Hook failure in Switzerland
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Hook failure in Switzerland
After a deadly accident during logging operations on 29.07.2003 the swiss CAA closed now the investigations. On this sad day the logging hook opened unattended. The falling tree striked a man to death.
The Canam logging hook "60" failed during the whole test series by the swiss CAA. On all tests unattended openings occured although the hook is technical in good shape.
Switzerland will now try to banish the hook on international level. Of course the hook couldn't be used furthermore in Switzerland.
The Canam logging hook "60" failed during the whole test series by the swiss CAA. On all tests unattended openings occured although the hook is technical in good shape.
Switzerland will now try to banish the hook on international level. Of course the hook couldn't be used furthermore in Switzerland.
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I checked their website and found a note here that mentioned inadvertent releases with a certain option. Have you checked into that option? If you're using the "Conventional" design vice the "Keeperless" design, then it sounds like you've discovered a known issue.
Of course, one might also ask under what circumstance an external load was being flown over a person on the ground that he might be struck by a falling load?
Does anyone have any more complete information or reports on the accident and subsequent investigation. Also the regulatory environment that controls external load operations and ground personnel safety? I would be very interested in reading all the pertinent information.
Does anyone have any more complete information or reports on the accident and subsequent investigation. Also the regulatory environment that controls external load operations and ground personnel safety? I would be very interested in reading all the pertinent information.
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This is certainly an unfortunate accident. Uncommanded release is something that should never have happened. Other cargo hook companies build even their remote hooks to FAA standards to try and prevent this. Canam does not have any FAA STC approved cargo hooks. Although this is not required, it is a higher level of safety and that is what it's all about.
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mustangpilot, be careful making assumptions with what an STC means. It is not necessarily a higher safety standard or a better piece of equipment, it merely means that is has met specific certification criteria. There are numerous examples of pieces of equipment that have met certification criteria that then fail with disastrous consequence.
Thread Starter
Other cargo hook companies build even their remote hooks to FAA standards to try and prevent this. Canam does not have any FAA STC approved cargo hooks.
"The available documentation for placing the cargo hook on the market does not comply with the requirements laid down by the STEG (federal law concerning the safety of technical equipment and devices):
• No declaration of conformity in accordance with EC machinery directives
exists.
• No CE mark is applied."
"In tests it was possible to prove that the Canam C60 cargo hook has a faulty design."
25 pages of investigations including high speed camera tests.
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tecpilot, although I have no affiliation with this company, I'm really not comfortable with what you're saying. Testing was done and you found a fault that unfortunately led to a fatality. Saying that this product should be banned on the international level may be premature.
The other things that I'm seeing are that a company was using a mechanical device that was not approved for use in your country. People were located beneath the helicopter during logging operations (I know, it is done, but should it be?).
This company seems to have a lot of related product lines. Presumably, there is a lot of logging that is occurring with these products. Is this an isolated incident or is this something that has missed the eyes of the FAA of TC of NTSB, etc.? Since the company's website clearly indicates that one design is subject to inadvertent releases, was the operator in question aware of this fact? Presumably not considering the method of operation chosen.
You may be 100% right that the product should be withdrawn, but from what you've given here so far I don't think you should continue to attack this company's international market.
The other things that I'm seeing are that a company was using a mechanical device that was not approved for use in your country. People were located beneath the helicopter during logging operations (I know, it is done, but should it be?).
This company seems to have a lot of related product lines. Presumably, there is a lot of logging that is occurring with these products. Is this an isolated incident or is this something that has missed the eyes of the FAA of TC of NTSB, etc.? Since the company's website clearly indicates that one design is subject to inadvertent releases, was the operator in question aware of this fact? Presumably not considering the method of operation chosen.
You may be 100% right that the product should be withdrawn, but from what you've given here so far I don't think you should continue to attack this company's international market.
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mustangpilot, be careful making assumptions with what an STC means. It is not necessarily a higher safety standard or a better piece of equipment, it merely means that is has met specific certification criteria. There are numerous examples of pieces of equipment that have met certification criteria that then fail with disastrous consequence.
The fault of the operator is that they should never have purchased this hook and should have investigated the background of their vendors equipment first.
Thread Starter
Matthew,
if you think i attack a company try to accuse the swiss authorities.
This an official paper, including safety recommendations.
I have nothing added to the official words and if it is not desired to publish and to discuss such problems on a professional pilots network, we don't need such a forum.
In this case the swiss authorities found a technical part not proven designed. Thats the truth and it's real.
