---------------------------------------------------------- Zenith601-List Digest Archive --- Total Messages Posted Thu 08/27/09: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:39 AM - Re: uk 601 xl aircraft cleared for flight (mirko) 2. 06:45 AM - Re: uk 601 xl aircraft cleared for flight (Gig Giacona) 3. 09:46 AM - Re: uk 601 xl aircraft cleared for flight (Pete54) 4. 10:17 AM - Re: Re: uk 601 xl aircraft cleared for flight (KARL POLIFKA) 5. 10:23 AM - Re: Re: uk 601 xl aircraft cleared for flight (Terry Turnquist) 6. 11:15 AM - Re: Re: uk 601 xl aircraft cleared for flight (jaybannist@cs.com) 7. 11:44 AM - Re: Re: uk 601 xl aircraft cleared for flight (Jay Maynard) 8. 11:47 AM - Re: Re: uk 601 xl aircraft cleared for flight (Paul Mulwitz) 9. 12:55 PM - Re: uk 601 xl aircraft cleared for flight (Pete54) 10. 01:04 PM - Re: Re: uk 601 xl aircraft cleared for flight (LHusky@aol.com) 11. 02:22 PM - Re: Re: uk 601 xl aircraft cleared for flight (MaxNr@aol.com) 12. 10:21 PM - Re: uk 601 xl aircraft cleared for flight (Scotsman) ________________________________ Message 1 _____________________________________ Time: 05:39:45 AM PST US Subject: Zenith601-List: Re: uk 601 xl aircraft cleared for flight From: "mirko" Does anyone know/seen the actual UK tests results? Would be great to hear what they had to say. I suppose the UK-boys would have some sort of agreement with Chris.H to keep certain information confidential. Regards, Mirko Read this topic online here: http://forums.matronics.com/viewtopic.php?p=259918#259918 ________________________________ Message 2 _____________________________________ Time: 06:45:55 AM PST US Subject: Zenith601-List: Re: uk 601 xl aircraft cleared for flight From: "Gig Giacona" psm(at)att.net wrote: > Hi Jim, > > While I believe you are correct, I am afraid this is as good as it > will get. The FAA apparently has decided there really is no problem > with the XL, so we can expect nothing more from them. What makes yo say that? Let's look at some quotes from the FAA response to the NTSB letter. "If the special review team finds an inherent design issue, the FAA will take appropriate action based on those findings." "If the special review team finds any inherent deficiencies, the FAA will decide on an appropriate an appropriate course of action." They make those statements or words to the same effect no less than 6 times in the letter. -------- 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=259928#259928 ________________________________ Message 3 _____________________________________ Time: 09:46:34 AM PST US Subject: Zenith601-List: Re: uk 601 xl aircraft cleared for flight From: "Pete54" I own a 2 year old XL which has been grounded by the LAA / CAA action in the UK. My understanding of the test results is that with no aileron tension and the balance weights fitted there was no tendency to flutter. Pretty much as expected as the German trials suggested there was the potential for flutter with less than 5 lbs force. (the test aircraft was instrumented to detect movement). The centre section modifications are I would guess an area of some 'difference' between the LAA and CH. The LAA analysis used a 'pin jointed' approach of load transmission between the wing spar and the centre section. This is unlikely due to the clamping force of the wing bolts - but it is a very conservative approach. Not surprisingly it results in the need for strengthening.... If anyone has any details on the Canadian testing I would be interested to get any details. -------- Pete Morris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=259964#259964 ________________________________ Message 4 _____________________________________ Time: 10:17:39 AM PST US From: "KARL POLIFKA" Subject: Re: Zenith601-List: Re: uk 601 xl aircraft cleared for flight In other words, the basis for the flutter testing was not following mainten ance procedures which specify cable tensioning! Karl ----- Original Message ----- From: Pete54 To: zenith601-list@matronics.com Sent: Thursday, August 27, 2009 12:45 PM Subject: Zenith601-List: Re: uk 601 xl aircraft cleared for flight een.com> I own a 2 year old XL which has been grounded by the LAA / CAA action in the UK. My understanding of the test results is that with no aileron tension and the balance weights fitted there was no tendency to flutter. Pretty much a s expected as the German trials suggested there was the potential for flutt er with less than 5 lbs force. (the test aircraft was instrumented to dete ct movement). The centre section modifications are I would guess an area of some 'diffe rence' between the LAA and CH. The LAA analysis used a 'pin jointed' appro ach of load transmission between the wing spar and the centre section. Thi s is unlikely due to the clamping force of the wing bolts - but it is a ver y conservative approach. Not surprisingly it results in the need for stren gthening.... If anyone has any details on the Canadian testing I would be interested t o get any details. -------- Pete Morris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=259964#259964 =========== =========== =========== =========== ________________________________ Message 5 _____________________________________ Time: 10:23:35 AM PST US From: Terry Turnquist Subject: Re: Zenith601-List: Re: uk 601 xl aircraft cleared for flight A long time ago the tails began falling off the v-tailed Bonanza and Beech and many owners with a hell of a lot more invested then we have wanted to p retend it wasn't an issue. But of course it was, and- after several more deaths an edumacated guess was made that the design was flawed, a fix was p rescribed and everyone (well, almost everyone) lived happily ever after. I hope this will be the case here. Terry Turnquist 601 XL- Plans --- On Thu, 8/27/09, Gig Giacona wrote: From: Gig Giacona Subject: Zenith601-List: Re: uk 601 xl aircraft cleared for flight psm(at)att.net wrote: > Hi Jim, > > While I believe you are correct, I am afraid this is as good as it > will get.