Re: DG-300/303 owners...

[Alan Montague]

Is there any scope for non-destructive testing by industrial
radiology?

X-rays are sensitive in showing up minor ripples in
children's bones? Would they work for the ripples in
my spar?

If so it might be financially viable.

Alan

[Marc Ramsey]

Alan Montague wrote:
> Is there any scope for non-destructive testing by industrial
> radiology?
>
> X-rays are sensitive in showing up minor ripples in
> children's bones? Would they work for the ripples in
> my spar?

There may well be alternative approaches, and that is why some of us
(including owners of other legacy DG gliders, like myself) are a bit
disturbed by the response of the DG factory. I don't expect them to pay
for the repair (or even inspection) of a legacy design like the 300, but
given that the original designer and many of the original engineers and
technicians now work for the "new" DG, they have the resources necessary
to find a better solution. In my mind, the reputations of the DG
designers, engineers, and inspectors is at stake here, whether or not
the current DG company feels they are obligated to take on any
responsibility beyond issuing what they consider to be a suitable TN.
If I were to buy a DG-808 now, why should I assume the factory won't
issue a draconian TN and leave me hanging 5 or 10 years down the line?

I again look at the Duo spar inspections as an example, the original
protocol involved cutting holes in the wing skin and visually inspecting
the spars, in short order SH evolved to using a borescope through the
existing inspection ports and a few holes drilled in the root rib and
aileron cutouts, eventually someone figured how to do it with
inexpensive lipstick cameras and long rods.

Marc

[Steve Davis]

At 17:36 16 April 2007, Marc Ramsey wrote:
>Alan Montague wrote:
>> Is there any scope for non-destructive testing by
>>industrial
>> radiology?
>>
>> X-rays are sensitive in showing up minor ripples in
>> children's bones? Would they work for the ripples
>>in
>> my spar?

I would think that an ultrasonic inspection method

could be developed for much less cost than radiography.
Ultrasonic might be able to look into the layers of
rovings
and see how deep the undulations are. You might want

to check with some companies which make composite
aircraft and composite spars. Cirrus Design, Scaled

Composites, Adam Aircraft etc..., and find out how
they
do NDT on their designs.

>I again look at the Duo spar inspections as an example,
>the original
>protocol involved cutting holes in the wing skin and
>visually inspecting
>the spars, in short order SH evolved to using a borescope
>through the
>existing inspection ports and a few holes drilled in
>the root rib and
>aileron cutouts, eventually someone figured how to
>do it with
>inexpensive lipstick cameras and long rods.
>
>Mark

[Steve Davis]

At 17:36 16 April 2007, Marc Ramsey wrote:
>Alan Montague wrote:
>> Is there any scope for non-destructive testing by
>>industrial
>> radiology?
>>
>> X-rays are sensitive in showing up minor ripples in
>> children's bones? Would they work for the ripples
>>in
>> my spar?

I would think that an ultrasonic inspection method

could be developed for much less cost than radiography.
Ultrasonic might be able to look into the layers of
rovings
and see how deep the undulations are. You might want

to check with some companies which make composite
aircraft and composite spars. Cirrus Design, Scaled

Composites, Adam Aircraft etc..., and find out how
they
do NDT on their designs.

>I again look at the Duo spar inspections as an example,
>the original
>protocol involved cutting holes in the wing skin and
>visually inspecting
>the spars, in short order SH evolved to using a borescope
>through the
>existing inspection ports and a few holes drilled in
>the root rib and
>aileron cutouts, eventually someone figured how to
>do it with
>inexpensive lipstick cameras and long rods.
>
>Mark

[[email protected]]

Such a major flaw in a wing spar should be replaced at the
manufacturers expense IMHO.

It is inexcusable for these wings to still be allowed to fly at lower
placarded limits as DG has no knowledge of the condition of the entire
fleet.
DG should sue Elan for screwing up and DG owners should get a free set
of wings to replace the bad ones they bought in good faith.
Its not like you can glue a new spar in the place where its bad!!

Regards

Al



On Apr 16, 11:39 am, Steve Davis >
wrote:
> At 17:36 16 April 2007, Marc Ramsey wrote:
>
> >Alan Montague wrote:
> >> Is there any scope for non-destructive testing by
> >>industrial
> >> radiology?
>
> >> X-rays are sensitive in showing up minor ripples in
> >> children's bones? Would they work for the ripples
> >>in
> >> my spar?
>
> I would think that an ultrasonic inspection method
>
> could be developed for much less cost than radiography.
> Ultrasonic might be able to look into the layers of
> rovings
> and see how deep the undulations are. You might want
>
> to check with some companies which make composite
> aircraft and composite spars. Cirrus Design, Scaled
>
> Composites, Adam Aircraft etc..., and find out how
> they
> do NDT on their designs.>I again look at the Duo spar inspections as an example,
> >the original
> >protocol involved cutting holes in the wing skin and
> >visually inspecting
> >the spars, in short order SH evolved to using a borescope
> >through the
> >existing inspection ports and a few holes drilled in
> >the root rib and
> >aileron cutouts, eventually someone figured how to
> >do it with
> >inexpensive lipstick cameras and long rods.
>
> >Mark

[Dan G]

On Apr 16, 9:26 pm, " >
wrote:
> Such a major flaw in a wing spar should be replaced at the
> manufacturers expense IMHO.
>

This would bankrupt DG, which benefits no-one.

> It is inexcusable for these wings to still be allowed to fly at lower
> placarded limits as DG has no knowledge of the condition of the entire
> fleet.