And also the next excerpt:
"At international level, the Federal Office for Civil Aviation should make an effort to prevent the use of the Canam C60 hook, on the basis of the exposed shortcomings."
"I don't think you should continue to attack this company's international market."
This an official paper, including safety recommendations.
I have nothing added to the official words and if it is not desired to publish and to discuss such problems on a professional pilots network, we don't need such a forum.
In this case the swiss authorities found a technical part not proven designed. Thats the truth and it's real.
And also the next excerpt:
"At international level, the Federal Office for Civil Aviation should make an effort to prevent the use of the Canam C60 hook, on the basis of the exposed shortcomings."
Thread Starter
Mustang, send me a PM with your usable Email adress. Seems i couldn't send attachments via PPRuNe Email function.
And we will see the report next time on official websites.
And we will see the report next time on official websites.
Last edited by tecpilot; 22nd Dec 2006 at 09:43.
MP,
I am by no means an expert, but have done some reserch into different hook styles for my employer.
As I understand it, the conventional style hooks (the ones with the tang sticking out) could be susceptible to load release if the wrong size/shape ring is used. Under unique circumstances the ring could get flipped over the tang and cause release. This is not just a possibility with Canam conventional hooks, but others as well.
The keeperless design has no tang for the ring to possibly get hooked on, so no inadvertent release. This appears to be the newer, improved design although it has what some may consider a drawback when it comes to hooking up the load. Instead of just slapping the ring on the hook the ground crew must insert the ring and then move it up to close the hook. It does not default to closed like the conventional design.
I'm not defending any particular design or brand. I just got the impression that you interpreted the description on the Canam website as admission of a known design flaw.
I am by no means an expert, but have done some reserch into different hook styles for my employer.
As I understand it, the conventional style hooks (the ones with the tang sticking out) could be susceptible to load release if the wrong size/shape ring is used. Under unique circumstances the ring could get flipped over the tang and cause release. This is not just a possibility with Canam conventional hooks, but others as well.
The keeperless design has no tang for the ring to possibly get hooked on, so no inadvertent release. This appears to be the newer, improved design although it has what some may consider a drawback when it comes to hooking up the load. Instead of just slapping the ring on the hook the ground crew must insert the ring and then move it up to close the hook. It does not default to closed like the conventional design.
I'm not defending any particular design or brand. I just got the impression that you interpreted the description on the Canam website as admission of a known design flaw.
Thread Starter
Tweedles,
It was shown during the test that the C60 hook couldn't withstand dynamic load processings.
Under theoretical circumstances a hook is statically loaded predominantly in the vertical or near vertical direction. During the "real life" means lifting loads trough the air dynamic and oscillate loads apply additionally. Eminently during logging operations but of course also on other slingload work it is absolute unavoidable that very shortime but mighty dynamic loads (strikes) interact with the hook. This could be amongst others during lifting the load, on rotating loads, during acceleration or decelleration or if two loads connected to the same hook beat each other.
To investigate by tests was how the locking mechanism of the hook reacts to different dynamic loads which are possible anytime in real life. Precise if the hook opened as a result of any forces on the cargo hook or as a result of lateral and/or rotational acceleration of the hook.
On independent test series this hook model opened under dynamic load factors due to the design.
"If the design solution of a “hinged joint closure with deflection” is retained, it is imperative to incorporate a mechanical safeguard which prevents the deflection from being overridden in the event of momentum due to the force of an impact. This means that the interlock mechanism must be additionally mechanically blocked to prevent rotation."
It was shown during the test that the C60 hook couldn't withstand dynamic load processings.
Under theoretical circumstances a hook is statically loaded predominantly in the vertical or near vertical direction. During the "real life" means lifting loads trough the air dynamic and oscillate loads apply additionally. Eminently during logging operations but of course also on other slingload work it is absolute unavoidable that very shortime but mighty dynamic loads (strikes) interact with the hook. This could be amongst others during lifting the load, on rotating loads, during acceleration or decelleration or if two loads connected to the same hook beat each other.
To investigate by tests was how the locking mechanism of the hook reacts to different dynamic loads which are possible anytime in real life. Precise if the hook opened as a result of any forces on the cargo hook or as a result of lateral and/or rotational acceleration of the hook.
On independent test series this hook model opened under dynamic load factors due to the design.
