What should the relationship between RAAus and CASA be?

[kaz3g]

The relationship between RAAus and CASA is a contractual one with the contract being in the form of a deed. CASA holds RAAus to account by auditing the latters performance. CASA holds the regulatory power under the Act granted by Parliament and, as Don said, RAAus is nothing but an advocacy body without the grant.

 

RAAus, the incorporated association, needs to conduct itself and discharge its obligations under the deed in a mature and professional manner. It has been sadly underachieving in both areas, at least for some considerable time. I can't help thinking that the RPL may well in part be a reflection of CASA's disappointment with RAAus and its abysmal performance.

 

RAAus, the members, should all recall that CASA is the Authority and has officers who no doubt follow discussions such as these very closely. Conversations should also therefore be mature and professional and not used simply as a means of railing against the regulator; something that seems to happen far too often in my view. This isn't to say that fair criticism should be avoided or that better ways of achieving high safety standards should not be proposed but they should be done recognising the facts of RAA's underperformance and the need for improvement.

 

 

[kgwilson]

I can't help thinking that the RPL may well in part be a reflection of CASA's disappointment with RAAus and its abysmal performance.

I can't see that at all. RPL has been around for more than 5 years across the Tasman. To me CASA is so obsessed with bureaucracy and regulation to protect its own axx that it takes the most conservative approach & watches what everyone else does, waits for the results or fallout before taking any decisive action.

 

 

[Guest Maj Millard]

The relationship between RAAus and CASA is a contractual one with the contract being in the form of a deed. CASA holds RAAus to account by auditing the latters performance. CASA holds the regulatory power under the Act granted by Parliament and, as Don said, RAAus is nothing but an advocacy body without the grant.RAAus, the incorporated association, needs to conduct itself and discharge its obligations under the deed in a mature and professional manner. It has been sadly underachieving in both areas, at least for some considerable time. I can't help thinking that the RPL may well in part be a reflection of CASA's disappointment with RAAus and its abysmal performance.

 

RAAus, the members, should all recall that CASA is the Authority and has officers who no doubt follow discussions such as these very closely. Conversations should also therefore be mature and professional and not used simply as a means of railing against the regulator; something that seems to happen far too often in my view. This isn't to say that fair criticism should be avoided or that better ways of achieving high safety standards should not be proposed but they should be done recognising the facts of RAA's underperformance and the need for improvement.

Kaz, We are not here to be subservient to CASA, they are after all nothing more than public servants with a job to serve the aviation community in this country. Unfortunatly their current charter doesn't include fostering the continuing growth and improvement of aviation in this country, which is often a high priority in other countries where they are smart enough to have realised the value of a healthy aviation scene. They are being paid their healthy wages with our tax dollars, and we have a right in this country to freely enjoy the sport of our choosing. It's their job to facilitate that..........Maj....

 

 

[Guest Andys@coffs]

Kaz, We are not here to be subservient to CASA........

Keep telling yourself that ....who knows in time if you say it enough it might even turn out that way.....

 

Meanwhile the rest of us will live within the reality that is the exact opposite of that as CASA has already proven once by suspending our ability to register....but its a good thing we weren't taking it lying down!...well some of us might have been ..........cause hell we sure weren't flyin around, hey!

 

After all they have a big book of rules.. against each rule there is a penalty levied if you choose to feel the need to be not subservient at any particular point in time...we on the other hand have a big....but completely empty book we can wave at them tit for tat!

