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Dutch XL crash findings
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aerobat

Joined: 07 Nov 2008
Posts: 21
Location: UK

Posted: Thu Jan 15, 2009 1:50 am Post subject: Dutch XL crash findings

This is from the Dutch safety board



http://www.safetyboard.nl/publications/dsb/intermediate_warning_accident_with_mla.pdf

psm(at)att.net
Guest

Posted: Thu Jan 15, 2009 3:28 am Post subject: Dutch XL crash findings

What a curious report!



 Here is a quote:



 As from 2006 until now at least seven accidents with different types of Zenair Zodiacs

 CH601’s have occurred caused by the collapse o f one or both wings as a result of wing

 overload. These accidents h ave occurred in int. al. the United States, the United Kingdom and

 Spain. Some investigations of these accidents revealed that the overload of the wings had

 different probable causes, for instance flutter in one or both wings.



 end of quote.



 I wonder where the Dutch folks got this information.  All the actual accident reports I have read indicated structural failure for unknown reasons.  Apparently, the Dutch folks have different reports that indicate overload and flutter.  Or perhaps they are just making up these facts . . .



 Paul

 XL getting close

 do not archive



 



 

 At 01:50 AM 1/15/2009, you wrote:

 [quote]--> Zenith601-List message posted by: "aerobat" <rhood2000(at)hotmail.com>



 This is from the Dutch safety board



  http://www.safetyboard.nl/publications/dsb/intermediate_warning_accident_with_mla.pdf 



 [b]

jmaynard

Joined: 27 Feb 2008
Posts: 394
Location: Fairmont, MN (FRM)

Posted: Thu Jan 15, 2009 5:18 am Post subject: Dutch XL crash findings

On Thu, Jan 15, 2009 at 03:28:05AM -0800, Paul Mulwitz wrote:

 	  Quote: 	
		   I wonder where the Dutch folks got this information.  All the actual 

 accident reports I have read indicated structural failure for unknown 

 reasons.  Apparently, the Dutch folks have different reports that indicate 

 overload and flutter.  Or perhaps they are just making up these facts . . .


	


They appear to have oulled it out of their...uhm...thin air.



The good news is that they're at least back from vacation.

-- 

Jay Maynard, K5ZC, PP-ASEL, AGI      http://www.conmicro.com

http://jmaynard.livejournal.com       http://www.tronguy.net

Fairmont, MN (KFRM)                        (Yes, that's me!)

AMD Zodiac CH601XLi N55ZC http://www.tronguy.net/N55ZC.shtml

_________________
Jay Maynard, K5ZC
AMD Zodiac XLi N55ZC

skyguynca

Joined: 05 Jun 2006
Posts: 128

Posted: Thu Jan 15, 2009 5:46 am Post subject: Dutch XL crash findings

Or perhaps they did a “real” investigation, real actual dynamic stress analysis thru computer animations…………and they did say that the fligh information came from the GPS unit recovered from the aircraft that provided the data that the plane was in level stable flight when the wing separated.  

   

David M.  

         

  

From: owner-zenith601-list-server(at)matronics.com [mailto:owner-zenith601-list-server(at)matronics.com] On Behalf Of Paul Mulwitz

 Sent: Thursday, January 15, 2009 3:28 AM

 To: zenith601-list(at)matronics.com

 Subject: Re: Dutch XL crash findings  

  

   

What a curious report!

 

 Here is a quote:

 

 As from 2006 until now at least seven accidents with different types of Zenair Zodiacs

 CH601s have occurred caused by the collapse o f one or both wings as a result of wing

 overload. These accidents h ave occurred in int. al. the United States, the United Kingdom and

 Spain. Some investigations of these accidents revealed that the overload of the wings had

 different probable causes, for instance flutter in one or both wings.

 

 end of quote.

 

 I wonder where the Dutch folks got this information.  All the actual accident reports I have read indicated structural failure for unknown reasons.  Apparently, the Dutch folks have different reports that indicate overload and flutter.  Or perhaps they are just making up these facts . . .

