 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
MaxNr(at)aol.com
Guest
|
 Posted: Fri May 11, 2007 8:43 pm Post subject: Load testing |
 |
|
A lot of discussion about loads on aircraft structures. It may be of interest to see an example of load testing. Click on this link, then click on "Load testing." This plane was developed by one of the members of my EAA chapter. Smaller than a 601XL, but same construction and made of 6061. This prototype was destroyed in its hangar by hurricane Ivan in 2004. The fuselage survives on the wall of the Indust Tech shop at Pensacola Jr College. It still looks airworthy if you stand back 10 feet. I'm not pushing this plane, but thought some pictures may be of interest.
Bob Dingley
Pace, FL
XL/Lyc Do not archive Click here: Welcome to the home of the Thatcher CX4
**************************************
See what's free at http://www.aol.com. [quote][b]
| | - The Matronics Zenith-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
| Back to top |
|
 |
Kurt.Schumacher(at)schumi
Guest
|
| Posted: Sat May 12, 2007 2:46 am Post subject: Load testing |
|
|
Interesting to see. Thatcher correctly differentiates between a design limit
load of 3.8 Gs, and an ultimate load of 5.7 Gs.
| Quote: | It may be of interest to see an example of load testing.
|
| Quote: | From Bob’s post I understand only one has been built, unluckily subsequently
destroyed by hurricane Ivan. What scares me is to see is the ultimate 5.7 G
|
load test on an airframe, which probably has been flown after passing this
test. There is no proof or a timestamp in the JPEG pictures shown on the
load test page, so I can be wrong - and this is not to blame anybody here!
Remember, FAR 23 only requests 3 seconds with ultimate load!
If properly designed to the specs there can (and will) be deformations left
from an ultimate load test. This probably is - aside post wing failure
effects when the debris hit the ground - what later can show up in the
reports e.g. as “rivet holes were elongated and oval shaped” – and must not
necessarily be happened during the mishap which might have lead to a crash.
Conclusion: Please never do load tests beyond the limit load on an airframe,
which will be flown later again!
-Kurt.
---
From: owner-zenith-list-server(at)matronics.com
[mailto:owner-zenith-list-server(at)matronics.com] On Behalf Of MaxNr(at)aol.com
Sent: Saturday, May 12, 2007 6:41 AM
To: Zenith-List(at)matronics.com
Subject: Load testing
A lot of discussion about loads on aircraft structures. It may be of
interest to see an example of load testing. Click on this link, then click
on "Load testing." This plane was developed by one of the members of my EAA
chapter. Smaller than a 601XL, but same construction and made of 6061. This
prototype was destroyed in its hangar by hurricane Ivan in 2004. The
fuselage survives on the wall of the Indust Tech shop at Pensacola Jr
College. It still looks airworthy if you stand back 10 feet. I'm not pushing
this plane, but thought some pictures may be of interest.
Bob Dingley
Pace, FL
XL/Lyc Do not archive Click here: Welcome to the home of the
Thatcher CX4
| | - The Matronics Zenith-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
| Back to top |
|
|
planecrazydld(at)yahoo.co
Guest
|
| Posted: Sat May 12, 2007 4:20 am Post subject: Load testing |
|
|
One of the things that botherresd me about the one XL crash investigation where they pointed out that the wing skin rivet holes were elongated, is that the rivets CH uses are pretty poor in head retention, and I would suspect that the inversion of the head with the accompanying increase in work hardening of the barrel to head corner does not make that situation any better.
The very fact that the rivet holes were elongated overall suggests poor workmanship and the "unzipping" of the rows of rivets as the heads pop off one after the other in a single smooth fluid run. I have seen this many times in static test failures - and those in products designed by the big ones.
Of course if the holes were sloppy in the first place the rivets were more brittle than design calls for as well...
"Kurt A. Schumacher" <Kurt.Schumacher(at)schumi.ch> wrote:
[quote]--> Zenith-List message posted by: "Kurt A. Schumacher"
Interesting to see. Thatcher correctly differentiates between a design limit
load of 3.8 Gs, and an ultimate load of 5.7 Gs.
| Quote: | It may be of interest to see an example of load testing.
|
| Quote: | From Bob’s post I understand only one has been built, unluckily subsequently
destroyed by hurricane Ivan. What scares me is to see is the ultimate 5.7 G
|
load test on an airframe, which probably has been flown after passing this
test. There is no proof or a timestamp in the JPEG pictures shown on the
load test page, so I can be wrong - and this is not to blame anybody here!
Remember, FAR 23 only requests 3 seconds with ultimate load!
