---------------------------------------------------------- Zenith-List Digest Archive --- Total Messages Posted Wed 06/03/09: 22 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:03 AM - Re: Re: Putting Flutter Issue to Bed (Dave) 2. 05:41 AM - Re: Re: Putting Flutter Issue to Bed (jaybannist@cs.com) 3. 05:42 AM - Re: Re: Putting Flutter Issue to Bed (Ken Lilja) 4. 06:42 AM - Re: Putting Flutter Issue to Bed (Gig Giacona) 5. 06:50 AM - Re: Putting Flutter Issue to Bed (hansriet) 6. 06:55 AM - Re: Putting Flutter Issue to Bed (steveadams) 7. 07:44 AM - Re: Re: Putting Flutter Issue to Bed (Rick Lindstrom) 8. 10:39 AM - Re: Re: Putting Flutter Issue to Bed (Dave) 9. 10:39 AM - Re: Re: Putting Flutter Issue to Bed (Dave) 10. 10:55 AM - Re: Re: Putting Flutter Issue to Bed (Dave) 11. 11:31 AM - Re: Re: Putting Flutter Issue to Bed (Dave) 12. 11:37 AM - Re: Putting Flutter Issue to Bed (Gig Giacona) 13. 12:12 PM - Re: Re: Putting Flutter Issue to Bed (Juan Vega) 14. 12:22 PM - Re: Re: Putting Flutter Issue to Bed (Rick Lindstrom) 15. 12:38 PM - Re: Re: Putting Flutter Issue to Bed (Dave) 16. 01:01 PM - Re: Re: Putting Flutter Issue to Bed (Dave) 17. 01:32 PM - Re: Re: Putting Flutter Issue to Bed (Rick Lindstrom) 18. 01:54 PM - Re: Re: Putting Flutter Issue to Bed (Frank Roskind) 19. 02:10 PM - Re: Re: Putting Flutter Issue to Bed (Frank Roskind) 20. 02:39 PM - Re: Re: Putting Flutter Issue to Bed (Gary Ray) 21. 02:57 PM - Re: Re: Putting Flutter Issue to Bed (jaybannist@cs.com) 22. 03:05 PM - Fw: Flap Gap Stop (jaybannist@cs.com) ________________________________ Message 1 _____________________________________ Time: 03:03:57 AM PST US From: "Dave" Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Hello Rick. I simply don't understand the anger here. There are owner/pilots who are wondering why this design has had a number of failures above the norm. The previous designs from CH did not have this issue so it appears that something is different. It's a fair question. I think that if you fly carefully and maintain it well there is not likely to be a problem, but I don't know that. Neither do I know that there is a problem, or what it might be. Please don't bring up the money you have spent and are trying to protect, in light of the loss of life, it's beyond crass. Finally, you are not a 601 XL, do not take questions and statements about it personally. Here's what we all know: Some XL's have experienced fatal airframe failures, cause unknown. (despite claims by some that it is pilot incompetence). The CH200, CH601HD/S, and other CH designs have not had this issue, despite similar designs and the fact that they are flown by similar pilots Tests have shown that flutter is not a likely cause, and the design has been changed to negate the possibilty of excessive -G forces. That about all we actually know, anything else is supposition. It is my hope that it was a fluke, and the issue will not repeat itself but will fade into memory. It's happened before. I would like to advocate for calm about the issue, anger and name calling will simply back people into defensive positions from which rational discussion will be unlikely. Fly safe. Do not Archive. > > > Hi, Gig. > > I just can't stand it any longer. As much as I try not to get down in the > mud here, there comes a point when I just can't let this stuff go by > without comment. > > Several posters here have decided that, despite the positive results of > the GVT and the lack of any single causal factor in the six 601 series > crashes worldwide, that there still remains a "problem" with the design. > Even though these guys fully admit they don't have any personal expertise > in aircraft design, they still insist on offering "solutions" such as > aileron mass balancing and changing the dynamics of the control system! > What chutzpah. > > Their continued insistance of an inherent design flaw in the 601 does very > real damage, to which these guys seem oblivious. All of us who have > invested our hard earned money and time in Chris Heintz's design now are > faced with significant loss in the values of our aircraft, are now > questioned about our sanity in flying the airplanes by those who simply > don't know any better, and an undeserved shadow has been placed on all > Zenith Aircraft designs as well. > > Here's what I now know: > ________________________________ Message 2 _____________________________________ Time: 05:41:15 AM PST US Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed From: jaybannist@cs.com -----Original Message----- From: Dave ?? > Hello Rick. I simply don't understand the anger here. ? > I would like to advocate for calm about the issue, anger and name calling will simply back people into defensive positions from which rational discussion will be unlikely.? ? ? Dave, I think you are slightly off base with your last post.? As I recall, it was anger and rage that sent the ZBAGers off on their rampage.? Because of the negative results of that rampage , I and others have every right to be angry about what we believe were their irresponsible activities. I think most on this list are willing to listen to and consider rational discussion, but most of what I see from the Zenith bashers is anything but rational.? Any one who argues that Zenith is solely responsible for these crashes because of a design flaw, and that they MUST issue design changes to correct that flaw is absolutely NOT rational. Citing the NTSB as an absolute and irrefutable source is not rational. Denying pilot responsibility and/or adverse meteorological conditions is not rational.? When and if I see rational discussion, you can believe I will listen and consider it. Otherwise, don't insult me with inane irrational comments - you could as well be talking to a stump on fire. Respectfully - Jay Bannister Do not archive ? ________________________________________________________________________ Email message sent from CompuServe - visit us today at http://www.cs.com ________________________________ Message 3 _____________________________________ Time: 05:42:00 AM PST US From: Ken Lilja Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed 2 Cessna Skycatcher prototypes have spun in. So much for certified manufactures knowing what they are doing. The NTSB has been recommending inerting the fuel tanks in airliners since flight 800 or before. They are finally doing it. Cost impact trumped safety. NTSB can only recommend changes, not require them. In a lot of incidents the cause is never determined. We will never know for sure. Ken Lilja ________________________________ Message 4 _____________________________________ Time: 06:42:47 AM PST US Subject: Zenith-List: Re: Putting Flutter Issue to Bed From: "Gig Giacona" d.goddard(at)ns.sympatico wrote: > (despite > claims by some that it is pilot incompetence). > Pilot error does not necessarily = pilot incompetence. 