers to decide what to buy, of course.
One switch that has not helped them is that the newest interpretations of JAR Ops has accepted small exposure windows on takeoff and landing, as long as the statistic probability of an engine failure is very small. For the S-92 we tossed out the -6 engine from the design because we thought the older JAR Ops would be in effect, calling for absolutely rock solid engine failure performance from rigs and small heliports. With the much smaller -6 engines, we would not have a very good rig OEI gross weight. We spent millions on the promise that JAR Ops would require hard OEI from rigs.
As ppruners might remember, I have advocated for the new softer OEI interpretations of JAR Ops (in spite of having poised the S-92 to meet it!) because it is actually correct, and less onerous on the operator. Thus the AB-139 might be over-powered for rig missions. Over-powered only in the way that extra power takes away some commercial advantage by absorbing some payload/range.
"I have advocated for the new softer OEI interpretations of JAR Ops (in spite of having poised the S-92 to meet it!) because it is actually correct, and less onerous on the operator"
It's a pity that we can go on holiday in a twin jet that can climb on one engine at a phenomenal rate (well over 1000 ft/min), but because it might be onerous on the operators, we try to modify the rotary regulations that started with such good intentions. The OEI requirements as they stand are not exactly startling; 100 ft a minute barely registers on the gauge and it doesn't take much turbulence and overcontrolling to turn it into a descent.
To now say that "actually it's okay to have periods of up to 9 seconds within which it's anyones guess what will happen if an engine fails" is a shame, to say the least.
Oil companies aren't bothered by fuel consumption in the same way an airline is. Do you think 1200 lbs an hour versus 950 is going to hurt them? If it eats the range, add bigger tanks (preferably on the outside so as the meet the latest certification standards!)
We're flying helicopters for commercial air transport that cost the same as business jets , or even small airliners if you look at S-92/225/101, and yet using performance standards that you'd associate with a light piston twin costing a couple of hundred thousand dollars.
It's a pity that we can go on holiday in a twin jet that can climb on one engine at a phenomenal rate (well over 1000 ft/min), but because it might be onerous on the operators, we try to modify the rotary regulations that started with such good intentions. The OEI requirements as they stand are not exactly startling; 100 ft a minute barely registers on the gauge and it doesn't take much turbulence and overcontrolling to turn it into a descent.
To now say that "actually it's okay to have periods of up to 9 seconds within which it's anyones guess what will happen if an engine fails" is a shame, to say the least.
Oil companies aren't bothered by fuel consumption in the same way an airline is. Do you think 1200 lbs an hour versus 950 is going to hurt them? If it eats the range, add bigger tanks (preferably on the outside so as the meet the latest certification standards!)
We're flying helicopters for commercial air transport that cost the same as business jets , or even small airliners if you look at S-92/225/101, and yet using performance standards that you'd associate with a light piston twin costing a couple of hundred thousand dollars.
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212man,
Each aspect has a cost, for helos, it is the lost payload that gets us, not the fuel cost. At 200 miles, it might be 2 or 3 pax, making the cost per seat mile for the whole machine too much. This is all speculation, however, I have not seen any payload range info to compare the several machines (the AB-139 site is particularly sparse on technical data, unless I am looking in the wrong spot).
Regarding the 9 seconds, I have posted perhaps 10 times that there is no reason to build engine quantities or power up, at the tremendous expense to the machine, so that engine failure is better protected than the other possible failure modes. The JAR logic is impeccable - with the JAR exposure times, the engine failure risk is as low as all the other risks. This is wise, I think.
The cost to the machine, in weight, operating cost and lost payload to have OEI hover is tremendous.
I only wish that pilots were as vocal for EGPWS, which would cure the 45% or so of accidents that are CFIT, as they were for full hover to hover OEI capability, which accounts for 0.0% of their accidents (in twins). Or for the ability to make a full instrument approach to a rig in zero-zero. Or for the ability to separate traffic in IFR as though it were VFR. Or for ........(you pick it).We are the product of conditioning since we were pups, where emergencies ment engine failures, and we practice them until we are purple. This sets an unconscious conditioning that we must break if we are to truly lower our accident rates.
Each aspect has a cost, for helos, it is the lost payload that gets us, not the fuel cost. At 200 miles, it might be 2 or 3 pax, making the cost per seat mile for the whole machine too much. This is all speculation, however, I have not seen any payload range info to compare the several machines (the AB-139 site is particularly sparse on technical data, unless I am looking in the wrong spot).