Well, they (and EASA) believe they've tested-to-destruction the worst
case, and under the new placard speeds (which are hardly low; the
DG300 always had a high VNE and rough air max) there's still the big
safety margin demanded by the regulations.

> DG should sue Elan for screwing up and DG owners should get a free set
> of wings to replace the bad ones they bought in good faith.
> Its not like you can glue a new spar in the place where its bad!!

The manufacturing screw-up happened too long ago for DG to sue Elan/
AMS (I get the impression they would if they could).


Dan

[Steve Davis]

The wings are reparable so they shouldn't have to
provide free replacements. Since it is a fiberglass
spar cap and the problem seems to be limited to the
wing root it MIGHT be possible to cut a slot into the

rovings and embed some Graphlite carbon fiber rods
into the spar cap. If this is doable the result could
be a far stronger spar than the original design. I

don't think you could do this with a carbon fiber spar
cap but i'm not sure about fiberglass.

http://www.marskeaircraft.com/carbonrod.html


>It is inexcusable for these wings to still be allowed
>to fly at lower
>placarded limits as DG has no knowledge of the condition
>of the entire
>fleet.
>DG should sue Elan for screwing up and DG owners should
>get a free
set
>of wings to replace the bad ones they bought in good
>faith.
>Its not like you can glue a new spar in the place where
>its bad!!
>
>Regards
>
>Al
>
>
>
>On Apr 16, 11:39 am, Steve Davis
>wrote:
>> At 17:36 16 April 2007, Marc Ramsey wrote:
>>
>> >Alan Montague wrote:
>> >> Is there any scope for non-destructive testing by
>> >>industrial
>> >> radiology?
>>
>> >> X-rays are sensitive in showing up minor ripples
>>>>in
>> >> children's bones? Would they work for the ripples
>> >>in
>> >> my spar?
>>
>> I would think that an ultrasonic inspection method
>>
>> could be developed for much less cost than radiography.
>> Ultrasonic might be able to look into the layers of
>> rovings
>> and see how deep the undulations are. You might want
>>
>> to check with some companies which make composite
>> aircraft and composite spars. Cirrus Design, Scaled
>>
>> Composites, Adam Aircraft etc..., and find out how
>> they
>> do NDT on their designs.>I again look at the Duo spar
>>>inspections as
an example,
>> >the original
>> >protocol involved cutting holes in the wing skin and
>> >visually inspecting
>> >the spars, in short order SH evolved to using a borescope
>> >through the
>> >existing inspection ports and a few holes drilled
>>>in
>> >the root rib and
>> >aileron cutouts, eventually someone figured how to
>> >do it with
>> >inexpensive lipstick cameras and long rods.
>>
>> >Mark
>
>
>

[John Schaffer]

I have sent a email to the factory, with no reply.

I am guessing that it would cost me $21K USD to get my wings fixed.

Does anyone have any idea on the cost of new wings from the factory?

Would it be cheaper for me?

Regards,

John "XLT"

[[email protected]]

On Apr 16, 3:48 pm, "Dan G" > wrote:
> On Apr 16, 9:26 pm, " >
> wrote:
>
> > Such a major flaw in a wing spar should be replaced at the
> > manufacturers expense IMHO.
>
> This would bankrupt DG, which benefits no-one.

If Boeing shipped a plane that was discovered to have a flaw in it
because their sub contractor failed to adhere to manufacturing specs
or QA procedures, Boeing would fix the problem then deal with the
sub. After all Boeing owns the paper for the sales contract.

So what is different here?

>
> > It is inexcusable for these wings to still be allowed to fly at lower
> > placarded limits as DG has no knowledge of the condition of the entire
> > fleet.
>
> Well, they (and EASA) believe they've tested-to-destruction the worst
> case, and under the new placard speeds (which are hardly low; the
> DG300 always had a high VNE and rough air max) there's still the big
> safety margin demanded by the regulations.

No DG would like to think they have found the worst case.
They dont know.

It will only take one crusty in his DG flying the old placard speeds,
making it clap hands and they are in a whole heap of trouble.

>
> > DG should sue Elan for screwing up and DG owners should get a free set
> > of wings to replace the bad ones they bought in good faith.
> > Its not like you can glue a new spar in the place where its bad!!
>
> The manufacturing screw-up happened too long ago for DG to sue Elan/
> AMS (I get the impression they would if they could).

No the DG site says this applies to DG303-Acros too which are recent
production.

This is a nightmare for DG300/303 owners, I almost became an owner
last summer as I was looking at a DG303 acro.

As an aside I posted some DG300 wing cross section shots from the one
that went in at Minden 10 years ago.
you can see the build quality really clearly here.
http://www.gliderforum.com/photos/photo-thumbnails.asp?albumid=55

Regards

Al

[[email protected]]

On Apr 16, 5:09 pm, Steve Davis >
wrote:
> The wings are reparable so they shouldn't have to
> provide free replacements. Since it is a fiberglass
> spar cap and the problem seems to be limited to the
> wing root it MIGHT be possible to cut a slot into the
>
> rovings and embed some Graphlite carbon fiber rods
> into the spar cap. If this is doable the result could
> be a far stronger spar than the original design. I
>

Cutting into a spar there is no good, you only move the problem
further out on the wing where the glue joint is!!

[Ann O'Rack[_2_]]

At 07:36 17 April 2007, wrote:
>On Apr 16, 3:48 pm, 'Dan G' wrote:
>> On Apr 16, 9:26 pm, '
>> wrote:
>>
>> > Such a major flaw in a wing spar should be replaced
>>>at the
>> > manufacturers expense IMHO.
>If Boeing shipped a plane that was discovered to have
>a flaw in it
>because their sub contractor failed to adhere to manufacturing
>specs
>or QA procedures, Boeing would fix the problem then
>deal with the
>sub. After all Boeing owns the paper for the sales
>contract.
>
>So what is different here?