58% of accidents are pilot error that doesn't mean they were all incompetent pilots. As I mentioned before none of the accident aircraft that are in question were being flown by a builder who flew the plane through Phase 1 testing. That is statistically significant because this is an aircraft where the majority of flying example were kit built aircraft flown by the people that built them and flew the phase 1 program. Further in the 2 in flight break-up accidents where we DO know or are at least pretty sure of the cause they were both pilot error. 1 The low time LSA pilot that took off into bad weather. 2. The French pilot that was doing aerobatics and survived due to having a BRS. That guy even reset his G meter before the investigators got there. -------- W.R. "Gig" Giacona 601XL Under Construction See my progress at www.peoamerica.net/N601WR Read this topic online here: http://forums.matronics.com/viewtopic.php?p=246591#246591 ________________________________ Message 5 _____________________________________ Time: 06:50:08 AM PST US Subject: Zenith-List: Re: Putting Flutter Issue to Bed From: "hansriet" [quote="d.goddard(at)ns.sympatico"]Please don't bring up the money you have spent and are trying to protect, in light of the loss of life, it's beyond crass. [/quote] I wholeheartedly agree. Stop bringing finances up to try to silence the people that would like to find an answer to the unexplained crashes. Frankly I'm shocked that not everybody wants to know the cause(s) of the accidents. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=246594#246594 ________________________________ Message 6 _____________________________________ Time: 06:55:59 AM PST US Subject: Zenith-List: Re: Putting Flutter Issue to Bed From: "steveadams" Before anyone gets too far in adding springs and weights to your control stick, consider what most other designs have used in the past to increase the pitch force gradient; an anti-servo trim tab. There is no need to reinvent the wheel if you are really concerned with this particular flying characteristic of the xl. Consider what would happen if a spring broke and suddenly your stick is quickly launched to full deflection. When you set out to fix something, you want to be pretty sure that you're not creating an entirely different and potentially more serious problem. In any event, I think pilot education and training is the key in this case. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=246596#246596 ________________________________ Message 7 _____________________________________ Time: 07:44:01 AM PST US From: Rick Lindstrom Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Hans, Dave. This is unbelievable. If either of you remember any of my previous posts on this subject, I've expressed that the loss of life in any aviation accident, especially among our Zenith family, affects all of us and hits home hard. And I've also said (multiple times) that as a 601 builder/pilot, I sure as hell want to know if there's any inherent flaw that would jeopardize me or any of my loved ones who fly with me. Dave, you caution against name calling, yet find my inclusion of the very real financial damage to both 601 owners and the manufacturer "beyond crass". (Huh? What's up with that?) The negative financial impact of undue public speculation not supported by the facts, especially in light of the GVT and Zenith's recommendations (supported by the FAA, even) is very real. I mentioned it because it does continuing damage to the 601 community. How is my bringing it up meant to silence anybody? Yes, the 601 has had a rash of accidents atypical of other Zenith designs. We know this. And there was a rush to find a smoking gun before all the facts were in, often leading to irresponsible speculation, demands that Zenith "do something", and even proposed airframe modifications made by people unqualified to do so. And it goes on. For some reason, the very valid suggestion that additional model specific pilot training might help gets dismissed. I can only conclude that there are some here who WANT to find a fatal flaw with the design. For what reason(s), I do not know. Rick Lindstrom N42KP -----Original Message----- >From: hansriet >Sent: Jun 3, 2009 6:49 AM >To: zenith-list@matronics.com >Subject: Zenith-List: Re: Putting Flutter Issue to Bed > > >[quote="d.goddard(at)ns.sympatico"]Please don't bring up the money you have spent and are trying to >protect, in light of the loss of life, it's beyond crass. >[/quote] > >I wholeheartedly agree. Stop bringing finances up to try to silence the people that would like to find an answer to the unexplained crashes. Frankly I'm shocked that not everybody wants to know the cause(s) of the accidents. > > >Read this topic online here: > >http://forums.matronics.com/viewtopic.php?p=246594#246594 > > ________________________________ Message 8 _____________________________________ Time: 10:39:05 AM PST US From: "Dave" Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed I've not been in contact with any Zbag members and I can't speak about their motives, but I'm not convinced that bashing Zeniths was one of them. As far as I know they all own XL's. As I recall before the name calling and such started their