Main Gear Boxes and The Grand Lottery
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Mark 9
Hyperbole aside if such a gearbox weighed 100kg more (1 passenger) wouldn't the trade-off be worth it.
Many years ago I attended a course at Bristol University on helicopter design. One of the lecturers was the Westland head of transmission design who had just produced the Lynx 'conformal' gear system. I remember him saying that If we designed a helicopter gearbox using the design principles of a car gearbox then the helicopter would be too heavy to get airborne. That wasn't hyperbole because in those days car gearboxes were made of cast iron and hugely overengineered to achieve the rigidity needed to tolerate the poor accuracy of the machining used in mass production. These days a typical car gearbox is computer designed and the casting process uses minimal material and is probably made using a weight-saving alloy. Modern mass production also produces components made to very fine tolerances.
My point is that if the car industry can step up to the plate I'm sure the helicopter industry can too. My feeling is the reluctance to go down a new path that will take the current designers down a new path given that 30 years with the same basic design gives them a thorough understanding of the strengths and weaknesses of it. Why take the risk (and spend huge amounts of time and money) going down another pathway when there is no regulatory or customer pressure to change.
The progress made since HARP is unlikely to have been realised if manufacturers had been left to do their thing with no pressure from those that use and regulate their products.
Can a transmission designer add to the debate please.
G.
Many years ago I attended a course at Bristol University on helicopter design. One of the lecturers was the Westland head of transmission design who had just produced the Lynx 'conformal' gear system. I remember him saying that If we designed a helicopter gearbox using the design principles of a car gearbox then the helicopter would be too heavy to get airborne. That wasn't hyperbole because in those days car gearboxes were made of cast iron and hugely overengineered to achieve the rigidity needed to tolerate the poor accuracy of the machining used in mass production. These days a typical car gearbox is computer designed and the casting process uses minimal material and is probably made using a weight-saving alloy. Modern mass production also produces components made to very fine tolerances.
My point is that if the car industry can step up to the plate I'm sure the helicopter industry can too. My feeling is the reluctance to go down a new path that will take the current designers down a new path given that 30 years with the same basic design gives them a thorough understanding of the strengths and weaknesses of it. Why take the risk (and spend huge amounts of time and money) going down another pathway when there is no regulatory or customer pressure to change.
The progress made since HARP is unlikely to have been realised if manufacturers had been left to do their thing with no pressure from those that use and regulate their products.
Can a transmission designer add to the debate please.
G.
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If it can be done on a small civil machine (MD 902) why can't it be feasible, from a design point of view, for a larger helicopter?
I've not wrked on any of the MD products so cannot say if or why not. Off hand though, it would most likely do with the weight of the structure versus the AUW of the final machine versus expected payload/range/cost with cost probably being the decider as always.
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It Just Takes Money -- Get It From The Oil Companies!
Bless the souls that were lost, may the engineers figure out how to keep this from happening again and may the oil companies give them the cash to do it.
WAH,
We saw a presentation by Brian Larder of the results from the (then Smith's - but now GE) system at the CAA Helicopter Research Management Committee in May 2007 - following the six-month trial by Smiths and Bristow. Following that I cannot recollect seeing anything except a mention in the CAA Research Report:
Jim
We saw a presentation by Brian Larder of the results from the (then Smith's - but now GE) system at the CAA Helicopter Research Management Committee in May 2007 - following the six-month trial by Smiths and Bristow. Following that I cannot recollect seeing anything except a mention in the CAA Research Report:
Publish the final report on the development and demonstration of enhanced Health & Usage Monitoring System (HUMS) Vibration Health Monitoring (VHM) data analysis
The initial six-month in-service trial of the enhanced HUMS VHM data analysis with a major UK offshore operator concluded in November 2006. The trial was successful and highlighted a number of defects which the current analysis system did not identify, including instrumentation defects. Further enhancements to the system are being progressed and sponsored jointly by the FAA, CAA and UK industry. A further six month in-service trial, scheduled to complete by June 2008, will be undertaken once the key sections of this work have been completed.
Publication of the report has been deferred in order to incorporate the results of additional work identified and the six month trial extension.
The initial six-month in-service trial of the enhanced HUMS VHM data analysis with a major UK offshore operator concluded in November 2006. The trial was successful and highlighted a number of defects which the current analysis system did not identify, including instrumentation defects. Further enhancements to the system are being progressed and sponsored jointly by the FAA, CAA and UK industry. A further six month in-service trial, scheduled to complete by June 2008, will be undertaken once the key sections of this work have been completed.