What is different is that the manufacturing company
(Glaser-Dirks) no longer exists, would you expect DG
to be responsible for a manufacturing problem in, e.g.,
an LS3 also? Yes they could come up with a better
solution than they have so far but expecting them to
pay for it just because they sell the spare parts is
a fantasy.

[[email protected]]

On Apr 17, 1:11 am, Ann O'Rack > wrote:
> At 07:36 17 April 2007, wrote:
>
> >On Apr 16, 3:48 pm, 'Dan G' wrote:
> >> On Apr 16, 9:26 pm, '
> >> wrote:
>
> >> > Such a major flaw in a wing spar should be replaced
> >>>at the
> >> > manufacturers expense IMHO.
> >If Boeing shipped a plane that was discovered to have
> >a flaw in it
> >because their sub contractor failed to adhere to manufacturing
> >specs
> >or QA procedures, Boeing would fix the problem then
> >deal with the
> >sub. After all Boeing owns the paper for the sales
> >contract.
>
> >So what is different here?
>
> What is different is that the manufacturing company
> (Glaser-Dirks) no longer exists, would you expect DG
> to be responsible for a manufacturing problem in, e.g.,
> an LS3 also? Yes they could come up with a better
> solution than they have so far but expecting them to
> pay for it just because they sell the spare parts is
> a fantasy.

DG acquired the IP and remains of the old Glaser-Dirks.
When acquiring the rights and user base to a company like that you
cant just pick and choose what you take responsibility for.
Also the 303's have been built by the new company so where do you draw
the line?

Plus DG also retained the original manufacturer (Elan/AMS).

[Andreas Maurer[_1_]]

On 17 Apr 2007 00:33:55 -0700, "
> wrote:


>So what is different here?

Boeing is still in business.

manufacturer of the DG-300/303 was Glaser Dirks which has been out of
business for several years now.
The current company DG Flugzeugbau merely does the service for all the
former Glaser Dirks aircraft prior to the DG-800.


>It will only take one crusty in his DG flying the old placard speeds,
>making it clap hands and they are in a whole heap of trouble.

The fact that no DG-300 ever loast its wings clearly proves that the
structure is strong enough to handle the flight loads.


>This is a nightmare for DG300/303 owners, I almost became an owner
>last summer as I was looking at a DG303 acro.

if you want to do aerobatocs in a 303, you're screwed.
99.9 percent of all other DG-300 pilots won't even notice the
restrictions.


Bye
Andreas

[Andreas Maurer[_1_]]

On Tue, 17 Apr 2007 01:39:59 +0100, John Schaffer
> wrote:

>
>I have sent a email to the factory, with no reply.
>
>I am guessing that it would cost me $21K USD to get my wings fixed.
>
>Does anyone have any idea on the cost of new wings from the factory?
>
>Would it be cheaper for me?

How often do you feel the need to fly with more than 450 kg and faster
than 250 kph...?
As long as you don't do that regularly, you can save a lot of money
and simply apply the new restrictions to your airspeed indicator and
POH.

Bye
Andreas

[Ola Røer Thorsen]

That will not work.

Carbon fibre and glass fibre do not have the same stiffness. The carbon
which is stiffer would have to carry the complete load and would break
unless being designed/dimensioned to replace the complete spar. It makes no
sense to mix the two in a spar like that.

Best regards,
Ola Røer Thorsen


Steve Davis wrote:

> The wings are reparable so they shouldn't have to
> provide free replacements. Since it is a fiberglass
> spar cap and the problem seems to be limited to the
> wing root it MIGHT be possible to cut a slot into the
>
> rovings and embed some Graphlite carbon fiber rods
> into the spar cap. If this is doable the result could
> be a far stronger spar than the original design. I
>
> don't think you could do this with a carbon fiber spar
> cap but i'm not sure about fiberglass.
>
> http://www.marskeaircraft.com/carbonrod.html

[[email protected]]

On Apr 17, 3:14 am, Andreas Maurer > wrote:
> On Tue, 17 Apr 2007 01:39:59 +0100, John Schaffer
>
> > wrote:
>
> >I have sent a email to the factory, with no reply.
>
> >I am guessing that it would cost me $21K USD to get my wings fixed.
>
> >Does anyone have any idea on the cost of new wings from the factory?
>
> >Would it be cheaper for me?
>
> How often do you feel the need to fly with more than 450 kg and faster
> than 250 kph...?
> As long as you don't do that regularly, you can save a lot of money
> and simply apply the new restrictions to your airspeed indicator and
> POH.
>
> Bye
> Andreas

Also, from your April 8 post:

Apart from the max T/O weight (and the prohibition of aerobatics for
the DG-303 Acro) none of this limitations is going to have any
practical influence on aircraft handling, don't you agree?


Andreas, do you own a DG-300? If not maybe you'd like to buy mine.
I'm partly joking and partly serious with that comment. It's still a
nice glider but it's not the glider I bought. Mine is not an acro but
was approved for mild aerobatics and I did those aerobatics. I'll
miss that. Also, I'd like to fly at 9.5 lbs/sq ft. or so sometimes.
525 kg isn't required for that but more than 450 kg is needed. With
450 kg only 9.0 is possible. The reduction in maneuvering speed is
probably a bigger deal than Vne but I know people around here who have
had trouble staying below 18,000 while at Vne. It's not very often
though.