objective was to have the airframe analysed/tested because Zenith was not interested in doing it. I think they should be satisfied that the testing has now been done. As far as the other arguments, Zenith is at fault etc. I haven't seen those arguments made, but if they were, I would likely disagree. My advocacy for calm rational thought about all of this is not directed solely at those who are angry at ZBAG, it's directed at bad behaviour on both sides. There is no proof that there is a major flaw in the XL design. Or that there is not. I think the testing was a prudent and good thing to do, and ZBAG may have helped in getting it done. There is credit and blame to go to both sides. If the accidents stop, so will the discussion for the most part. Indeed I thought it had died out until whoever started this thread decided to have one more swipe at the other side. ----- Original Message ----- From: jaybannist@cs.com To: zenith-list@matronics.com Sent: Wednesday, June 03, 2009 9:30 AM Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed -----Original Message----- From: Dave To: zenith-list@matronics.com > Hello Rick. I simply don't understand the anger here. > I would like to advocate for calm about the issue, anger and name calling will simply back people into defensive positions from which rational discussion will be unlikely. Dave, I think you are slightly off base with your last post. As I recall, it was anger and rage that sent the ZBAGers off on their rampage. Because of the negative results of that rampage , I and others have every right to be angry about what we believe were their irresponsible activities. I think most on this list are willing to listen to and consider rational discussion, but most of what I see from the Zenith bashers is anything but rational. Any one who argues that Zenith is solely responsible for these crashes because of a design flaw, and that they MUST issue design changes to correct that flaw is absolutely NOT rational. Citing the NTSB as an absolute and irrefutable source is not rational. Denying pilot responsibility and/or adverse meteorological conditions is not rational. When and if I see rational discussion, you can believe I will listen and consider it. Otherwise, don't insult me with inane irrational comments - you could as well be talking to a stump on fire. Respectfully - Jay Bannister Do not archive ________________________________ Message 9 _____________________________________ Time: 10:39:48 AM PST US From: "Dave" Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed I didn't know that Ken, did Cessna address the issue? ----- Original Message ----- From: "Ken Lilja" Sent: Wednesday, June 03, 2009 9:41 AM Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed > > 2 Cessna Skycatcher prototypes have spun in. So much for certified > manufactures knowing what they are doing. > The NTSB has been recommending inerting the fuel tanks in airliners since > flight 800 or before. They are finally doing it. Cost impact trumped > safety. NTSB can only recommend changes, not require them. In a lot of > incidents the cause is never determined. We will never know for sure. > Ken Lilja > > > ________________________________ Message 10 ____________________________________ Time: 10:55:56 AM PST US From: "Dave" Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed No question that pilot error causes accidents, but unknown remains unknown, we can't simply assign it to pilot error no matter how convenient that would be. And we should have to assume that similar pilots flying other CH designs would make on average the same number of errors per 100 flights and that does not seem reflected in the results. The numbers as they stand right now would appear to indicate that there is something about this aircraft that is different from the others. ----- Original Message ----- From: "Gig Giacona" Sent: Wednesday, June 03, 2009 10:41 AM Subject: Zenith-List: Re: Putting Flutter Issue to Bed > > > d.goddard(at)ns.sympatico wrote: >> (despite >> claims by some that it is pilot incompetence). >> > > > Pilot error does not necessarily = pilot incompetence. 58% of accidents > are pilot error that doesn't mean they were all incompetent pilots. > > As I mentioned before none of the accident aircraft that are in question > were being flown by a builder who flew the plane through Phase 1 testing. > That is statistically significant because this is an aircraft where the > majority of flying example were kit built aircraft flown by the people > that built them and flew the phase 1 program. > > Further in the 2 in flight break-up accidents where we DO know or are at > least pretty sure of the cause they were both pilot error. > > 1 The low time LSA pilot that took off into bad weather. > 2. The French pilot that was doing aerobatics and survived due to having a > BRS. That guy even reset his G meter before the investigators got there. > > -------- > W.R. "Gig" Giacona > 601XL Under Construction > See my progress at www.peoamerica.net/N601WR > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=246591#246591 > > > ________________________________ Message 11 ____________________________________ Time: 11:31:52 AM PST US From: "Dave" Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Hello Rick, Please accept that it a description of an action and not of you, certainly not name calling. Yes, I am totally unconcerned about any potential loss resulting from a bad reputation related to this aircraft and I would never bring up money in a situation that has cost someone their life. I am very concerned for the people who for reasons unknown have had accidents in them, and I probably would applaud any efforts to keep any further accidents from happening. I would however not have supported any attempt to ground them without substantial proof that they are flawed. Training is everything, but you have to know that a particular flight characteristic exists before you can train for it and there are those here who would not have these issues discussed at all. So, a vocal minority from