 

Andy

 

 

[Dafydd Llewellyn]

There seems to me to be a good argument for putting the RAA maintenance system on a less shaky basis. That is, take some steps to ensure that it can withstand serious scrutiny. The SOLE really important thing that the RAA system allows, is DIY maintenance. As Nev pointed out, an aircraft owner/pilot has high motivation. How about providing him with some real knowledge? For example, how many L2s have a copy of FAA AC 43.13-1? How many maintenance courses does RAA conduct, and what accreditation does it give attendees? I'm not an L2 so I do not know the answer to these questions - but I do know something of how the GFA system used to function in the 1980s; the GFA published National Gliding School course notes, which were valuable maintenance information. I've never seen anything equivalent from RAA. Yes, that was then and this is now - but if it comes to the crunch - and Don Ramsay is correct about how little that would take - then giving the L2 setup some real credibility should be a high priority, I'd have thought. Not my problem - but I suggest you people think about it instead of waving your arms. For a start, how is the Tech Manager going to cope with this as well as the registration issue and his other duties?

 

 

[DonRamsay]

If RA-Aus is to be able to logically argue that L1 and L2 maintenance should continue as it is then it has to have reasonable evidence that this is a safe system of maintenance compared with the fully "professional" LAME system.

 

There is I would suggest, zero evidence to support L1 maintenance other than there has not been a statistical trail of carnage related to poor L1 maintenance (although Jabiru engine maintainers might be proving otherwise). The lack of failures due to poor L1 maintenance may have more to do with luck and the fact that pretty well everyone over 50 has lived through a time when car engines were simple and owner maintenance was typical.

 

Compare then the young person coming to Rec Flying who has never as much as changed a spark plug on a lawnmower who assiduously learns to fly and is awarded L1 maintenance privileges with zero knowledge/skill testing.

 

How often in recent years have L2s had to do the maintenance equivalent of a BFR? How many got their L2 as a sweetheart deal with an obliging Tech Manager? I know of one L3 (a former long-serving Board Member) that I wouldn't let near my lawnmower (if i owned one).

 

Professionalism is something that, unfortunately, we don't automatically associate with RA-Aus, the organisation that has administered amateur aviation for 30 years. Like it or lump it, if RA-Aus does not become professional we will lose the privileges that were so hard won by the pioneers - albeit in easier times.

 

Like FactHunter and others have said, without owner (or L2) Maintenance RA-Aus loses its reason for being.

 

RA-Aus has an obligation to its members to continually provide CASA with the comfort of knowing Recreational Aviation is being administered with a high regard for and achievement of practical safety. We have not done that, I would suggest, for much of the last few years. And who knows that better than Lee Ungermann and his boss Jonathan Aleck?

 

 

[Dafydd Llewellyn]

If RA-Aus is to be able to logically argue that L1 and L2 maintenance should continue as it is then it has to have reasonable evidence that this is a safe system of maintenance compared with the fully "professional" LAME system.There is I would suggest, zero evidence to support L1 maintenance other than there has not been a statistical trail of carnage related to poor L1 maintenance (although Jabiru engine maintainers might be proving otherwise). The lack of failures due to poor L1 maintenance may have more to do with luck and the fact that pretty well everyone over 50 has lived through a time when car engines were simple and owner maintenance was typical.

 

Compare then the young person coming to Rec Flying who has never as much as changed a spark plug on a lawnmower who assiduously learns to fly and is awarded L1 maintenance privileges with zero knowledge/skill testing.

 

How often in recent years have L2s had to do the maintenance equivalent of a BFR? How many got their L2 as a sweetheart deal with an obliging Tech Manager? I know of one L3 (a former long-serving Board Member) that I wouldn't let near my lawnmower (if i owned one).

 

Professionalism is something that, unfortunately, we don't automatically associate with RA-Aus, the organisation that has administered amateur aviation for 30 years. Like it or lump it, if RA-Aus does not become professional we will lose the privileges that were so hard won by the pioneers - albeit in easier times.

 

Like FactHunter and others have said, without owner (or L2) Maintenance RA-Aus loses its reason for being.

 

RA-Aus has an obligation to its members to continually provide CASA with the comfort of knowing Recreational Aviation is being administered with a high regard for and achievement of practical safety. We have not done that, I would suggest, for much of the last few years. And who knows that better than Lee Ungermann and his boss Jonathan Aleck?