Regarding the 9 seconds, I have posted perhaps 10 times that there is no reason to build engine quantities or power up, at the tremendous expense to the machine, so that engine failure is better protected than the other possible failure modes. The JAR logic is impeccable - with the JAR exposure times, the engine failure risk is as low as all the other risks. This is wise, I think.
The cost to the machine, in weight, operating cost and lost payload to have OEI hover is tremendous.
I only wish that pilots were as vocal for EGPWS, which would cure the 45% or so of accidents that are CFIT, as they were for full hover to hover OEI capability, which accounts for 0.0% of their accidents (in twins). Or for the ability to make a full instrument approach to a rig in zero-zero. Or for the ability to separate traffic in IFR as though it were VFR. Or for ........(you pick it).We are the product of conditioning since we were pups, where emergencies ment engine failures, and we practice them until we are purple. This sets an unconscious conditioning that we must break if we are to truly lower our accident rates.
Last edited by NickLappos; 8th Aug 2004 at 17:48.
I have no wish to hijack this thread but as Nick and 212man have opened the can, it might be appropriate to provide (my view of) the JAA policy on offshore performance.
When the 1995 version of JAR-OPS 3 was written in the early 90s it was decided that it would have to be in compliance with ICAO Annex 6 Part III; this required (even for Operations in Performance Class 2) the provision of deck-edge clearance and (for operations in a hostile environment) flyaway; which in effect - for the North Sea - was a zero exposure regime; existing operations were grandfathered until 2010.
Around the time of the implementation date of 1995, the discussion on offshore performance was centred on how to show compliance with zero exposure. Informed wisdom at that time was that this could only be achieved with Category A helideck procedures (as one of the requirements was to show the 15’ deck edge clearance). However, such procedures that were in existence (very few at that time) could only provide limited approach/take-off directions with a minimum deck size of 2D (shortly after that Sikorsky provided a S76C+ procedure with a minimum deck size of 1.5D).
With this in mind, working groups extensively explored the problem and decide to concentrate on a solution based upon the concept of ‘exposure time’ -
This was put forward and accepted by all interested parties in 1998 (NPA - 8) but, because of the unease shown by at least one major Authority, the concept was limited until 2010 and a number of statistical procedures were introduced to improve confidence in the methodology. JAR-OPS 3 was amended in 1999 as Revision 1.
One of the major problems with our industry is that our tools are extremely expensive to develop and produce and the launch of new products is rare. We are fortunate to be in one of those rare periods at the moment when exciting products are just about to hit the market. However it must not be forgotten that in 2010, operators will still be using the 332L, the S61 and early marks of the S76.
212man has said that it is a shame that we cannot reproduce the performance of the ETOPS twins that are now the backbone of the transatlantic fleet. None of us would disagree with that but it must be understood that we have in our hands the most flexible aviation tool that has ever been produced and the provision of that flexibility comes at a cost. One of the costs of that (expensive provision of) flexibility is the longevity of equipment; whatever (operational) regulations are specified, they apply to the whole population of helicopters - older helicopters could be protected (grandfathered) but this cannot be to the detriment of newer craft which are by definition safer and more expensive but not necessarily more productive (see the previous discussion on the provision of the crashworthy floor for the EC225).
Another trade-off is the installed power to provide: adequate OEI power in the cruise; fuel consumption to ensure adequate payload/range; and power to eliminate/reduce the exposure to an engine failure on take-off or landing. You will already know that provision of these conflicting features (simplistically) is a trade off between the last two - fuel burn and take-off /landing performance (the AB139 argument put forward by Nick).
Discussions in the JAA over the last couple of years have been concerned with what to do in 2010 when the exposure time concept is due to end. Perceived wisdom now has it that there may be a method of providing zero exposure without reverting to Category A procedures. It would appear that, at least for the later versions of the AS332, B412, S76, EC225, S92 and of course the AB139, zero exposure is possible with the provision of risk assessed take-off and landing procedures giving deck-edge clearance and, for those helidecks that are situated in a hostile environment, a limitation on drop down to avoid ditching. It has been observed that such performance is possible even in ISA nil wind conditions.
Using the inherent environmental conditions that obtain in the North Sea which appear to indicate that:
Nick’s choice of the - CT7-8X for the S92 was clearly appropriate as it is unlikely that the dash 6 would have been able to provide zero exposure in 2010 - it also has allowed a growth in the operational weight of the S92 to 26,150lbs - not sure that would have been possible with the dash 6. The CT7-8C will also provide additional power margins that might be needed by future contracts yet to be specified. A similar tale exists for the AB139 but for once the (designed in) installed power appears to provide a growth path that we have rarely seen for new helicopters.