both sides ruining it for everyone! Wow, first time that's happened! ----- Original Message ----- From: "Rick Lindstrom" Sent: Wednesday, June 03, 2009 11:42 AM Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed > > > Hans, Dave. > > This is unbelievable. > > If either of you remember any of my previous posts on this subject, I've > expressed that the loss of life in any aviation accident, especially among > our Zenith family, affects all of us and hits home hard. And I've also > said (multiple times) that as a 601 builder/pilot, I sure as hell want to > know if there's any inherent flaw that would jeopardize me or any of my > loved ones who fly with me. > > Dave, you caution against name calling, yet find my inclusion of the very > real financial damage to both 601 owners and the manufacturer "beyond > crass". (Huh? What's up with that?) The negative financial impact of undue > public speculation not supported by the facts, especially in light of the > GVT and Zenith's recommendations (supported by the FAA, even) is very > real. I mentioned it because it does continuing damage to the 601 > community. How is my bringing it up meant to silence anybody? > > Yes, the 601 has had a rash of accidents atypical of other Zenith designs. > We know this. And there was a rush to find a smoking gun before all the > facts were in, often leading to irresponsible speculation, demands that > Zenith "do something", and even proposed airframe modifications made by > people unqualified to do so. And it goes on. For some reason, the very > valid suggestion that additional model specific pilot training might help > gets dismissed. > > I can only conclude that there are some here who WANT to find a fatal flaw > with the design. For what reason(s), I do not know. > > Rick Lindstrom > N42KP > > -----Original Message----- >>From: hansriet >>Sent: Jun 3, 2009 6:49 AM >>To: zenith-list@matronics.com >>Subject: Zenith-List: Re: Putting Flutter Issue to Bed >> >> >>[quote="d.goddard(at)ns.sympatico"]Please don't bring up the money you >>have spent and are trying to >>protect, in light of the loss of life, it's beyond crass. >>[/quote] >> >>I wholeheartedly agree. Stop bringing finances up to try to silence the >>people that would like to find an answer to the unexplained crashes. >>Frankly I'm shocked that not everybody wants to know the cause(s) of the >>accidents. >> >> >> >> >>Read this topic online here: >> >>http://forums.matronics.com/viewtopic.php?p=246594#246594 >> >> >> >> >> >> >> >> >> >> > > > ________________________________ Message 12 ____________________________________ Time: 11:37:51 AM PST US Subject: Zenith-List: Re: Putting Flutter Issue to Bed From: "Gig Giacona" d.goddard, First Skycatcher info: http://www.avweb.com/cgi-bin/texis/scripts/avweb-search/search.html?query=Skycatcher Second, Head over to ZBAG and look around you will see a bunch of guys that won't take "yes" for an answer unless the question is "Is there a design problem?" They went out and hired a expert and paid good money for him. When he came back with a "No" answer they found some guy who says he is a Zenith builder and an expert and he ran computer simulations and said "Yes" there is a flutter problem. Simulations that did not have GVT tests as a basis I might add. (Note: this is the data they sent to the NTSB but refuse to release to the other builders) So they pitched and moaned for GVT to be done. Zenair did them and the answer was "No" and the bitching and moaning continues. Just is the last day or so there is a thread over at ZBAG with the theory that the HS is to small. A thread complete with ideas on making the HS larger. Here's a link go check them out for yourself. If after reading it you don't understand that it is not only what is said here but what is going on over there that upsets some of let me know. http://groups.yahoo.com/group/ZBAG/ Third, the 601XL is a different airplane with different handling characteristics than previous CH designs. Is it easier because of those characteristics for a pilot to rip the wings off? Maybe. It certainly would explain things. Is there a issue with increasing G force causing decreasing elevator feedback? I don't know. I asked one of this list's members that owns a flying factory version in which he just got his CFI-LS rating that question and haven't seen an answer yet. -------- W.R. "Gig" Giacona 601XL Under Construction See my progress at www.peoamerica.net/N601WR Read this topic online here: http://forums.matronics.com/viewtopic.php?p=246647#246647 ________________________________ Message 13 ____________________________________ Time: 12:12:09 PM PST US From: Juan Vega Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Dave, you are wrong. Factor out pilot error on each accident, and the accident rate falls well within norms for GA E-AB. Juan -----Original Message----- >From: Dave >Sent: Jun 3, 2009 1:46 PM >To: zenith-list@matronics.com >Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed > > >No question that pilot error causes accidents, but unknown remains unknown, >we can't simply assign it to pilot error no matter how convenient that would >be. And we should have to assume that similar pilots flying other CH designs >would make on average the same number of errors per 100 flights and that >does not seem reflected in the results. The numbers as they stand right now >would appear to indicate that there is something about this aircraft that is >different from the others. > >----- Original Message ----- >From: "Gig Giacona" >To: >Sent: Wednesday, June 03, 2009 10:41 AM >Subject: Zenith-List: Re: Putting Flutter Issue to Bed > > >> >> >> d.goddard(at)ns.sympatico wrote: >>> (despite >>> claims by some that it is pilot incompetence). >>> >> >> >> Pilot error does not necessarily = pilot incompetence. 