ELAN seems to be the responsible party here. Are they still the same
company? My understanding is they only split off the aviation
division to form AMS but the original ELAN company is still the same.
Please correct me if I'm wrong.

Bob

[Andreas Maurer]

Hi Bob,

On 17 Apr 2007 16:58:55 -0700, wrote:

>Andreas, do you own a DG-300? If not maybe you'd like to buy mine.

Thank you for your kind offer, but I (respectively my club) already
own 2 DG-300...

.... and the pilots who fly them regard stories about 18.000 ft cloud
base and difficulties of staying below Vne as science fiction. :)

>ELAN seems to be the responsible party here. Are they still the same
>company? My understanding is they only split off the aviation
>division to form AMS but the original ELAN company is still the same.
>Please correct me if I'm wrong.

I have no idea about the situation of ELAN - but I'm pretty sure that
their product liability has expired.
Bye
Andreas

[Shawn[_3_]]

Andreas Maurer wrote:
> Hi Bob,
>
> On 17 Apr 2007 16:58:55 -0700, wrote:
>
>> Andreas, do you own a DG-300? If not maybe you'd like to buy mine.
>
> Thank you for your kind offer, but I (respectively my club) already
> own 2 DG-300...
>
> ... and the pilots who fly them regard stories about 18.000 ft cloud
> base and difficulties of staying below Vne as science fiction. :)

What, you've never worried about the lift being too strong? You need to
come west!



Shawn

[Steve Davis]

'....and the pilots who fly them regard' might need
to be changed to 'the
pilots who flew them regard' unless an inexpensive
method of inspecting
and repairing them is developed by someone.

>Thank you for your kind offer, but I (respectively
>my club) already
>own 2 DG-300...
>
>.... and the pilots who fly them regard stories about
>18.000 ft cloud
>base and difficulties of staying below Vne as science
>fiction. :)
>
>>ELAN seems to be the responsible party here. Are they
>>still the same
>>company? My understanding is they only split off the
>>aviation
>>division to form AMS but the original ELAN company
>>is still the same.
>>Please correct me if I'm wrong.
>
>I have no idea about the situation of ELAN - but I'm
>pretty sure that
>their product liability has expired.
>Bye
>Andreas
>

[Bob Kuykendall]

On Apr 18, 12:30 pm, Steve Davis >
wrote:
> '....and the pilots who fly them regard' might need
> to be changed to 'the
> pilots who flew them regard' unless an inexpensive
> method of inspecting
> and repairing them is developed by someone.

Hmmm... I wonder who that "someone" might be. Whoever they are,
they're pretty brave to get wrapped up in this mess.

On the topic of inexpensive, that will have to be relative at best.

>From correspondence and conversation with various engineers and
composites technicians, it appears that the scarf ratio for composite
repairs is determined by the ratio of the shear strength of the epoxy
to the tensile strength of the fibers. For a spar repair in E-glass,
it seems to come out on the order of 40:1, and perhaps 15% greater for
S-glass, let's say conservatively around 60:1.

My guess, based on my experience with wet fiberglass layups, is that
the degree of fiber "ondulation" will vary linearly through the depth
of the spar cap. That is, the worst "ondulation" will be at the
extreme outer fibers of the spar cap, and that there will be no
ondulation at the inner (last laid) fibers, and half way through that
depth the ondulation will be half as bad as the worst. The shame of
that is that the extreme outer fibers of a cantilever beam are the
ones with the greatest stress.

Anyhow, if the "ondulation" varies as I guess, part of the inspection
and repair process will be to assess what degree of "ondulation" is
acceptable, and how much spar cap has to be ground away to get to
acceptable fiber.

Suppose, for example, that the "Ondulated" fiber were to extend down
through 8mm of spar cap. Then you (or, more likely, the repair tech)
would have to grind out a scarf that extends spanwise through
8*60=480mm, call it a half a meter of span plus probably the full
length of the spar butt, call it a full meter. After grinding that
out, you'd have to build up the material removed by laying in new
straight rovings.

After executing the spar scarf, you'd have to repair all the
collateral damage inflicted on the wing skin when trenching down to
the spar. Probably the easiest way to do that would be with a
prefabricated patch panel, made in the original wing mold, that
encompasses the sandwich directly over the first half-meter of spar
plus 50mm or so chordwise fore and aft of the spar. The repair tech
would fit this patch panel, splice the inner skin, and execute an
outer skin scarf around the perimeter of the patch panel. After that,
gelcoat, sand, and polish to hide.

That is just my own half-informed guess at what the spar repair
entails. Your actual mileage has already varied. The response to my
own emails to DG has been on what I would call the chilly side. Their
position on this matter seems to be holding firm as follows:

* Supplementary explanations of the problem and surrounding issues
(such as the one I posted earlier) are unhelpful, since the
explanation posted on the DG Web site clearly addresses all aspects of
the issue. Beyond that, only "experts" are qualified to understand the
problem.

* Photos of affected spars are unhelpful because only "experts" are
qualified to read them, for everyone else they are just frightening.

* The inspection must be performed by DG-trained workers.

Regarding some of the repairs I've seen suggested, such as splinting
the spar with Graphlite rod, I think that those are non-starters at
best. I think that the only reasonable repair schemes are those that
restore the structure to its as-designed strength and stiffness.
Repairs that substantially alter the stress distribution through the
structure could well cause other unknown and unexpected problems.

Thanks, and best regards to all

Bob K.
Disclaimer: I'm the guy behind:
http://www.hpaircraft.com/hp-24

I'm an amateur - don't try this at work!

