EC225
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Nick:
Is it possible to answer these implied questions (or give the latest position) for onshore and offshore performance?
Is there such a thing as performance gurantees?
Is it possible to answer these implied questions (or give the latest position) for onshore and offshore performance?
Is there such a thing as performance gurantees?
(HeliComparator) Having (probably rightly) been given grief for battling on so long, I am not going to be the one to raise the issues of Group A performance and definitely not the one to mention the OEI OGE hover performance of the 92. However I think you will find that neither aircraft have finalised Group A/ Cat A performance supplements yet and until they do, both are a little restrictive - for example from memory I think the current S92 clear airfield takeoff distance is fixed at 3800' (1150 metres). That will I'm sure change in the fullness of time following more flight testing.
(Hugh Martin) No one has yet compared Group/Cat A performance. Do the aircraft need 800 metres of runway to take off which is more than some fixed wing aircraft need?
I hope that anyone who has ordered 225's or 92's have included a performance guarantee in their contract with the supplier.
I hope that anyone who has ordered 225's or 92's have included a performance guarantee in their contract with the supplier.
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HughMartin,
The 800 lb number fits with the comments we get from customers. We settled on the 1000lbs by using the quick loading potential of using the back bulkhead as the "back stop" for the baggage, thus allowing the baggage to be properly restrained without tieing it down. The actual baggage area can hold much more (I have said 2,000 lbs in the past, but I should confirm that number).
The latest item from Helicomparitor about Cat A distances is actually accurate! (Ouch.) but only temporarily. The OEI performance of the 92 is excellent (2700HP for OEI helps) , but when we certified, we quickly ripped off a Cat A procedure that didn't take a long time to develop, the real one is coming and is quite respectable.
Mars,
Performance is a technical aspect that can be Guaranteed, but typically is not because performance from the major manufacturers is usually not a problem - nobody lasts long if they publish unachievable performance, since promises don't deliver the goods, in the end. If performance miseries are suffered, it is seldom the airframe (rotors and transmissions) that is the questionable item, it is the constancy of engine power.
The 800 lb number fits with the comments we get from customers. We settled on the 1000lbs by using the quick loading potential of using the back bulkhead as the "back stop" for the baggage, thus allowing the baggage to be properly restrained without tieing it down. The actual baggage area can hold much more (I have said 2,000 lbs in the past, but I should confirm that number).
The latest item from Helicomparitor about Cat A distances is actually accurate! (Ouch.) but only temporarily. The OEI performance of the 92 is excellent (2700HP for OEI helps) , but when we certified, we quickly ripped off a Cat A procedure that didn't take a long time to develop, the real one is coming and is quite respectable.
Mars,
Performance is a technical aspect that can be Guaranteed, but typically is not because performance from the major manufacturers is usually not a problem - nobody lasts long if they publish unachievable performance, since promises don't deliver the goods, in the end. If performance miseries are suffered, it is seldom the airframe (rotors and transmissions) that is the questionable item, it is the constancy of engine power.
Last edited by NickLappos; 5th Aug 2004 at 11:14.
Nick
Its interesting that the current TCDS from EASA still limits the baggage weight to 700 lbs. When will that change? I know you think I have got a downer on the 92 but that isn't true. I hope that you do get up to 1000lbs otherwise that will be a serious problem for N Sea operators.
Having looked at the list of "non-conformities" for the 225's certification, I hardly think they could be considered to be the extensive grandfathering that you originally suggested. Yes it is non-compliant with the latest standards in a few paras, but that's a few out of many hundreds and all they mainly seem to be due to the crash resistance / fuel systems that we talked about earlier. Things like the flaw tolerance and turbine burst protection seem to be covered. So could I say that provided you don't crash, they are about as safe as each other?
Of course as I suggested earlier, creating certification standards and their compliance-with does not necessarily maximise safety in a particular role. Thinking about the crashworthy fuel system, and I'm afraid being rather North-Sea-centred, I can't think of any accidents here in the last 25 years where having a crashworthy fuel system would have made any difference (someone tell me if I'm wrong!). However I can think of several where evacuating the aircraft in/under water was a key factor in occupant survival (or not in some cases). Whilst both aircraft meet the legal requirements, the 92 has very small escape windows (much smaller than the current N Sea fleet) whilst the 225's windows are more than half as big again. My contention is therefore that this single factor negates the advantages of meeting full crashworthiness regs for aircraft operating over water for oil support (unless all passengers are supermodel waifs!
).
HughMartin
Regarding your point about L2 air data errors, this is off topic but I believe the reason why you perceive the error to be so high is that the Area Nav will double any error when calculating the return groundspeed. I don't want to clog the thread with this so PM me if you want further explanation
Its interesting that the current TCDS from EASA still limits the baggage weight to 700 lbs. When will that change? I know you think I have got a downer on the 92 but that isn't true. I hope that you do get up to 1000lbs otherwise that will be a serious problem for N Sea operators.