58% of accidents >> are pilot error that doesn't mean they were all incompetent pilots. >> >> As I mentioned before none of the accident aircraft that are in question >> were being flown by a builder who flew the plane through Phase 1 testing. >> That is statistically significant because this is an aircraft where the >> majority of flying example were kit built aircraft flown by the people >> that built them and flew the phase 1 program. >> >> Further in the 2 in flight break-up accidents where we DO know or are at >> least pretty sure of the cause they were both pilot error. >> >> 1 The low time LSA pilot that took off into bad weather. >> 2. The French pilot that was doing aerobatics and survived due to having a >> BRS. That guy even reset his G meter before the investigators got there. >> >> -------- >> W.R. "Gig" Giacona >> 601XL Under Construction >> See my progress at www.peoamerica.net/N601WR >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=246591#246591 >> >> >> >> >> >> >> >> >> >> > > ________________________________ Message 14 ____________________________________ Time: 12:22:56 PM PST US From: Rick Lindstrom Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Hi, Dave. Forgive me for being "crass" again, but as someone who works closely at times with LSA and kit aircraft manufacturers, I AM concerned about any undeserved loss of reputation that can hinder their ability to remain viable. Without the manufacturer, ongoing support and resolution of issues such as these becomes much more difficult. And we all suffer as a result. True, the devaluation of the individual aircraft is a very small factor when compared to the tragic loss of life, but it remains an issue nonetheless to those who have invested their hard earned time and money. Whether or not there is loss of life in no way changes their situations, which appears undeserved given the latest data. At some point we have to consider ALL of the unintended consequences of knee jerk speculation, and keep them in mind when contemplating our positions and actions. You recently commented in a previous post that Zenith did nothing when these crashes began. This is also a common misconception. Zenith was prohibited from releasing any preliminary crash findings prior to the NTSB's findings, but they had people on the ground with the NTSB assisting with the investigations. The lack of instant info from Zenith infuriated some here, and ZBAG was created out of the desire that something be done NOW, appropriate or not. I only posted here because of all of the misconceptions and half-truths still flying around, even after the GVT results were released. Those who disagreed with the premise that the airframe is flawed in some terrible way were told that they had their heads in the sand or were in denial. On the surface, the 601 appears to have a higher than usual accident rate based on six crashes. But if you go through each accident, one by one, a clearer picture emerges strongly suggesting the airplane is indeed safe IF properly built and maintained, and the pilot understands the operating limitations. The recent testing also pointed out that flap stops, likely to have been left off some airframes, are needed to insure rigidity in the flap system. This is a good thing. Sure, I'd like my 601 to be able to withstand the most severe weather and extreme control inputs, but this expectation isn't rational given what the airplane is, and isn't. Rick -----Original Message----- >From: Dave >Sent: Jun 3, 2009 2:27 PM >To: zenith-list@matronics.com >Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed > > >Hello Rick, Please accept that it a description of an action and not of you, >certainly not name calling. Yes, I am totally unconcerned about any >potential loss resulting from a bad reputation related to this aircraft and >I would never bring up money in a situation that has cost someone their >life. I am very concerned for the people who for reasons unknown have had >accidents in them, and I probably would applaud any efforts to keep any >further accidents from happening. I would however not have supported any >attempt to ground them without substantial proof that they are flawed. >Training is everything, but you have to know that a particular flight >characteristic exists before you can train for it and there are those here >who would not have these issues discussed at all. So, a vocal minority from >both sides ruining it for everyone! Wow, first time that's happened! > >----- Original Message ----- >From: "Rick Lindstrom" >To: >Sent: Wednesday, June 03, 2009 11:42 AM >Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed > > >> >> >> Hans, Dave. >> >> This is unbelievable. >> >> If either of you remember any of my previous posts on this subject, I've >> expressed that the loss of life in any aviation accident, especially among >> our Zenith family, affects all of us and hits home hard. And I've also >> said (multiple times) that as a 601 builder/pilot, I sure as hell want to >> know if there's any inherent flaw that would jeopardize me or any of my >> loved ones who fly with me. >> >> Dave, you caution against name calling, yet find my inclusion of the very >> real financial damage to both 601 owners and the manufacturer "beyond >> crass". (Huh? What's up with that?) The negative financial impact of undue >> public speculation not supported by the facts, especially in light of the >> GVT and Zenith's recommendations (supported by the FAA, even) is very >> real. I mentioned it because it does continuing damage to the 601 >> community. How is my bringing it up meant to silence anybody? >> >> Yes, the 601 has had a rash of accidents atypical of other Zenith designs. >> We know this. And there was a rush to find a smoking gun before all the >> facts were in, often leading to irresponsible speculation, demands that >> Zenith "do something", and even proposed airframe modifications made by >> people unqualified to do so. And it goes on. For some reason, the very >> valid suggestion that additional model specific pilot training might help >> gets dismissed. >> >> I can only conclude that there are some here who WANT to find a fatal flaw >> with the design. For what reason(s), I do not know. >> >> Rick Lindstrom >> N42KP >> >> -----Original Message----- >>>From: