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Flutter Testing shows 601/650 OK
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jeffrey_davidson(at)earth
Guest

Posted: Sun May 24, 2009 6:55 am Post subject: Flutter Testing shows 601/650 OK

Jay,  

      I understand your very human need for an explanation.  We all want to find out what caused these accidents.  This is particularly true if one cause is responsible.  Actually, we want to learn from all accidents, particularly fatal ones.  But that doesn't mean that the need for an answer justifies grabbing at whatever theory comes along and holding that up as the true cause.  We need to proceed on facts and at this time, we have no choice but to realize that we don't have the facts to conclusively explain what has happened despite multiple extensive investigations.  You need to realize that we may never have the ultimate answer despite all our efforts.  

      Jeff Davidson  

    

   

Time: 07:48:22 PM PST US  

From: Jay Maynard <jmaynard(at)conmicro.com>  

Subject: Re: Zenith601-List: Re: Flutter Testing shows 601/650 OK  

   

   

On Sat, May 23, 2009 at 07:11:46PM -0700, Ron Lendon wrote:  

 	  Quote: 	
		   Well that is not unexpected news.  I am really glad to hear it.  It is   

 really a shame all this even took place just because of a few   

 uninformed whiners.  

   
	


Okkay, fine. How do YOU explain the inflight breakups? Bear in mind that builder and pilot error cannot explain every 601XL inflight breakup.  

       [quote][b]

Gig Giacona

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

Posted: Tue May 26, 2009 1:51 pm Post subject: Re: Flutter Testing shows 601/650 OK

 	  Quote: 	

Time: 07:48:22 PM PST US  

From: Jay Maynard <jmaynard>  

Subject: Re: Zenith601-List: Re: Flutter Testing shows 601/650 OK  

Okkay, fine. How do YOU explain the inflight breakups? Bear in mind that builder and pilot error cannot explain every 601XL inflight breakup.  

Actually if you add maintenance to builder and pilot error, yes you can.

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

d.goddard(at)ns.sympatico
Guest

Posted: Tue May 26, 2009 5:07 pm Post subject: Flutter Testing shows 601/650 OK

That would require quite a leap. The cause is unknown, unknown to you as 

well as everyone else.



A more proper response to the question would have been "I don't."



These incidents have occurred, they seem to have stopped for a short while 

now, with any luck they won't re-occur. I'm not sure that lack of 

maintenance explains it either, some seem to be as fixated on cable tension 

as others were on flutter. The results I saw posted from the tests seemed to 

indicate that cable tensions were not quite as critical as supposed. So far 

nothing has been identified as an issue causing the problems. Each item 

stroked off the list should be regarded as a positive, not a reason to start 

pissing on each other again. Flight safety should be a primary concern to 

all of us, not winning bull***t arguments on mailgroups.



---

jmaynard

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

Posted: Tue May 26, 2009 5:24 pm Post subject: Flutter Testing shows 601/650 OK

On Tue, May 26, 2009 at 10:06:07PM -0300, Dave wrote:

 	  Quote: 	
		   Flight safety should be a primary concern to all of us, not winning

 bull***t arguments on mailgroups.


	


I will happily "lose" this argument if it means that we *know* - not merely

think we know - what causes Zodiac inflight breakups and how to prevent

them.

-- 

Jay Maynard, K5ZC, PP-ASEL, CFI-SP   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

daveaustin2(at)primus.ca
Guest

Posted: Tue May 26, 2009 5:52 pm Post subject: Flutter Testing shows 601/650 OK

Is it reasonable to expect that we will "know" absolutely for sure?  not 

many things in life are that clear.

Dave Austin  601HDS - 912

jmaynard

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

Posted: Tue May 26, 2009 5:57 pm Post subject: Flutter Testing shows 601/650 OK

On Tue, May 26, 2009 at 09:50:54PM -0400, Dave Austin wrote:

 	  Quote: 	
		   Is it reasonable to expect that we will "know" absolutely for sure?  not 

 many things in life are that clear.


	


If we find a smoking gun somewhere, we'll have a reasonable amount of

certainty. If not, then we'll have to muddle along - and put up with the

effects of a bad reputation for the airplane. Which would you rather have?

-- 

Jay Maynard, K5ZC, PP-ASEL, CFI-SP   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

d.goddard(at)ns.sympatico
Guest

Posted: Wed May 27, 2009 2:13 am Post subject: Flutter Testing shows 601/650 OK

I think the only people who have lost so far were flying at the time.