 

 Paul

 XL getting close

 do not archive

 

 

 

 

 At 01:50 AM 1/15/2009, you wrote:

 

   

--> Zenith601-List message posted by: "aerobat" <rhood2000(at)hotmail.com>

 

 This is from the Dutch safety board

 

 http://www.safetyboard.nl/publications/dsb/intermediate_warning_accident_with_mla.pdf   

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jmaynard

Joined: 27 Feb 2008
Posts: 394
Location: Fairmont, MN (FRM)

Posted: Thu Jan 15, 2009 6:02 am Post subject: Dutch XL crash findings

On Thu, Jan 15, 2009 at 05:44:26AM -0800, skyguynca(at)skyguynca.com wrote:

 	  Quote: 	
		   Or perhaps they did a "real" investigation, real actual dynamic stress

 analysis thru computer animations


	


If so, why didn't they say so? They probably didn't have time in the few

days since they got back from vacation.

-- 

Jay Maynard, K5ZC, PP-ASEL, AGI      http://www.conmicro.com

http://jmaynard.livejournal.com       http://www.tronguy.net

Fairmont, MN (KFRM)                        (Yes, that's me!)

AMD Zodiac CH601XLi N55ZC http://www.tronguy.net/N55ZC.shtml

_________________
Jay Maynard, K5ZC
AMD Zodiac XLi N55ZC

K Dilks

Joined: 22 Sep 2008
Posts: 108
Location: UK

Posted: Thu Jan 15, 2009 6:26 am Post subject: Re: Dutch XL crash findings

What good is the data from the GPS in relation to previous over stressing of the frame?

  Yes it broke in level flight but it could well have been over stressed many times before and finally something went.

 Bit like and engine blowing up because  50 ours ago it was run low on oil and suffered accelerated wear.

 Sad but I suspect a similar outcome as the Yuba city crash .....undetermined cause.

 My 2 cents 

Kev

_________________
Back home .................

Gig Giacona

Joined: 10 Jan 2006
Posts: 1416
Location: El Dorado Arkansas USA

Posted: Thu Jan 15, 2009 6:42 am Post subject: Re: Dutch XL crash findings

Has there been any official investigation that stated the flutter was the cause? If so I haven't seen it. The one official investigation that I have seen (Yuba City) specifically ruled out flutter.



This paragraph...

"Some investigations of these accidents revealed that the overload of the wings had different probable causes, for instance flutter in one or both wings."



Should be replaced with...

"An investigation of one of these accidents revealed that the overload of the wings caused the accident, and rumors have mentioned possibilities for instance flutter in one or both wings but was ruled out in the one accident investigated."

_________________
W.R. "Gig" Giacona
601XL Under Construction
See my progress at www.peoamerica.net/N601WR

jaybannist(at)cs.com
Guest

Posted: Thu Jan 15, 2009 6:42 am Post subject: Dutch XL crash findings

This is an uninformed, veiled indictment of Chris Heintz's design of the 601XL; and the fact that US-built XLs are not subject to international airworthiness standards.

 

 Keep in mind that the subject airplane should properly be called a "CZAW Zodiac 601XL",  NOT a Zenair Zodiac CH 601XL.

 

 Quote: "From a global examination of the drawings of the American design it appeared that the results of the calculations of strength conducted by the designer might have been too optimistic."

 

 No where do they allow that "...some modifications were applied to the model in order to enable the aircraft to comply with the requirement of having a maximum take off mass of 450 kg." might have contributed to the failure. 

 

 No where do they mention that these modifications are not in the "American design" and do not bear Chris Heintz's name (probably for very good reasons).

 

 No where do they mention that nearly all of the failed XLs were CZAW manufactured or CZAW kits.

 

 No where do they allow that CZAW might have used substandard materials in their construction.  

