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NTSB recommends grounding of 601XLs in US
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jmaynard

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

Posted: Thu Apr 16, 2009 8:18 am Post subject: NTSB recommends grounding of 601XLs in US

On Thu, Apr 16, 2009 at 08:47:15AM -0700, ashontz wrote:

 	  Quote: 	
		   If you're instead an aviation consumer, like I said on the ZBAG list

 before being banned for it, go order a kit from Cessna.


	


As I said on the other list: bite my crank.



I have fully legitimate interests in seeing the issue resolved in whatever

way turns out to be technically and economically feasible. I don't have the

time invested that you do, but I suspect I've got somewhere around four times

the money invested - money I'll be paying off for years, even if my airplane

never flies again.



I don't give a fuzzy rat's ass if you or anyone else think I've got no

credibility because I haven't pulled rivets and turned wrenches. I don't

care if you hold those who aren't building from plans in utter, smoldering,

sneering contempt. That's your problem, not mine.



The Zodiac world encompasses more than just those folks building from plans.

We need to pull together for a solution that will work for all of us.

-- 

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

jmaynard

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

Posted: Thu Apr 16, 2009 8:19 am Post subject: NTSB recommends grounding of 601XLs in US

On Thu, Apr 16, 2009 at 09:13:33AM -0700, Gig Giacona wrote:

 	  Quote: 	
		   One nice thing about them giving their report to the NTSB is that it

 should now be available through the Freedom of Information Act and I have

 already started the process to file an FOI request. When received I will

 place the information in a public forum where those who desire can examine

 it.


	


FWIW, I believe the report should be made public, as well.



 	  Quote: 	
		   This will probably get me banned from reading the ZBAG forum as has

 already happened with at least one other person that spoke up there but I

 can live with that.


	


That member was banned not for speaking up; he was banned for speaking up in

a way that showed that he is, and always has been, uninterested in working

to further the work of the group. His presence was always somewhat

disruptive, and became dramatically so this morning.

-- 

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

craig(at)craigandjean.com
Guest

Posted: Thu Apr 16, 2009 8:22 am Post subject: NTSB recommends grounding of 601XLs in US

Re ZBAG: to a man with a hammer, everything looks like a nail.



-- Craig

jmaynard

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

Posted: Thu Apr 16, 2009 9:32 am Post subject: NTSB recommends grounding of 601XLs in US

On Thu, Apr 16, 2009 at 10:09:17AM -0700, Sabrina wrote:

 	  Quote: 	
		   I think you have a couple of things wrong as to the requirements of the

 regs.  Although a CFI-SP may not need a medical CERTIFICATE, the FAA/DPE

 examiner has the absolute right to deny your CFI-SP if he determines you

 do not meet the all the requirements in the FARs (physical/mental/skill.)


	


Indeed she does. Until this DPE decided she wasn't comfortable flying in a

Zodiac, I wasn't upset at all.



Her decision, even though I understand it and respect her right to make it,

left me in the lurch, and when Juan and Andrew dropped their separate bits

of drivel on this list, they added fuel tot he fire.



 	  Quote: 	
		   In otherwords, just as a private pilot who is very upset over being served

 with divorce papers should ground himself for a short duration, a sport

 pilot has the same duty.  You seem too riled up over this NTSB letter to

 be flying much less instructing.


	


I have no intention of doing either until I can give honest, safe answers to

all of the questions on the PAVE personal safety checklist:



Pilot: Am I up to the mission? Recency, experience, ratings, physical

       condition all count here.

Aircraft: Is the aircraft safe and suitable? Do I have enough fuel and other

       supplies on board?

enVironment: Is the weather suitable? Are the intended airports in usable

       condition, and not hazardous due to things like snow on the runway?

External factors: Do I have alternate plans? Am I being pressured to make

       the trip by factors that would override a decision based on safety?



In this case, I get mad every time Andrew lets loose with another blast at

those who he considers not good enough to be flying a Zodiac...but I also

calm down afterwards, too. As long a we don't have that discussion at the

airport, it's not an issue. 