- The FAA apparently has decided there really is no problem > with the XL, so we can expect nothing more from them. What makes yo say that? Let's look at some quotes from the FAA response to the NTSB letter. "If the special review team finds an inherent design issue, the FAA will ta ke appropriate action based on those findings." "If the special review team finds any inherent deficiencies, the FAA will d ecide on an appropriate an appropriate course of action." They make those statements or words to the same effect no less than 6 times in the letter. -------- 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=259928#259928 le, List Admin. =0A=0A=0A ________________________________ Message 6 _____________________________________ Time: 11:15:40 AM PST US Subject: Re: Zenith601-List: Re: uk 601 xl aircraft cleared for flight From: jaybannist@cs.com Terry Turnquist wrote: ? A long time ago the tails began falling off the v-tailed Bonanza and Beech and many owners with a hell of a lot more invested then we have wanted to pretend it wasn't an issue. But of course it was, and? after several more deaths an edumacated guess was made that the design was flawed, a fix was prescribed and everyone (well, almost everyone) lived happily ever after. I hope this will be the case here. Terry, If you followed the Bonanza, you would know that saying "the tails began falling off the v-tailed Bonanza"? is very misleading.? Yes, there were failures, but in ALL cases, the airplanes were in extremely turbulent air. Most were in thunderstorm-related turbulence, but one was caught in the wing-tip vortex of an airliner.? The V tails weren't just "falling off".? They were being ripped off.? The only design "flaw" was that they were not designed to fly into thunder storms.? Since the "fix", V-tailed Bonanza drivers that fly into thunderstorms now lose their wings first. Jay Bannister Do not archive ________________________________ Message 7 _____________________________________ Time: 11:44:41 AM PST US From: Jay Maynard Subject: Re: Zenith601-List: Re: uk 601 xl aircraft cleared for flight On Thu, Aug 27, 2009 at 01:54:48PM -0400, jaybannist@cs.com wrote: > If you followed the Bonanza, you would know that saying "the tails began > falling off the v-tailed Bonanza"? is very misleading.? Yes, there were > failures, but in ALL cases, the airplanes were in extremely turbulent air. > Most were in thunderstorm-related turbulence, but one was caught in the > wing-tip vortex of an airliner.? The V tails weren't just "falling off".? > They were being ripped off.? The only design "flaw" was that they were not > designed to fly into thunder storms.? Since the "fix", V-tailed Bonanza > drivers that fly into thunderstorms now lose their wings first. Quite so. OTOH, the fix did one thing more: it restored the reputation of the airplane. That's why I expect a fix to be developed and made available (and, likely, required for SLSA Zodiacs). -- 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 ________________________________ Message 8 _____________________________________ Time: 11:47:13 AM PST US From: Paul Mulwitz Subject: Re: Zenith601-List: Re: uk 601 xl aircraft cleared for flight Hi Guys, Let me add my own version of the Bonanza story (yes, I lived through all that . . .) The story I kept hearing for a decade or so of in-flight breakups of V-tail Bonanzas was it was all because of poor pilots who lost control of the planes, got going too fast (it was very slick) and proceeded to pull up too hard and pull the tail off. It was said often that these guys just weren't up to flying a high performance plane like a Bonanza. Of course, none of them were around to defend themselves from this slander. Paul XL awaiting engineering changes. At 10:54 AM 8/27/2009, you wrote: >Terry Turnquist wrote: > >A long time ago the tails began falling off the v-tailed Bonanza and >Beech and many owners with a hell of a lot more invested then we >have wanted to pretend it wasn't an issue. But of course it was, >and after several more deaths an edumacated guess was made that the >design was flawed, a fix was prescribed and everyone (well, almost >everyone) lived happily ever after. I hope this will be the case here. > > >Terry, > >If you followed the Bonanza, you would know that saying "the tails >began falling off the v-tailed Bonanza" is very misleading. Yes, >there were failures, but in ALL cases, the airplanes were in >extremely turbulent air. Most were in thunderstorm-related >turbulence, but one was caught in the wing-tip vortex of an >airliner. The V tails weren't just "falling off". They were being >ripped off. The only design "flaw" was that they were not designed >to fly into thunder storms. Since the "fix", V-tailed Bonanza >drivers that fly into thunderstorms now lose their wings first. > >Jay Bannister >Do not archive ________________________________ Message 9 _____________________________________ Time: 12:55:13 PM PST US Subject: Zenith601-List: Re: uk 601 xl aircraft cleared for flight From: "Pete54" There are some similarities, if only about restoring the reputation. Whilst I understand the need for aileron circuit tension I tend to support the UK authorities stance. The CS-VLA design code, which all UK modern