I admire your desire to *know* with absolute certainty but it may very well 

never happen. I expect the real answer is to keep an open mind, be cautious 

and fly carefully. Becoming fixated on one idea or another will lead to the 

positions already taken such as "I know flutter is the problem and I'm 

installing mass balance devices so I'll be completely safe" or " I know for 

a fact that there is no possible problem with this aircraft and everyone who 

has crashed was a bad pilot and deserved what they got". Both are pretty 

much unsubstantiated beliefs.



In time the aircraft will prove itself or a likely source of the problems 

will be found. But even if a likely source is identified, it will not likely 

address every incident all the time, if you stacked up all the aircraft 

accidents that ever happened, it might turn out that unexplained is the 

largest stack.



---

steveadams

Joined: 10 Jan 2006
Posts: 191

Posted: Wed May 27, 2009 5:27 am Post subject: Re: Flutter Testing shows 601/650 OK

So what do we know? We know that review of the design by multiple independent parties have found the design meets structural design parameters, both through computer modeling and destructive testing. Sure the modeling can not identify or predict every flaw, but as a non-engineer, I have to assume that they looked at all the common things people have brought up in this list like torsional loads on the structure in worst case scenarios. We know that flutter testing showed no evidence of flutter with cable tensions down to 10. Each aircraft is different theoretically, but this is pretty strong evidence that flutter is not the smoking gun, at least in aircraft built and maintained to design specs. We know that the aircraft has a lot of pitch authority, and have seen unquestioned examples of pilots using the stick to remove their wings in flight. We know that in at least some of the accidents there was evidence of extremely high negative G forces. We know by example in other aircraft designs, that lack of model specific training and experience can prove fatal. For example, pilot induced oscillations in a gyro. We know that most of the accidents involved pilots with relatively little time in the 601xl, regardless of the number of total hours they had. Having never flown in a 601, I can't speak from experience about the handling qualities of the airplane, I can only speak as a casual outside observer to this entire mess. While there are some here that say you just can't blame all of the accidents on pilot error/lack of experience in flying the 601, to me all the evidence thus far is like a neon sign pointing in that direction. That's my opinion for what it's worth.



Steve

Zodiac CH640 N621J

Gig Giacona

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

Posted: Wed May 27, 2009 5:54 am Post subject: Re: Flutter Testing shows 601/650 OK

 	  d.goddard(at)ns.sympatico wrote: 	
		  That would require quite a leap. The cause is unknown, unknown to you as 

well as everyone else.



	




I assume you were responding to me. And if you look at all GA accidents the two items Jay listed plus the one I added are responsible for the vast majority of accidents. So it isn't that much of a leap.

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

Larry Webber

Joined: 05 Jun 2008
Posts: 63
Location: West Kingston Rhode Island

Posted: Wed May 27, 2009 5:54 am Post subject: Flutter Testing shows 601/650 OK

The aircraft doesnt have a bad reputation C what it does have is a bunch of 

 useless speculators trying to solve a problem from their armchairs. Why dont

 we give it a rest. Its the badmouthing causing all the bull***t  as soon as 

 my project is complete im heading for UP. you all can do what you want 

 Larry Webber 601xl/corvair chugger 



  

[quote] Date: Tue C 26 May 2009 20:56:14 -0500

 From: jmaynard(at)conmicro.com

 To: zenith-list(at)matronics.com

 Subject: Re: Re: Flutter Testing shows 601/650 OK

 

 --> Zenith-List message posted by: Jay Maynard <jmaynard(at)conmicro.com>

 

 On Tue C May 26 C 2009 at 09:50:54PM -0400 C Dave Austin wrote:

 > Is it reasonable to expect that we will "know" absolutely for sure? not 

 > many things in life are that clear.

 

 If we find a smoking gun somewhere C we'll have a reasonable amount of

 certainty. If not C then we'll have to muddle along - and put up with the

 effects of a bad reputation for the airplane. Which would you rather have?

 -- 

 Jay Maynard C K5ZC C PP-ASEL C CFI-SP http://www.conmicro.com

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

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

 AMD Zodiac CH601XLi N55ZC htt-========================

 

 

 

Windows Live™: Keep your life in sync. Check it out.   	  Quote: 	
		  [b]

_________________
how do you eat an elephant ? one bite at a time

jmaynard

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

Posted: Wed May 27, 2009 6:17 am Post subject: Flutter Testing shows 601/650 OK

On Wed, May 27, 2009 at 09:53:25AM -0400, Lawrence Webber wrote:

 	  Quote: 	
		   The aircraft doesnt have a bad reputation, what it does have is a bunch of

 useless speculators trying to solve a problem from their armchairs. Why

 dont we give it a rest. Its the badmouthing causing all the bull***t as

 soon as my project is complete im heading for UP. you all can do what you

 want


	


The NTSB's report did not help matters, and there's no "useless speculators"

there. Argue all you want about the NTSB's abilities and whether you think

they have axes to grind, but the fact remains that, to people outside the

Zodiac community, the airplane's reputation has been badly damaged - and if

you need to sell yours, then that will hit you square in the wallet.