Don, I entirely agree apart from one point: I suggest it is not LAME maintenance that RAA needs to match (no hope of that; you'd have to go a fair way towards what is in CARs Part 4 &4A); but the GFA system - which would be a practical possibility. I strongly suggest you talk to Trevor Bange on this subject.

 

 

[M61A1]

Compare then the young person coming to Rec Flying who has never as much as changed a spark plug on a lawnmower who assiduously learns to fly and is awarded L1 maintenance privileges with zero knowledge/skill testing.

Perhaps then L1 maintenance should be part of the student pilot training and assessment.

[kaz3g]

Kaz, We are not here to be subservient to CASA, they are after all nothing more than public servants with a job to serve the aviation community in this country. Unfortunatly their current charter doesn't include fostering the continuing growth and improvement of aviation in this country, which is often a high priority in other countries where they are smart enough to have realised the value of a healthy aviation scene. They are being paid their healthy wages with our tax dollars, and we have a right in this country to freely enjoy the sport of our choosing. It's their job to facilitate that..........Maj....

I'm afraid I disagree, Maj. The job that CASA has is to implement the relevant legislation and that has nothing to do with "serving" the aviation community. It's all about keeping the flying public safe.

 

The legislation unfortunately does not, as you say, extend to the promotion of aviation per se and if you truly believe that you have a right to "freely" enjoy your sport outside the control of the regulator you are very sadly mistaken indeed.

 

Rights are always accompanied by Responsibilities, Maj. RAA was given responsibility for licensing and registration according to set rules and its track record thus far is a long way from good. It's rights to "licence" pilots of lighter aircraft for tv relational purposes is hanging in the balance right now and, in my view, its monopoly is severely dented by the advent of the RPL.

 

Why would you register your home built pride and joy with RAA when you can go VH Experimental and enjoy a one off rego and licence fee and still maintain it?

 

Why should CASA continue to cop flack from the legislators when an awful lot of aviation accidents involve RAA aircraft. I haven't kept count but 2013 has not been a good year!

 

Kaz

 

 

[coljones]

I'm afraid I disagree, Maj. The job that CASA has is to implement the relevant legislation and that has nothing to do with "serving" the aviation community. It's all about keeping the flying public safe.The legislation unfortunately does not, as you say, extend to the promotion of aviation per se and if you truly believe that you have a right to "freely" enjoy your sport outside the control of the regulator you are very sadly mistaken indeed.

 

Rights are always accompanied by Responsibilities, Maj. RAA was given responsibility for licensing and registration according to set rules and its track record thus far is a long way from good. It's rights to "licence" pilots of lighter aircraft for tv relational purposes is hanging in the balance right now and, in my view, its monopoly is severely dented by the advent of the RPL.

 

Why would you register your home built pride and joy with RAA when you can go VH Experimental and enjoy a one off rego and licence fee and still maintain it?

 

Why should CASA continue to cop flack from the legislators when an awful lot of aviation accidents involve RAA aircraft. I haven't kept count but 2013 has not been a good year!

 

Kaz

It is also about keeping the non-flying public safe as we fly over their heads and property.

 

 

[facthunter]

Single engine planes operating into places like Bankstown and Moorabbin that fly over populated areas are of more concern, realistically. Lately there has been a lot of failures due to having not enough fuel on board. The standard generally would not be good or certainly not improving.. The average person is not as "savvy' with mechanical things as they used to be, that would be a fact. Perhaps this has to be addressed as I can't imagine how we can totally make up for it. As Dafydd says it is a throw away white goods society. Whether an aeroplane could operate as a use and chuck away article is hard to imagine. To be safe it would have to be very sophisticated with inbuilt strain indicators or such to get away from the idea of inspections of the structure, which by it's very nature and use can be subject to overloads. Complexity is the opposite of the way we want to go. GA aircraft deteriorate to an unsafe condition easily too. Lying idle , exposed to rain hail . Water entering the fuel system Cylinder and valve stems rusting.