"If the design solution of a “hinged joint closure with deflection” is retained, it is imperative to incorporate a mechanical safeguard which prevents the deflection from being overridden in the event of momentum due to the force of an impact. This means that the interlock mechanism must be additionally mechanically blocked to prevent rotation."
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tecpilot, it was a word of caution. Additionally, by chopping the first part of my sentence you've changed what I said. I'll repeat, "...from what you've given here so far I don't think you should continue to attack this company's international market." Your call on what you wish to continue to say publicly. I'm sure the Swiss authorities will handle it properly.
tweedles, thanks for the info. I guess I do consider the "conventional" design to have an inherent design flaw. That's okay in this business, because many design flaws only have to be communicated to the customer so that the flaw can be operationally eliminated. For example, if the flaw is only when you use the wrong attachment rings, then tell everyone to use the right ones. If we demanded that everything be perfect even when not used according to manufacturers directions, then design costs would skyrocket.
mustangpilot. I'm not kidding you. McDonald's hamburgers meet quality control standards. That doesn't mean that they're better than the burger at your local greasy spoon. Just because the local greasy spoon hasn't applied for ISO9002 (or whatever) doesn't make it inferior. Additionally, if it has applied and failed, it merely means that it doesn't meet those standards (ie not enough pickles), again not necessarily inferior.
Specific to this argument is FAR 27.865 or FAR29.865. Essentially the hook has to withstand a static load of 2.5 times the maximum rated load, with the load applied vertically and applied at the maximum angle that can be achieved in service but not less than 30 degrees. Both those numbers can be reduced under certain conditions. I didn't see anything in there about dynamic loads.
tweedles, thanks for the info. I guess I do consider the "conventional" design to have an inherent design flaw. That's okay in this business, because many design flaws only have to be communicated to the customer so that the flaw can be operationally eliminated. For example, if the flaw is only when you use the wrong attachment rings, then tell everyone to use the right ones. If we demanded that everything be perfect even when not used according to manufacturers directions, then design costs would skyrocket.
mustangpilot. I'm not kidding you. McDonald's hamburgers meet quality control standards. That doesn't mean that they're better than the burger at your local greasy spoon. Just because the local greasy spoon hasn't applied for ISO9002 (or whatever) doesn't make it inferior. Additionally, if it has applied and failed, it merely means that it doesn't meet those standards (ie not enough pickles), again not necessarily inferior.
Specific to this argument is FAR 27.865 or FAR29.865. Essentially the hook has to withstand a static load of 2.5 times the maximum rated load, with the load applied vertically and applied at the maximum angle that can be achieved in service but not less than 30 degrees. Both those numbers can be reduced under certain conditions. I didn't see anything in there about dynamic loads.
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tecpilot, it was a word of caution. Additionally, by chopping the first part of my sentence you've changed what I said. I'll repeat, "...from what you've given here so far I don't think you should continue to attack this company's international market." Your call on what you wish to continue to say publicly. I'm sure the Swiss authorities will handle it properly.
tweedles, thanks for the info. I guess I do consider the "conventional" design to have an inherent design flaw. That's okay in this business, because many design flaws only have to be communicated to the customer so that the flaw can be operationally eliminated. For example, if the flaw is only when you use the wrong attachment rings, then tell everyone to use the right ones. If we demanded that everything be perfect even when not used according to manufacturers directions, then design costs would skyrocket.
mustangpilot. I'm not kidding you. McDonald's hamburgers meet quality control standards. That doesn't mean that they're better than the burger at your local greasy spoon. Just because the local greasy spoon hasn't applied for ISO9002 (or whatever) doesn't make it inferior. Additionally, if it has applied and failed, it merely means that it doesn't meet those standards (ie not enough pickles), again not necessarily inferior.
Specific to this argument is FAR 27.865 or FAR29.865. Essentially the hook has to withstand a static load of 2.5 times the maximum rated load, with the load applied vertically and applied at the maximum angle that can be achieved in service but not less than 30 degrees. Both those numbers can be reduced under certain conditions. I didn't see anything in there about dynamic loads.
tweedles, thanks for the info. I guess I do consider the "conventional" design to have an inherent design flaw. That's okay in this business, because many design flaws only have to be communicated to the customer so that the flaw can be operationally eliminated. For example, if the flaw is only when you use the wrong attachment rings, then tell everyone to use the right ones. If we demanded that everything be perfect even when not used according to manufacturers directions, then design costs would skyrocket.
mustangpilot. I'm not kidding you. McDonald's hamburgers meet quality control standards. That doesn't mean that they're better than the burger at your local greasy spoon. Just because the local greasy spoon hasn't applied for ISO9002 (or whatever) doesn't make it inferior. Additionally, if it has applied and failed, it merely means that it doesn't meet those standards (ie not enough pickles), again not necessarily inferior.