homebuilts must meet states that the controls must not flutter, even under cable failure conditions. Loosing the tension in the circuit can occur for a variety of reasons and I'm not keen on the aircraft having the potential for ripping itself to pieces if that happens. Cable jumps a pulley, fairlead wears/loosens, a lot of things could happen. I'll try and post the drawings tomorrow from work. I would guess that CH may not issue these as the liability issues are complex. However I know a guy building a recent xl kit which was imported from the US (mine is a CZAW kit), his airframe has a considerable number of beefed up components within it compared with mine - generally around the centre section, but also including the aft wing spar attachment. Whilst I've been frustrated to hell by the lack of speed and indecision by the LAA we will mod my aircraft and get it flying and put this behind us. -------- Pete Morris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=260026#260026 ________________________________ Message 10 ____________________________________ Time: 01:04:21 PM PST US From: LHusky@aol.com Subject: Re: Zenith601-List: Re: uk 601 xl aircraft cleared for flight I look forward to seeing those drawings. Larry Husky Madras, Oregon In a message dated 8/27/2009 12:56:05 P.M. Pacific Daylight Time, peter.morris@optimusaberdeen.com writes: --> Zenith601-List message posted by: "Pete54" There are some similarities, if only about restoring the reputation. Whilst I understand the need for aileron circuit tension I tend to support the UK authorities stance. The CS-VLA design code, which all UK modern homebuilts must meet states that the controls must not flutter, even under cable failure conditions. Loosing the tension in the circuit can occur for a variety of reasons and I'm not keen on the aircraft having the potential for ripping itself to pieces if that happens. Cable jumps a pulley, fairlead wears/loosens, a lot of things could happen. I'll try and post the drawings tomorrow from work. I would guess that CH may not issue these as the liability issues are complex. However I know a guy building a recent xl kit which was imported from the US (mine is a CZAW kit), his airframe has a considerable number of beefed up components within it compared with mine - generally around the centre section, but also including the aft wing spar attachment. Whilst I've been frustrated to hell by the lack of speed and indecision by the LAA we will mod my aircraft and get it flying and put this behind us. -------- Pete Morris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=260026#260026 ________________________________ Message 11 ____________________________________ Time: 02:22:33 PM PST US From: MaxNr@aol.com Subject: Zenith601-List: Re: Re: uk 601 xl aircraft cleared for flight I certainly would like to see drawings of the mods either from ZAC or smuggled out of the UK. This is encouraging. I would like to resume work on my project. About that Bonanza thing. I went through that with a friend who had a Bonanza. The later models (such as his) needed an increased ruddervator area due to higher GW & power. Beech just added more chord ahead of the fwd ruddervator spar. This new area was not adequately supported. Following accidents, there was an AD that reduced airspeed. Then came kits from about three vendors to support the L.E. My friend's 35 ended up with brackets attached to the fuselage side and supporting the L.E. Problem solved. Vne restored. The 35's were always unforgiving for the inexperienced. A noted local gent bought the farm early 50's in VFR-to-IFR conditions. It was then known as a grave yard spiral. He was very experienced, with combat time in SE-5s and Spads. (But no instrument rating) RTD 601XL plans #6-6791 (wings) ________________________________ Message 12 ____________________________________ Time: 10:21:56 PM PST US Subject: Zenith601-List: Re: uk 601 xl aircraft cleared for flight From: "Scotsman" "In other words, the basis for the flutter testing was not following maintenance procedures which specify cable tensioning! Karl [quote] ---" Sorry Karl, but if I remember correctly the latest XL crash was on an aircraft that had recently tensioned the cables and had these confirmed as being correct (I think it was 6 hours before the incident flight but I stand corrected). Is it not possible that the issue is more complex than just tightening the cables? As in the descriptions of the Bonanza incident, the first place which receives the blame in a crash of unknown cause is the pilot which is not dissimilar to our situation except it is the pilot/builder. The matter is highly subjective without clear evidence but I do find it unusual (especially in the latest incident) that a commercial pilot would fly outside of the envelope of the aircraft (especially with the aircraft's history of wing failure) as it would appear that the aircraft in question's aileron cables were appropriately tensioned. As in the Bonanza incidents only time will tell whether aileron cable tension alone is a sufficient control. At least there appears to be progress in the publication of the various testing results regardless of which side of the fence you sit on. James -------- Cell +27 83 675 0815 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=260146#260146 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message zenith601-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Zenith601-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/zenith601-list Browse Digests http://www.matronics.com/digest/zenith601-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.