 

The individual owner/pilot MUST have the responsibility to maintain the plane even IF they don't have the ability themselves. IF they can't do it they must find someone else who has the skill and is prepared/ WILLING to do it. Whilst a LAME might be expected to maintain an LSA or factory built plane how could most of them want to or be able to repair planes that are more one-off? ( and who really knows what "life" they might be expected to achieve, when things like corrosion protection are hardly addressed?) in some builds. A pipe frame fuselage with interconnected members that is pressurised with nitrogen is an example of a self test structure. A crack will let the gas out . Nev.

 

 

[ruffasguts]

If RA-Aus is to be able to logically argue that L1 and L2 maintenance should continue as it is then it has to have reasonable evidence that this is a safe system of maintenance compared with the fully "professional" LAME system.There is I would suggest, zero evidence to support L1 maintenance other than there has not been a statistical trail of carnage related to poor L1 maintenance (although Jabiru engine maintainers might be proving otherwise). The lack of failures due to poor L1 maintenance may have more to do with luck and the fact that pretty well everyone over 50 has lived through a time when car engines were simple and owner maintenance was typical.

 

Compare then the young person coming to Rec Flying who has never as much as changed a spark plug on a lawnmower who assiduously learns to fly and is awarded L1 maintenance privileges with zero knowledge/skill testing.

 

How often in recent years have L2s had to do the maintenance equivalent of a BFR? How many got their L2 as a sweetheart deal with an obliging Tech Manager? I know of one L3 (a former long-serving Board Member) that I wouldn't let near my lawnmower (if i owned one).

 

Professionalism is something that, unfortunately, we don't automatically associate with RA-Aus, the organisation that has administered amateur aviation for 30 years. Like it or lump it, if RA-Aus does not become professional we will lose the privileges that were so hard won by the pioneers - albeit in easier times.

 

Like FactHunter and others have said, without owner (or L2) Maintenance RA-Aus loses its reason for being.

 

RA-Aus has an obligation to its members to continually provide CASA with the comfort of knowing Recreational Aviation is being administered with a high regard for and achievement of practical safety. We have not done that, I would suggest, for much of the last few years. And who knows that better than Lee Ungermann and his boss Jonathan Aleck?

L3 is not a maintenance authority

 

Mick W

 

 

[Dafydd Llewellyn]

I'm afraid I disagree, Maj. The job that CASA has is to implement the relevant legislation and that has nothing to do with "serving" the aviation community. It's all about keeping the flying public safe.The legislation unfortunately does not, as you say, extend to the promotion of aviation per se and if you truly believe that you have a right to "freely" enjoy your sport outside the control of the regulator you are very sadly mistaken indeed.

 

Rights are always accompanied by Responsibilities, Maj. RAA was given responsibility for licensing and registration according to set rules and its track record thus far is a long way from good. It's rights to "licence" pilots of lighter aircraft for tv relational purposes is hanging in the balance right now and, in my view, its monopoly is severely dented by the advent of the RPL.

 

Why would you register your home built pride and joy with RAA when you can go VH Experimental and enjoy a one off rego and licence fee and still maintain it?

 

Why should CASA continue to cop flack from the legislators when an awful lot of aviation accidents involve RAA aircraft. I haven't kept count but 2013 has not been a good year!

 

Kaz

Why, indeed? Not this little black duck, certainly.

 

 

[M61A1]

L3 is not a maintenance authorityMick W

RAAus tech manual sect 4.1 say's it is.