As was indicated in a previous post, the provision of regulations is not the bottom line; some customers have a duty of care that extends well beyond compliance with regulations. It has become increasingly clear that ‘standards’ are within the bailiwick of the customer and not the operator; it is those customers who will specify whether the certification, performance, operational equipment and staff training standards are adequate and, with the exception of certification, will ensure that they are raised if they are not!
When the 1995 version of JAR-OPS 3 was written in the early 90s it was decided that it would have to be in compliance with ICAO Annex 6 Part III; this required (even for Operations in Performance Class 2) the provision of deck-edge clearance and (for operations in a hostile environment) flyaway; which in effect - for the North Sea - was a zero exposure regime; existing operations were grandfathered until 2010.
Around the time of the implementation date of 1995, the discussion on offshore performance was centred on how to show compliance with zero exposure. Informed wisdom at that time was that this could only be achieved with Category A helideck procedures (as one of the requirements was to show the 15’ deck edge clearance). However, such procedures that were in existence (very few at that time) could only provide limited approach/take-off directions with a minimum deck size of 2D (shortly after that Sikorsky provided a S76C+ procedure with a minimum deck size of 1.5D).
With this in mind, working groups extensively explored the problem and decide to concentrate on a solution based upon the concept of ‘exposure time’ -
This was put forward and accepted by all interested parties in 1998 (NPA - 8) but, because of the unease shown by at least one major Authority, the concept was limited until 2010 and a number of statistical procedures were introduced to improve confidence in the methodology. JAR-OPS 3 was amended in 1999 as Revision 1.
One of the major problems with our industry is that our tools are extremely expensive to develop and produce and the launch of new products is rare. We are fortunate to be in one of those rare periods at the moment when exciting products are just about to hit the market. However it must not be forgotten that in 2010, operators will still be using the 332L, the S61 and early marks of the S76.
212man has said that it is a shame that we cannot reproduce the performance of the ETOPS twins that are now the backbone of the transatlantic fleet. None of us would disagree with that but it must be understood that we have in our hands the most flexible aviation tool that has ever been produced and the provision of that flexibility comes at a cost. One of the costs of that (expensive provision of) flexibility is the longevity of equipment; whatever (operational) regulations are specified, they apply to the whole population of helicopters - older helicopters could be protected (grandfathered) but this cannot be to the detriment of newer craft which are by definition safer and more expensive but not necessarily more productive (see the previous discussion on the provision of the crashworthy floor for the EC225).
Another trade-off is the installed power to provide: adequate OEI power in the cruise; fuel consumption to ensure adequate payload/range; and power to eliminate/reduce the exposure to an engine failure on take-off or landing. You will already know that provision of these conflicting features (simplistically) is a trade off between the last two - fuel burn and take-off /landing performance (the AB139 argument put forward by Nick).
Discussions in the JAA over the last couple of years have been concerned with what to do in 2010 when the exposure time concept is due to end. Perceived wisdom now has it that there may be a method of providing zero exposure without reverting to Category A procedures. It would appear that, at least for the later versions of the AS332, B412, S76, EC225, S92 and of course the AB139, zero exposure is possible with the provision of risk assessed take-off and landing procedures giving deck-edge clearance and, for those helidecks that are situated in a hostile environment, a limitation on drop down to avoid ditching. It has been observed that such performance is possible even in ISA nil wind conditions.
Using the inherent environmental conditions that obtain in the North Sea which appear to indicate that:
Nick’s choice of the - CT7-8X for the S92 was clearly appropriate as it is unlikely that the dash 6 would have been able to provide zero exposure in 2010 - it also has allowed a growth in the operational weight of the S92 to 26,150lbs - not sure that would have been possible with the dash 6. The CT7-8C will also provide additional power margins that might be needed by future contracts yet to be specified. A similar tale exists for the AB139 but for once the (designed in) installed power appears to provide a growth path that we have rarely seen for new helicopters.
As was indicated in a previous post, the provision of regulations is not the bottom line; some customers have a duty of care that extends well beyond compliance with regulations. It has become increasingly clear that ‘standards’ are within the bailiwick of the customer and not the operator; it is those customers who will specify whether the certification, performance, operational equipment and staff training standards are adequate and, with the exception of certification, will ensure that they are raised if they are not!