I didn't fly yesterday after speaking to the DPE because I was too upset.

I'll probably be calmed down enough to fly in another day or so. Whether

that state will persist will depend on lots of things that I can only partly

control.



 	  Quote: 	
		   As part of ZBAG you should have expected this result and planned

 accordingly.


	


Well, I expected that the NTSB would have had something to say...but, by

their own admission, recommending an immediate grounding of an entire fleet

of aircraft is quite unusual for them. What's even more unusual to me was

that the DPE, a lady who's respected around these parts as a calm,

level-headed aviator with lots of experience flying, teaching, and building

airplanes, would decide she wasn't interested in flying in my airplane any

longer, after being quite interested the other times I'd spoken to her.



 	  Quote: 	
		   Building an airplane would have taught you over and over again how to

 handle major disappointments.  You seem to have a bad case of "get

 there/get it itis."


	


I've been reevaluating my decision to fly my airplane ever since I became

aware of the controversy last year. So far, the evaluation has always come

out the same: keep it properly maintained, fly it conservatively and well

within the performance envelope, and don't do anything stupid, and it's a

safe aircraft to fly. I see no reason to change that evaluation. The

information the NTSB based its report on has been known for several months,

after all.



Am I an aeronautical engineer? No. I have, however, considered the opinions

of lots of folks who are, on both sides of the issue. That's all I can do.



 	  Quote: 	
		   You are very entertaining on TV and the Internet and I wish you nothing

 but the best.


	


Thanks.

-- 

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

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Thu Apr 16, 2009 9:33 am Post subject: Re: NTSB recommends grounding of 601XLs in US

No, I got banned for speaking up and reminding them that the original purpose was to have a third party check out the design, that's all. In fact, if i remember correctly I'm the one that originally asked if anyone want to chip in to have someone look at the plans. Remember Jay. I was THE ORIGINAL ZBAG member. And my intention was never to have it go anywhere near where you guys took it, it was simply so that several guys with $100 each could pool their money together to hire an maybe a retired aeronautical engineer who wanted to packet $3,000 or $4,000 for 3 weeks worth of work farting around in his underwear weekday morning drinking coffee, reviewing the plans, running some numbers and maybe coming to some sort of decision or suggestion. It was not meant as a forum to shoot yourselves and eveyone else in the foot. Someone mentioned lawyer for whatever reason in like the first week of group online discussions and I emphatically and publicly stated as well as encouraged others to drop the whole damn thing if that's where a group of knuckheads wanted to take it. Even mentioning such a thing is wrongheaded and the wrong mentality.



 	  jmaynard wrote: 	
		  On Thu, Apr 16, 2009 at 09:13:33AM -0700, Gig Giacona wrote:

 	  Quote: 	
		   One nice thing about them giving their report to the NTSB is that it

 should now be available through the Freedom of Information Act and I have

 already started the process to file an FOI request. When received I will

 place the information in a public forum where those who desire can examine

 it.



	


FWIW, I believe the report should be made public, as well.



 	  Quote: 	
		   This will probably get me banned from reading the ZBAG forum as has

 already happened with at least one other person that spoke up there but I

 can live with that.



	


That member was banned not for speaking up; he was banned for speaking up in

a way that showed that he is, and always has been, uninterested in working

to further the work of the group. His presence was always somewhat

disruptive, and became dramatically so this morning.

-- 

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

jmaynard

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

Posted: Thu Apr 16, 2009 9:53 am Post subject: NTSB recommends grounding of 601XLs in US

On Thu, Apr 16, 2009 at 10:33:21AM -0700, ashontz wrote:

 	  Quote: 	
		   jmaynard wrote:

 > That member was banned not for speaking up; he was banned for speaking up in

 > a way that showed that he is, and always has been, uninterested in working

 > to further the work of the group. His presence was always somewhat

 > disruptive, and became dramatically so this morning.

 No, I got banned for speaking up and reminding them that the original

 purpose was to have a third party check out the design, that's all.