 

 

[Dafydd Llewellyn]

Single engine planes operating into places like Bankstown and Moorabbin that fly over populated areas are of more concern, realistically. Lately there has been a lot of failures due to having not enough fuel on board. The standard generally would not be good or certainly not improving.. The average person is not as "savvy' with mechanical things as they used to be, that would be a fact. Perhaps this has to be addressed as I can't imagine how we can totally make up for it. As Dafydd says it is a throw away white goods society. Whether an aeroplane could operate as a use and chuck away article is hard to imagine. To be safe it would have to be very sophisticated with inbuilt strain indicators or such to get away from the idea of inspections of the structure, which by it's very nature and use can be subject to overloads. Complexity is the opposite of the way we want to go. GA aircraft deteriorate to an unsafe condition easily too. Lying idle , exposed to rain hail . Water entering the fuel system Cylinder and valve stems rusting.The individual owner/pilot MUST have the responsibility to maintain the plane even IF they don't have the ability themselves. IF they can't do it they must find someone else who has the skill and is prepared/ WILLING to do it. Whilst a LAME might be expected to maintain an LSA or factory built plane how could most of them want to or be able to repair planes that are more one-off? ( and who really knows what "life" they might be expected to achieve, when things like corrosion protection are hardly addressed?) in some builds. A pipe frame fuselage with interconnected members that is pressurised with nitrogen is an example of a self test structure. A crack will let the gas out . Nev.

I was, actually, trying to make the point that drifting all the way to the "whitegoods" approach is a pretty horrendous scenario; it makes flying the prerogative of a wealthy few, in fact. The whole basis of the RAA has been affordable flying; the key to that is a really competent DIY maintenance ethos. That being so, I do not understand why you people are not jumping up and down to defend the L2 system - which in fact means it needs a serious shake-up, I suspect, because at present I doubt it would survive serious scrutiny. GA aircraft in the past had an economic life of about 40 years - i.e. at least double the life of most motor vehicles. The "throw-away" society suits manufacturers down to the ground; it's the ultimate expression of planned obsolescence, which started before WW2 as Rooseveldt's "new deal". We cannot afford it any more; it's time to start building consumer products that last longer. That will only happen if the consumers demand it. If you keep buying rubbish, you will keep having rubbish served up. This ethos also demands a high grade of maintenance practice. The GA maintenance system provides this, but it came into being (and its associated rules did also) in order to maintain aircraft built very much in the manner of WW2 military aircraft. That style is obsolescent, and so are the maintenance procedures that go with it, to a large degree.

 

As Nev points out, it is quite possible to design aircraft with damage-tolerant structure; in fact that is obligatory for Transport-category aircraft nowadays. Almost no light GA aircraft and no recreational aircraft of my knowledge has this; it costs more to certificate than a single load-path structure. Very few (if any) recreational aircraft have a published safe fatigue life; though it's quite possible to do so.

 

No manufacturer will incorporate such features unless his competition is forced to do likewise, because the bloody stupid customers (that's you lot) always buy the cheapest thing with the snazziest paint job. So it won't get better until or unless sufficient of the consumers get sufficient maintenance know-how to demand better-built aircraft. So there is no hope of turning this overall "whitegoods" trend around that does not involve better maintenance training of as many potential purchasers as possible.

 

So if RAA has a future at all, it will need to focus on upgrading the L2 maintenance system - because that way the buyers will be much better informed.

 

So - what are you all waiting for?

 

 

[M61A1]

A question for Dafydd.

 

As an engineer, do you think that at some stage, not too far down track, that we will begin to have a bunch of fatigue related issues on some of these very lightly designed but flash aircraft?

 

I've seen some really nice but really lightly built aircraft and I've often wondered whether or not some kind of fatigue life was part of the manufacturers engineering calculations.

 

 

[DonRamsay]

RAAus tech manual sect 4.1 say's it is.

RA-Aus MAINTENANCE AUTHORITIES

2. Four levels of RA-Aus Maintenance Authority may be granted to RA-Aus

 

members:

 

c. Level Three: for suitable persons to act as regional supervisors, coordinators and

 

points of contact for maintenance activities.

 

 

[DonRamsay]

Don, I entirely agree apart from one point: I suggest it is not LAME maintenance that RAA needs to match (no hope of that; you'd have to go a fair way towards what is in CARs Part 4 &4A); but the GFA system - which would be a practical possibility. I strongly suggest you talk to Trevor Bange on this subject.

