Eta crashed

[Erich Kohlenberger]

Hi!

Eta had an inflight fuselage breakage during spin tests.
More (in german) on
http://www.mainpost.de/mainfranken/mellrichstadt/mellrichstadt/6048,2371565.
html?fCMS=de3beaa38036aaaf2051952ede286a6c

bye
Erich Kohlenberger

[Bob Kuykendall]

Here's a link to an AltaVista Babel Fish German-to-English
translation:

http://babelfish.altavista.com/babelfish/urltrurl?url=http%3A%2F%2
Fwww.mainpost.de%2Fmainfranken%2Fmellrichstadt%2Fm ellrichstadt%2F6
048%2C2371565.html%3FfCMS%3Dde3beaa38036aaaf205195 2ede286a6c&lp=de
_en&tt=url

[must be all on one line]

Yes, it reads sort of funny, but you can get the gist
of it: The aft fuselage broke during a spin recovery
tests towards type certification. Two people on board,
both parachuted safely and later helped recover the
aircraft.

Bob K.

[Stefan]

Erich Kohlenberger wrote:
>
> Eta had an inflight fuselage breakage during spin tests.

So it didn't "crash", but broke up during a test flight, not the same in
my opinion. (You should have become a journalist!) Still far from
perfect, though.

Stefan

[Robert John]

At 15:06 02 October 2003, Stefan wrote:
>Erich Kohlenberger wrote:
>>
>> Eta had an inflight fuselage breakage during spin
>>tests.
>
>So it didn't 'crash', but broke up during a test flight,
>not the same in
>my opinion. (You should have become a journalist!)
>Still far from
>perfect, though.

>Stefan
>
Big pile of bits all over the ground - I'd call that
a 'crash' not a 'landing' :-) Rob

[Stewart Kissel]

From Websters Dictionary online:
Main Entry: 1crash
Pronunciation: 'krash
Function: verb
Etymology: Middle English crasschen
Date: 15th century
transitive senses
1 a : to break violently and noisily



At 15:06 02 October 2003, Stefan wrote:
>Erich Kohlenberger wrote:
>>
>> Eta had an inflight fuselage breakage during spin
>>tests.
>
>So it didn't 'crash', but broke up during a test flight,
>not the same in
>my opinion. (You should have become a journalist!)
>Still far from
>perfect, though.
>
>Stefan
>

[Vaughn Simon]

"Stefan" > wrote in message
...
> Erich Kohlenberger wrote:
> >
> > Eta had an inflight fuselage breakage during spin tests.
>
> So it didn't "crash", but broke up during a test flight, not the same in
> my opinion.

Boy! Talk about "spin", Erich should be working for the government.
There is a distinction here that I fail to get. From what little
information we have, it apparently broke up in flight, the occupants bailed
out, and then gravity took its natural course until the failed airframe
(crashed, fell, bumped, decellerated, sprinkled, oopsied) into/onto the
surface of the earth. Help me with the finer points of English please; how
is this not a crash?

(You should have become a journalist!) Still far from
> perfect, though.

Yes; much less than perfect. We all lose a bit when this stuff happens
and I wish these people the very best.


Vaughn


>
> Stefan

[Vaughn Simon]

"Vaughn Simon" > wrote in message
...
>
> "Stefan" > wrote in message
> ...
..
>
> Boy! Talk about "spin", Erich should be...

Sorry, got the name wrong, should have been "Stefan".

Vaughn

[Bob Johnson]

Enough already, I thought the acid test was a landing that one walks
away from, and these intrepid airmen did this, I gather, hand in hand.
Sounds like a hard landing to me.

BJ

Stewart Kissel wrote:

> From Websters Dictionary online:
> Main Entry: 1crash
> Pronunciation: 'krash
> Function: verb
> Etymology: Middle English crasschen
> Date: 15th century
> transitive senses
> 1 a : to break violently and noisily
>
> At 15:06 02 October 2003, Stefan wrote:
> >Erich Kohlenberger wrote:
> >>
> >> Eta had an inflight fuselage breakage during spin
> >>tests.
> >
> >So it didn't 'crash', but broke up during a test flight,
> >not the same in
> >my opinion. (You should have become a journalist!)
> >Still far from
> >perfect, though.
> >
> >Stefan
> >

[303pilot]

It didn't crash, it made a landing with less than optimal amounts of control
input/response.