Publication of the report has been deferred in order to incorporate the results of additional work identified and the six month trial extension.
Interesting read and time line WAH.
The HUMS graph appears to show the failure time line especially from 193 to 40, was this ignored \ filed due to lack of understanding I presume the times were inserted after failure of item, and with hind sight.
In 2001? was so little known that it did not raise questions in engendering\ HUMS department?.
As a pilot and engineer it would have made me ask the questions regarding the leap in readings at the 193+ point even if I did not understand the graph enough to pick out the previous information
The HUMS graph appears to show the failure time line especially from 193 to 40, was this ignored \ filed due to lack of understanding I presume the times were inserted after failure of item, and with hind sight.
In 2001? was so little known that it did not raise questions in engendering\ HUMS department?.
As a pilot and engineer it would have made me ask the questions regarding the leap in readings at the 193+ point even if I did not understand the graph enough to pick out the previous information
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Dieso, thanks for that snippet. My understanding of the event also came from the engineers - and at a pretty umimpeachable level too; I have little doubt that the AAIB report was, well, shall we say rather skewed?
Even so, infinitely more factual than the shamefully dishonest coverage by the repulsive local rag, the Aberdeen Press and Journal.
Even so, infinitely more factual than the shamefully dishonest coverage by the repulsive local rag, the Aberdeen Press and Journal.
WAH
Ref your post #64 I think you are on a different HUMS planet from us lot on the N Sea. There is no way that the tech log would have a deferred defect entry saying "dodgy HUMS M6* reading on gearwheel x, keeping an eye on it...". It might say that an element of the HUMS system itself was U/S, with a total of 25 flight hrs being allowed until the problem is fixed.
So your comments about pilots needing to be concerned about looking at HUMS trends is totally wide of the mark.
Regarding the Norne accident, I believe that HUMS was not mandatory in Norway at that time, and perhaps it was not taken as seriously as it should have been?
Its worth bearing in mind that engineering actions in the event of an adverse HUMS trend depends on the equipment manufacturer. For example, since the IHUMS system was invented by Bristow, when there is a HUMS issue on our 332L, S76A etc, we (our HUMS type engineer) will decide what to do about it. However if its EuroARMS or M'ARMS on an L2 or 225, as soon as an amber or red traffic light is produced by the groundstation, its straight on the phone to Eurocopter and they decide what to do about it.
But at no point in that loop is the pilot involved, nor should he be since he generally doesn't understand the issues and is in no position to decide whether the aircraft is serviceable or not.
Can I also point out that whilst you said
that presupposes that the thresholds were correctly set. A very brave assumption since the thresholds are generally set by guesswork, modified only in the light of excessive false alarms or failure to detect a failure. Its for this reason that the GE work is so important.
HC
Ref your post #64 I think you are on a different HUMS planet from us lot on the N Sea. There is no way that the tech log would have a deferred defect entry saying "dodgy HUMS M6* reading on gearwheel x, keeping an eye on it...". It might say that an element of the HUMS system itself was U/S, with a total of 25 flight hrs being allowed until the problem is fixed.
So your comments about pilots needing to be concerned about looking at HUMS trends is totally wide of the mark.
Regarding the Norne accident, I believe that HUMS was not mandatory in Norway at that time, and perhaps it was not taken as seriously as it should have been?
Its worth bearing in mind that engineering actions in the event of an adverse HUMS trend depends on the equipment manufacturer. For example, since the IHUMS system was invented by Bristow, when there is a HUMS issue on our 332L, S76A etc, we (our HUMS type engineer) will decide what to do about it. However if its EuroARMS or M'ARMS on an L2 or 225, as soon as an amber or red traffic light is produced by the groundstation, its straight on the phone to Eurocopter and they decide what to do about it.
But at no point in that loop is the pilot involved, nor should he be since he generally doesn't understand the issues and is in no position to decide whether the aircraft is serviceable or not.