	


Not true, and your own words show it:



 	  Quote: 	
		   Someone mentioned lawyer for whatever reason in like the first week of

 group online discussions and I emphatically and publicly stated as well as

 encouraged others to drop the whole damn thing if that's where a group of

 knuckheads wanted to take it. Even mentioning such a thing is wrongheaded

 and the wrong mentality.


	


Sorry, but lots of folks say lots of things; unless ZBAG itself hired a

lawyer, your words are just proof that you oppose the goals and work of ZBAG

- and, as such, do not belong on the ZBAG mailing list.

-- 

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

William Dominguez

Joined: 09 Apr 2008
Posts: 118

Posted: Thu Apr 16, 2009 10:04 am Post subject: NTSB recommends grounding of 601XLs in US

Gig, 



You won't be banned from ZBAG for expressing your concerns, for posting disagreement with the way thinks turned out or for posting any relevant information you find thru the freedom of information act. You could get banned, if you engagage in descructive critizism of the group of any of its members. This is why Andrew got banned, not because of his position in this matter, but because of the way he chose to vent it. 

William Dominguez

Zodiac 601XL Plans

Miami Florida

http://www.geocities.com/bill_dom

--- On Thu, 4/16/09, Gig Giacona <wrgiacona(at)gmail.com> wrote:

[quote]

From: Gig Giacona <wrgiacona(at)gmail.com>

Subject: Re: NTSB recommends grounding of 601XLs in US

To:  zenith-list(at)matronics.com

Date: Thursday, April 16, 2009, 12:13 PM



--> Zenith-List message posted by: "Gig Giacona" <[url=/mc/compose?to=wrgiacona(at)gmail.com]wrgiacona(at)gmail.com[/url]>



Yes the NTSB was already involved and they made no mention of flutter other than the lack of any evidence for it in the Yuba City report.



Look, I don't know what the all of the underlying motivations of all the ZBAG members are and neither do you. I do remember when it was started because most of it started right here in this forum and the original intent was not to become a lobbying organization  for the grounding of the aircraft fleet. It was to have a third party look at some things that it was felt Zenith wasn't and then to provide that information to it's members and Zenith. There was never mentioned that the information would be shared with the NTSB. Hell, they aren't  even sharing it with none ZBAG participants. I watched as that changed in the ZBAG forum and was made somewhat sick by it.



One nice thing about them giving their report to the NTSB is that it should now be available through the Freedom of Information Act and I have already started the process to file an FOI request. When received I will place the information in a public forum where those who desire can examine it.



This will probably get me banned from reading the ZBAG forum as has already happened with at least one other person that spoke up there but I can live with that.



--------

W.R. &quot;Gig&quot; Giacona

601XL Under Construction

See my progress at www.peoamerica.net/N601WR





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=239538#239========================http://www.matronics.com/Nav=               - MATRONICS cs.com" bsp;               -Matt Dralle, List Adontribution" target="_blank">http://www.matronics.com/contribution  [quote][b]

_________________
William Dominguez
Zodiac 601XL Plans
Miami Florida
http://www.geocities.com/bill_dom

psm(at)att.net
Guest

Posted: Thu Apr 16, 2009 10:18 am Post subject: NTSB recommends grounding of 601XLs in US

Hi Jay,



This is a great example of how an unbiased and reasonable person 

would interpret the NTSB ruling.  I understand I am a biased person, 

but I also came to the conclusion that safety considerations dictate 

grounding my plane after the NTSB decision.  Up to this point I 

didn't consider all the possible problems sufficient to cause 

grounding of the fleet.



I know you feel injured, and I do too.  However, I hope you will 

eventually reach the conclusion that it is perfectly reasonable to 

get this serious problem with the XL corrected before risking your 

life by flying yours again.



Perhaps I am brainwashed by the FAA bureaucrats, but I still consider 

safety as the top priority in flying.



Hang in there.



Paul

XL grounded



P.S.  I learned a long time ago that Andy's comments consistently 

brought me to a rage so I set my email program to send his messages 

immediately to the trash.  I suggest you consider doing the same 

thing.  Please remember that reading any messages on this forum is at 

the reader's option.