FWIW, I'm with Stephan, if I see "crash" I assume that someone was at the
controls when the integration of the aircraft components became suboptimal
for future use.


"Stewart Kissel" > wrote in
message ...
> From Websters Dictionary online:
> Main Entry: 1crash
> Pronunciation: 'krash
> Function: verb
> Etymology: Middle English crasschen
> Date: 15th century
> transitive senses
> 1 a : to break violently and noisily
>
>
>
> At 15:06 02 October 2003, Stefan wrote:
> >Erich Kohlenberger wrote:
> >>
> >> Eta had an inflight fuselage breakage during spin
> >>tests.
> >
> >So it didn't 'crash', but broke up during a test flight,
> >not the same in
> >my opinion. (You should have become a journalist!)
> >Still far from
> >perfect, though.
> >
> >Stefan
> >
>
>
>

[Stewart Kissel]

Okay, we can call any sort of "event" we choose. According to articles I=
have read, the things cost more the $1 million US to build. Will the ma=
nufacturer be able to absorb this sort of hit?

[Bob Kuykendall]

Let's try posting that URL again, and see if I can make it not
line-break:

http://babelfish.altavista.com/babelfish/urltrurl?url=http%3A%2F%2Fwww.mainpost.de%2Fmainfr anken%2Fmellrichstadt%2Fmellrichstadt%2F6048%2C237 1565.html%3FfCMS%3Dde3beaa38036aaaf2051952ede286a6 c&lp=de_en&tt=url

Bob K.

[Markus Feyerabend]

Stewart,
There is no such thing as "the manufacturer" for the ETA. Instead, a group
of wealthy people financed the design and the building of the prototypes.
Several different companys contributed by building parts of the plane. The
web site www.eta-aircraft.de is run by the design bureau.

Markus



Stewart Kissel schrieb in Nachricht ...
>Okay, we can call any sort of "event" we choose. According to articles I=
> have read, the things cost more the $1 million US to build. Will the ma=
>nufacturer be able to absorb this sort of hit?
>
>
>
>

[Robert Danewid]

Please explain, I do not understand.

If a 747 (just a little bit larger than the eta...) breaks up in flight
due to overloading, killing 400 passengers, it is not a an accident. So
what is it then?

Robert

Stefan wrote:
> Vaughn Simon wrote:
>
>>information we have, it apparently broke up in flight, the occupants bailed
>>out, and then gravity took its natural course until the failed airframe
>>(crashed, fell, bumped, decellerated, sprinkled, oopsied) into/onto the
>>surface of the earth. Help me with the finer points of English please; how
>>is this not a crash?
>
>
> Ok. Technically (and linguisitcally), it *is* a crash. Nothing wrong.
>
> However, when I read the headline "aircraft crashed", I understand
> "accident", and I guess that's what the vast majority does. My mistake,
> agreed, as it wasn't written anywhere whether the plane broke up during
> normal flight, did a bad landing or was destroyed voluntarily. Anyway,
> "accident" ist what that headline implies.
>
> But it wasn't an accident. It was a test flight to explore the limit,
> and they found the limit, although a bit earlier than they wanted, I
> guess. That's exactly what test flights are for.
>
> So a better headline would be "eta fails spin test".
>
> Stefan

[Stefan]

Robert Danewid wrote:
>
> Please explain, I do not understand.

Then read my post more carefully.

Stefan

[Bob Kuykendall]

Earlier, Stefan > wrote:

> ...But it wasn't an accident. It
> was a test flight to explore the limit,
> and they found the limit, although a
> bit earlier than they wanted, I guess.
> That's exactly what test flights are for...

I'm not sure I completely agree with that assessment of the situation.

The way I understand it, the limits they were expecting to explore
were control and handling limits, not structural limits. The way I
read the Babel Fish translated report, they placed the aircraft into a
spin, executed a recovery, and were surprised by a structural failure
of the aft fuselage during the recovery.

I think that if they were really executing a structural test, they
probably wouldn't have had two people on board.

Going forward, it will be very interesting to follow the investigation
of why the structure failed. Did the maneuvers performed apply
loadings beyond the expected ultimate limit? Or did the structure fail
to provide the expected strength and stiffness?

And if the latter, were the stresses miscalculated or did the stucture
not perform as expected?