Having looked at the list of "non-conformities" for the 225's certification, I hardly think they could be considered to be the extensive grandfathering that you originally suggested. Yes it is non-compliant with the latest standards in a few paras, but that's a few out of many hundreds and all they mainly seem to be due to the crash resistance / fuel systems that we talked about earlier. Things like the flaw tolerance and turbine burst protection seem to be covered. So could I say that provided you don't crash, they are about as safe as each other?
Of course as I suggested earlier, creating certification standards and their compliance-with does not necessarily maximise safety in a particular role. Thinking about the crashworthy fuel system, and I'm afraid being rather North-Sea-centred, I can't think of any accidents here in the last 25 years where having a crashworthy fuel system would have made any difference (someone tell me if I'm wrong!). However I can think of several where evacuating the aircraft in/under water was a key factor in occupant survival (or not in some cases). Whilst both aircraft meet the legal requirements, the 92 has very small escape windows (much smaller than the current N Sea fleet) whilst the 225's windows are more than half as big again. My contention is therefore that this single factor negates the advantages of meeting full crashworthiness regs for aircraft operating over water for oil support (unless all passengers are supermodel waifs!
).HughMartin
Regarding your point about L2 air data errors, this is off topic but I believe the reason why you perceive the error to be so high is that the Area Nav will double any error when calculating the return groundspeed. I don't want to clog the thread with this so PM me if you want further explanation
Nick
Based on accident data on the N Sea, YES! Is there any point in addressing safety issues which have not contributed to fatal accidents whilst ignoring those issues which exacerbate fatal accidents? This is a North-Sea-centric view I know, but then surely the oil & gas industry is one of your prime target customers?
Do you really believe that window exit size is not very important? - if so that's very sad and shows that you are out of touch with your (oil & gas) customers opinions. That will cost you sales.
Don't take it to heart so Nick, no-one who is important enough to spend 18 million dollars on a product has time to read this forum!
Based on accident data on the N Sea, YES! Is there any point in addressing safety issues which have not contributed to fatal accidents whilst ignoring those issues which exacerbate fatal accidents? This is a North-Sea-centric view I know, but then surely the oil & gas industry is one of your prime target customers?
Do you really believe that window exit size is not very important? - if so that's very sad and shows that you are out of touch with your (oil & gas) customers opinions. That will cost you sales.
Don't take it to heart so Nick, no-one who is important enough to spend 18 million dollars on a product has time to read this forum!
Last edited by HeliComparator; 5th Aug 2004 at 20:35.
I seem to recall (have read the reports but not immediately to hand) that one or two (or in fact rather more) injuries/fatalities in the Brent Spar and Comorant accidents were directly attributable to old seat design standards.
I think window size is probably close to the hearts of those pax who have had to egress under water too (above two accidents, plus the Claymore S-61 for example). Maybe that's why the 76 and 332 L1 have enlarged rear window nowadays!
I think window size is probably close to the hearts of those pax who have had to egress under water too (above two accidents, plus the Claymore S-61 for example). Maybe that's why the 76 and 332 L1 have enlarged rear window nowadays!
212man
The prime cause of both those accidents was crew error, which no amount of certification standards would have fixed (perhaps a bit harsh), however you are probably right that better seats etc would have helped and that is why I am confident that we will not see the 225 on the North Sea without the crashworthy floor and seat option - oil companies simply could not justify not-having this mod. This does not appear on the TCDS as its an option, but I believe it gives crash protection/energy absorbtion substantially the same as the JAR 29 requirements if you go for it.
Nick
By the way, (since you're being nasty to me again) any answer on the 700lbs baggage limit on the current EASA TCDS? Considering you are delivering to European customers within the next few months, (assuming you can sort out the production line delays) aren't you leaving it a bit late to sort this out?
The prime cause of both those accidents was crew error, which no amount of certification standards would have fixed (perhaps a bit harsh), however you are probably right that better seats etc would have helped and that is why I am confident that we will not see the 225 on the North Sea without the crashworthy floor and seat option - oil companies simply could not justify not-having this mod. This does not appear on the TCDS as its an option, but I believe it gives crash protection/energy absorbtion substantially the same as the JAR 29 requirements if you go for it.
Nick
By the way, (since you're being nasty to me again) any answer on the 700lbs baggage limit on the current EASA TCDS? Considering you are delivering to European customers within the next few months, (assuming you can sort out the production line delays) aren't you leaving it a bit late to sort this out?
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HC,
The answer to the 700 lbs is above. The old number was replaced by the new 1,000 lb capacity, which is on the new, as yet unposted TCDS.
You asked,"European customers within the next few months, (assuming you can sort out the production line delays) aren't you leaving it a bit late to sort this out?"