How many of you find yourself beginning conversations with pilot friends by

explaining the latest news from Zenair's GVT, in reply to questions?

-- 

Jay Maynard, K5ZC, PP-ASEL, CFI-SP   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

PatrickW

Joined: 27 Oct 2006
Posts: 380
Location: Fort Worth, Texas

Posted: Wed May 27, 2009 6:20 am Post subject: Re: Flutter Testing shows 601/650 OK

 	  d.goddard(at)ns.sympatico wrote: 	
		  These incidents have occurred, they seem to have stopped for a short while now, with any luck they won't re-occur. 	


A couple of possible reasons.



1)  Perhaps builders & pilots have been more vigilant recently, and are doing more thorough inspections, and are finding things that are getting addressed that otherwise would have lead to problems.



2)  Or perhaps people are flying less often than they were before.  We've just recently come out of winter in the northern regions.



There are more Zodiacs now than there were a couple years ago, so I hope the decrease in accidents is because people are more aware now than maybe they were before.



Are you guys finding anything on your planes that the rest of us should be on the lookout for...?



- Pat

d.goddard(at)ns.sympatico
Guest

Posted: Wed May 27, 2009 6:48 am Post subject: Flutter Testing shows 601/650 OK

We were not talking about all GA, we were talking about 601XL's, and you 

said if you added the items that YOU could explain EVERY incident. You 

can't, unexplained is unexplained. If the investigating bodies don't know, 

neither do you.



 	  Quote: 	
		  >How do YOU explain the inflight breakups? Bear in mind that builder and 

>pilot error cannot explain every 601XL inflight breakup.


	


 	  Quote: 	
		  Actually if you add maintenance to builder and pilot error, yes you can.


	




---

d.goddard(at)ns.sympatico
Guest

Posted: Wed May 27, 2009 7:04 am Post subject: Flutter Testing shows 601/650 OK

Lawrence, I would hasten to point out that all the  discussion SHOULD have been aimed at finding out IF there is a way to avoid  future incidents and thereby avoid future loss of life and an inevitable bad  reputation. Simply calling those trying to identify potential issues names is  hardly productive. They thought it might be a flutter issue and it looks like  they were wrong, there still may be an issue. Nobody knows. Does the aircraft  have a bad reputation? I'm sure that amoung some it does, crashes will do that  sort of thing. I don't think it deserves one but the numbers would indicate that  some extra thought and caution is required. 

  

 Frankly I'd be far happier reading a hundred messages  asking "Could it be this?" only to have potential concerns erased one by  one than reading a single one demanding that everyone shut up about it  and deny there have been issues. 

 [quote]   ---

Gig Giacona

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

Posted: Wed May 27, 2009 8:09 am Post subject: Re: Flutter Testing shows 601/650 OK

But the 601XL's don't exist in a vacuum. When you don't know what brought one down it is wise to look at what brings down GA aircraft as a whole. The AOPA knows this applies to all flying and it is why there is a Nall report each year and why the NTSB produces accident reports. I don't read just 601XL accident reports I read most of them.



Over 16% of the fatal GA accidents have "Other/Unknown" as the cause. It is the very nature of fatal accidents especially GA and even more especially EXP-HB and LSA that you never know the cause.  The reason for this is obvious, the only people that really know are dead.



In replying to Lawrence you wrote,



 	  Quote: 	
		  Frankly I'd be far happier reading a hundred messages asking "Could it be this?" only to have potential concerns erased one by one than reading a single one demanding that everyone shut up about it and deny there have been issues. 	


 



I disagree. Look at what happened with the whole flutter issue. In not one single accident report was flutter ever mentioned. The only time it was mentioned in one it was to say there was no physical evidence of it. Yet the guys over at ZBAG created so much speculation around the issue that the NTSB ignored their own reports and listed it in the alert letter.



This isn't helpful. The constant harping on what error might be in the aircraft may well be covering the real problem which could well be pilot error magnified by a uniqueness in the flight characteristics of the plane.