hansriet >>>Sent: Jun 3, 2009 6:49 AM >>>To: zenith-list@matronics.com >>>Subject: Zenith-List: Re: Putting Flutter Issue to Bed >>> >>> >>>[quote="d.goddard(at)ns.sympatico"]Please don't bring up the money you >>>have spent and are trying to >>>protect, in light of the loss of life, it's beyond crass. >>>[/quote] >>> >>>I wholeheartedly agree. Stop bringing finances up to try to silence the >>>people that would like to find an answer to the unexplained crashes. >>>Frankly I'm shocked that not everybody wants to know the cause(s) of the >>>accidents. >>> >>> >>> >>> >>>Read this topic online here: >>> >>>http://forums.matronics.com/viewtopic.php?p=246594#246594 >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >> >> >> >> >> > > ________________________________ Message 15 ____________________________________ Time: 12:38:40 PM PST US From: "Dave" Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Glad to see that Cessna is actively and aggressively testing their design, hope it works out. I was unable to read ZBAG's discussion without creating a Yahoo account, they don't permit non-members to read messages. I don't think I want to create such an account right now but it appears from your description that they have a few members who can't admit they might be wrong. That's too bad, they started out with good intentions and if they can accept the results they will have been successful. The idea as I understand it was to test the airframe, job done I think. The questions in your "third" paragraph are good ones, I think there are some who would rather we don't ask those questions. I come up with the same maybe in relation to the first, but as much as I regard the sensitive pitch as unusual, I really don't think it's a big issue. I'm very hopeful that the number of flying hours for the XL will increase without incident and it will outrun any bad reputation. ----- Original Message ----- From: "Gig Giacona" Sent: Wednesday, June 03, 2009 3:37 PM Subject: Zenith-List: Re: Putting Flutter Issue to Bed > > d.goddard, > > First Skycatcher info: > http://www.avweb.com/cgi-bin/texis/scripts/avweb-search/search.html?query=Skycatcher > > Second, Head over to ZBAG and look around you will see a bunch of guys > that won't take "yes" for an answer unless the question is "Is there a > design problem?" They went out and hired a expert and paid good money for > him. When he came back with a "No" answer they found some guy who says he > is a Zenith builder and an expert and he ran computer simulations and said > "Yes" there is a flutter problem. Simulations that did not have GVT tests > as a basis I might add. (Note: this is the data they sent to the NTSB but > refuse to release to the other builders) So they pitched and moaned for > GVT to be done. Zenair did them and the answer was "No" and the bitching > and moaning continues. Just is the last day or so there is a thread over > at ZBAG with the theory that the HS is to small. A thread complete with > ideas on making the HS larger. Here's a link go check them out for > yourself. If after reading it you don't understand that it is not only > what is said here but what is going on over ther! > e that upsets some of let me know. > > http://groups.yahoo.com/group/ZBAG/ > > Third, the 601XL is a different airplane with different handling > characteristics than previous CH designs. Is it easier because of those > characteristics for a pilot to rip the wings off? Maybe. It certainly > would explain things. Is there a issue with increasing G force causing > decreasing elevator feedback? I don't know. I asked one of this list's > members that owns a flying factory version in which he just got his CFI-LS > rating that question and haven't seen an answer yet. > ________________________________ Message 16 ____________________________________ Time: 01:01:52 PM PST US From: "Dave" Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Nothing to forgive, different people have different views on what is important or even proper, I stand by my position. Remember that these issues were originally brought on by crashes, then exacerbated by silence. I am doubtful that the NTSB demanded that Zenith exhibit absolute silence in the face of what appeared at the time to be a serious issue, but I don't know. I doubt that I said specifically that Zenith did nothing, I'm generally not keen on making definitive statements about such things, but I might have. I think I recall saying that Zenith did not wish to do the testing that ZBAG wanted. I still understand that to be the case. Yes, the requirement to check the cable tensions, the elevator stops, and the flap stops are all good news. These little things may be the smoking gun everyone is still looking for. ----- Original Message ----- From: "Rick Lindstrom" > > Hi, Dave. Forgive me for being "crass" again, but as someone who works > closely at times with LSA and kit aircraft manufacturers, I AM concerned > about any undeserved loss of reputation that can hinder their ability to > remain viable. Without the manufacturer, ongoing support and resolution of > issues such as these becomes much more difficult. And we all suffer as a > result. > > True, the devaluation of the individual aircraft is a very small factor > when compared to the tragic loss of life, but it remains an issue > nonetheless to those who have invested their hard earned time and money. > Whether or not there is loss of life in no way changes their situations, > which appears undeserved given the latest data. At some point we have to > consider ALL of the unintended consequences of knee jerk speculation, and > keep them in mind when contemplating our positions and actions. > > You recently commented in a previous post that Zenith did nothing when > these crashes began. This is also a common misconception. Zenith was > prohibited from releasing any preliminary crash findings prior to the > NTSB's findings, but they had people on the ground with the NTSB assisting > with the investigations. The lack of instant info from Zenith infuriated > some