Dafydd,

I was not suggesting we try to match LAME but that if we had L2 taken away then that's all that's left.

 

Fortunately for us all Trevor Bange is now on the Board and I'm happy to leave that techo stuff to him and stick to counting beans and having my aircraft looked after by the best L2 I can find. We are very lucky in the Hunter Valley to have an exceptional one in Keith Rule.

 

 

[Dafydd Llewellyn]

A question for Dafydd.As an engineer, do you think that at some stage, not too far down track, that we will begin to have a bunch of fatigue related issues on some of these very lightly designed but flash aircraft?

I've seen some really nice but really lightly built aircraft and I've often wondered whether or not some kind of fatigue life was part of the manufacturers engineering calculations.

I think you can count on it. The ASTM standard - the version I have is F2245-04; presumably there are later revisions - is silent on the subject of structural fatigue. maybe the later revisions are more realistic, but if so I'm unaware of it. So was BCAR S preliminary edition. BCAR-S edition 3 has a "motherhood" statement (S 627) which really is largely meaningless. JAR-VLA gives some "safe" stress values - but for composite structures, one should design to strain values, not stress values. The JAR-VLA stresses seem to correspond with about three times what I would consider to be the strain level at which the life approaches indefinite. Most of these standards seem to be watered-down versions of the superseded American standard, CAR 3, and it was likewise silent on fatigue issues. The problems people are now having with SIDs for Cessna twins, is a direct result of this omission from the basic design standards.

 

The reason for this omission from recreational aircraft standards appears to be the belief that private-owner aircraft seldom exceed 100 hours per year. However when the same standards are applied to aircraft for training, that philosophy goes out the window. The gliding types were grumbling last year because a popular two-seater is grounded at 15,000 hours . . .

 

Fatigue life is a difficult thing to pin down; the current rule in FAR Part 23 (as explained in FAA AC 23.13A) is that one calculates the mean time to failure under a statistical loading spectrum (based of thousands of measurements of G-loads) and divides it by eight, to obtain a "safe life". The "safe life" is a probability thing; generally one can think in terms of the probability of failure reaching a maximum of one in a thousand per flying hour, at the end of the "safe life". So one could exceed the safe life if one were prepared to accept a higher level of risk - and the risk increases progressively. So quite a few of these aircraft will no doubt survive well past what their "safe life" would be, if anybody had calculated it - but sooner or later . . .

 

Fatigue of rivetted aluminium alloy structures is pretty well understood; the research started in 1947. Metals fail by repeated tensile load cycles. Composites are quite different; they normally fatigue by inter-laminar shear - and as a consequence of the ongoing shringage of the resin matrix, which never really ceases. We still do not have full knowledge for composites, and the sensitivity varies enormously according to the detail design.

 

When you combine these considerations with the very light structures dictated by the tight MTOW limits, fatigue failure is a certainty, in the fullness of time. And if somebody get exuberant and starts throwing the things around, the life can be consumed ten times as fast, quite easily.

 

So yes, I think the overall situation is totally insane. There will inevitably be a spate of failures, and the authorities will knee-jerk and tighten up on it, and some aircraft types will end up on the ground; and it does not take much in the way of commonsense to guess which ones are likely to suffer this.

 

 

[Dafydd Llewellyn]

Dafydd,I was not suggesting we try to match LAME but that if we had L2 taken away then that's all that's left.

 

Fortunately for us all Trevor Bange is now on the Board and I'm happy to leave that techo stuff to him and stick to counting beans and having my aircraft looked after by the best L2 I can find. We are very lucky in the Hunter Valley to have an exceptional one in Keith Rule.

I was suggesting that CASA may be a lot more happy about the GFA system than it is about the RAA system. If that's the case (and I do not know whether it is, but I would expect so) then it would seem only commonsense for RAA to go cap in hand to GFA and find out how they do it. This is no time to be parochial in one's thinking.