It's really far too early to speculate, but it will be interesting to
see if perhaps bending loads applied by the elevator plus bending and
torsional loads from the rudder combined to produce stresses in excess
of the expected maximums.

I hope that they were carrying a flight recorder, and that it (unlike
too many dented Cambridge Model 20s) yields usable data.

Anyhow, I'm glad the pilot and observer weren't injured badly. That's
what's most important.

Thanks, and best regards to all

Bob K.

[Jack]

18 posts on this subject line: a large portion of them debating the meaning
of the word "crash" -- yes, the season is over.

What kind of wax shall we use this year?



Jack

[Bill Daniels]

"Howard Franks" > wrote in message
...
> I have always assumed the recent (last 20 years) composite
> gliders to be very robust, i.e. no issues flying right
> up against placarded limitations at anytime (maybe
> once or twice nipping over?).
>
> Perhaps the Eta break-up is a sign that we are reaching
> the structural/design limitations of the current materials
> and the designers ability to optimise gliders for performance.
> Are we at the point of diminishing returns where the
> small increase in performance only comes at a far greater
> risk of structural failure (similar to the Americas
> Cup yachts).
>
>
> This coupled with the recent Schempp-Hirth issues (agreed
> manufacturing not design defects), and the AD restricting
> GROB 103s is leading me to rethink just how tough these
> things are.
>

There seems to be a prevalent attitude that all gliders are much stronger
than the POH says. At least, as a CFI-G, I have a hard time convincing
pilots that those placards mean just what they say. This is particularly a
problem when it comes to overloading 2-seaters. Exceed a placarded limit
and you become a test pilot - maybe a dead one.

I think gliders are just as strong as the manufacturer says, but no
stronger - and only then if the design and manufacturing rules are followed
to the letter. The problem with the Schempp-Hirth gliders seems to be that
the manufacturer's own procedures were not followed. The issue with the
G103's MAY be that errors in design occurred. None of this says that
composite construction is the problem, just that the process needs to be
carefully controlled and monitored. (It also says that reputable
manufacturers sometimes make mistakes that aren't found until after the
gliders are in the field.)

As for the Eta, this may turn out to be an intriguing case. At 31 meters it
is certainly pushing the limits. Bob K. perceptively speculated about
bending and twisting loads on the tailboom. It could also be that the spin
recovery has to be performed exactly right of the airspeeds get way, way out
of hand. I would expect that the Eta will be placarded against intentional
spins for this reason.

Bill Daniels

[Stefan]

Bill Daniels wrote:
>
> I think gliders are just as strong as the manufacturer says, but no
> stronger

Most Gliders are built in JAR country and are certified by JAR rules.
For the utility category, JAR requires an allowed load of 5.3g at Vne
and 4.0g at Vm. JAR further requires that the break load be no lower
than 1.5 times the allowed load.

Since every extra strengh comes at a price in weight and money, the
break load of most gliders acually *is* 1.5 times the allowed load. This
is when the glider is new. Take some turbulence, and the safety cusion
is rather small.

> As for the Eta, this may turn out to be an intriguing case. At 31 meters it
> is certainly pushing the limits.

Actually this is the whole idea of the Eta project: pushing the limits.
Remember that the first prototype was too heavy and extra work was
required to bring the take off mass down to 850 kg! (The 850 kg limit is
again required by JAR as well as by contest rules.)

Stefan

[Robert John]

Never assume the glider is stronger than the placarded
limits. As quite rightly stated earlier, exceed them
and you become a test pilot - especially so on excess
speed where there is little margin.

A friend of mine broke the boom on a SF34 (best thing
to do to the beast, some might say;-) recovering from
an intentional spin. He's a Chief Flying Instructor
and engineer so one presumes he knows what he's doing
but even he was caught out. These things are not unbreakable
in flight.

The loads on spin recovery can be quite unpredictable,
especially if the recovery pull-up is done with some
twisting moment still present on the tail - hence we
are trained to stop the spin, unstall the wings, recover,
not one 'pot-stirring', stress-inducing manoeuvre.