Nick,
I take your point entirely about the relative merits of other systems and welcome the efforts by Honeywell and Sikorsky, along with Eurocopter and the HTT concept, to develop these technologies.
What annoys me about the exposure time concept is its migration to the onshore environment (not yet but manufactures are pushing for it). I am not so concerned about the offshore environment because I think the deck edge exposure is genuinely very small and we all stand a fighting chance of getting away with it.
However, when confronted by large, hard obstacles with no escape route, during a take off, and the regulator/manufacturer is saying "oh they're within the exposure period" I'm less happy. Ditching or soft ground is one thing, hitting trees or buildings is another thing entirely. The passengers will not be aware of this fact!
I do understand your point Nick, though the airline accident rate is also predominently CFIT induced. The test would be would we be happy sending our kids on holiday every year in an airliner that may or may not climb away after take off if an engine fails? If not, then why would we expect the kids father and his passengers to do it daily?
Thanks Jim for the informed detail on JAA thinking.
I take your point entirely about the relative merits of other systems and welcome the efforts by Honeywell and Sikorsky, along with Eurocopter and the HTT concept, to develop these technologies.
What annoys me about the exposure time concept is its migration to the onshore environment (not yet but manufactures are pushing for it). I am not so concerned about the offshore environment because I think the deck edge exposure is genuinely very small and we all stand a fighting chance of getting away with it.
However, when confronted by large, hard obstacles with no escape route, during a take off, and the regulator/manufacturer is saying "oh they're within the exposure period" I'm less happy. Ditching or soft ground is one thing, hitting trees or buildings is another thing entirely. The passengers will not be aware of this fact!
I do understand your point Nick, though the airline accident rate is also predominently CFIT induced. The test would be would we be happy sending our kids on holiday every year in an airliner that may or may not climb away after take off if an engine fails? If not, then why would we expect the kids father and his passengers to do it daily?
Thanks Jim for the informed detail on JAA thinking.
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Thanks to both of you for beginning a whole new thread's subject, a very worthy one! I think I know who JimL is, now, having perhaps had a very nice dinner at EHOC one year with him. Am I right, JimL?
The technology of helos and airplanes is markedly different here, 212man, and it is worth having a solid discourse on it.
Maube a Moderator could slip this into a new thread, and we can begin the discussion there.
The technology of helos and airplanes is markedly different here, 212man, and it is worth having a solid discourse on it.
Maube a Moderator could slip this into a new thread, and we can begin the discussion there.
Sorry to have started a new topic; just a pet hate!
I'm sure you are probably correct in your guess Nick, the name and knowledge tend to lead to one person!
I'm sure you are probably correct in your guess Nick, the name and knowledge tend to lead to one person!
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hmm, more interesting discussions back there...... As mentioned before, CHC about to get pilots trained on the S-92..... Bristow preparing to train pilots on the EC225..... Shell north sea contract being tendered for right now..... 
I seem to have been absent from this forum for a couple of days- I had to check into the local hospital to see what was wrong when I found myself in agreement with one of Nick's posts..........
I have always thought that far too much emphasis was placed on engine failure scenarios, both from aircraft design and crew training points of view. As Nick quite rightly says, most accidents are not caused by engine failures but by some other unanticipatable chain of disconnected circumstances that happen to come together at the wrong time (phew - long sentence!).
Unfortunately for Nick and myself, there is an argument (that I can almost go along with but not quite) that, whilst it is accepted that engine failures do not cause significant numbers of accidents, that is at least one source of accident that can be dealt with pretty robustly by technology / expenditure. Other mutifarious sources of accident are much harder or impossible to fix - so lets concentrate on the ones we can fix!
This opinion seems to be held by those who charter our aircraft, so regardless of what Nick or I think, it must be given credence. Here the S92 appears to score well as its installed single engine power to weight ratio is second only to the AB139. Assuming that modern aircraft's rotor systems are pretty much as efficient as each others, you would think this is a good measure of single engine performance.
But of course things are never quite as simple as that! If we are looking at stay-up-ability in the cruise on one engine, there is little to choose between the 92 and the 225 and, without rigorous analysis my inclination would be that the 92 wins here (ie higher % gross weight at high density altitude at Vy than the 225).