Specific to this argument is FAR 27.865 or FAR29.865. Essentially the hook has to withstand a static load of 2.5 times the maximum rated load, with the load applied vertically and applied at the maximum angle that can be achieved in service but not less than 30 degrees. Both those numbers can be reduced under certain conditions. I didn't see anything in there about dynamic loads.
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mustangpilot,
Your points are very valid. There should be safety standards, and there are. Restaurants might cause food poisoning in some people. If so, the restaurant is investigated to see how things happened. I believe that is what has happened in Switzerland, as it occurs in your country and mine.
The problem with analogies like I've introduced is they can lead to confusion. It appears I've done that. Safety and certification are closely related but frequently are dealt with seperately. Just because something is not certified does not mean it is unsafe, similiarly just because something is certified it doesn't mean it can't be dangerous. Many people have gotten food poisoning from restaurants that have passed public health inspection, and people do eat in places without adequate public health, without always getting sick (granted, not something I try to do too often).
I think an STC is a good way to go, but for cost and perhaps other reasons, some companies don't opt to go that way. That doesn't mean they're unsafe, nor uncertifiable. That's all I'm saying.
Perhaps we should agree that we disagree?
Happy Holidays!
Matthew.
Your points are very valid. There should be safety standards, and there are. Restaurants might cause food poisoning in some people. If so, the restaurant is investigated to see how things happened. I believe that is what has happened in Switzerland, as it occurs in your country and mine.
The problem with analogies like I've introduced is they can lead to confusion. It appears I've done that. Safety and certification are closely related but frequently are dealt with seperately. Just because something is not certified does not mean it is unsafe, similiarly just because something is certified it doesn't mean it can't be dangerous. Many people have gotten food poisoning from restaurants that have passed public health inspection, and people do eat in places without adequate public health, without always getting sick (granted, not something I try to do too often).
I think an STC is a good way to go, but for cost and perhaps other reasons, some companies don't opt to go that way. That doesn't mean they're unsafe, nor uncertifiable. That's all I'm saying.
Perhaps we should agree that we disagree?
Happy Holidays!
Matthew.
Last edited by Matthew Parsons; 22nd Dec 2006 at 21:26.
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dynamic loads are covered in paragraph (d) of FAR 29.865...
(d) The critically configured jettisonable external loads must be shown by a combination of analysis, ground tests, and flight tests to be both transportable and releasable throughout the approved operational envelope without hazard to the rotorcraft during normal flight conditions. In addition, these external loads—must be shown to be releasable without hazard to the rotorcraft during emergency flight conditions.
(d) The critically configured jettisonable external loads must be shown by a combination of analysis, ground tests, and flight tests to be both transportable and releasable throughout the approved operational envelope without hazard to the rotorcraft during normal flight conditions. In addition, these external loads—must be shown to be releasable without hazard to the rotorcraft during emergency flight conditions.
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Matthew
Sounds good but,
if you don't go at least through a certification process, if you don't test a product according to the latest test conditions and latest stand of knowledge, if you don't have a wide and meaningful documentation
how you could be know if a product is safe or unsafe?
Tragically now we know the problems with this part. Sure it's cheaper to have no STC, but anyone have to pay...
That doesn't mean they're unsafe, nor uncertifiable.
if you don't go at least through a certification process, if you don't test a product according to the latest test conditions and latest stand of knowledge, if you don't have a wide and meaningful documentation
how you could be know if a product is safe or unsafe?
Tragically now we know the problems with this part. Sure it's cheaper to have no STC, but anyone have to pay...
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Unfortunately this operator should have first checked with other hook operators about the Canam hooks. There are not very many. I actually don't know of any operators with Canam in the U.S. There is a reason for that......
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Quality Standards: MIL-1-45208A, MIL-C-45662, AQAP-1 (less 207), ISO 9002 Pending, transport Canada AMO pending
I took this off their site today. Now, I don't have any idea as to what exactly the various standards specify, but I am sure if they work to MIL then they will be working to the same standard as every other item made to that standard....... Or am I missing something here??
I took this off their site today. Now, I don't have any idea as to what exactly the various standards specify, but I am sure if they work to MIL then they will be working to the same standard as every other item made to that standard....... Or am I missing something here??