The Yuba City accident is a perfect example for such a scenario. Experienced pilot is in cruse flight. The plane is trimmed and everything great. Either the pilot or passenger leans forward and the seat belt hangs on the stick when they lean back they go into a climb and the pilot overcompensates with down elevator and over stresses the airframe to failure.



I'm not saying this is what happened but we do KNOW that the elevator has lots of authority. So much so that the designer has added a down elevator limiting modification. But many here and especially over in ZBAG have so fixated on there being a design error that they seem to refuse to consider pilot error which is the largest single cause of GA accidents.

[quote="d.goddard(at)ns.sympatico"]We were not talking about all GA, we were talking about 601XL's, and you 

said if you added the items that YOU could explain EVERY incident. You 

can't, unexplained is unexplained. If the investigating bodies don't know, 

neither do you.



 	  Quote: 	
		  >How do YOU explain the inflight breakups? Bear in mind that builder and 

>pilot error cannot explain every 601XL inflight breakup.



	


 	  Quote: 	
		  Actually if you add maintenance to builder and pilot error, yes you can.

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

d.goddard(at)ns.sympatico
Guest

Posted: Wed May 27, 2009 12:18 pm Post subject: Flutter Testing shows 601/650 OK

You're right, the constant sniping is not useful, nor is speculation posing 

as fact. I have no idea what ZBAG said as I am not part of it and all I've 

seen is heated rephrasing of their position. They did what they felt was 

right and while it may be inconvenient for some, I can't disagree with the 

stated motives I've seen which was to have the airframe tested. I've said 

all along we don't know and shouldn't leap to conclusions.



I simply posited that you don't know and should have answered that you have 

no answer. It was YOUR position as shown that YOU had the answer to all of 

them. I said you don't. Nobody does. There is no argument here as far as I'm 

concerned. It is never my aim to start or continue the pissing contest here. 

The two basic tenets I've seen here are that there is definitely a problem 

(and this is what it is....) and there is definitely not a problem (and shut 

up about it....), neither position is right as far as I am concerned. It 

appears to me there MAY be a problem, currently unknown and my private 

speculation as to the cause is not so far from the one you advanced.



As far as you disagreeing with me, agreement is not guaranteed. it shouldn't 

be a problem that we disagree.



Do not archive.



---

ggower_99(at)yahoo.com
Guest

Posted: Wed May 27, 2009 12:45 pm Post subject: Flutter Testing shows 601/650 OK

Very easy,  just invite them for a flight   

  

 Saludos

 Gary Gower

 Do not archive.



--- On Wed, 5/27/09, Jay Maynard <jmaynard(at)conmicro.com> wrote:



  	  Quote: 	
		  

From: Jay Maynard <jmaynard(at)conmicro.com>

Subject: Re: Re: Flutter Testing shows 601/650 OK

To: zenith-list(at)matronics.com

Date: Wednesday, May 27, 2009, 10:11 AM



 --> Zenith-List message posted by: Jay Maynard <jmaynard(at)conmicro.com (jmaynard(at)conmicro.com)>



On Wed, May 27, 2009 at 09:53:25AM -0400, Lawrence Webber wrote:

 	  Quote: 	
		   The aircraft doesnt have a bad reputation, what it does have is a bunch of

 useless speculators trying to solve a problem from their armchairs. Why

 dont we give it a rest. Its the badmouthing causing all the bull***t as

 soon as my project is complete im heading for UP. you all can do what you

 want


	


The NTSB's report did not help matters, and there's no "useless speculators"

there. Argue all you want about the NTSB's abilities and whether you think

they have axes to grind, but the fact remains that, to people outside the

Zodiac community, the airplane's reputation has been badly damaged - and if

you need to sell  yours, then that will hit you square in the wallet.



How many of you find yourself beginning conversations with pilot friends by

explaining the latest news from Zenair's GVT, in reply to questions?

-- 

Jay Maynard, K5ZC, PP-ASEL, CFI-SP   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



_-========================p;  --> http://www.matronics.com/Navigator?Zenith-List

sp; --> ht=                               -Matt Drallnics.com/contribution" target=_blank>http://www.matronics.com/contributio==============





	


         [quote][b]

ggower_99(at)yahoo.com
Guest

Posted: Wed May 27, 2009 12:53 pm Post subject: Flutter Testing shows 601/650 OK

I think that what we learned from all of this, and should NEVER should forget since our Student hours...

 To do a GOOD preflight every time...  Not just wipe the leading edge and kick (sp?) the tires...   On every airplane we now fly... 601XL or not.