If properly designed to the specs there can (and will) be deformations left
from an ultimate load test. This probably is - aside post wing failure
effects when the debris hit the ground - what later can show up in the
reports e.g. as “rivet holes were elongated and oval shaped” – and must not
necessarily be happened during the mishap which might have lead to a crash.
Conclusion: Please never do load tests beyond the limit load on an airframe,
which will be flown later again!
-Kurt.
---
From: owner-zenith-list-server(at)matronics.com
[mailto:owner-zenith-list-server(at)matronics.com] On Behalf Of MaxNr(at)aol.com
Sent: Saturday, May 12, 2007 6:41 AM
To: Zenith-List(at)matronics.com
Subject: Load testing
A lot of discussion about loads on aircraft structures. It may be of
interest to see an example of load testing. Click on this link, then click
on "Load testing." This plane was developed by one of the members of my EAA
chapter. Smaller than a 601XL, but same construction and made of 6061. This
prototype was destroyed in its hangar by Get the Yahoo! toolbar and [url=http://us.rd.yahoo.com/evt=48225/*http://new.toolbar.yahoo.com/toolbar/features/mail/index.php]be alerted to new email [/url]wherever you're surfing. [quote][b]
| | - The Matronics Zenith-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
| Back to top |
|
|
planejim(at)bellsouth.net
Guest
|
| Posted: Sat May 12, 2007 4:33 am Post subject: Load testing |
|
|
Listers,
A side note on the Thatcher CX4 which may or may interest you. At Sun N fun 2007 the designer had a flying example on the field. This information has no bearing on the ongoing 601XL accident thread, and you can just disregard this message rather than going on further so as to save your time. Those who may be interested in the CX4, read on.
Several builders of the type came through the Basic Sheetmetal Workshop. I am the CoChairman of this workshop so I had an interest in their questions and comments. They were asking advise about the riveting technique that Mr. thatcher was using. I always make an effort to talk with the designer of the various aircraft types so that we provide the correct information to builders as they come through our workshop seeking information and help.
I had a short visit with Mr Thatcher at his airplane. There were several folks there asking questions. I first asked him about the technique he was using, where he calls for countersinking .020" skin and installing flush Avdel-Avex rivets, because this was not a normal procedure with such thin skin. He advised me and I later confirmed by looking at his information package that he also uses T-88 adhesive in the metal joints where he uses the flush rivets with the countersunk .020" skin. There is a sequence that he goes through in this process, so as to avoid "making the holes in the skin too big".
Here is an intersting item that some of the builders made me aware of as they came through the shop. Mr. Thatcher offers an alternative riveting method which he also mentions in his information package. That alternative method is "The Zenith Aircraft Procedure" of reshaping the head of the rivet during the installation and NOT countersinking the .020" skin. He noted that he just liked the look of the flush rivets and the smooth finish it produces. Mr. Thatcher confirmed the alternate method with me as we talked. I didn't ask him why he used both methods.
Please accept this as just general information which has limited value.
do not archive
Jim Hoak 601HD
[quote] ---
| | - The Matronics Zenith-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
| Back to top |
|
|
rosestar(at)sonic.net
Guest
|
| Posted: Sat May 12, 2007 7:09 am Post subject: Load testing |
|
|
The report of elongated holes concerns me. Can the impact cause that?
Or was it in the construction of the plane? I wish the NTSB would do a
study on that aspect of the plane to determine whether the elongation
was caused by the impact or something else.
Brad
On Saturday, May 12, 2007, at 05:19 AM, David Downey wrote:
| Quote: | One of the things that botherresd me about the one XL crash
investigation where they pointed out that the wing skin rivet holes
were elongated, is that the rivets CH uses are pretty poor in head
retention, and I would suspect that the inversion of the head with the
accompanying increase in work hardening of the barrel to head corner
does not make that situation any better.
The very fact that the rivet holes were elongated overall suggests
poor workmanship and the "unzipping" of the rows of rivets as the
heads pop off one after the other in a single smooth fluid run. I have
seen this many times in static test failures - and those in products
designed by the big ones.
Of course if the holes were sloppy in the first place the rivets were
more brittle than design calls for as well...
"Kurt A. Schumacher" <Kurt.Schumacher(at)schumi.ch> wrote:
Interesting to see. Thatcher correctly differentiates between a design
limit
load of 3.8 Gs, and an ultimate load of 5.7 Gs.
> It may be of interest to see an example of load testing.