Can I also point out that whilst you said
If HUMS was within the thresholds, then there's obviously nothing wrong
HC
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Gearbox IHUMS
I was not directly involved but I seem to remember that a system was being developed in the days before the Airlog intrusion that involved taking a downlog from the DAPU and transmitting it back to base on the flight positioning system to be monitored by the IHUMS engineer. This would occur about every ten minutes. There was also an inflight SOAP facility involving a laser snining through a transparent tube. I feel that this would be a more practical system than the pilot being confronted with a diluge of information.
"But at no point in that loop is the pilot involved, nor should he be since he generally doesn't understand the issues and is in no position to decide whether the aircraft is serviceable or not."
Why not!! he is the person who is responsible for the craft, who says he does not or should not be trained to understand at least the basic issues?.
Looking at the graph it would appear to me that there was a significant change in levels at 193, if I was confronted regularly with the typical daily graph & saw this steep increase I would want an explanation & want it before I flew.
It should be possible to produce a daily trend graph that shows the variation from the norm then changes such as that would stand out as an anomaly to be examined
Why not!! he is the person who is responsible for the craft, who says he does not or should not be trained to understand at least the basic issues?.
Looking at the graph it would appear to me that there was a significant change in levels at 193, if I was confronted regularly with the typical daily graph & saw this steep increase I would want an explanation & want it before I flew.
It should be possible to produce a daily trend graph that shows the variation from the norm then changes such as that would stand out as an anomaly to be examined
mtoroshanga
I was involved, and there was never any plan nor actuality of sending DAPU/ HUMS data by data link back to base. There was some trialling done of a full-flow spectrographic oil analysis system, but it was unsucessful. There was also a trial of an exhaust gas debris monitor (detecting metal swarf coming out of the engine exhaust) but again, unsucessful and in general the emphasis was on the health of the one gearbox, the two engines being less important.
500e - sorry, wrong planet. He is not the person that is responsible for the airworthiness of the aircraft - he is just responsible for driving it safely.
HC
I was involved, and there was never any plan nor actuality of sending DAPU/ HUMS data by data link back to base. There was some trialling done of a full-flow spectrographic oil analysis system, but it was unsucessful. There was also a trial of an exhaust gas debris monitor (detecting metal swarf coming out of the engine exhaust) but again, unsucessful and in general the emphasis was on the health of the one gearbox, the two engines being less important.
500e - sorry, wrong planet. He is not the person that is responsible for the airworthiness of the aircraft - he is just responsible for driving it safely.
HC
OK I had better change my point to WAH to being "I think you are on a different HUMS planet from Bristow".
I suspect that the fundamental difference might be that I believe CHC (?) has a paper techlog, whereas Bristow has a computer-based techlog that records almost everything except for what goes into the paper-based part of it which represents the exchange between the pilots and engineering. What we pilots call the techlog contains only such things as daily/turnround inspections, pilot signing for the aircraft, any pilot reported defects, any deferred defects, configuration changes, groundruns/airtests required etc. It has no information about maintenance work carried out on the aircraft except a number of hours to run to the next inspection.
But I am puzzled how you can allow an aircraft to fly with a HUMS parameter exceeding a threshold? As far as I know we never do that, unless its decided that the problem is a sensor rather than the transmission itself. I certainly don't see how you can have a deferred defect that calls into question the airworthiness of the transmission. That is definitely not in the MMEL!
Are there any pilots out there from WAH and Mitchaa's company that would care to comment on whether they see and are in a position to interpret HUMS trend data and over-ride an engineering decision?
(WAH - posts crossed but never mind!)
HC
I suspect that the fundamental difference might be that I believe CHC (?) has a paper techlog, whereas Bristow has a computer-based techlog that records almost everything except for what goes into the paper-based part of it which represents the exchange between the pilots and engineering. What we pilots call the techlog contains only such things as daily/turnround inspections, pilot signing for the aircraft, any pilot reported defects, any deferred defects, configuration changes, groundruns/airtests required etc. It has no information about maintenance work carried out on the aircraft except a number of hours to run to the next inspection.
But I am puzzled how you can allow an aircraft to fly with a HUMS parameter exceeding a threshold? As far as I know we never do that, unless its decided that the problem is a sensor rather than the transmission itself. I certainly don't see how you can have a deferred defect that calls into question the airworthiness of the transmission. That is definitely not in the MMEL!
Are there any pilots out there from WAH and Mitchaa's company that would care to comment on whether they see and are in a position to interpret HUMS trend data and over-ride an engineering decision?
(WAH - posts crossed but never mind!)