[[email protected]]

On Apr 18, 4:40 am, Andreas Maurer > wrote:
> Hi Bob,
>
> On 17 Apr 2007 16:58:55 -0700, wrote:
>
> >Andreas, do you own a DG-300? If not maybe you'd like to buy mine.
>
> Thank you for your kind offer, but I (respectively my club) already
> own 2 DG-300...
>
> ... and the pilots who fly them regard stories about 18.000 ft cloud
> base and difficulties of staying below Vne as science fiction. :)
>
> >ELAN seems to be the responsible party here. Are they still the same
> >company? My understanding is they only split off the aviation
> >division to form AMS but the original ELAN company is still the same.
> >Please correct me if I'm wrong.
>
> I have no idea about the situation of ELAN - but I'm pretty sure that
> their product liability has expired.
> Bye
> Andreas

Andreas,

I was only trying to make light of a difficult situation. The DG-300
is still a nice glider. It's just not as nice as it was 10 days
ago.

> ... and the pilots who fly them regard stories about 18.000 ft cloud
> base and difficulties of staying below Vne as science fiction. :)

The airport we fly out of here is at 6,200 feet, about 1.900 meter.
On a good summer day the cloud base can be at 20,000 feet, 6.100
meter. That is only sometimes but 16,000 isn't unusual. It's the
high desert and sometimes you can go pretty fast. The science fiction
is more down by Roswell.

Bob

[Steve Davis]

You have described a $20K repair on a product
which might not be worth $20K right after the
repair. My suggestion for the rods was to try
a $2K or less repair which would allow current
users the peace of mind to continue flying their
gliders.
My understanding of the DG 300 is that
it has a very stiff wing, presumably even with
undulations in the spar caps. Since Graphlite
ships in two and three ft. dia. spools it must be
plenty flexible and it is far stronger than the
equivalent amount of fiberglass rovings. My
suggestion would be to saw several kerfs of
varying lengths and depths through the undulation
area extending for some length on either side of
the area possibly to the end of the spar stubs.
Graphlite rods could be epoxied into the kerfs,
like rebar in concrete, and they would take the
load from the rovings they butt up against.
I suppose fiberglass cloth could be wrapped and
epoxied around the spar butt to prevent the rods
from popping out, if that could happen, but I think
you would have a much stronger than designed spar
with a very stiff wing. I have heard of someone cutting
a kerf in wooden spars and putting in the Graphlite
rods
to improve the strength.

[Tony Verhulst]

> I was only trying to make light of a difficult situation. The DG-300
> is still a nice glider. It's just not as nice as it was 10 days
> ago.

But much more affordable.

Tony V.

[Bob Kuykendall]

Earlier, Steve Davis > wrote:
> You have described a $20K repair on a product
> which might not be worth $20K right after the
> repair.

I assume that you're replying to my post of 1:39 today - though it
doesn't appear so in the Google view of r.a.s. Please let me know if
otherwise.

Yes, in the right hands that might be a $20K repair - I know a lot of
folks who can manage that, and I'm sure they're salivating over the
fallout of this situation. But if there's lots of them to do, a
relatively modest investment in tooling can easily cut the costs down
to around a third of that, possibly less. For example, it's virtually
a no-brainer to build a scarf-router to precisely mill out the
required chunk of wing spar. And the pre-fabbed skin repair panels are
easy, the layup is dirt simple and takes about an hour to do four;
with cure cycles you could probably yield 8 per day from a single wing
mold set.

I remember when the G103 team was here fixing spar spigots. There was
a lot of hand-wringing and gnashing of teeth around a repair that
requires hacking huge chunks out of the spar stub. But in the end,
they just lined them up and churned them out, and when they were done
they all fit fine, looked like new, and no problems since.

And, yeah, if it was some dogmeat glider only worth $20K last month,
this might all be moot. But the fact is that DG300 have typically
commanded around twice that, sometimes much more for young and well-
equipped examples.

> My suggestion for the rods was to try
> a $2K or less repair which would allow current
> users the peace of mind to continue flying their
> gliders.
> My understanding of the DG 300 is that
> it has a very stiff wing, presumably even with
> undulations in the spar caps.

A for effort, but I think that the modulii mismatch between the
Graphlite and the fiberglass is probably too big to make it work
practically, even if the DG is reputed to be "stiff." The axiom of
such things is that as much as you might prefer it otherwise, stresses
are transferred not to the strongest parts but to the stiffest. If you
put any Graphlite into the spar, its stiffer modulus will make it try
to take on all of the stress, or fail its glue bond trying. So you'd
basically have to put in enough Graphlite to take all of the load, and
scarf it in shallow enough to yield enough bond area to get all the
load out of the fiberglass into it. And when you're done with that,
the surgery is likely no less traumatic than if you'd just done a
repair-manual scarf.

Another thing to consider is that if you execute an innovative repair,
you are probably on the hook to validate it with test it to
destruction, or at least to the somewhat-draconian EASA standard of
6.3*1.725. Whereas with a textbook repair, you may be justified in
only testing to design load or not testing at all.

> Since Graphlite
> ships in two and three ft. dia. spools it must be
> plenty flexible and it is far stronger than the
> equivalent amount of fiberglass rovings.

Yes, that's the way we've been buying Graphlite ribbon (not rod) for
the HP-24 and Glidair projects. Its flexibility is relative, though;
with a Young's Modulus of about 23 million it is much stiffer than the
equivalent profiles of pultruded fiberglass and is in fact 15% to 20%
stiffer than the equivalent hand-laid carbon tape or roving. For new
glider wing spar designs I think it is certainly the greatest thing
since sliced cheese, but it doesn't always play nice with others.