Rob

At 09:12 03 October 2003, Stefan wrote:
>Bill Daniels wrote:
>>
>> I think gliders are just as strong as the manufacturer
>>says, but no
>> stronger
>
>Most Gliders are built in JAR country and are certified
>by JAR rules.
>For the utility category, JAR requires an allowed load
>of 5.3g at Vne
>and 4.0g at Vm. JAR further requires that the break
>load be no lower
>than 1.5 times the allowed load.
>
>Since every extra strengh comes at a price in weight
>and money, the
>break load of most gliders acually *is* 1.5 times the
>allowed load. This
>is when the glider is new. Take some turbulence, and
>the safety cusion
>is rather small.
>
>> As for the Eta, this may turn out to be an intriguing
>>case. At 31 meters it
>> is certainly pushing the limits.
>
>Actually this is the whole idea of the Eta project:
>pushing the limits.
>Remember that the first prototype was too heavy and
>extra work was
>required to bring the take off mass down to 850 kg!
>(The 850 kg limit is
>again required by JAR as well as by contest rules.)
>
>Stefan
>

[Martin Gregorie]

On 2 Oct 2003 15:36:37 -0700, (Bob Kuykendall)
wrote:

>Earlier, Stefan > wrote:
>
>> ...But it wasn't an accident. It
>> was a test flight to explore the limit,
>> and they found the limit, although a
>> bit earlier than they wanted, I guess.
>> That's exactly what test flights are for...
>
>I'm not sure I completely agree with that assessment of the situation.
>
>The way I understand it, the limits they were expecting to explore
>were control and handling limits, not structural limits. The way I
>read the Babel Fish translated report, they placed the aircraft into a
>spin, executed a recovery, and were surprised by a structural failure
>of the aft fuselage during the recovery.
>
>I think that if they were really executing a structural test, they
>probably wouldn't have had two people on board.
>
>Going forward, it will be very interesting to follow the investigation
>of why the structure failed. Did the maneuvers performed apply
>loadings beyond the expected ultimate limit? Or did the structure fail
>to provide the expected strength and stiffness?
>
>And if the latter, were the stresses miscalculated or did the stucture
>not perform as expected?
>
>It's really far too early to speculate, but it will be interesting to
>see if perhaps bending loads applied by the elevator plus bending and
>torsional loads from the rudder combined to produce stresses in excess
>of the expected maximums.
>
>I hope that they were carrying a flight recorder, and that it (unlike
>too many dented Cambridge Model 20s) yields usable data.
>
.....and that the rate was set high enough to show anything.

Last time I flew I had a logger running at its usual 4 second
recording interval. On the way back to the field I remembered I hadn't
stalled or spun in quite a while, so I ran through a HASSEL check and
then a couple of stalls and 4-5 incipient spins, always recovering
after 1/4 - 1/3 turn. I was surprised to see just how little of this
appeared in the trace; the 4 sec interval was enough to average the
series of maneuvers out into 2-3 wide turns combined with a fairly
constant high descent rate. I suspect the Eta logger would need
sub-second sampling to show anything useful al all.

>Anyhow, I'm glad the pilot and observer weren't injured badly. That's
>what's most important.
>
Agreed.


--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

[Jona]

> The loads on spin recovery can be quite unpredictable,
> especially if the recovery pull-up is done with some
> twisting moment still present on the tail - hence we
> are trained to stop the spin, unstall the wings, recover,
> not one 'pot-stirring', stress-inducing manoeuvre.
>

This is an interesting point - I guess lots of pilots employ a mushy
some/loads/a bit of rudder (very slightly ahead of ) stick-forward.
Quickly followed by pull back.

We do this because it works and no one has explained exactly WHY
there are mysterious pauses in the official spin recovery.

--

Jonathan

[Stefan]

Robert John wrote:
>
> Never assume the glider is stronger than the placarded
> limits.

Don't get me wrong: I didn't say because there's a safety cushion of 50%
you should go for it. Don't! I said theres a safety cushion of *only* 50%
to catch the unpredictable. Besides, as you pointed out, the placarded
load limits are for "straight" load only. Add some twisting forces, and bang!

Stefan

[Brian Case]

<snip>

.. JAR further requires that the break load be no lower
> than 1.5 times the allowed load.


Yes, 1.5 times is the ulimiate design factor for the aircraft. However
1.0 times the allowed load is the limit facter. If you exceed the
limit factor you may (will?) damage the aircraft structure but it will
not fail until 1.5 times the limit. This is especially true of metal
structures where the material itself will fail (i.e. Break) at about
1.5 times the yeild strength(i.e. bend permanently).

Brian Case
CFIIG/ASEL




<snip>

[W.J. \(Bill\) Dean \(U.K.\).]