  

 Yes, I know, a few armchairs will write:  I always do a perfect preflight...

  

 Just a thought.

  

 Saludos

 Gary Gower.

  

 



--- On Wed, 5/27/09, PatrickW <pwhoyt(at)yahoo.com> wrote:



  	  Quote: 	
		  

From: PatrickW <pwhoyt(at)yahoo.com>

Subject: Re: Flutter Testing shows 601/650 OK

To: zenith-list(at)matronics.com

Date: Wednesday, May 27, 2009, 10:20 AM



 --> Zenith-List message posted by: "PatrickW" <pwhoyt(at)yahoo.com (pwhoyt(at)yahoo.com)>

d.goddard(at)ns.sympatico wrote:

 	  Quote: 	
		   These incidents have occurred, they seem to have stopped for a short while now, with any luck they won't re-occur.


	


A couple of possible reasons.



1)  Perhaps builders & pilots have been more vigilant recently, and are doing more thorough inspections, and are finding things that are getting addressed that otherwise would have lead to problems.



2)  Or perhaps people are flying less often than they were before.  We've just recently come out of winter in the northern regions.



There are more Zodiacs now than there were a couple years ago, so I hope the decrease in accidents is because people are more aware now than maybe they were before.



Are you guys  finding anything on your planes that the rest of us should be on the lookout for...?



- Pat



--------

Patrick

XL/650/Corvair

N63PZ (reserved)





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=245545#245545

http:========================



	


           [quote][b]

Juan Vega Jr

Joined: 13 Jan 2009
Posts: 157

Posted: Thu May 28, 2009 3:09 pm Post subject: Flutter Testing shows 601/650 OK

Three times this weekend, people have asked,  "what kind of plane is that", I respond,  "zodiac".  They respnd,  "isn't that the one that folded Etc. etc. etc.   "  I say yes,  "mostly due to pilots that don't know what Manauvering speed is..".  



Juan



--

cookwithgas

Joined: 06 Nov 2007
Posts: 159

Posted: Thu May 28, 2009 5:44 pm Post subject: Re: Flutter Testing shows 601/650 OK

Guys:



I've been reading these flutter posts once again till I'm blue in the face (All my tools are packed up and I honestly don't have anything else to do right now). These planes are sturdy, stable, and safe airplanes.  I've got 130 hours on mine.  I have flown it round trip from Omaha to Rapid City, South Dakota and round trip from Omaha to Orleans, Indiana and most recently one-way from Omaha to Dallas, Texas.  Each one of these 5+ hour (each way) trips was pure joy and full of excitement with a huge dose of accomplishment.  I built almost every piece to this thing and I installed every part, piece by piece to realize a dream I have had for years.  I know what's in there and I know how she flies - like a dream. 



Of the builders that are flying completed 601XL's - Juan, Gary, me and many others, there is a similar message - go fly and stop yammering on the internet.  



Then there is Jay Maynard who purchased his from a store. Jay I can understand why you keep stirring the pot here because there are hundreds of parts you don't understand.  It makes sense because you wrote a check and picked up your airplane from the airplane store.  No disrespect (I'm happy for you), but there is no way you can understand what most of us are talking about here.  I welcome your emails, but you aren't really in the same arena as most of the guys here pulling rivets alone in the garage with a passion that an airplane purchaser can't comprehend. 



Lastly there are the builders that aren't flying yet.  God bless you guys.   When you aren't building you are worrying over the project.  You wonder if you did this or that correctly months ago on a certain part.  You loose sleep often wondering if you drilled the spars upside down or if you made two left parts instead of a left and a right.  There is a whole list of other issues for scratch vs. kit builders, but you are out there working away by your lonesome.  When you are on the computer, this noise crops up about wings falling off.  Worst of all, you don't have the reinforcement of a joyride every week to remind you of what a great job you did in building your own airplane and how great the 601XL flies.



Point is that if you have built one of these great airplanes and fly it regularly you say "hogwash" to all this speculation and yammering.  This thing is sturdy and reliable.  I do my pre-flight and fly with complete confidence once a week if time allows.  If you are building and reading all this speculation, keep your chin up and keep building carefully and diligently.  It will all come together and it will be a flying machine that will take you safely on many adventures.  If you are losing sleep over the safety, then save up $4K+ and install a BRS.  For a builder-stud like you, a BRS is no problem to install.  I salute those of you with un-finished projects out in the shop who are riveting and dreaming.  



Take care, and Happy Flying.



Scott Laughlin

601XL/Corvair

130 Hours

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