Perhaps we could borrow that loaner 332L2 from you once Bond is finished with it, as I understand you are so late with the job of again retreading that old warhorse that they have missed a contract. So tell me again about "Late?"
212Man,
If you know if anyone who buys an "optional"crashworthiness feature, please just make sure it is certified by EASA to meet the newest regs, without exceptions on the TCDS. Otherwise there is no independant measure of the actual safety capability of the "option." Oh, and make sure it has really big windows, since HC might be afraid to fly in it, otherwise. You remember him, he thinks if an accident is caused by "pilot error", the occupants need not be protected.
The answer to the 700 lbs is above. The old number was replaced by the new 1,000 lb capacity, which is on the new, as yet unposted TCDS.
You asked,"European customers within the next few months, (assuming you can sort out the production line delays) aren't you leaving it a bit late to sort this out?"
Perhaps we could borrow that loaner 332L2 from you once Bond is finished with it, as I understand you are so late with the job of again retreading that old warhorse that they have missed a contract. So tell me again about "Late?"
212Man,
If you know if anyone who buys an "optional"crashworthiness feature, please just make sure it is certified by EASA to meet the newest regs, without exceptions on the TCDS. Otherwise there is no independant measure of the actual safety capability of the "option." Oh, and make sure it has really big windows, since HC might be afraid to fly in it, otherwise. You remember him, he thinks if an accident is caused by "pilot error", the occupants need not be protected.
Last edited by NickLappos; 6th Aug 2004 at 00:51.
Nick
The 1000lbs is not on any new EASA TCDS because I got a copy straight from the horse's mouth 2 days ago. Assuming you do manage to push the loading to the limits of the CofG and get EASA to agree, will it be like the S76 where crews have to be issued with a programmable calculator to work out the CofG for each trip so that they don't exceed limits, or like the L & L2 where you just load up and go flying safe in the knowledge that Cof G is well within limits. I guess you were caught out with empty CofG after having to add that barn door horizontal stabiliser to try to fix the pitch stability problems that have plagued development.
"Perhaps we could borrow that loaner 332L2 from you once Bond
is finished with it"
I guess that's your way of admitting that there are production line delays at SK. You are determinded that I work for EC even though I have told you that I don't and its pretty obvious I'm a N Sea pilot. Sometimes people will just not be told!
You said of me "he thinks if an accident is caused by "pilot error", the occupants need not be protected". Of course they need to be protected but all the protection in the world is no use if they drown alive. Never mind, you can fix the problem by an addition to the limitation section of the flight manual that says "carriage of fat passengers, or passengers wearing bulky survival clothing, is prohibited"
Ridiculing the concept of large windows will not win you any favours with your customers (the oil companies) so I just hope for your sake they are not reading.
At least you are maintaining your integrity by not trying to deny that the 92's windows are significantly smaller than those fitted to current N Sea heavies - well done!
The 1000lbs is not on any new EASA TCDS because I got a copy straight from the horse's mouth 2 days ago. Assuming you do manage to push the loading to the limits of the CofG and get EASA to agree, will it be like the S76 where crews have to be issued with a programmable calculator to work out the CofG for each trip so that they don't exceed limits, or like the L & L2 where you just load up and go flying safe in the knowledge that Cof G is well within limits. I guess you were caught out with empty CofG after having to add that barn door horizontal stabiliser to try to fix the pitch stability problems that have plagued development.
"Perhaps we could borrow that loaner 332L2 from you once Bond
is finished with it"
I guess that's your way of admitting that there are production line delays at SK. You are determinded that I work for EC even though I have told you that I don't and its pretty obvious I'm a N Sea pilot. Sometimes people will just not be told!
You said of me "he thinks if an accident is caused by "pilot error", the occupants need not be protected". Of course they need to be protected but all the protection in the world is no use if they drown alive. Never mind, you can fix the problem by an addition to the limitation section of the flight manual that says "carriage of fat passengers, or passengers wearing bulky survival clothing, is prohibited"
Ridiculing the concept of large windows will not win you any favours with your customers (the oil companies) so I just hope for your sake they are not reading.
At least you are maintaining your integrity by not trying to deny that the 92's windows are significantly smaller than those fitted to current N Sea heavies - well done!
Last edited by HeliComparator; 6th Aug 2004 at 07:30.
NL
There is no question about the windows being approved - of course they are. However just meeting the minimum legal requirements is not always good enough for your customers. I can only assume that EC are not only pleased, but absolutely delighted with your windows because they will be able to make sales against you on just that issue.
I've no idea whether any 225s are late - you'd have to ask someone at EC although why bother as you seem to know already.
Nick, this all started with some pretty wild statements from you when 225 certification was announced. Some of the things you said were:
Do you still stand by all of this or do you think you were a little hasty and possibly misled your awestruck audience? Being the highly respected hero of rotorheads, do you think you have any responsibility to ensure that your posts are unbiased and accurate or does commercial interest always override?