 

 No where do they mention that Zenair terminated their relationship with CZAW. (Wonder why?)

 

 From a global examination of the findings of the Dutch Safety Board, it appears that their conclusions are based on a  vague speculation, a LACK of information and are probably prejudiced. 

 

 Jay in Dallas

 Do not archive

 

   

 

   

 

 --

n85ae

Joined: 14 Mar 2007
Posts: 403

Posted: Thu Jan 15, 2009 6:56 am Post subject: Re: Dutch XL crash findings

The Dutch are reasonable people. The report is a "warning", that the plane

was not doing anything unusual and the wing simply broke off. 



Seems pretty obvious to me what they're saying. 



Regards,

Jeff

jmaynard

Joined: 27 Feb 2008
Posts: 394
Location: Fairmont, MN (FRM)

Posted: Thu Jan 15, 2009 7:02 am Post subject: Dutch XL crash findings

On Thu, Jan 15, 2009 at 06:56:53AM -0800, n85ae wrote:

 	  Quote: 	
		   The Dutch are reasonable people. The report is a "warning", that the plane

 was not doing anything unusual and the wing simply broke off. 

 

 Seems pretty obvious to me what they're saying. 


	


You are, however, assuming they're competent. Their conduct of this

investigation very strongly suggests otherwise, from their departure on

vacation at its very beginning to their utter ignoring of other

investigations and their refusal to allow people who actually know things to

participate. The final straw is their statement on the potential cause

which, so far, is totally unsupported by any facts or even any documentation

of their conjectures.

-- 

Jay Maynard, K5ZC, PP-ASEL, AGI      http://www.conmicro.com

http://jmaynard.livejournal.com       http://www.tronguy.net

Fairmont, MN (KFRM)                        (Yes, that's me!)

AMD Zodiac CH601XLi N55ZC http://www.tronguy.net/N55ZC.shtml

_________________
Jay Maynard, K5ZC
AMD Zodiac XLi N55ZC

skyguynca

Joined: 05 Jun 2006
Posts: 128

Posted: Thu Jan 15, 2009 7:59 am Post subject: Dutch XL crash findings

Jay, I have all Zeniths plans and have built and flown the 601HD and a big 

fan of Zenith planes so please do not think that I am bashing.



Now they did not list anything but the gps to give reference how they knew 

the plane was straight and level. I sure they did stress calculations and 

measurements and tons of stuff they did not list because it has nothing to 

do with publishing the conclusion.



Lets not "read into" what is not there oh and if you know what day they came 

back from vacation and how many days they took off please list it and your 

source.



Lets try to leave comments like that out of they conversation for their is 

no proof they just came back adn that they have been on vacation since the 

accident.



How ever they have posted their report and I understand that the "601XL 

Club" (oh and i have 601XL plans too) is not happy with the findings. Well 

you have the right to challenge them with the Dutch investigating 

authorities, but you do not have the right to slander them and make 

statements insinuating that they did not do a investigation because they 

were on vacation and now just making stuff up to put in their "officail" 

report.



David M.

Petaluma, CA



---

z601(at)anemicaardvark.co
Guest

Posted: Thu Jan 15, 2009 8:08 am Post subject: Dutch XL crash findings

Ignoring that this report appears to have an undertone of something put 

together, perhaps a bit hurriedly, when everyone returned from vacation, it 

again says little more than "something broke, and we don't know why."



What it troubling to me is that the accidents seem to get lumped together as 

though they were all one aircraft model, but they aren't. There's the Czech 

version, the AMD versions, and as many experimental versions as there are 

builders.



I would think Chris Heintz' measurements and tests are valid only for the US 

versions. Lacking information on the Czech variants, are these tests totally 

applicable?



I also wonder a little about the factory built copies, since we have one 

accident in which it was known there were various deficiencies at the time of 

delivery. True, these were corrected, but what does it say about factory 

quality control at the time of construction of that particular aircraft?