> My
> suggestion would be to saw several kerfs of
> varying lengths and depths through the undulation
> area extending for some length on either side of
> the area possibly to the end of the spar stubs.
> Graphlite rods could be epoxied into the kerfs,
> like rebar in concrete, and they would take the
> load from the rovings they butt up against.
> I suppose fiberglass cloth could be wrapped and
> epoxied around the spar butt to prevent the rods
> from popping out, if that could happen, but I think
> you would have a much stronger than designed spar
> with a very stiff wing.

As I wrote, that might work, but it inflicts trauma on the same order
as the textbook repair, involves a pretty big modulus mismatch, and
has no track record. I'd like to see it tried, though, it'd be an
interesting experiment.

> I have heard of someone cutting
> a kerf in wooden spars and putting in the Graphlite
> rods
> to improve the strength.

Yes, I've heard of that too - I think it was on a Bowlus Baby
Albatross.

Thanks, and best regards to all

Bob K.

[Steve Davis]

Yes Bob, I was responding to your earlier post.
Thanks for your reply; there seems to be a lot
more going on in the spar than I had realized.
I was just guesstimating at the value of a DG 300
now vs. after a repair. With the current 'fix'
from DG I suspect a lot of them will just sit in
trailers not getting flown, or bought.
Also, is this a problem with both the top and
bottom spar caps of the wings or just one cap?
Thanks for your information.
Steve

>> You have described a $20K repair on a product
>> which might not be worth $20K right after the
>> repair.
>
>I assume that you're replying to my post of 1:39 today
>- though it
>doesn't appear so in the Google view of r.a.s. Please
>let me know if
>otherwise.
>
>Yes, in the right hands that might be a $20K repair
>- I know a lot of
>folks who can manage that, and I'm sure they're salivating
>over the
>fallout of this situation. But if there's lots of them
>to do, a
>relatively modest investment in tooling can easily
>cut the costs down
>to around a third of that, possibly less. For example,
>it's virtually
>a no-brainer to build a scarf-router to precisely mill
>out the
>required chunk of wing spar. And the pre-fabbed skin
>repair panels are
>easy, the layup is dirt simple and takes about an hour
>to do four;
>with cure cycles you could probably yield 8 per day
>from a single wing
>mold set.

[Steve Davis]

Yes Bob, I was responding to your earlier post.
Thanks for your reply; there seems to be a lot
more going on in the spar than I had realized.
I was just guesstimating at the value of a DG 300
now vs. after a repair. With the current 'fix'
from DG I suspect a lot of them will just sit in
trailers not getting flown, or bought.
Also, is this a problem with both the top and
bottom spar caps of the wings or just one cap?
Thanks for your information.
Steve

>> You have described a $20K repair on a product
>> which might not be worth $20K right after the
>> repair.
>
>I assume that you're replying to my post of 1:39 today
>- though it
>doesn't appear so in the Google view of r.a.s. Please
>let me know if
>otherwise.
>
>Yes, in the right hands that might be a $20K repair
>- I know a lot of
>folks who can manage that, and I'm sure they're salivating
>over the
>fallout of this situation. But if there's lots of them
>to do, a
>relatively modest investment in tooling can easily
>cut the costs down
>to around a third of that, possibly less. For example,
>it's virtually
>a no-brainer to build a scarf-router to precisely mill
>out the
>required chunk of wing spar. And the pre-fabbed skin
>repair panels are
>easy, the layup is dirt simple and takes about an hour
>to do four;
>with cure cycles you could probably yield 8 per day
>from a single wing
>mold set.

[brianDG303]

On Apr 18, 6:30 pm, Steve Davis >
wrote:
.. With the current 'fix'
> from DG I suspect a lot of them will just sit in
> trailers not getting flown, or bought.
>

Steve, this all came out about ten days ago. Last weekend at the field
there was quite a bit of chatter about it, and I had to answer a lot
of questions about how I was planning on dealing with my 303. And the
answer is, I'm so happy with the glider I just don't really care.
Andreas is correct, this will not affect me until I decide to sell it,
and that is some years down the line. The focus in this thread is on
how to fix the problem; my interest is on how to test at the lowest
cost. Let's say 50% of the gliders are affected, that means that the
cost to fix half the gliders is exactly nothing. While the testing
process is being worked out I'll be flying, and having fun.

As it happens, I have the last plane (DG303 # 486) ever made by ELAN,
and the 27th ACRO. It will be interesting to look back on this in a
year or two.

[Jack]

brianDG303 wrote:

> As it happens, I have the last plane (DG303 # 486) ever made by ELAN,
> and the 27th ACRO. It will be interesting to look back on this in a
> year or two.

Who made the final 25 units, and what is the source of this information?


Jack

[Marc Ramsey]

Jack wrote:
> brianDG303 wrote:
>
>> As it happens, I have the last plane (DG303 # 486) ever made by ELAN,
>> and the 27th ACRO. It will be interesting to look back on this in a
>> year or two.
>
> Who made the final 25 units, and what is the source of this information?

AMS Flight made the last 25, after they bought out ELAN's aircraft
business and bought the production rights from DG Flugzeugbau...

Marc

[Jack]

Marc Ramsey wrote:

> AMS Flight made the last 25, after they bought out ELAN's aircraft
> business and bought the production rights from DG Flugzeugbau...

And they continued the defective construction techniques,
in the same facility, probably using the same personnel?

No wonder they are staying silent.


Jack

[Marc Ramsey]

Jack wrote:
> Marc Ramsey wrote:
>
>> AMS Flight made the last 25, after they bought out ELAN's aircraft
>> business and bought the production rights from DG Flugzeugbau...
>
> And they continued the defective construction techniques,
> in the same facility, probably using the same personnel?
>
> No wonder they are staying silent.