There is no question about the windows being approved - of course they are. However just meeting the minimum legal requirements is not always good enough for your customers. I can only assume that EC are not only pleased, but absolutely delighted with your windows because they will be able to make sales against you on just that issue.
I've no idea whether any 225s are late - you'd have to ask someone at EC although why bother as you seem to know already.
Nick, this all started with some pretty wild statements from you when 225 certification was announced. Some of the things you said were:
Yep, that's the competition. Read carefully, however! Only the IFR certificate meets the JAR, meaning the autopilot and displays. The rest of the aircraft was not qualified to meet the latest regs regarding its structure, but rather it meets the older DGAC requirements.
That being said, I do not know of any data to show that the EC 225 meets this turbine burst requirement.
I still have heard nothing from you on the certification basis of the 225, so I can surely assume it is grandfathered a great deal.
"You said of me "he thinks if an accident is caused by "pilot error", the occupants need not be protected". Of course they need to be protected but all the protection in the world is no use if they drown alive. "
I thought most people were alive before they drowned; tends to define the whole concept?
I know they were pilot error: most accidents are (though the Claymore 61 was a MGB failure).
I can't see where there is confusion on this, clearly the 225 has a lot of much older main componants than the s-92 has, and these have been certified to an earlier standard, full stop (or period as the Americans would say). The 155 is in a similar boat; lots of 365 stuff in it (even crashworthy fuel tanks are an optional extra, and that's under the floor!)
Quibling over how long it takes to activate the back up gearbox lubrication, for instance, is missing the point; no actions have to be instant (okay, tail rotor failure in the hover, before anyone jumps on that point!). A double generator failure in may require immediate actions over and above the auto shed items, but still within a reasonable time frame. Even a fire drill should take a sensible period to execute, unless you are into shutting down the wrong engine.
It's a shame that this has degenerated to such a level on what seems to be a pretty clear cut topic. The 225 is basically old with new bits added, the 92 is basically new.
I have to say, though, that I far prefer the French concept of PFD/ND displays compared to the 92 and 139. I think by evolving from the basic Airbus displays with the 332 L2 through the 155/135 and the improved versions into the 225 they have got it right. The NH-90 is a step further again and that's superb.
I thought most people were alive before they drowned; tends to define the whole concept?
I know they were pilot error: most accidents are (though the Claymore 61 was a MGB failure).
I can't see where there is confusion on this, clearly the 225 has a lot of much older main componants than the s-92 has, and these have been certified to an earlier standard, full stop (or period as the Americans would say). The 155 is in a similar boat; lots of 365 stuff in it (even crashworthy fuel tanks are an optional extra, and that's under the floor!)
Quibling over how long it takes to activate the back up gearbox lubrication, for instance, is missing the point; no actions have to be instant (okay, tail rotor failure in the hover, before anyone jumps on that point!). A double generator failure in may require immediate actions over and above the auto shed items, but still within a reasonable time frame. Even a fire drill should take a sensible period to execute, unless you are into shutting down the wrong engine.
It's a shame that this has degenerated to such a level on what seems to be a pretty clear cut topic. The 225 is basically old with new bits added, the 92 is basically new.
I have to say, though, that I far prefer the French concept of PFD/ND displays compared to the 92 and 139. I think by evolving from the basic Airbus displays with the 332 L2 through the 155/135 and the improved versions into the 225 they have got it right. The NH-90 is a step further again and that's superb.
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Both types have their pros and cons. We could get into a similar argument over the S76C+ and the EC 155.
Lets wait until next summer and see how the clients like each type here on the N Sea UK/Norwegian Sectors. After all the pilots have little say in this matter, it is the clients' beancounters who have the casting vote!
g33
Lets wait until next summer and see how the clients like each type here on the N Sea UK/Norwegian Sectors. After all the pilots have little say in this matter, it is the clients' beancounters who have the casting vote!
g33
Well said!
Not much point comparing the 155B1 with the C+ though; no contest! (tongue in cheek before offence taken by someone)
Not much point comparing the 155B1 with the C+ though; no contest! (tongue in cheek before offence taken by someone)
g33 - Well said, though this forum would be a bit dull without some irrational debate going on!
212man you said
I agree except that I would change new to newish - remember the engines are CT7s which go back to before I was born, the the gearbox is modified black hawk and the head could be called old fashioned, but yes the fuselage is all-new whereas the 225 fuselage is basically L2.
I don't think there can be to much disagreement on the above, what got me going was Nick's implication that the 225 met virtually none of the new standards whilst the 92 met all (although the dry run one was passed only by using smoke and mirrors!). In fact, as we have seen from the TCDS, there are very few areas where the 225 doesn't meet the latest regs - those are probably insoluable with the current fuselage configuration.