I have always understood that the first composite gliders were well
over-engineered, because the manufacturers were dealing with a new
technology and did not want any risk of failure. I have not heard of any
problems with old glass gliders due simply to age or high hours.

As designers and manufacturers have gained experience I imagine they have
been able to design and build to the limits rather than way past them, so
gaining performance and reducing cost. There are a number of cases where
older designs have had the limitations increased without any modification to
the airframe.

Perhaps one problem we now have is stall/spin recovery. The usual cause of
disaster from a stall/spin is hitting something (usually the ground) before
recovering to normal flight.

There is another problem, flying outside limits while recovering to normal
flight. This can happen with any type if the recovery is handled badly, I
have known of cases involving a Ka6E and more than one K13.

Modern types of glider are easy to fly, and normally reluctant to depart
into
an inadvertent stall/spin (and often difficult to make spin deliberately).
However, many of them can depart violently into a steep spin, and recovery
has to be immediate and correct or Vne will be exceeded. This is most
likely to happen when ballasted and thermalling hard in strong lift.

I know of three fatal accidents where it appears that the glider went
outside limits while recovering from what appeared to be an inadvertent
stall/spin recovery.

1. ASW20CL at Dunstable (I think more than 10years ago), the glider
reached a speed in the dive which made the dive irrecoverable; the C. of G.
may have been aft of limit.

2. Nimbus 4DM at Minden on 13th July 1999.

http://www.ntsb.gov/publictn/publictn.htm , then
http://www.ntsb.gov/publictn/2002/AAB0206.htm or
http://www.ntsb.gov/publictn/2002/AAB0206.pdf .

From the report it would appear that the glider departed into a stall/spin
while thermalling, and was overstressed in the subsequent dive while
recovering.

The brakes opened during the recovery, which reduced the 'g' limitations;
correspondence to Rec. Aviation Soaring indicates that some pilots have
experienced inadvertent deployment of the brakes on this type of glider.
There was also a suggestion that the pilots may have been incapacitated by a
problem with their oxygen system, thought there was no evidence to back
this.

3. Nimbus 4DM in Spain 1999.

Referred to in the report of the Minden accident above.

Quote: "the pilot stated they were in a turn when a heavy thermal caused the
glider to enter a steep descending spiral. The pilot could not recover the
aircraft from the spiral and the glider quickly exceeded Vne. The pilot
then reported that the right wing failed and he bailed out." The second
pilot was unable to bail out.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

>
> "Howard Franks" > wrote in message
> ...
>
> I have always assumed the recent (last 20 years) composite
> gliders to be very robust, i.e. no issues flying right
> up against placarded limitations at anytime (maybe
> once or twice nipping over?).
>
> Perhaps the Eta break-up is a sign that we are reaching
> the structural/design limitations of the current materials
> and the designers ability to optimise gliders for performance.
> Are we at the point of diminishing returns where the
> small increase in performance only comes at a far greater
> risk of structural failure (similar to the Americas
> Cup yachts).
>
> This coupled with the recent Schempp-Hirth issues (agreed
> manufacturing not design defects), and the AD restricting
> GROB 103s is leading me to rethink just how tough these
> things are.
>

[Mike Borgelt]

On Fri, 3 Oct 2003 14:48:55 +0100, "W.J. \(Bill\) Dean \(U.K.\)."
> wrote:


>
>I know of three fatal accidents where it appears that the glider went
>outside limits while recovering from what appeared to be an inadvertent
>stall/spin recovery.
>
>1. ASW20CL at Dunstable (I think more than 10years ago), the glider
>reached a speed in the dive which made the dive irrecoverable; the C. of G.
>may have been aft of limit.
>
>2. Nimbus 4DM at Minden on 13th July 1999.
>
>http://www.ntsb.gov/publictn/publictn.htm , then
>http://www.ntsb.gov/publictn/2002/AAB0206.htm or
>http://www.ntsb.gov/publictn/2002/AAB0206.pdf .
>
>From the report it would appear that the glider departed into a stall/spin
>while thermalling, and was overstressed in the subsequent dive while
>recovering.
>
>The brakes opened during the recovery, which reduced the 'g' limitations;
>correspondence to Rec. Aviation Soaring indicates that some pilots have
>experienced inadvertent deployment of the brakes on this type of glider.
>There was also a suggestion that the pilots may have been incapacitated by a
>problem with their oxygen system, thought there was no evidence to back
>this.
>
>3. Nimbus 4DM in Spain 1999.
>
>Referred to in the report of the Minden accident above.
>
>Quote: "the pilot stated they were in a turn when a heavy thermal caused the
>glider to enter a steep descending spiral. The pilot could not recover the
>aircraft from the spiral and the glider quickly exceeded Vne. The pilot
>then reported that the right wing failed and he bailed out." The second
>pilot was unable to bail out.
To which can be added the in flight breakup of a Blanik L13 at
Narromine NSW in about 1996 or 97 I think it was.
Two dead, instructor and student.