One of my concerns when the whole LSA thing was initially proposed was that 

having manufacturers propose their own standards, etc. was a little like the 

fox guarding the hen house. Does anyone know if the demonstrator the guys at 

Mexico, Mo use was build at AMD, or at Mexico?



I'm just thinking and curious. My mind is far from made up on the causes, and 

I wonder if we may not be seeing several problems, not just one.

-- 

=============================================

                Do not archive.

=============================================

                Jim B Belcher

    BS, MS Physics, Math, Computer Science

                  A&P/IA

     Retired aerospace technical manager

=============================================

jmaynard

Joined: 27 Feb 2008
Posts: 394
Location: Fairmont, MN (FRM)

Posted: Thu Jan 15, 2009 8:10 am Post subject: Dutch XL crash findings

On Thu, Jan 15, 2009 at 07:56:13AM -0800, David Mikesell wrote:

 	  Quote: 	
		   but you do not have the right to slander them and make statements

 insinuating that they did not do a investigation because they were on

 vacation and now just making stuff up to put in their "officail" report.


	


Sorry. Until they show their work, all we have to go on is their bald

statements - and that includes their statement that they would not be able

to do anything for some time after grounding the entire fleet because they

were going on vacation. We would not stand for that in the US; I have no

idea why the Europeans put up with it. In any event, that greatly harms

their credibility, because it is so completely unprofessional of them.

-- 

Jay Maynard, K5ZC, PP-ASEL, AGI      http://www.conmicro.com

http://jmaynard.livejournal.com       http://www.tronguy.net

Fairmont, MN (KFRM)                        (Yes, that's me!)

AMD Zodiac CH601XLi N55ZC http://www.tronguy.net/N55ZC.shtml

_________________
Jay Maynard, K5ZC
AMD Zodiac XLi N55ZC

psm(at)att.net
Guest

Posted: Thu Jan 15, 2009 8:23 am Post subject: Dutch XL crash findings

I think it is safe to assume the demonstrator was built by the Zenith 

folks rather than AMD.  The demonstrator has hinge-less ailerons,a 

Jabiru 3300 engine, and Center Y stick.  The AMD planes (I believe) 

have Continental engines, piano hinge ailerons, and dual sticks.



Paul

XL getting close

do not archive

At 08:09 AM 1/15/2009, you wrote:

 	  Quote: 	
		  Does anyone know if the demonstrator the guys at

Mexico, Mo use was build at AMD, or at Mexico?

jmaynard

Joined: 27 Feb 2008
Posts: 394
Location: Fairmont, MN (FRM)

Posted: Thu Jan 15, 2009 8:27 am Post subject: Dutch XL crash findings

On Thu, Jan 15, 2009 at 08:23:52AM -0800, Paul Mulwitz wrote:

 	  Quote: 	
		   The AMD planes (I believe) have Continental engines, piano hinge ailerons,

 and dual sticks.


	


This is correct.

-- 

Jay Maynard, K5ZC, PP-ASEL, AGI      http://www.conmicro.com

http://jmaynard.livejournal.com       http://www.tronguy.net

Fairmont, MN (KFRM)                        (Yes, that's me!)

AMD Zodiac CH601XLi N55ZC http://www.tronguy.net/N55ZC.shtml

_________________
Jay Maynard, K5ZC
AMD Zodiac XLi N55ZC

Jeyoung65(at)aol.com
Guest

Posted: Thu Jan 15, 2009 8:37 am Post subject: Dutch XL crash findings

 	  Quote: 	
		  From the report it would appear that the wing was not bent or broken just  

the attachments to the fuselage. As I have a 601HD I do not know how the 601XL  
	


wings are attached. Does anyone know what they are talking about "upper and  

lower reinforcement of the right hand wing main spar"? Are these parts of the  

fuselage (my: 6F-6-1 and -3)?  Jerry of Ga    DO NOT  ARCHIVE

 

"The right hand wing folded up and backwards in flight, whereby the upper  

lining of the wing hit

the upper side of the fuselage, behind the  canopy.