 

 

[M61A1]

I think you can count on it. The ASTM standard - the version I have is F2245-04; presumably there are later revisions - is silent on the subject of structural fatigue. maybe the later revisions are more realistic, but if so I'm unaware of it. So was BCAR S preliminary edition. BCAR-S edition 3 has a "motherhood" statement (S 627) which really is largely meaningless. JAR-VLA gives some "safe" stress values - but for composite structures, one should design to strain values, not stress values. The JAR-VLA stresses seem to correspond with about three times what I would consider to be the strain level at which the life approaches indefinite. Most of these standards seem to be watered-down versions of the superseded American standard, CAR 3, and it was likewise silent on fatigue issues. The problems people are now having with SIDs for Cessna twins, is a direct result of this omission from the basic design standards.The reason for this omission from recreational aircraft standards appears to be the belief that private-owner aircraft seldom exceed 100 hours per year. However when the same standards are applied to aircraft for training, that philosophy goes out the window. The gliding types were grumbling last year because a popular two-seater is grounded at 15,000 hours . . .

 

Fatigue life is a difficult thing to pin down; the current rule in FAR Part 23 (as explained in FAA AC 23.13A) is that one calculates the mean time to failure under a statistical loading spectrum (based of thousands of measurements of G-loads) and divides it by eight, to obtain a "safe life". The "safe life" is a probability thing; generally one can think in terms of the probability of failure reaching a maximum of one in a thousand per flying hour, at the end of the "safe life". So one could exceed the safe life if one were prepared to accept a higher level of risk - and the risk increases progressively. So quite a few of these aircraft will no doubt survive well past what their "safe life" would be, if anybody had calculated it - but sooner or later . . .

 

Fatigue of rivetted aluminium alloy structures is pretty well understood; the research started in 1947. Metals fail by repeated tensile load cycles. Composites are quite different; they normally fatigue by inter-laminar shear - and as a consequence of the ongoing shringage of the resin matrix, which never really ceases. We still do not have full knowledge for composites, and the sensitivity varies enormously according to the detail design.

 

When you combine these considerations with the very light structures dictated by the tight MTOW limits, fatigue failure is a certainty, in the fullness of time. And if somebody get exuberant and starts throwing the things around, the life can be consumed ten times as fast, quite easily.

 

So yes, I think the overall situation is totally insane. There will inevitably be a spate of failures, and the authorities will knee-jerk and tighten up on it, and some aircraft types will end up on the ground; and it does not take much in the way of commonsense to guess which ones are likely to suffer this.

Thanks for your reply. I thought that may be the case, So we can all wait for the knee jerk after something goes bad, I'll bet it won't just affect the type/s involved though. We'll all have to suffer.

 

 

[turboplanner]

Cheaper bolts and fittings from Bunnings it seems;the leadership doesn't promote the safety which leads to the quality which provides the safety.

 

Why is this?

 

The underlying reason is apathy.

 

Why is this?

 

 

[Guest Andys@coffs]

.......Composites are quite different; they normally fatigue by inter-laminar shear - and as a consequence of the ongoing shringage of the resin matrix, which never really ceases. We still do not have full knowledge for composites, and the sensitivity varies enormously according to the detail design........

Given the statement above it would seem that life for composites would instead of cycles or hours be simply elapsed time? If Elapsed time are we talking a number that is likely to be seen in a humans lifetime? Measuring elapsed time since manufacture would seem to me to be relatively easy and not something that a dodgy logbook can hide whereas cycles/hours flown in a RAAus aircraft is something I wouldn't want to be betting my life on....unless they were my hours/cycles, or have I misunderstood?