At 10:29 AM 4/16/2009, you wrote:

 	  Quote: 	
		  What's even more unusual to me was

that the DPE, a lady who's respected around these parts as a calm,

level-headed aviator with lots of experience flying, teaching, and building

airplanes, would decide she wasn't interested in flying in my airplane any

longer, after being quite interested the other times I'd spoken to her.

William Dominguez

Joined: 09 Apr 2008
Posts: 118

Posted: Thu Apr 16, 2009 10:20 am Post subject: NTSB recommends grounding of 601XLs in US

You still don't get it. You got banned because of the way you expressed yourself. It is clear in the list rules that you cannot be disrespectful to others or be hostile to the group. And that is exactly what you did, don't you pretend now that you where just speaking up, please.

William Dominguez

Zodiac 601XL Plans

Miami Florida

http://www.geocities.com/bill_dom

--- On Thu, 4/16/09, ashontz <ashontz(at)nbme.org> wrote:

[quote]

From: ashontz <ashontz(at)nbme.org>

Subject: Re: NTSB recommends grounding of 601XLs in US

To: zenith-list(at)matronics.com

Date: Thursday, April 16, 2009, 1:33 PM

--> Zenith-List message posted by: "ashontz" <[url=/mc/compose?to=ashontz(at)nbme.org]ashontz(at)nbme.org[/url]>

No, I got banned for speaking up and reminding them that the original purpose was to have a third party check out the design, that's all. In fact, if i remember correctly I'm the one that originally asked if anyone want to chip in to have someone look at the plans. Remember Jay. I was THE ORIGINAL ZBAG member. And my intention was never to have it go anywhere near where you guys took it, it was simply so that several guys with $100 each could pool their money together to hire an maybe a retired aeronautical engineer who wanted to packet $3,000 or $4,000 for 3 weeks worth of work farting around in his underwear weekday morning drinking coffee, reviewing the plans, running some numbers and maybe coming to some sort of decision or suggestion. It was not meant as a forum to shoot yourselves and eveyone else in the foot. Someone mentioned lawyer for whatever reason in like the first week  of group online discussions and I emphatically and publicly stated as well as encouraged othe!

 rs to drop the whole damn thing if that's where a group of knuckheads wanted to take it. Even mentioning such a thing is wrongheaded and the wrong mentality.

jmaynard wrote:

 	  Quote: 	
		   On Thu, Apr 16, 2009 at 09:13:33AM -0700, Gig Giacona wrote:

 >  One nice thing about them giving their report to the NTSB is that it

 >  should now be available through the Freedom of Information Act and I have

 >  already started the process to file an FOI request. When received I will

 >  place the information in a public forum where those who desire can examine

 >  it.

 > 

 > 

 FWIW, I believe the report should be made public, as well.

 >  This will probably get me banned from reading the ZBAG forum as  has

 >  already happened with at least one other person that spoke up there but I

 >  can live with that.

 > 

 > 

 That member was banned not for speaking up; he was banned for speaking up in

 a way that showed that he is, and always has been, uninterested in working

 to further the work of the group. His presence was always somewhat

 disruptive, and became dramatically so this morning.

 -- 

 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

--------

Andy Shontz

do not archive

CH601XL - Corvair

www.mykitlog.com/ashontz

Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=23955tronics.com/Navigator?Zenith-List"  --> http========================  [quote][b]

_________________
William Dominguez
Zodiac 601XL Plans
Miami Florida
http://www.geocities.com/bill_dom

psm(at)att.net
Guest

Posted: Thu Apr 16, 2009 10:39 am Post subject: NTSB recommends grounding of 601XLs in US

Hi Sabrina,



You have my greatest respect for trying to engineer a solution to the 

mass balance problem.  However, I would feel a lot better if the 

design came from Chris.



Have you used your special relationship with ZAC to ask if we can 

have a mass balance design released from them?



Paul

do not archive



At 11:19 AM 4/16/2009, you wrote:

 	  Quote: 	
		  Comments?