However performance in the OEI OGE hover is a different matter. Surprisingly the 92 is quite bad at this and at around 30 deg C nil wind the 225 has about 1000 lbs better payload than the 92 (which is getting close to zero payload in SAR configuration). For a while I couldn't work out be this could be - surely the 92's rotor system wasn't desparately inefficient, disc loadings are similar etc. Then it dawned on me that in the hover, its the plan view that determines drag to the rotor downwash. Whilst the 225 has the usual Super Puma mediocre sort of drag, the 92, with its flat topped fueslage (is it a discarded design by Shorts Belfast?) and huge sponson area must surely present massive drag to the downwash.
This is very significant to any civil SAR operators. Its rather embarrasing to fall into the sea during SAR training, and even though that engine failure is a pretty remote probability, civil SAR operators that I know limit training to safe single engine hover weights. On the 92 with its current engines that T4.5 limit somewhere just above absolute zero, you just couldn't safely SAR train in other than cold weather - not much use if you live in the Middle East, or even England's south coast on a nice day.
More relevant to the N Sea, this must have some knock-on effect on performance with the approach of the end to performance class 2 with exposure time offshore. During the critical part of an offshore takeoff at low speed before reaching Vtoss, there must be a substantial downwash component to the relative airflow and the 92 is likely to suffer from high drag to airflow from this direction. Just how significant this could be I'm not sure - have SK or EC done any flight testing or even modelling to see how they shape up to the new proposals?
We seem to have got off my favourite subject of windows somehow, but in case anyone was interested, the S92's windows are about 14.5" by 19" whilst the smallest of the 225's are 17.5" by 28". Not interested -well try measuring you shoulder width (hips for the ladies) and see if its more or less than 14.5" - if more then don't forget to twist round on your side before trying to get out of a 92 underwater!
I have always thought that far too much emphasis was placed on engine failure scenarios, both from aircraft design and crew training points of view. As Nick quite rightly says, most accidents are not caused by engine failures but by some other unanticipatable chain of disconnected circumstances that happen to come together at the wrong time (phew - long sentence!).
Unfortunately for Nick and myself, there is an argument (that I can almost go along with but not quite) that, whilst it is accepted that engine failures do not cause significant numbers of accidents, that is at least one source of accident that can be dealt with pretty robustly by technology / expenditure. Other mutifarious sources of accident are much harder or impossible to fix - so lets concentrate on the ones we can fix!
This opinion seems to be held by those who charter our aircraft, so regardless of what Nick or I think, it must be given credence. Here the S92 appears to score well as its installed single engine power to weight ratio is second only to the AB139. Assuming that modern aircraft's rotor systems are pretty much as efficient as each others, you would think this is a good measure of single engine performance.
But of course things are never quite as simple as that! If we are looking at stay-up-ability in the cruise on one engine, there is little to choose between the 92 and the 225 and, without rigorous analysis my inclination would be that the 92 wins here (ie higher % gross weight at high density altitude at Vy than the 225).
However performance in the OEI OGE hover is a different matter. Surprisingly the 92 is quite bad at this and at around 30 deg C nil wind the 225 has about 1000 lbs better payload than the 92 (which is getting close to zero payload in SAR configuration). For a while I couldn't work out be this could be - surely the 92's rotor system wasn't desparately inefficient, disc loadings are similar etc. Then it dawned on me that in the hover, its the plan view that determines drag to the rotor downwash. Whilst the 225 has the usual Super Puma mediocre sort of drag, the 92, with its flat topped fueslage (is it a discarded design by Shorts Belfast?) and huge sponson area must surely present massive drag to the downwash.
This is very significant to any civil SAR operators. Its rather embarrasing to fall into the sea during SAR training, and even though that engine failure is a pretty remote probability, civil SAR operators that I know limit training to safe single engine hover weights. On the 92 with its current engines that T4.5 limit somewhere just above absolute zero, you just couldn't safely SAR train in other than cold weather - not much use if you live in the Middle East, or even England's south coast on a nice day.
More relevant to the N Sea, this must have some knock-on effect on performance with the approach of the end to performance class 2 with exposure time offshore. During the critical part of an offshore takeoff at low speed before reaching Vtoss, there must be a substantial downwash component to the relative airflow and the 92 is likely to suffer from high drag to airflow from this direction. Just how significant this could be I'm not sure - have SK or EC done any flight testing or even modelling to see how they shape up to the new proposals?