 

Andy

 

 

[Dafydd Llewellyn]

Given the statement above it would seem that life for composites would instead of cycles or hours be simply elapsed time? If Elapsed time are we talking a number that is likely to be seen in a humans lifetime? Measuring elapsed time since manufacture would seem to me to be relatively easy and not something that a dodgy logbook can hide whereas cycles/hours flown in a RAAus aircraft is something I wouldn't want to be betting my life on....unless they were my hours/cycles, or have I misunderstood?Andy

We may someday come to calendar time limits for composite airframes, but there's definitely no universal rule of thumb in sight for that; they are mainly addressed by ongoing inspection. There is tremendous variation in the way composite airframes are put together; some are very good in regard to fatigue potential. Some have features that make me shake my head. I consider the Jabiru airframes that I am familiar with, to be in the former category, mostly. Some gliders are definitely in the latter group. So what advice can one give to owners?

 

Firstly, read the fine print in the maintenance manual carefully; not all manufacturers are irresponsible about this.

 

Secondly, some airframes have specific locations which can serve as indicators; for example, the bushing in the eye of the lift-strut lug on Jabiru wings; it will loosen before fatigue of the wing itself becomes critical. I've yet to see one that has come loose in service - but if you find one loose, do NOT glue it back into place, scrap the wing - and its mate! (same with the fuselage lug to which the lower end of the lift-strut attaches).

 

Thirdly, keep an eye on obvious critical load-path items, for example the end fittings of lift struts, and the fuselage carry-through structure to which they attach. If the lift-strut end fittings are aluminium, it may be prudent to have them dye-checked periodically. Do not lose sight of the fact that most airframes have metal parts at critical connections; the metal part may be more of a concern than the rest of the composite structure.

 

In composite aircraft, particularly ones with cantilever wings, a point of concern is the joint between the main spar web and the spar cap - especially where the spar cap is a block of rovings built into the wing skin sandwich, that is connected to the spar web by bog when the wing is assembled. This form of joint is usually uninspectable. This was the case with quite a lot of European glass gliders; the only inkling one can get is by measuring the wing natural frequency, but by the time that's affected to a detectable degree, it may be too late. These are in the head-shake class. Gliders are designed by stiffness, because of their very long wings, so they usually have excess strength and may not be as susceptible to fatigue as more lightly-built short-wing aircraft.

 

Steel is often considered to have a limiting stress below which fatigue does not occur. However, bad detail design will cause fatigue failure in steel parts also (especially if they are corroded). The fuselage carry-through member in Skyfox models is a case in point; however that was dealt with by the add-on reinforcing tube. I'd look carefully at this area in any related designs (Kitfox, Avid, etc) but I have no personal experience of those.

 

Because fatigue was not required to be addressed in the original design of so many recreational aircraft, it will eventually be dealt with by Airworthiness Directives. The problem with that is that, firstly, somebody probably has to die before the air safety authorities will do the investigation that will eventually lead to an AD - and secondly, the air safety authorities are disinclined to investigate accidents to recreational aircraft.

 

So, your safety in these aircraft depends upon your vigilance - and that depends on the level of your knowledge.

 

For myself, I'm flying an aircraft type for which I designed the fatigue life extension modification.

 

 

[DonRamsay]

Clearly I am no expert in this area but there are a couple of things one could deduce. Firstly, an RA-Aus registered J230 with a design MTOW of 700kg is unlikely to have ever been flown close to its MTOW. Combine that with your view that it is well constructed in the first place and it would seem to me that you have an aircraft likely to do well compared to most others regarding fatigue life. But even a J230 will get to the geriatric stage one day.

 

If you apply the same logic at the other end of the Jab scale, a J120 with an MTOW of 500kg that, quite possibly, is frequently flown above its design MTOW could you have a significant fatigue issue much earlier?

 

And then there is the exposure to UV - kept in a hangar or outdoors?

 

We have Jabiru celebrating its 25 years in the air on the cover of the October SportPilot and we certainly don't hear much (anything?) about Jab structural issues in their older aircraft. That has to be encouraging. Now, if only the engines . . .