Gig Giacona

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

Posted: Thu Apr 16, 2009 10:48 am Post subject: Re: NTSB recommends grounding of 601XLs in US

 	  psm(at)att.net wrote: 	
		  Hi Sabrina,



You have my greatest respect for trying to engineer a solution to the 

mass balance problem.  However, I would feel a lot better if the 

design came from Chris.

Paul

	




Why, you have already stated here that Chris' solution to correcting the issue of possible flutter isn't good enough for you?

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

d.goddard(at)ns.sympatico
Guest

Posted: Thu Apr 16, 2009 10:53 am Post subject: NTSB recommends grounding of 601XLs in US

If you are concerned about putting mass balances on the aileron itself, then 

place them in the wing with a linkage to the aileron. As long as they 

counteract and balance the control surface, location is of little 

consequence. Piper uses this arrangement.



---

psm(at)att.net
Guest

Posted: Thu Apr 16, 2009 11:03 am Post subject: NTSB recommends grounding of 601XLs in US

Hi Gig,



Perhaps you have misinterpreted my statements.



I do feel a need to respect the NTSB decision that mass balance is 

needed on the ailerons.  Yes, this is in conflict with Chris's 

judgement that the mass balance is not needed.



Still, Chris is the principal designer for this airplane.  He is the 

one who is best qualified to design a mass balance solution.  This is 

a different issue from his judgement as to the need for such a 

design.  He is the only person in the world who can be sure any new 

design change doesn't have an impact on other parts of the 

design.  There are other engineers, including Sabrina, who can do a 

reasonable job of the mass balance design, but none of them really 

knows all the considerations that went into the whole design.  It may 

be that the additional weight on the ailerons calls for bigger bolts 

on the horizontal stabilizer.



I would be much happier with a mass balance design from Chris than 

anybody else.



Paul

XL grounded



At 11:48 AM 4/16/2009, you wrote:

 	  Quote: 	
		  Why, you have already stated here that Chris' solution to correcting 

the issue of possible flutter isn't good enough for you?

notsew_evets(at)frontiern
Guest

Posted: Thu Apr 16, 2009 11:13 am Post subject: NTSB recommends grounding of 601XLs in US

Just think:

Someday we will all fly out together and meet for an overnight camping trip. 

We will sit by the campfire with beers in our hands and sing Cum by yaaaa.

We will spread nothing but love.  Together as one.....

I can wait, can yous ?



XOXO

---

Gig Giacona

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

Posted: Thu Apr 16, 2009 11:19 am Post subject: Re: NTSB recommends grounding of 601XLs in US

 	  psm(at)att.net wrote: 	
		  Hi Gig,



Perhaps you have misinterpreted my statements.



I do feel a need to respect the NTSB decision that mass balance is 

needed on the ailerons.  Yes, this is in conflict with Chris's 

judgement that the mass balance is not needed. 	


Nope, no misinterpretation here just a sort of sad irony. You don't trust the guy enough to believe him over a bunch of NTSB bureaucrats yet you still want him to design a modification. 



You are showing a lot of faith in the NTSB. What happens if another government agency and one that actually has the power to do something other than send a letter and press release out decides that Chris is right and everybody just needs to check the tension on their cables?

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

japhillipsga(at)aol.com
Guest

Posted: Thu Apr 16, 2009 11:26 am Post subject: NTSB recommends grounding of 601XLs in US

Folks, I'm a little behind in all this. Who or what is ZBAG and how do they have a dog in this fight? Bill

 do not archive

 

 

 --

Gig Giacona

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

Posted: Thu Apr 16, 2009 11:44 am Post subject: Re: NTSB recommends grounding of 601XLs in US

 	  japhillipsga(at)aol.com wrote: 	
		  Folks, I'm a little behind in all this. Who or what is ZBAG and how do they have a dog in this fight? Bill

 do not archive

 

 -- 	




ZBAG= Zenith Builders Analysis Group are a bunch of people that through some money in a hat because they thought Zenith wasn't doing enough quick enough to find out if there was a problem with the 601XL.



According to the NTSB notice the information they gathered and gave to the NTSB had some bearing on the the creation of the notice.