here, and ZBAG was created out of the desire that something be done > NOW, appropriate or not. ________________________________ Message 17 ____________________________________ Time: 01:32:29 PM PST US From: Rick Lindstrom Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Was it Mark Twain who said something like "Better to say nothing, and let others think you a fool, than to open your mouth and remove all doubt"? Zenith could have released all sorts of info that essentially said nothing new, but chose not to until the results were in. Not the greatest PR move, but certainly understandable. And no company wants to take on an expensive test regime based soley on speculation from an ad hoc group, but when the evidence suggested that there MAY be some flutter factor involved, it was done. BTW, I don't think are "sides" in this issue, just a group that has a common goal but way different methodologies. At some point, various personalities became much more invested in being "right" than finding causes, and minds slammed shut. But I'm pleased that I'll be flying one of the most tested LSAs available, after all of the dust settles. Rick -----Original Message----- >From: Dave >Sent: Jun 3, 2009 4:01 PM >To: zenith-list@matronics.com >Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed > > >Nothing to forgive, different people have different views on what is >important or even proper, I stand by my position. Remember that these issues >were originally brought on by crashes, then exacerbated by silence. I am >doubtful that the NTSB demanded that Zenith exhibit absolute silence in the >face of what appeared at the time to be a serious issue, but I don't know. I >doubt that I said specifically that Zenith did nothing, I'm generally not >keen on making definitive statements about such things, but I might have. I >think I recall saying that Zenith did not wish to do the testing that ZBAG >wanted. I still understand that to be the case. > >Yes, the requirement to check the cable tensions, the elevator stops, and >the flap stops are all good news. These little things may be the smoking gun >everyone is still looking for. > >----- Original Message ----- >From: "Rick Lindstrom" >To: >> >> Hi, Dave. Forgive me for being "crass" again, but as someone who works >> closely at times with LSA and kit aircraft manufacturers, I AM concerned >> about any undeserved loss of reputation that can hinder their ability to >> remain viable. Without the manufacturer, ongoing support and resolution of >> issues such as these becomes much more difficult. And we all suffer as a >> result. >> >> True, the devaluation of the individual aircraft is a very small factor >> when compared to the tragic loss of life, but it remains an issue >> nonetheless to those who have invested their hard earned time and money. >> Whether or not there is loss of life in no way changes their situations, >> which appears undeserved given the latest data. At some point we have to >> consider ALL of the unintended consequences of knee jerk speculation, and >> keep them in mind when contemplating our positions and actions. >> >> You recently commented in a previous post that Zenith did nothing when >> these crashes began. This is also a common misconception. Zenith was >> prohibited from releasing any preliminary crash findings prior to the >> NTSB's findings, but they had people on the ground with the NTSB assisting >> with the investigations. The lack of instant info from Zenith infuriated >> some here, and ZBAG was created out of the desire that something be done >> NOW, appropriate or not. > > ________________________________ Message 18 ____________________________________ Time: 01:54:15 PM PST US From: Frank Roskind Subject: RE: Zenith-List: Re: Putting Flutter Issue to Bed In the beginning of this discussion=2C I suggested that flutter tends to oc cur at high true airspeeds=2C often under cases of low density altitude=2C where calibrated airspeeds tend to be low compared to true airspeeds=2C bec ause flutter is dependent of true airspeed. I further suggested that was n ot the place to look I also think that relatively experienced pilots can h andle decreasing stick force with greater deflection=2C although from a hum an factors design standpoinnt that is not the most desirable arrangement. No one has suggested any kind of divergent displacement or similar instabli lty=2C so the decreasing stick force should not have caused an accident. T he pilot would notice the increased g- force in the butt accelerometer long before the wings came off. I do not think the issue is a design flaw per se. The incidents seem to be more likely to indicate some kind of cracking. The XL has a greater canti lever than the earlier 601's. It stands to reason that an irregularity in the construction of the wing root which causes a small stress riser would b e more critical in the XL than those earlier 601's. I wonder if there is a n inexpensive way to get non-destructive testing of the wing spars and root s at the connection for a meaningful number of XLs=2C as I think that even a susceptiblity to cracking would not manifest itself in the vast majority of specimens. A further inidication would be oxidized material near the po int of failure in crashed aircraft=2C and I would like to know if any has b een found I think that owners who are irked by the constant discussion otf the failur es have a reasonable point=2C as the discussion serves to diminish the valu e of their investments of money and effort. Unfortunately=2C speculation w ill continue until a nominal cause is accepted by the general population=2C and a correction is also implemented. Ironically=2C were the flutter prop onents of ZBAG correct=2C the answer would have been derived=2C a solution implemented and the value restored. ZBAG could have served to enhance the value of the fleet. Now we need another hypothesis=2C and need to verify o ne at last to restore the aircraft's reputation. I also think that detractors need to put safety into perspective. A few ye ars back Cessna single