Set against that, I think all pilots will be aware that to be the first to operate a new type is always risky. No matter how careful the manufacturer's boffins and certification authority are, a tiny mistake or oversight could be disasterous. (S76 spindles, EH101 tail rotors etc) That's why I would prefer to be in the first company to be operating the 225 rather than the 92 - the very fact that it is partly old tech reduces the risk! Nick will have a field day with that comment but its my opinion!
There's also the fact that, as you pointed out, the 225 screens are miles ahead of the 92, as are the autopilot upper modes etc. I had a big grin on my face after I flew it which is only just wearing off, whereas following flying the 92 my modest grin only lasted a few hours!
Although there has been considerable conflict on this thread, at least it has given the subject a good airing and I'm sure both Nick & I are man enough to take it!
212man you said
It's a shame that this has degenerated to such a level on what seems to be a pretty clear cut topic. The 225 is basically old with new bits added, the 92 is basically new.
I don't think there can be to much disagreement on the above, what got me going was Nick's implication that the 225 met virtually none of the new standards whilst the 92 met all (although the dry run one was passed only by using smoke and mirrors!). In fact, as we have seen from the TCDS, there are very few areas where the 225 doesn't meet the latest regs - those are probably insoluable with the current fuselage configuration.
Set against that, I think all pilots will be aware that to be the first to operate a new type is always risky. No matter how careful the manufacturer's boffins and certification authority are, a tiny mistake or oversight could be disasterous. (S76 spindles, EH101 tail rotors etc) That's why I would prefer to be in the first company to be operating the 225 rather than the 92 - the very fact that it is partly old tech reduces the risk! Nick will have a field day with that comment but its my opinion!
There's also the fact that, as you pointed out, the 225 screens are miles ahead of the 92, as are the autopilot upper modes etc. I had a big grin on my face after I flew it which is only just wearing off, whereas following flying the 92 my modest grin only lasted a few hours!
Although there has been considerable conflict on this thread, at least it has given the subject a good airing and I'm sure both Nick & I are man enough to take it!
Last edited by HeliComparator; 6th Aug 2004 at 12:12.
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I wonder who will have the last say, HC or NL?
This thread could go on for years. I like flying all aircraft, especially bad ones as they are more of a challenge! I wonder which of these two I would like the best?
g33
This thread could go on for years. I like flying all aircraft, especially bad ones as they are more of a challenge! I wonder which of these two I would like the best?
g33
But hasn't this been the most interesting discussion that we have had on PPRUNE for some time - the technical content has been excellent and, in view of its interactive nature (and the quality of protagonists), beats ends-up any article in an aviation magazine.
I for one wish it to continue until all the important elements have been aired; we still have not seen comparative examples of payload range or completed the discussion on offshore performance - and how it will be achieved.
Wouldn't we like to be enlightened on the (expected) provision of Category A procedures and find out whether, at last, we will get the total flexibility that will provide a continuum from helipad to clear area with variable Vtoss, configurable heights and distances.
HeliComparator and Nick have between them explored why the EC225 does not (and cannot) meet all of the requirements of the latest revision of FAR 29; but I for one would like to know what drove the decision for the size of the pop-out windows. I would also like to know why, if as HC says, there is an option for the reinforced floor and stroking seats, they have not been included in the EC 225 EASA TCDS (even as partial compliance). Will some operators not specify this option? Would that be acceptable to a regulator?
Also of interest to me (and I am sure the pilots of the North Sea and Canadian Eastern Seaboard) would be some detail on the ditching provision and what 'sea state' was applied to the testing regime; and if the helicopter cannot stay upright for the time it takes for the passengers to evacuate, will the evacuation be able to be completed in one breath-hold from the time that the helicopter inverts. Was there any testing of the evacuation procedures associated with the pop-out windows and can a large oil worker get out when wearing an integrated survival suit with a re-breather.
Of interest to the Norwegian pilots will be the sound levels in the cockpit and the comfort level in the Cabin. Have the vibration levels been reduced to an acceptable level and, whilst on the subject of vibration, will the Vibration Health Monitoring meet the requirements of the extant regulations.
If HeliComparator is, as he says, a North Sea pilot, where does he find the time to take part in this high energy, high technical level discussion; why is he conducting this examination and not a member of Eurocopter team? Does Sikorsky know (and appreciate) that Nick is worth 20% on their sales - is he adequately remunerated?
I for one wish it to continue until all the important elements have been aired; we still have not seen comparative examples of payload range or completed the discussion on offshore performance - and how it will be achieved.
Wouldn't we like to be enlightened on the (expected) provision of Category A procedures and find out whether, at last, we will get the total flexibility that will provide a continuum from helipad to clear area with variable Vtoss, configurable heights and distances.