We seem to have got off my favourite subject of windows somehow, but in case anyone was interested, the S92's windows are about 14.5" by 19" whilst the smallest of the 225's are 17.5" by 28". Not interested -well try measuring you shoulder width (hips for the ladies) and see if its more or less than 14.5" - if more then don't forget to twist round on your side before trying to get out of a 92 underwater!
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HC does it again. For those who would like true data, and not an EC salesman's idea of how to measure 1,000 lbs, email me and I will provide same.
Last edited by NickLappos; 12th Aug 2004 at 05:58.
Oh dear Nick you do seem obsessionally determined that all aspects of the 92 will be better than the 225 at any cost. If you could just give a little ground and say that some tiny bit of the 225 might be ever so slightly better than the 92 then your credibility would be so much higher! Out of interest, have you ever flown a 225, or even a 332L2? Or even touched one? If not, you should get out more and not spend so much time on this forum. Your products would be the better for it!
Why do you have to pass OEI OGE performance data via PMs - are you too embarrassed to post it publicly?
Your statement "As far as absent, nobody missed you" is I'm sure based on as much careful research and unbiased opinion as most of the rest of your posts on this thread. Between you and me I have received a certain amount of fan mail during this discourse. (thankyou John Nipple et al)
Oh and by the way, didn't you know that all French Eurocopter people are on holiday throughout the month of August and not interested in internet chat forums?
'course I could be Lu!!!!!
(maybe not)
Why do you have to pass OEI OGE performance data via PMs - are you too embarrassed to post it publicly?
Your statement "As far as absent, nobody missed you" is I'm sure based on as much careful research and unbiased opinion as most of the rest of your posts on this thread. Between you and me I have received a certain amount of fan mail during this discourse. (thankyou John Nipple et al)
Oh and by the way, didn't you know that all French Eurocopter people are on holiday throughout the month of August and not interested in internet chat forums?
'course I could be Lu!!!!!
(maybe not)
Last edited by HeliComparator; 10th Aug 2004 at 00:13.
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O.K. Enough already!
Who cares whether the airspeed indicator or the seat cushion or the wheels or the lead/lag damper has been certificated under some grandfather clause. The regulatory authorities are not simple!
If either manufacturer (EC or SK) was really concerned with the "grandfather" aspect of certification, and its affect/effect on airworthiness, shouldn't we expect/insist that such manufacturer would withdraw any "grandfather" basis certifications from its existing aircraft, thus rendering them non-airwothy? Could it be that all these protestations are really nothing more than "my sh$t is better than your sh$t"
It would seem that perhaps someone in SK (If we are to believe a current post) does not condone the principles of "grandfathering" when it comes to certification. Don't try to tell me that the 92 is a completely new design and doesn't embody anything from previously certificated helicopters.
If that isn't true, then O.K, who paid who to get this sleight of hand past the regulatory authorities, or is it a generally accepted method of certification.
Methinks that Nick doth protest too much. If there is a real safety issue with the "old rules", why not do something positive other than bleat about it when some other manufacturer improves on an older design. For Chri$ts sake, the S92 isn't a new "design", it's simply a variation of existing technology. (Ditto the EC 225)
Life's for living, get on with it!
STL
Who cares whether the airspeed indicator or the seat cushion or the wheels or the lead/lag damper has been certificated under some grandfather clause. The regulatory authorities are not simple!
If either manufacturer (EC or SK) was really concerned with the "grandfather" aspect of certification, and its affect/effect on airworthiness, shouldn't we expect/insist that such manufacturer would withdraw any "grandfather" basis certifications from its existing aircraft, thus rendering them non-airwothy? Could it be that all these protestations are really nothing more than "my sh$t is better than your sh$t"
It would seem that perhaps someone in SK (If we are to believe a current post) does not condone the principles of "grandfathering" when it comes to certification. Don't try to tell me that the 92 is a completely new design and doesn't embody anything from previously certificated helicopters.
If that isn't true, then O.K, who paid who to get this sleight of hand past the regulatory authorities, or is it a generally accepted method of certification.
Methinks that Nick doth protest too much. If there is a real safety issue with the "old rules", why not do something positive other than bleat about it when some other manufacturer improves on an older design. For Chri$ts sake, the S92 isn't a new "design", it's simply a variation of existing technology. (Ditto the EC 225)
Life's for living, get on with it!
STL
Last edited by SawThe Light; 10th Aug 2004 at 06:38.
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SawtheLight,
I can tell that you don't see the light. It is not that older aircraft are grandfathered, it is that progress must be made.