HC
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HUMS, GE neural model, existing flight instrumentation, new gearbox design. We can always improve from where we are today...
As an engineer I am used to embracing new technology. Too much information or too little knowledge is dangerous, but with proper system engineering and end-user training I can see how SKY and EC should be able to improve on their existing condition monitoring systems.
What what I've gleaned on the various threads the technology is there, it just needs to be firmed up to better provide the engineer and ultimately the end-user (flight commander) pre-flight check data to decide if the equipment is serviceable and as safe as reasonably practicable.
Is it not better to err on the side of caution e.g. if HUMS thresholds are exceeded because they are not "tuned" then surely non-acceptance of helos by engineers and pilots will up the ante to get this issue resolved. If this methodology is impractical then the GE prototype system should be further developed to enhance the current available HUMS threshold setting methodology.
Who pays for this way forward? Might I suggest a joint venture between the operators, helo manufacturers and the oil companies, who generally end up owning the helos and leasing them out to the operators.
It also sounds like various operators are applying HUMS exceedences differently. Why is there no synergy here, surely the system design is universal, therefore the executive actions should also be? Collectively there must be enough collated historical HUMS data globally to allow the manufacturers to issue better guidelines and thresholds, even to the level of each helo's custom thresholds, or is the onus squarely on the operator's HUMS support team?
It seems crazy that SKY is only now developing an updated MGB to satisfy their Canadian military contract obligations versus having this capability for the S-92a units. Prevention is better than cure, especially when their 1 x10^9 extremely remote classification is gone....
As an engineer I am used to embracing new technology. Too much information or too little knowledge is dangerous, but with proper system engineering and end-user training I can see how SKY and EC should be able to improve on their existing condition monitoring systems.
What what I've gleaned on the various threads the technology is there, it just needs to be firmed up to better provide the engineer and ultimately the end-user (flight commander) pre-flight check data to decide if the equipment is serviceable and as safe as reasonably practicable.
Is it not better to err on the side of caution e.g. if HUMS thresholds are exceeded because they are not "tuned" then surely non-acceptance of helos by engineers and pilots will up the ante to get this issue resolved. If this methodology is impractical then the GE prototype system should be further developed to enhance the current available HUMS threshold setting methodology.
Who pays for this way forward? Might I suggest a joint venture between the operators, helo manufacturers and the oil companies, who generally end up owning the helos and leasing them out to the operators.
It also sounds like various operators are applying HUMS exceedences differently. Why is there no synergy here, surely the system design is universal, therefore the executive actions should also be? Collectively there must be enough collated historical HUMS data globally to allow the manufacturers to issue better guidelines and thresholds, even to the level of each helo's custom thresholds, or is the onus squarely on the operator's HUMS support team?
It seems crazy that SKY is only now developing an updated MGB to satisfy their Canadian military contract obligations versus having this capability for the S-92a units. Prevention is better than cure, especially when their 1 x10^9 extremely remote classification is gone....
We are obviously following different procedure paths, but yes you are correct we fly our aircraft with exceedances above thresholds every day otherwise they would never get off the ground. I would be mightily surprised if you did not either as exceedances are regular occurences.
Either way, I see no reason why the pilot should get involved in the process, and don't believe the logic bears much scrutiny. The same logic would apply to wear tolerances on mechanical componants, leak rates, crack propogation etc etc.
WAH et al,
Here is the latest position on the GE system:
The GE Aviation meeting referred to in the briefing is to be held at Aberdeen on the 29th April - the AAIB have been invited.
212man, I totally agree with your statements on this - these are not matter for the casual consideration of pilots; HUMS are complex systems - too complex in fact, the setting of the threshholds is more of an art than science and awaits the development of appropriate systems for trend and cluster modelling.
If the aircraft is declared servicable in the tech-log (or substitute) and satisfies the contraints of the MEL it is fit to go - only issues discovered on the preflight walk-around and during start-up (and, of course, operational considerations) are within the remit of the pilot.