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

d.goddard(at)ns.sympatico
Guest

Posted: Thu Apr 16, 2009 12:02 pm Post subject: NTSB recommends grounding of 601XLs in US

Wouldn't that be a great solution!  What if an investigation determines that 

the aircraft "might" be safe that way, but would be much safer with mass 

balanced ailerons. Would you simply ignore the modification because your 

cables will always be exactly the right tension? Perhaps the designer will 

look at a mass balance solution designed by someone else, maybe a bright 

young kid, and say it looks ok for those owners who prefer a belt AND 

suspenders solution. If I remember correctly NOTHING in my pilot training 

advocated ignoring a possible safety issue because it was inconvenient or 

expensive to acknowledge it.





---

tigerrick(at)mindspring.c
Guest

Posted: Thu Apr 16, 2009 12:11 pm Post subject: NTSB recommends grounding of 601XLs in US

Thank you, Steve, for reminding us that we're all in this together. I wonder if any other builders group beats the crap out of each other like this. (sigh) I've resisted the temptation to jump in here amidst all the sturm and drang, but after talking to Zenith this morning, maybe I can share a bit.



I can certainly understand the frustration of everyone here, desparate for a "solution" but not seeing one immediately forthcoming. No one wants to have second doubts about the aircraft they're flying, while entrusting their lives (and the lives of others) in. So, here's what I'm thinking, but it's ONLY my OPINION!



When the 601 XL airframe is overstressed, the failure mode usually reveals itself by a failure of the wing at the spar and/or spar attach point(s). This has happened six times. And it's really disconcerting to see crash photos showing both wings on one side of the fuselage, and these images are haunting to say the least.



WHY the airframe gets overstressed is still a matter of hot debate, some conjecture and fact mixed together, with nothing conclusive from any official investigative agency (yet) nor the manufacturer. Still no single smoking gun. Which makes it a lot harder to ID a single main causal factor.



LSA aircraft are typically designed to ASTM standards, which do NOT require comprehensive flutter analysis. However, Zenith has engaged two outside aeronautical engineers who are currently in the process of evaluating the design to Part 23 standards, which do include flutter analysis.



The FAA concurs with Zenith that the design is safe to fly IF the aileron cable tensions are within spec and IF it's flown within its normal flight envelope, for both hinged and hingeless ailerons. The NTSB report raises some good points, AND some curious ones, but is still woefully short of scientific analysis, and seems to rely mostly on circumstantial and eye-witness evidence for its recommendations.



So before I change, modify, beef up, re-engineer, or "improve" anything, I'm going to (a) wait for more info from those whom I trust, and (b) keep my aileron cable tension within spec, and (c) fly as I normally do - with a light touch.



Call me Pollyanna, but I'm not losing any sleep over this.



Off the soapbox for now,



Rick Lindstrom

Zenvair N42KP



do not archive



--

jaybannist(at)cs.com
Guest

Posted: Thu Apr 16, 2009 12:39 pm Post subject: NTSB recommends grounding of 601XLs in US

Obviously off line and strictly between you and me:  It is my opinion that the hard-core members of the ZBAG group feel that there is a fatal flaw in the design of the 601XL , therefore feel cheated by Zenith and Chris Heintz and they want revenge.  I believe it is their goal to put Zenith out of business and establish grounds for suing Zenith.  They have contributed nothing positive. In spite of the extensive testing that Zenith has done, they still persist in their insistance that it is a flawed design.   If they have discovered anything, they have not shared it with Zenith nor Zodiac builders and flyers.  Instead (in spite of a lack of any real evidence), they have speculated that there is an aileron flutter problem and have shared that with the NTSB.  The NTSB is by nature a "sky is falling" organization, so they published that represensible letter that is full of inuendo, speculat  ion, half-truths and outright lies. This has made the ZBAG guys almost giddy; and they are now saying "I told you so".  I seriously doubt that there is a flutter problem, but Zenith will probably come up with a modification that will get this off their backs, whether it is really necessary or not.  I'm also guessing that a Zenith modification will not satisfy the ZBAG guys. I certainly could be wrong, but we will see.

 

 Jay

 

   

 

   

 

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