If you and others fail to see the improvements, they will no longer be made. If you fail to see the improvements, it is our fault for not having shown you the difference and the value. And it is the fault of those who say, irrationally, that there is no improvement in the new designs.
I can tell that you don't see the light. It is not that older aircraft are grandfathered, it is that progress must be made.
If you and others fail to see the improvements, they will no longer be made. If you fail to see the improvements, it is our fault for not having shown you the difference and the value. And it is the fault of those who say, irrationally, that there is no improvement in the new designs.
STL, you raise an interesting point and one that is not generally understood by the casual observer; it is not a question whether the regulatory authorities are simple or not (your judgement) but that regulations for certification and operations are differently applied.
Firstly certification (I have to say, not my forte):
If one were to examine FAR 27/29 one would be forgiven for assuming that any new helicopter (not new type) would be built to the standard that is seen. You will have observed from this thread that such an assumption would be false; the only way to establish the certification standard of the aircraft is to examine the TCDS (and as we have discovered, this might not tell the whole story as an individual aircraft might include a crashworthy floor, stroking seats and any number of STCs) - this information will be given in the C of A and the Flight Manual. Thus (simplistically) any change to the certification codes will only come into effect when a new type is certificated. (when the present round of new development has been completed, when will the next medium helicopter be produced - 2020?)
If one wanted to establish the certification status of any aircraft type for reasons of comparison, it would require a reconstruction of the certification code that existed at the time that the aircraft was awarded its type certificate - including any methods of compliance given in the AC. Why would anyone want to conduct such an academic exercise? Well I have already given you the answer to that in a previous post; at least one major oil company is producing a mathematical model to establish the safety benefits (and costs) of moving from old to newer technology on a number of their contracts. As the oil companies have various worthwhile causes competing for their budget, a shift to newer technology will have to be justified on a standard accounting basis. The certification status will be one of many elements that will have to be considered - for the GOM, the number of engines and pilots will also be part of that calculation.
I think that it has already been established without doubt that FAR 29 - from the revision status that obtained when the S92 was given its type certificate - will result in much safer aircraft. That is why Eurocopter has gone out of its way, and beyond that which is required for upgrading an existing type, to meet newer certification requirements. The discussion that we have seen on this thread has been a journey of exploration into some of these voluntary upgrades that have been applied - and very illuminating it has been. So you can see, no sleight of hand is required that’s the way the system works - could it be any other way?
I think it is quite clear that the S92 is a new civil type - using tried and tested components found to have been cost effective in previous designs. The EC255 is not a new civil type but EC has found it appropriate to apply the newest standards where it is technically feasible and economically justifiable.
Now for operations (of which I have a little knowledge):
When examining Annex 6 Part III, FAR 91, 135, JAR-OPS 3 etc. it is entirely clear what operational rules apply (well perhaps not that clear - for which I have to take some of the blame). Unless a rule is specifically directed at the date of the Individual C of A it will apply to all (aircraft, operator, pilots) who have to comply with the regulations.
Let’s take an example (and one which is coming gradually into play in this thread) FAR 29.1 establishes that the S92 has to be certificated in Category A; what does that mean? Well leaving aside any airworthiness elements (which are extremely important in themselves) Nick has indicated that it required a quick and simple Category A procedure to be incorporated into the Flight Manual. However, the fact that the aircraft has been certificated in Category A is only the entry price as far as ICAO and European regulations are concerned it is the operational code that establishes how the aircraft is to be operated.
All of those of you who operate offshore will know that Operations in Performance Class 1 to a helideck is not always possible (due to the size, the obstacles, the environment etc) - even though it might be hugely desirable. No Category A procedure can cope with all of the elements extant in offshore take-off and landing. The present European code permits (until 2010) operations in Performance Class 2 - with exposure. As Nick has pointed out in his last post ‘progress has to be made’; it is clear, even though operation in Performance Class 1 is not always possible, operations with zero exposure are possible using risk assessed procedures and data produced by the manufacturers from models validated with limited flight data - at very little extra cost in the provision of data and little or no cost in reduction of payload.
HC in one of his latest posts, quite clearly indicated that the data required to fly zero exposure procedures is closely related to the OEI OGE hover performance; other features such as the NR beep or the (automatic) NR+10 of the EC225 provide stored energy. The combination of these elements (and the use of appropriate take-off and landing procedures) by utilising vertical acceleration and stored energy will give zero exposure by ensuring deck-edge clearance and minimising drop down. The operational code (unless otherwise stated) can make that a requirement for all aircraft at any stage; all that is required is that stake holders agree to the required changes.