They haven't been silent, see the second item posted at:

http://www.ams-flight.si/

Marc

[Jack]

Marc Ramsey wrote:

> [AMS-Flight] haven't been silent, see the second item posted at:
>
> http://www.ams-flight.si/

Thanks.

After reading that one wonders is there no one available to AMS who
can translate German to English more clearly?

As a relative newcomer to soaring it surprises me how much of a
garage-level industry is the production of sailplanes which cost so
dearly. To think that AMS could not be bothered to keep production
records which recorded changes in their processes is shocking.

"Amateurish" does not begin to cover it.


Jack

[Marc Ramsey]

Jack wrote:
> After reading that one wonders is there no one available to AMS who can
> translate German to English more clearly?

I wouldn't expect anyone there to do a particularly good job translating
German to English, any more than I would expect someone in the US to do
a good job of translating German to Slovenian.

> As a relative newcomer to soaring it surprises me how much of a
> garage-level industry is the production of sailplanes which cost so
> dearly. To think that AMS could not be bothered to keep production
> records which recorded changes in their processes is shocking.
>
> "Amateurish" does not begin to cover it.

Glaser-Dirks was pretty clearly responsible for establishing the
inspection protocols and record keeping requirements. Apparently they
didn't consider this part of the manufacturing process important enough
to monitor. Why would Elan or AMS keep record of something that
Glaser-Dirks didn't request?

Marc

[Jack]

Marc Ramsey wrote:

> Glaser-Dirks was pretty clearly responsible for establishing the
> inspection protocols and record keeping requirements. Apparently they
> didn't consider this part of the manufacturing process important enough
> to monitor. Why would Elan or AMS keep record of something that
> Glaser-Dirks didn't request?

An at least equally valid supposition is that the original
manufacturer and certificate holder could not imagine that someone
would take shortcuts in the process which could be expected to
result in a substandard product. Doing so not only deviated from the
specs but could be expected to actually reduce the strength of the
wing, according to DG-FZB.

Thank you for reminding me that AMS is in Slovenia and not in
Germany. However, the point was obvious -- that the employment of a
good translator would enhance their presentation to English speaking
customers. The neglect of this nicety is consistent with their
disregard for proper production techniques. All in all, their
involvement in the production of any glider will likely remove that
glider from my list of prospective future purchases.


Jack

[bagmaker]

just wondering how much a NEW set of wings, 808 profile with butt adaption and tongue/fork width to suit 300/303 series would be worth.
Mr DG would be tooled up already, the new specs could be added to the manual and the glider is upgraded.
You Americans could then buy up the old 303 wings and bolt them to your beloved tinships for training!


There is always an outside to the square.

Bagger
(diving for flamesuit, as usual)

[Marc Ramsey]

> The neglect of this nicety is consistent with their disregard
> for proper production techniques. All in all, their involvement in the
> production of any glider will likely remove that glider from my list of
> prospective future purchases.

The funny part is, my DG-303 had better fit and finish than the DG-800s
that were coming out of Germany at the time. My attitude on this is a
bit different than yours, Glaser-Dirks was responsible for ensuring that
all critical aspects of the work done by their subcontractors was of the
necessary high quality. DG Flugzeugbau obviously subcontracts out parts
of the manufacture of their current gliders, given that pretty much the
same people are involved on the DG side, why should I believe that they
are paying any more attention now than they were during the Glaser-Dirks
days?

Marc

[Andreas Maurer[_1_]]

On Wed, 18 Apr 2007 09:31:47 -0600, Shawn >
wrote:

>
>What, you've never worried about the lift being too strong? You need to
>come west!

At the moment I keep my hopes upon global warming.... :)


Bye
Andreas

[Jack]

Marc Ramsey wrote:

> DG Flugzeugbau obviously subcontracts out parts
> of the manufacture of their current gliders, given that pretty much the
> same people are involved on the DG side, why should I believe that they
> are paying any more attention now than they were during the Glaser-Dirks
> days?



A question we all should be asking. The problem is seven months
along already and these companies are only now beginning to generate
some sort of response, and little of it constructive.


Jack

[Andreas Maurer]

On 18 Apr 2007 19:30:12 GMT, Steve Davis
> wrote:

>'....and the pilots who fly them regard' might need
>to be changed to 'the
>pilots who flew them regard' unless an inexpensive
>method of inspecting
>and repairing them is developed by someone.

LOL... noone in my club is considering to stop flying our DG-300's...


Bye
Andreas

[Shawn[_3_]]

Andreas Maurer wrote:
> On Wed, 18 Apr 2007 09:31:47 -0600, Shawn >
> wrote:
>
>> What, you've never worried about the lift being too strong? You need to
>> come west!
>
> At the moment I keep my hopes upon global warming.... :)

Nevada-like weather in Germany? I don't think even Al Gore could go
that far. ;-)



Shawn

[Andreas Maurer]

On Thu, 19 Apr 2007 09:49:59 -0600, Shawn >
wrote:

>Nevada-like weather in Germany? I don't think even Al Gore could go
>that far. ;-)

In 2003 we were "close" (for a duration of two weeks):
Temperatures over 40 degrees C and cloud base over 10.000 ft...