HeliComparator and Nick have between them explored why the EC225 does not (and cannot) meet all of the requirements of the latest revision of FAR 29; but I for one would like to know what drove the decision for the size of the pop-out windows. I would also like to know why, if as HC says, there is an option for the reinforced floor and stroking seats, they have not been included in the EC 225 EASA TCDS (even as partial compliance). Will some operators not specify this option? Would that be acceptable to a regulator?
Also of interest to me (and I am sure the pilots of the North Sea and Canadian Eastern Seaboard) would be some detail on the ditching provision and what 'sea state' was applied to the testing regime; and if the helicopter cannot stay upright for the time it takes for the passengers to evacuate, will the evacuation be able to be completed in one breath-hold from the time that the helicopter inverts. Was there any testing of the evacuation procedures associated with the pop-out windows and can a large oil worker get out when wearing an integrated survival suit with a re-breather.
Of interest to the Norwegian pilots will be the sound levels in the cockpit and the comfort level in the Cabin. Have the vibration levels been reduced to an acceptable level and, whilst on the subject of vibration, will the Vibration Health Monitoring meet the requirements of the extant regulations.
If HeliComparator is, as he says, a North Sea pilot, where does he find the time to take part in this high energy, high technical level discussion; why is he conducting this examination and not a member of Eurocopter team? Does Sikorsky know (and appreciate) that Nick is worth 20% on their sales - is he adequately remunerated?
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JimL
I stand corrected.
Seconds out round 2, ding ding
g33
P.S. Nick, a genuine question because I don't know the answer and not because I am trying to wind you up again!
Why is the S92's birdstrike compliance based on an Equivalent Level of Safety in the EASA TCDS?
I stand corrected.
Seconds out round 2, ding ding
g33
P.S. Nick, a genuine question because I don't know the answer and not because I am trying to wind you up again!
Why is the S92's birdstrike compliance based on an Equivalent Level of Safety in the EASA TCDS?
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ppruners,
In all due respect to the point of view of Heli-non-Comparitor, please take care with anything he says about certification in general, or the certification details of any helicopter, especially a Sikorsky one!
g33,
We equivilent safety certified one component. The birdstrike certification must be done with tests, almost nothing else will do. When that TCDS was issued, we discovered that we had tested everything exposed on the aircraft to a fairtheewell, but we "forgot" the main rotor pitch links, which are about 1.5" in diameter, and made of solid titanium. It didn't matter that the bird wouldn't stand a chance against that rod, we had to do some pull tests that the FAA approved, in conjunction with loads measured when bird strikes were made on objects of the same diameter and got the equivilent safety approval. To clean that equivilence up, we started up the bird cannon and shot a pitch link about 2 months ago. This was approved on the last issue of the TCDS, which should be posted shortly with that equivilent safety removed.
Other than that one test, the original approval was gained by shooting everything, tail drive shaft covers, tail rotor pitch mechanism, rotor fairings, engine lips, main blade tips and tail rotors. The extensive comparison of test data to analysis was a real research project, and we learned a lot! The bird hits with the force of a 4 Kg sledge hammer at 80 knots, so the upper fairing and drive shaft covers are built as if they were ballistically tolerant.
Regarding window size, we sized ours by taking a Sikorsky engineer who weighs 300 lbs (21 stone - 136 Kg!!) and dressing him in a standard immersion suit, then having him crawl through the openings we proposed. The windows on the S-92 pass this test, and are all push out type. The films of this fellow popping out of the window are a sight to behold! Some rather large Norwegian Union guys also duplicated the test (probably because Heli-non-Comparitor had talked to them) and they were tickled pink with the S-92 windows, which is one of the many reasons why they will be looking out of them on their own S-92's very shortly!
In all due respect to the point of view of Heli-non-Comparitor, please take care with anything he says about certification in general, or the certification details of any helicopter, especially a Sikorsky one!
g33,
We equivilent safety certified one component. The birdstrike certification must be done with tests, almost nothing else will do. When that TCDS was issued, we discovered that we had tested everything exposed on the aircraft to a fairtheewell, but we "forgot" the main rotor pitch links, which are about 1.5" in diameter, and made of solid titanium. It didn't matter that the bird wouldn't stand a chance against that rod, we had to do some pull tests that the FAA approved, in conjunction with loads measured when bird strikes were made on objects of the same diameter and got the equivilent safety approval. To clean that equivilence up, we started up the bird cannon and shot a pitch link about 2 months ago. This was approved on the last issue of the TCDS, which should be posted shortly with that equivilent safety removed.
Other than that one test, the original approval was gained by shooting everything, tail drive shaft covers, tail rotor pitch mechanism, rotor fairings, engine lips, main blade tips and tail rotors. The extensive comparison of test data to analysis was a real research project, and we learned a lot! The bird hits with the force of a 4 Kg sledge hammer at 80 knots, so the upper fairing and drive shaft covers are built as if they were ballistically tolerant.