>From Bob’s post I understand only one has been built, unluckily
subsequently
destroyed by hurricane Ivan. What scares me is to see is the ultimate
5.7 G
load test on an airframe, which probably has been flown after passing
this
test. There is no proof or a timestamp in the JPEG pictures shown on
the
load test page, so I can be wrong - and this is not to blame anybody
here!
Remember, FAR 23 only requests 3 seconds with ultimate load!
If properly designed to the specs there can (and will) be deformations
left
from an ultimate load test. This probably is - aside post wing failure
effects when the debris hit the ground - what later can show up in the
reports e.g. as “rivet holes were elongated and oval shaped” – and
must not
necessarily be happened during the mishap which might have lead to a
crash.
Conclusion: Please never do load tests beyond the limit load on an
airframe,
which will be flown later again!
-Kurt.
---
From: owner-zenith-list-server(at)matronics.com
[mailto:owner-zenith-list-server(at)matronics.com] On Behalf Of
MaxNr(at)aol.com
Sent: Saturday, May 12, 2007 6:41 AM
To: Zenith-List(at)matronics.com
Subject: Load testing
A lot of discussion about loads on aircraft structures. It may be of
interest to see an example of load testing. Click on this link, then
click
on "Load testing." This plane was developed by one of the members of
my EAA
chapter. Smaller than a 601XL, but same construction and made of 6061.
This
prototype was destroyed in its hangar by
<image.tiff>
|
| Quote: |
Get the Yahoo! toolbar and be alerted to new email wherever you're
surfing.
Bradford J. DeMeo
|
Attorney At Law
Estates and Trusts
565 West College Avenue
Santa Rosa, CA 95401
(707) 545-3232
CONFIDENTIALITY STATEMENT: The information contained in this email
message is intended only for the personal and confidential use of the
designated recipients named above. This message may be an
attorney-client communication and, as such, is privileged and
confidential. If the reader of this message is not the intended
recipient or an agent responsible for delivering it to the intended
recipient, you are hereby notified that you have received this document
in error, and that any review, dissemination, distribution or copying
of this message is strictly prohibited. If you have received this
communication in error, please notify us immediately by telephone and
return the original message to us by mail. Thank you.
IRS Circular 230 Disclosure: As required by U.S. Treasury Regulations
governing tax practice, you are hereby advised that any written tax
advice contained herein was not written or intended to be used (and
cannot be used) by any taxpayer for the purpose of avoiding penalties
that may be imposed under the U.S. Internal Revenue Code.
| | - The Matronics Zenith-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
| Back to top |
|
|
John Bolding
Joined: 23 May 2006
Posts: 281
|
| Posted: Sat May 12, 2007 8:06 am Post subject: Load testing |
|
|
One of the reasons that we can afford these airplanes is because the government ( Big Brother) does NOT do what you are wishing for. When that happens it called a certified airplane and we know how much those cost.
Several yrs ago the Adventurer amphib had a breakup in flight on one of it's early completions. A group of concerned builders pooled their dollars and hired a competent composite engineer that had an aero background ,or maybe it was an aero engineer that had a composite background( Martin Hollman) to find the cause. He did. Came up with a fix .Everybody happy.
I REALLY don't see any help coming from anywhere except from outside.
Those that are affected (601 builders)can choose a leader and attack the problem or you can turn this into a Scotchbrite thing and type it into submission. Your choice.
Couple yrs ago before the Corvairs started breaking cranks I tried to get the Corvair group ( about a thousand) to each contribute $20-100 so we could get a professional analysis done of the torsional vibration signature of the crank. Had it all lined up with Rousch Industries, had them send a copy of the quote to William. Only 2 people bellied up to the bar. Mark Lankford, who was later to experience a broken crank and Dan Bensen, engineer type who KNOWS whats going on with all the drive line changes made to the engine.
OK guys Fish or cut bait.??
LOW&SLOW John Bolding
| Quote: |
The report of elongated holes concerns me. Can the impact cause that? Or was it in the construction of the plane? I wish the NTSB would do a study on that aspect of the plane to determine whether the elongation was caused by the impact or something else.
Brad
|
<?/b><?/font><?/pre><?/body><?/html> [quote][b]
| | - The Matronics Zenith-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
| Back to top |
|
|
MaxNr(at)aol.com
Guest
|
| Posted: Sat May 12, 2007 9:04 am Post subject: Load Testing |
|
|
This aircraft was flown first, then load tested and retired. Then came the hurricane. (Which also destroyed my Beech) There are several dozen kits under construction. One by my Shop instructor who is in the first picture.
Bob
**************************************
See what's free at http://www.aol.com. [quote][b]
| | - The Matronics Zenith-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