Jim
Here is the latest position on the GE system:
Current work comprises an in-service demonstration of an Artificial Intelligence (AI) based anomaly detection and diagnostic system to enhance the performance of current HUMS. A demonstration system covering all 35 shafts in the Super Puma main rotor, accessory, intermediate and tail rotor gearboxes has been developed and tested using all available IHUMS data up to March 2006. The first six-month in-service trial of the system at Bristow Helicopters was completed in November 2006 and was very successful. Further enhancements to the system were identified, developed and implemented in the trials system, largely under FAA funding, and a further six-month in-service trial undertaken which was completed in June 2008. The results of this trial demonstrated further improvement. The final two research tasks covering data mining and data reasoning have been completed and are to be reported by end March. A final summary report is to be produced for publication in the public domain in the summer. The last progress meeting with GE Aviation took place on 15 January 2009; the next is scheduled for 29 April 2009.
Presentations on this work were given by GE Aviation at the 10 June 2008 Oil & Gas UK ASTG Symposium and at the 11/12 June 2008 RAeS Maritime Operations of Rotorcraft conference. A paper proposing full implementation of the research was presented to the Oil & Gas UK Board on 15 October 2008 and approved. GE Aviation will be progressing implementation via OEMs for aircraft with OEM supplied HUMS, and this would be assisted if a clear indication of ‘customer’ demand were available. GE Aviation will deal with helicopter operators direct for ‘legacy’ HUMS. GE Aviation is proposing to hold a seminar in Aberdeen to help launch implementation.
Presentations on this work were given by GE Aviation at the 10 June 2008 Oil & Gas UK ASTG Symposium and at the 11/12 June 2008 RAeS Maritime Operations of Rotorcraft conference. A paper proposing full implementation of the research was presented to the Oil & Gas UK Board on 15 October 2008 and approved. GE Aviation will be progressing implementation via OEMs for aircraft with OEM supplied HUMS, and this would be assisted if a clear indication of ‘customer’ demand were available. GE Aviation will deal with helicopter operators direct for ‘legacy’ HUMS. GE Aviation is proposing to hold a seminar in Aberdeen to help launch implementation.
212man, I totally agree with your statements on this - these are not matter for the casual consideration of pilots; HUMS are complex systems - too complex in fact, the setting of the threshholds is more of an art than science and awaits the development of appropriate systems for trend and cluster modelling.
If the aircraft is declared servicable in the tech-log (or substitute) and satisfies the contraints of the MEL it is fit to go - only issues discovered on the preflight walk-around and during start-up (and, of course, operational considerations) are within the remit of the pilot.
Jim
Last edited by JimL; 16th Apr 2009 at 13:04.
The graph shown early in the thread shows a large upward trend, are people saying that the manufacturers said this was within tolerances?? or the HUMMS was faulty ??.
If we say the indication was correct (as it turned out) why was it not acted upon or if a fault rectified as a matter of urgency.
Why is it not OK for the person strapping themselves in to ask questions about ANY method that helps make flying safer, I do not think or expect all pilots to understand in depth the system but there should be a custom graph showing expected readings and if the days \ flights data shows a marked deviation engineering should be there to explain.
HeliComparator why bother with walk round check then, you says can I fly it safely, if I am current this should be taken as read, as don't want to die so my walk round will as thorough as I can make it & any further information that is available will be factored into the go\ no go equation.
maxwelg2 The comments posted by you seem to be along the same lines as I think, everyone should be in the loop if you remove 1 link the whole chain is broken.
If we say the indication was correct (as it turned out) why was it not acted upon or if a fault rectified as a matter of urgency.
Why is it not OK for the person strapping themselves in to ask questions about ANY method that helps make flying safer, I do not think or expect all pilots to understand in depth the system but there should be a custom graph showing expected readings and if the days \ flights data shows a marked deviation engineering should be there to explain.
HeliComparator why bother with walk round check then, you says can I fly it safely, if I am current this should be taken as read, as don't want to die so my walk round will as thorough as I can make it & any further information that is available will be factored into the go\ no go equation.
maxwelg2 The comments posted by you seem to be along the same lines as I think, everyone should be in the loop if you remove 1 link the whole chain is broken.
Thread Starter
The British Walkaround Inspection does not an American Preflight Inspection make!
I was looked at with great disdain when I began to open cowlings and the like and was told "that just isn't the done thing, mate!"
At some operations there was no need to even do the walkaround ( of either type) but at some it was amazing what could be found lurking within the cowlings.
On one occasion I pulled a full bed sheet out of a hidey hole underneath the tail rotor drive shaft on a Bell 212. The reaction to my demanding a proper inspection of the aircraft by the engineering staff was interesting to say the least....and not because it was based upon a lot of embarrassment or professional concern.