Regarding window size, we sized ours by taking a Sikorsky engineer who weighs 300 lbs (21 stone - 136 Kg!!) and dressing him in a standard immersion suit, then having him crawl through the openings we proposed. The windows on the S-92 pass this test, and are all push out type. The films of this fellow popping out of the window are a sight to behold! Some rather large Norwegian Union guys also duplicated the test (probably because Heli-non-Comparitor had talked to them) and they were tickled pink with the S-92 windows, which is one of the many reasons why they will be looking out of them on their own S-92's very shortly!
Ah...the truth at last...never mind the window size...the pitch stability...hand held calculators ( made necessary because the FAA requires a Weight and Balance computation for each takeoff)...and all that....The Truth of this argument is the Bean Counters shall determine which aircraft is the winner....not the pilots, engineers, mechanics...sales types or PR spin masters.
Both machines are probably a pleasure to drive...but for me...I prefer the idea of driving one of Nick's homebuilts to a wrong way turning French built thing. I know the reputation of the Sikorsky machines and how well built they are....afterall...names like 55,56,58,61,64,76,53, 60, and now 92....are industry standards.
There must be a reason the large EC machines have not caught on over here.
Both machines are probably a pleasure to drive...but for me...I prefer the idea of driving one of Nick's homebuilts to a wrong way turning French built thing. I know the reputation of the Sikorsky machines and how well built they are....afterall...names like 55,56,58,61,64,76,53, 60, and now 92....are industry standards.
There must be a reason the large EC machines have not caught on over here.
SASless
The bean counters will always win the day but in this case, I don't think anyone can tell which aircraft will be cheaper to operate. SK have come up with some pretty cheap PBH deals but not sure for how long they are guaranteed not to go up (excuse negative logic!) A number of oil companies are looking fairly closely at the other aspects - safety and ability to do the role, such as carrying a big drill bit that has to be fork-lifted into the aircraft (not sure how you could do that with the 92 - you can't get up to the airstair door and anyway your big lump would end up right at the front and upset the C of G). Nick, are people going for some sort of non-airstair door option?
Once you see beyond SK's excellent marketing hype, I don't think there's a clear cut winner.
The EC machines will never take off in a big way (excuse pun) in the USA in the same way that EC machines predominate in France. Something to do with patriotism, language barriers, and in some cases not realising that Europe even exists!
Nick
Are you going to answer my points about your rather bold initial statements or are you too embarrassed?
Regarding window sizes, would you like to post the window aperture sizes or should I - that way Rotorheads can try it at home on a piece of paper and judge for themselves whether your 300lbs engineer was 8 ft tall and/or had his bones removed, or whether he was just a normal burger-eating guy
JimL
You ask a few questions that I cannot answer as I don't work for EC so can't give you the "why"s however to answer a couple of your points, both aircraft's ditching certification is to sea state 6 (does anyone know what that means?).
Regarding crashworthy floors etc it is an option that some customers will not take. EC have sold several to VIP customers in the Middle East and I would doubt that they have taken that option. Not taking the option saves a lot of weight which would be a good thing in those temperatures. As it is an option, I wouldn't have thought it could feature on the TCDS which is concerned with the basic aircraft, not the optional extras. However I can't imagine oil companies not requiring it.
Regarding noise levels, my only contribution to that is that there seems to be an issue on the L2 with cockpit noise. I find when flying the L versus L2 that the noise levels seem to be the same, however after a long flight on the L2 my ears can be ringing. Its something to do with the 3 fans / forced cooling system for the CRT screens ( which use something like 500w of power). On the 225, I am glad to say that the LCD screens of course use a tiny fraction of the power and only 1 fan is fitted, and I think it only runs if you put on the cockpit ventilation.
We haven't talked about vibration levels yet - an extremely difficult thing to analyse scientifically as the vibration modes set up in an airframe have peaks and nulls according to where you measure. So I'll give it the subjective treatment!
The 92 has 4 blades and a number of anti-vibration generators that work by measuring local vibration and creating anti-phase vibrations to cancel out by means of a motor rotating an eccentric weight. The motor's speed/phase and the eccentricity of the weight is controlled to ensure the correct amplitude and phase. With this sytem turned off, the aircraft is pretty rough at speed. With it turned on its fine, although when I flew it some passengers were complaining about cabin vibration levels. Since then I think SK have added more generators and improved the system, but I suspect there would still be substantial variations in the vibration levels throughout the fuselage.
The 225 has 5 blades and a couple of anti-vibration generators. The principle is the same however the method is slightly different in that rather than having rotating weights, the 225's system uses actuators to move a weight around. EC do this because it has faster response to changes and of course the 225 like its predecessors has a rotor rpm that varies according to collective position (goes up as you raise the lever). It also has the automatic Nr+10 which automatically increases rotor speed by 10 rpm as the airspeed falls through 25 kts. With the system on, the aircraft is very smooth in the cockpit throughout the speed range (don't know anything about the cabin vibration level) and when it was turned off, there was a just-detectable increase in vibration when I was sitting in the right hand seat, but an undetectable change when I was sitting in the jump seat. EC say that the necessity for the generators is really only at medium speeds, say 90-110 kts where it gets a bit whoppy without them.