Intentional spin(Annual spin check!) which developed into a spiral and
the glider was overstressed in the recovery, bending the rear fuselage
and preventing recovery from the dive.
Neither pilot was wearing a parachute.

Just my opinion but intentional spinning is something that should be
treated with great caution. Brief the exercise properly, wear
parachutes and be prepared to use them. Best done in something like
Pitts S2 which is likely to hang together rather than a slippery
sailplane.

Mike Borgelt

[Slingsby]

"W.J. \(Bill\) Dean \(U.K.\)." > wrote in message >...
> I have always understood that the first composite gliders were well
> over-engineered, because the manufacturers were dealing with a new
> technology and did not want any risk of failure. I have not heard of any
> problems with old glass gliders due simply to age or high hours.
>
> As designers and manufacturers have gained experience I imagine they have
> been able to design and build to the limits rather than way past them, so
> gaining performance and reducing cost. There are a number of cases where
> older designs have had the limitations increased without any modification to
> the airframe.
************************************************** *******************************

Until recently I thought of the Grob 103 as an over-engineered glider,
especially the fuselage and tail. It is quite heavy and I don't have
first hand knowledge of any with broken tail booms. I do know of
several which have been ground-looped without structural damage.

[Vaughn]

"Slingsby" > wrote in message
om...
>
> Until recently I thought of the Grob 103 as an over-engineered glider,
> especially the fuselage and tail. It is quite heavy and I don't have
> first hand knowledge of any with broken tail booms. I do know of
> several which have been ground-looped without structural damage.

I have heard of, but not seen, G-103's with snapped tail booms.
Locally, over the years, we have had at least two snapped tail booms on
plastic gliders, both from unavoidable groundloops in off-field landings.
It happens.

Vaughn

[Pat Russell]

Which Eta was it?

[Paul Remde]

Who owned that one?


"Markus Feyerabend" > wrote in message
...
> No. 2 D-KFEM
>
> Regards,
> Markus
>
>
>
> Pat Russell schrieb in Nachricht >...
> >Which Eta was it?
> >
>
>

[Markus Feyerabend]

Don´t know, but from the registration it could be Erwin Mueller...!?
I´ll try to find out tomorrow..

Regards,
Markus

Paul Remde schrieb in Nachricht ...
>Who owned that one?
>
>
>"Markus Feyerabend" > wrote in message
...
>> No. 2 D-KFEM
>>
>> Regards,
>> Markus
>>
>>
>>
>> Pat Russell schrieb in Nachricht >...
>> >Which Eta was it?
>> >
>>
>>
>
>

[Shaber CJ]

>From: "303pilot" brentUNDERSCOREsullivanATbmcDOTcom
>Date: 10/2/2003 10:05 AM Pacific Daylight Time
>Message-id: >
>...
>FWIW, I'm with Stephan, if I see "crash" I assume that someone was at the
>controls when the integration of the aircraft components became suboptimal
>for future use...
>
Open your mind and you will find the true meaning...

[Pat Russell]

>No. 2 D-KFEM

Thanks.

That one was 100 kg lighter than No. 1. I wonder how much of
the weight reduction was due to weakening the fuselage.

[Alex Chappell]

At 20:12 05 October 2003, Pat Russell wrote:
>Er...
>Perhaps I should have asked how much of the weakening
>of the
>fuselage was due to the weight reduction.
>
>
>
The weight reduction was mainly in the wings, by using
a foam which absorbed less epoxy.

[Markus Feyerabend]

The web site says as much as 35kg per wing could be
saved with the new method. The rest (30kg) obviously
comes from a lighter fuselage.At 20:54 05 October 2003, Alex Chappell wrote:>>>The weight reduction was mainly in the wings, by using>a foam which absorbed less epoxy.