A second interesting event was looking over the aircraft after a tail rotor change and airtest and a signed release for flight (as indicated by the tech log) to see one of the tail rotor pitch change links dangling loose from one end.
I was looked at with great disdain when I began to open cowlings and the like and was told "that just isn't the done thing, mate!"
At some operations there was no need to even do the walkaround ( of either type) but at some it was amazing what could be found lurking within the cowlings.
On one occasion I pulled a full bed sheet out of a hidey hole underneath the tail rotor drive shaft on a Bell 212. The reaction to my demanding a proper inspection of the aircraft by the engineering staff was interesting to say the least....and not because it was based upon a lot of embarrassment or professional concern.
A second interesting event was looking over the aircraft after a tail rotor change and airtest and a signed release for flight (as indicated by the tech log) to see one of the tail rotor pitch change links dangling loose from one end.
500e
I bother to walkround because its a required part of the maintenance schedule/pilots preflight check as detailed in the Flight Manual.
I can't help thinking that you have never actually looked at a HUMS groundstation. On the EC225 M'ARMS system for example, it monitors over 30 items in the transmission. For each of these items, there are on average about 10 different parameters to be graphed. Are you saying that before you go flying you want to check each of those 300 graphs? You had better come in early for your 07:00 departure then!
On the other hand, are you saying that you will allow the experienced licenced engineers trained in HUMS to trawl through the data, find a dodgy looking graph that in fact they asess as OK, show it to you so that you can say
"I don't care that I am not a licenced engineer, I haven't done the HUMS course, I have no experience of looking at HUMS graphs, but nevertheless I disagree with your assessment and refuse to fly the aircraft"?
If so you would have a very unhappy existance if you worked for a mainstream operator. This is my last response on this matter.
HC
I bother to walkround because its a required part of the maintenance schedule/pilots preflight check as detailed in the Flight Manual.
I can't help thinking that you have never actually looked at a HUMS groundstation. On the EC225 M'ARMS system for example, it monitors over 30 items in the transmission. For each of these items, there are on average about 10 different parameters to be graphed. Are you saying that before you go flying you want to check each of those 300 graphs? You had better come in early for your 07:00 departure then!
On the other hand, are you saying that you will allow the experienced licenced engineers trained in HUMS to trawl through the data, find a dodgy looking graph that in fact they asess as OK, show it to you so that you can say
"I don't care that I am not a licenced engineer, I haven't done the HUMS course, I have no experience of looking at HUMS graphs, but nevertheless I disagree with your assessment and refuse to fly the aircraft"?
If so you would have a very unhappy existance if you worked for a mainstream operator. This is my last response on this matter.
HC
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"I don't care that I am not a licenced engineer, I haven't done the HUMS course, I have no experience of looking at HUMS graphs, but nevertheless I disagree with your assessment and refuse to fly the aircraft"?
Using the available tools to maximum advantage is the only way to move this technology forward.
Everybody from the HUMS engineer to the pilot to the PAX should have confidence that the condition monitoring and preventative maintenance schedules are as good as they can be within our current technological (and budgetary) limits. If this means being able to present the data in laymans terms/with minimal additional training then so be it.
Post-diagnosis is key to preventing future occurrences. My current perception is that HUMS is not user-friendly enough to be confidently used and does not have a universal application structure, hence differing interpretations of the data sets. Until that is resolved I'd rather trust the invasive inspections via boroscope and increased inspection frequency on critical items as/where required.
maxwelg2
I quite agree on that one - as I said in an earlier post, we invented IHUMS in 1990 and it was a great step forward, but since then there has been no real progress (and in some ways, some of the newer OEM HUMS systems are not as good as IHUMS). It still behaves a bit like a research project with "black art" and "interpretation" being key concepts. It needs a complete rethink in terms of the usability to bring it into mainstream, but of course that takes money, which is never available (despite oil at $140) until after some people have died.
HC
I quite agree on that one - as I said in an earlier post, we invented IHUMS in 1990 and it was a great step forward, but since then there has been no real progress (and in some ways, some of the newer OEM HUMS systems are not as good as IHUMS). It still behaves a bit like a research project with "black art" and "interpretation" being key concepts. It needs a complete rethink in terms of the usability to bring it into mainstream, but of course that takes money, which is never available (despite oil at $140) until after some people have died.
HC