A 5 blade system does seem to be intrinsically smoother for some reason that only Nick could explain (but I'm sure won't, even though its on the S61!) so seems to be a more elegant solution rather than trying to beat the natural vibration of a 4-bladed system into submission.
When I flew both aircraft we were well below max weight, so which one turns out to be smoother in service is hard to say and will depend on other things such as ease of tracking/balancing etc. However until the verdict is announced, my money is on the 225 being smoother.
The bean counters will always win the day but in this case, I don't think anyone can tell which aircraft will be cheaper to operate. SK have come up with some pretty cheap PBH deals but not sure for how long they are guaranteed not to go up (excuse negative logic!) A number of oil companies are looking fairly closely at the other aspects - safety and ability to do the role, such as carrying a big drill bit that has to be fork-lifted into the aircraft (not sure how you could do that with the 92 - you can't get up to the airstair door and anyway your big lump would end up right at the front and upset the C of G). Nick, are people going for some sort of non-airstair door option?
Once you see beyond SK's excellent marketing hype, I don't think there's a clear cut winner.
The EC machines will never take off in a big way (excuse pun) in the USA in the same way that EC machines predominate in France. Something to do with patriotism, language barriers, and in some cases not realising that Europe even exists!
Nick
Are you going to answer my points about your rather bold initial statements or are you too embarrassed?
Regarding window sizes, would you like to post the window aperture sizes or should I - that way Rotorheads can try it at home on a piece of paper and judge for themselves whether your 300lbs engineer was 8 ft tall and/or had his bones removed, or whether he was just a normal burger-eating guy
JimL
You ask a few questions that I cannot answer as I don't work for EC so can't give you the "why"s however to answer a couple of your points, both aircraft's ditching certification is to sea state 6 (does anyone know what that means?).
Regarding crashworthy floors etc it is an option that some customers will not take. EC have sold several to VIP customers in the Middle East and I would doubt that they have taken that option. Not taking the option saves a lot of weight which would be a good thing in those temperatures. As it is an option, I wouldn't have thought it could feature on the TCDS which is concerned with the basic aircraft, not the optional extras. However I can't imagine oil companies not requiring it.
Regarding noise levels, my only contribution to that is that there seems to be an issue on the L2 with cockpit noise. I find when flying the L versus L2 that the noise levels seem to be the same, however after a long flight on the L2 my ears can be ringing. Its something to do with the 3 fans / forced cooling system for the CRT screens ( which use something like 500w of power). On the 225, I am glad to say that the LCD screens of course use a tiny fraction of the power and only 1 fan is fitted, and I think it only runs if you put on the cockpit ventilation.
We haven't talked about vibration levels yet - an extremely difficult thing to analyse scientifically as the vibration modes set up in an airframe have peaks and nulls according to where you measure. So I'll give it the subjective treatment!
The 92 has 4 blades and a number of anti-vibration generators that work by measuring local vibration and creating anti-phase vibrations to cancel out by means of a motor rotating an eccentric weight. The motor's speed/phase and the eccentricity of the weight is controlled to ensure the correct amplitude and phase. With this sytem turned off, the aircraft is pretty rough at speed. With it turned on its fine, although when I flew it some passengers were complaining about cabin vibration levels. Since then I think SK have added more generators and improved the system, but I suspect there would still be substantial variations in the vibration levels throughout the fuselage.
The 225 has 5 blades and a couple of anti-vibration generators. The principle is the same however the method is slightly different in that rather than having rotating weights, the 225's system uses actuators to move a weight around. EC do this because it has faster response to changes and of course the 225 like its predecessors has a rotor rpm that varies according to collective position (goes up as you raise the lever). It also has the automatic Nr+10 which automatically increases rotor speed by 10 rpm as the airspeed falls through 25 kts. With the system on, the aircraft is very smooth in the cockpit throughout the speed range (don't know anything about the cabin vibration level) and when it was turned off, there was a just-detectable increase in vibration when I was sitting in the right hand seat, but an undetectable change when I was sitting in the jump seat. EC say that the necessity for the generators is really only at medium speeds, say 90-110 kts where it gets a bit whoppy without them.
A 5 blade system does seem to be intrinsically smoother for some reason that only Nick could explain (but I'm sure won't, even though its on the S61!) so seems to be a more elegant solution rather than trying to beat the natural vibration of a 4-bladed system into submission.
When I flew both aircraft we were well below max weight, so which one turns out to be smoother in service is hard to say and will depend on other things such as ease of tracking/balancing etc. However until the verdict is announced, my money is on the 225 being smoother.