engine aircraft were subject to an AD about the seat s sliding back. No one at the time pointed out that even with the seat sli ding accidents=2C the 172 was the safest GA aircraft. It would be helpful to put the XL record into a similar perspective. Are competing aircraft re ally safer=2C or simply subject to a different set of risks? _________________________________________________________________ Insert movie times and more without leaving Hotmail=AE. http://windowslive.com/Tutorial/Hotmail/QuickAdd?ocid=TXT_TAGLM_WL_HM_Tut orial_QuickAdd_062009 ________________________________ Message 19 ____________________________________ Time: 02:10:50 PM PST US From: Frank Roskind Subject: RE: Zenith-List: Re: Putting Flutter Issue to Bed Correction=2C I meant high density altitude=2C low pressure. From: frankroskind@HOTMAIL.COM Subject: RE: Zenith-List: Re: Putting Flutter Issue to Bed In the beginning of this discussion=2C I suggested that flutter tends to oc cur at high true airspeeds=2C often under cases of low density altitude=2C where calibrated airspeeds tend to be low compared to true airspeeds=2C bec ause flutter is dependent of true airspeed. I further suggested that was n ot the place to look I also think that relatively experienced pilots can h andle decreasing stick force with greater deflection=2C although from a hum an factors design standpoinnt that is not the most desirable arrangement. No one has suggested any kind of divergent displacement or similar instabli lty=2C so the decreasing stick force should not have caused an accident. T he pilot would notice the increased g- force in the butt accelerometer long before the wings came off. I do not think the issue is a design flaw per se. The incidents seem to be more likely to indicate some kind of cracking. The XL has a greater canti lever than the earlier 601's. It stands to reason that an irregularity in the construction of the wing root which causes a small stress riser would b e more critical in the XL than those earlier 601's. I wonder if there is a n inexpensive way to get non-destructive testing of the wing spars and root s at the connection for a meaningful number of XLs=2C as I think that even a susceptiblity to cracking would not manifest itself in the vast majority of specimens. A further inidication would be oxidized material near the po int of failure in crashed aircraft=2C and I would like to know if any has b een found I think that owners who are irked by the constant discussion otf the failur es have a reasonable point=2C as the discussion serves to diminish the valu e of their investments of money and effort. Unfortunately=2C speculation w ill continue until a nominal cause is accepted by the general population=2C and a correction is also implemented. Ironically=2C were the flutter prop onents of ZBAG correct=2C the answer would have been derived=2C a solution implemented and the value restored. ZBAG could have served to enhance the value of the fleet. Now we need another hypothesis=2C and need to verify o ne at last to restore the aircraft's reputation. I also think that detractors need to put safety into perspective. A few ye ars back Cessna single engine aircraft were subject to an AD about the seat s sliding back. No one at the time pointed out that even with the seat sli ding accidents=2C the 172 was the safest GA aircraft. It would be helpful to put the XL record into a similar perspective. Are competing aircraft re ally safer=2C or simply subject to a different set of risks? Insert movie times and more without leaving Hotmail=AE. See how. _________________________________________________________________ Lauren found her dream laptop. Find the PC that=92s right for you. http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290 ________________________________ Message 20 ____________________________________ Time: 02:39:26 PM PST US From: "Gary Ray" Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Can someone provide a link to the flap stop drawing. I have not seen it on the Zenith site. Gary Ray davgray@sbcglobal.net ________________________________ Message 21 ____________________________________ Time: 02:57:55 PM PST US Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed From: jaybannist@cs.com Gary, and Others who have asked, Here is what my drawings show for the flap gap stop. On my drawings, dated 04/05 for an XL, this is shown on drawing 6-S-3. Jay Bannister -----Original Message----- From: Gary Ray Sent: Wed, 3 Jun 2009 4:31 pm Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Can someone provide a link to the flap stop drawing. I have not seen it on the Zenith site. Gary Ray davgray@sbcglobal.net ________________________________________________________________________ Email message sent from CompuServe - visit us today at http://www.cs.com ________________________________ Message 22 ____________________________________ Time: 03:05:18 PM PST US Subject: Zenith-List: Fwd: Flap Gap Stop From: jaybannist@cs.com -----Original Message----- From: jaybannist@cs.com Sent: Wed, 3 Jun 2009 4:55 pm Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Gary, and Others who have asked, Here is what my drawings show for the flap gap stop. On my drawings, dated 04/05 for an XL, this is shown on drawing 6-S-3. Jay Bannister -----Original Message----- From: Gary Ray Sent: Wed, 3 Jun 2009 4:31 pm Subject: Re: Zenith-List: Re: Putting Flutter Issue to Bed Can someone provide a link to the flap stop drawing. I have not seen it on the Zenith site. Gary Ray davgray@sbcglobal.net Email message sent from CompuServe - visit us today at http://www.cs.com ________________________________________________________________________ Email message sent from CompuServe - visit us today at http://www.cs.com ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message zenith-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Zenith-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/zenith-list Browse Digests http://www.matronics.com/digest/zenith-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.