Even if such changes to the operational code are not made (which is unlikely), customers are likely to require such performance as part of their duty of care to their passengers and responsibility to their share-holders.
I disagree with STL's "O.K. Enough already" - let the debate continue.
Firstly certification (I have to say, not my forte):
If one were to examine FAR 27/29 one would be forgiven for assuming that any new helicopter (not new type) would be built to the standard that is seen. You will have observed from this thread that such an assumption would be false; the only way to establish the certification standard of the aircraft is to examine the TCDS (and as we have discovered, this might not tell the whole story as an individual aircraft might include a crashworthy floor, stroking seats and any number of STCs) - this information will be given in the C of A and the Flight Manual. Thus (simplistically) any change to the certification codes will only come into effect when a new type is certificated. (when the present round of new development has been completed, when will the next medium helicopter be produced - 2020?)
If one wanted to establish the certification status of any aircraft type for reasons of comparison, it would require a reconstruction of the certification code that existed at the time that the aircraft was awarded its type certificate - including any methods of compliance given in the AC. Why would anyone want to conduct such an academic exercise? Well I have already given you the answer to that in a previous post; at least one major oil company is producing a mathematical model to establish the safety benefits (and costs) of moving from old to newer technology on a number of their contracts. As the oil companies have various worthwhile causes competing for their budget, a shift to newer technology will have to be justified on a standard accounting basis. The certification status will be one of many elements that will have to be considered - for the GOM, the number of engines and pilots will also be part of that calculation.
I think that it has already been established without doubt that FAR 29 - from the revision status that obtained when the S92 was given its type certificate - will result in much safer aircraft. That is why Eurocopter has gone out of its way, and beyond that which is required for upgrading an existing type, to meet newer certification requirements. The discussion that we have seen on this thread has been a journey of exploration into some of these voluntary upgrades that have been applied - and very illuminating it has been. So you can see, no sleight of hand is required that’s the way the system works - could it be any other way?
I think it is quite clear that the S92 is a new civil type - using tried and tested components found to have been cost effective in previous designs. The EC255 is not a new civil type but EC has found it appropriate to apply the newest standards where it is technically feasible and economically justifiable.
Now for operations (of which I have a little knowledge):
When examining Annex 6 Part III, FAR 91, 135, JAR-OPS 3 etc. it is entirely clear what operational rules apply (well perhaps not that clear - for which I have to take some of the blame). Unless a rule is specifically directed at the date of the Individual C of A it will apply to all (aircraft, operator, pilots) who have to comply with the regulations.
Let’s take an example (and one which is coming gradually into play in this thread) FAR 29.1 establishes that the S92 has to be certificated in Category A; what does that mean? Well leaving aside any airworthiness elements (which are extremely important in themselves) Nick has indicated that it required a quick and simple Category A procedure to be incorporated into the Flight Manual. However, the fact that the aircraft has been certificated in Category A is only the entry price as far as ICAO and European regulations are concerned it is the operational code that establishes how the aircraft is to be operated.
All of those of you who operate offshore will know that Operations in Performance Class 1 to a helideck is not always possible (due to the size, the obstacles, the environment etc) - even though it might be hugely desirable. No Category A procedure can cope with all of the elements extant in offshore take-off and landing. The present European code permits (until 2010) operations in Performance Class 2 - with exposure. As Nick has pointed out in his last post ‘progress has to be made’; it is clear, even though operation in Performance Class 1 is not always possible, operations with zero exposure are possible using risk assessed procedures and data produced by the manufacturers from models validated with limited flight data - at very little extra cost in the provision of data and little or no cost in reduction of payload.
HC in one of his latest posts, quite clearly indicated that the data required to fly zero exposure procedures is closely related to the OEI OGE hover performance; other features such as the NR beep or the (automatic) NR+10 of the EC225 provide stored energy. The combination of these elements (and the use of appropriate take-off and landing procedures) by utilising vertical acceleration and stored energy will give zero exposure by ensuring deck-edge clearance and minimising drop down. The operational code (unless otherwise stated) can make that a requirement for all aircraft at any stage; all that is required is that stake holders agree to the required changes.
Even if such changes to the operational code are not made (which is unlikely), customers are likely to require such performance as part of their duty of care to their passengers and responsibility to their share-holders.
I disagree with STL's "O.K. Enough already" - let the debate continue.