Bye
Andreas

[mart]

I read the report on the DG website and it all looks very nice except the last words; end of discussion. That rubs me the wrong way.
As far as I know this is not a warranty issue but a building mistake and I think you stay liable for that, no time expire.
It seems to me that some business will have an insurance to cover the loss for the pilots.
I was at the Elan factory a number of years ago. They were building there the very first DG 1000. So there was defenitely a close business contact.
If DG would have to pay they might go bankrupt.Due the previous bankrupty they might not be liable anyway.
But Elan is a very big ski-factory. The gliders were made on the same terrain,behind the same fence. After seeing the gliders build I saw them build ski's by the 1000's. There is money there to compensate or fix the gliders.
I think all the 300/303 pilots should put $100 in an account and have somebody find out who is liable.

[Steve Davis]

I doubt that you stay liable through bankruptcy.
DG is not Glazer-Dirks nor is it Rolladin-Schneider
and when DG bought the assets of those bankrupt
companies it didn't buy the liability of them. The
liabilities, debts to suppliers, warranties, shareholders
rights, employee compensation issues, etc... all
were disposed of by the bankruptcy court.
By buying the company name, assets and tooling
etc...DG got the goodwill of the customer base and
may have taken on the obligation to monitor the
status of legacy product but it did not take on an
obligation to provide free repair.
Also, they seem to believe that the third option,
the wings are strong enough with reduced operating
limits is sufficient.

Bob K. mentioned 'Hmmm... I wonder who that
'someone' might be. Whoever they are, they're
pretty brave to get wrapped up in this mess.'

This could also be applied to DG. If they specify
an inspection and repair procedure for this mess
does it imply that they are accepting some liability
for payment and warranty if someone other than
DG does the work?

At 03:06 21 April 2007, Mart wrote:
>
>I read the report on the DG website and it all looks
>very nice except
>the last words; end of discussion. That rubs me the
>wrong way.
>As far as I know this is not a warranty issue but a
>building mistake
>and I think you stay liable for that, no time expire.
>It seems to me that some business will have an insurance
>to cover the
>loss for the pilots.
>I was at the Elan factory a number of years ago. They
>were building
>there the very first DG 1000. So there was defenitely
>a close business
>contact.
>If DG would have to pay they might go bankrupt.Due
>the previous
>bankrupty they might not be liable anyway.
>But Elan is a very big ski-factory. The gliders were
>made on the same
>terrain,behind the same fence. After seeing the gliders
>build I saw
>them build ski's by the 1000's. There is money there
>to compensate or
>fix the gliders.
>I think all the 300/303 pilots should put $100 in an
>account and have
>somebody find out who is liable.
>
>
>
>
>--
>mart
>

[JJ Sinclair]

I too believe the restrictions on the 300 will scarcely be noticed by
the average pilot, but if someone is concerened (acro) their ship can
easily be proof-loaded to 5.3 G's. Stan Hall wrote a good paper on
just how to go about it, published in Soaring. Basically you mount the
wing inverted on a sturdy test stand, secure it so it won't twist and
then sand-bag that puppy to the flight limits, usually 5.3 G's. Then
you know the wing is stong enough for anything it should see in flight
if the ship is flown within the flight envelope.
JJ

[John Schaffer]

Just got a reply back from DG regarding the DG300 wings. When asked aboutthe cost and availability I got and I quote

"Dear Mr. Schaffer,

unfortunately we can not offer you a new wing for DG-300."

[brianDG303]

I was not able to follow the explaination, but in the original post at
DG they seem to say the wing that was tested (and was bad) failed at
just over 9.0 G's, but they want a safety factor of 1.5 which is 9.64
G's. I could have this wrong though. However, it seems in line with
the actually very modest restrictions, other than Acro, and only 35 or
37 Acro's were built.

Something I've always wondered is just exactly what made an Acro other
than the foot straps, the G meter, and the decal. Whatever it is it
doesn't seem to weigh anything.





On Apr 21, 5:34 am, JJ Sinclair > wrote:
> I too believe the restrictions on the 300 will scarcely be noticed by
> the average pilot, but if someone is concerened (acro) their ship can
> easily be proof-loaded to 5.3 G's. Stan Hall wrote a good paper on
> just how to go about it, published in Soaring. Basically you mount the
> wing inverted on a sturdy test stand, secure it so it won't twist and
> then sand-bag that puppy to the flight limits, usually 5.3 G's. Then
> you know the wing is stong enough for anything it should see in flight
> if the ship is flown within the flight envelope.
> JJ

[Marc Ramsey]

brianDG303 wrote:
> Something I've always wondered is just exactly what made an Acro other
> than the foot straps, the G meter, and the decal. Whatever it is it
> doesn't seem to weigh anything.

When I bought mine I was told that the structural changes consisted of a
slightly beefed up tail boom...

Marc

[Marc Ramsey]

John Schaffer wrote:
> Just got a reply back from DG regarding the DG300 wings. When asked
> aboutthe cost and availability I got and I quote
>
> "Dear Mr. Schaffer,
>
> unfortunately we can not offer you a new wing for DG-300."

AMS Flight currently has the molds, tooling and production rights, not
DG. They could build more if they wanted to...

Marc

[Steve Davis]

They could probably inspect and repair the
existing wings cheaper than supplying new
ones. Perhaps after some time an ultrasonic
inspection method could be developed and
only the bad wings could be sent to DG for
repair? I wouldn't be surprised if they try
to develop a cheaper way to inspect the spars
as some European clubs could delay purchases
of new DG gliders pending a satisfactory
resolution of this problem at least for their
club and members.

At 21:06 21 April 2007, John Schaffer wrote:
>
>Just got a reply back from DG regarding the DG300 wings.
>When asked
>aboutthe cost and availability I got and I quote
>
>'Dear Mr. Schaffer,
>
>unfortunately we can not offer you a new wing for DG-300.'
>
>
>
>
>--
>John Schaffer
>