· The right hand wing did not break.

· The upper reinforcement of  the right hand wing main spar had been buckled 

and twisted,

slightly forward  of the wing-fuselage attachment.

· The lower reinforcement of the right wing  main spar had been twisted just 

in front of the  wingfuselage

attachment."

 

 

In a message dated 1/15/2009 10:59:34 A.M. Eastern Standard Time,  

skyguynca(at)skyguynca.com writes:




<skyguynca(at)skyguynca.com>



Jay, I have all Zeniths plans and have  built and flown the 601HD and a big 

fan of Zenith planes so please do not  think that I am bashing.

jaybannist(at)cs.com
Guest

Posted: Thu Jan 15, 2009 8:54 am Post subject: Dutch XL crash findings

I am guessing that they are referring to the upper and lower wing spar caps.  Coincidentally, there is some question about the integrity of the materials used by CZAW for these very parts.

 

 Jay in Dallas

 Do not archive

 

   

 

   

 

 --

n85ae

Joined: 14 Mar 2007
Posts: 403

Posted: Thu Jan 15, 2009 8:59 am Post subject: Re: Dutch XL crash findings

 	  jmaynard wrote: 	
		  The final straw is their statement on the potential cause

which, so far, is totally unsupported by any facts or even any documentation

of their conjectures. 	




This is what they said in the Preliminary Conclusion, perhaps your version

of English and mine are vastly different. It still reads the same to me, but

maybe I'm a dummy ...? 



Jeff



The investigation conducted by the Dutch Safety Board into the cause of this accident is ongoing.

Nevertheless the Board, with regard to the seven similar accidents elsewhere in the world, and in

anticipation of the definitive outcome of its investigation of this accident, holds the opinion that it is

appropriate to warn all those who are directly or indirectly involved in the operation of this type of

aircraft for the apparent risks in doing so.

tiethoff

Joined: 02 Sep 2008
Posts: 23

Posted: Thu Jan 15, 2009 9:13 am Post subject: Dutch XL crash findings

Jay, you  wrote:

  

 "Coincidentally, there is some question about the integrity of  the materials used by CZAW for these very parts." 

  

 What do you have to prove this ? Did you ever compare all  the drawings ? By the way, i am from Holland and have all the confidence in the  authorities that are trying to find the reason why this particular plane came  down. This sort of investigation takes al long time and is in the best interest  of all of us. Everybody has a right to an opinion but please don't shout till  you have seen the outcome of all this.

  

 Kindest regards from Holland.

  

 



  



  From: jaybannist(at)cs.com (jaybannist(at)cs.com) 

 Sent: Thursday, January 15, 2009 5:53 PM

 To: zenith601-list(at)matronics.com (zenith601-list(at)matronics.com)  

 Subject: Re: Dutch XL crash  findings

 



 I am guessing that they are  referring to the upper and lower wing spar caps.  Coincidentally, there is  some question about the integrity of the materials used by CZAW for these very  parts.



Jay in Dallas

Do not archive



 



 



--

jaybannist(at)cs.com
Guest

Posted: Thu Jan 15, 2009 9:48 am Post subject: Dutch XL crash findings

Eric,

 

 I beg your pardon ?  I really don't understand your reply.  Who is shouting, and what is there to prove? There IS a question about the materials used.  A question is just that - a question.  How can you prove a question ?  There are many questions in the report.  Why didn't you ask where their proof is ?

 

 Obviously, I personally have many questions about the performance of the Dutch Safety Board handling this situation.

 

 The report did not specifically address the grounding of 601Xls.  The final sentence warns about the risk of operating "this type of aircraft". Does that mean that the grounding has been lifted or is it still in effect ?

 

 Kindest regards from The United States of America

 

 Jay in Dallas

 Do not archive

 

   

 

   

 

 --

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