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#41
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Victor Bravo wrote:
On Jun 25, 7:01 am, Gig 601Xl Builder wrote: So either you were dealing with a broken 601XL or as I said before you are full of crap. Sorry to ruin your day, I'm not full or crap this time. The aircraft was inspected by myself and two other people from our EAA chapter. I did not measure the movement, and I rough guessed three inches total movement, which would be 1.5 each way. I could be wrong and it may have only been 1 inch... but it was more than a half inch I assure you. Now Gig, why do you think that anyone who says they found XYZ on another airplane is automatically full of crap because it's not that way on your airplane? Well my plane is being built according to the plans. And you can rest assured there that the Horz Stab can't be moved 3 inches without bending the attach points past the point where they have been damaged. |
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On Mon, 7 Jul 2008 00:06:58 -0700 (PDT), Victor Bravo
wrote: On Jun 25, 7:01 am, Gig 601Xl Builder wrote: So either you were dealing with a broken 601XL or as I said before you are full of crap. Sorry to ruin your day, I'm not full or crap this time. The aircraft was inspected by myself and two other people from our EAA chapter. I did not measure the movement, and I rough guessed three inches total movement, which would be 1.5 each way. I could be wrong and it may have only been 1 inch... but it was more than a half inch I assure you. Now Gig, why do you think that anyone who says they found XYZ on another airplane is automatically full of crap because it's not that way on your airplane? I can't think of any force acting on the airframe in flight that would do what you are doing with your hand. A combination of any-all of: vibration, asymmetrical loads from slipstream swirling back on the fuselage, sideslip angle, gusts, rudder input slightly moving the fuselage, etc. etc. If you ever did "slow flight" in a Piper Tomahawk, and the instructor told you to turn around and look at the tail, you would damn well know how much a tail can shake back and forth from just air loads! Now I'm not saying you couldn't bend the attach points enough to make it move 3" but you'd only get to do that once on my plane before I hit you with a baseball bat. You can come out and try to move the stab tips of my T-craft back and forth all you want... and it won't move... and I won' even threaten to whack you with a bat much less actually do it. Your comment shows me that you know your stabilizer can be moved, and you know it's not good for the airplane. If it moves it was not built to plans. The stab on a correctly built Zenith aircraft does NOT move without significant (excessive) force. ** Posted from http://www.teranews.com ** |
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On Mon, 7 Jul 2008 00:20:53 -0700 (PDT), Victor Bravo
wrote: On Jun 24, 7:27 pm, clare at snyder dot ontario dot canada wrote: Build a 2000 lb 601. Do you have any idea of how much strength, stiffness, redundancy, and flight safety can be gained from an additional ONE POUND of aluminum designed into the right places on a light aircraft? My friend, you need to spend some quality time building balsa wood free flight models and learning how aircraft structure works. Believe me, I know. However, I ALSO know that many builders beef up this, and overbuild that because they THINK they know better than the engineer who designed it. Unlike MANY light experimental and ultralight aircraft, the Zenith WAS actually designed by an engineer, and a damned good one at that. I have seen a whole lot of overweight planes. A little here, and a little their really adds up. And there has not been a single case of a zenith aircraft crashing due to a design deficiency. EVERY ONE has been caused by pilot error and/or careless assembly (like leaving out bolts when installing the wings) Unlike the Texas Parasol (totally un-engineered) which claimed a life in May when the (previously identified as faulty and dangerous designed - disputed vehemently by the designer) wing folded in flight. ** Posted from http://www.teranews.com ** |
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clare at snyder dot ontario dot canada wrote:
Unlike the Texas Parasol (totally un-engineered) which claimed a life in May when the (previously identified as faulty and dangerous designed - disputed vehemently by the designer) wing folded in flight. ** Posted from http://www.teranews.com ** Clare, you son of a bitch. That airplane was a very heavy -overbuilt- TWO seater! Not a Texas Parasol and Not a Chuckbird Now how the hell am I - or the design - supposed to take the blame for that? Ass-Whole |
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cavelamb himself wrote:
FOR WHAT IT'S WORTH - THIS IS A SINGLE SEAT AIRPLANE. This one was NOT built to spec. And Clare, you are a hateful lying coniving son of a bitch. ------------------------------------ Aircraft Profile http://www.airport-data.com/aircraft/C-IHBT.html Aircraft Manufacturer: Chuckbird Model: TEXAS CHUCKBIRD X2 Search all Chuckbird TEXAS CHUCKBIRD X2 Year built: 2002 Serial Number (C/N): 2002 Number of Seats: 2 Number of Engines: 1 Engine Type: Reciprocating Engine Manufacturer and Model: ROTAX SERIES Status: Registered This was what was reported... ------------------------------------ ark: C-IHBT Common Name: Chuckbird Model Name: TEXAS CHUCKBIRD X2 Serial No: 2002 owner Clint, died on impact. Saw a report that spar broke in gusty winds. ------------------------------------ Clare, did YOU submit that "report"? Because the airplane went down in rough terrain and there were no witnesses cited. ------------------------------------ Quoting Q - Believe me, I know. However, I ALSO know that many builders beef up this, and overbuild that because they THINK they know better than the engineer who designed it. |
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cavelamb himself wrote:
Clare, did YOU submit that "report"? Because the airplane went down in rough terrain and there were no witnesses cited. The RCMP report stated there were eyewitnesses, though I have not seen any report that credited an eyewitness with any opinion of what went wrong or description of the crash...... "2008-05-30 18:54 PDT Shortly after noon on the 30th of May, 2008, the Fort St. John R.C.M.P. received reports of a possible plane crash in the Charlie Lake area. Eye witnesses assisted police in narrowing the area to be searched. A small aircraft was located a short while later by first responders, in a heavily wooded area off of the Golf Course Rd., at Charlie Lake. The lone occupant of the aircraft was found deceased. The name of the deceased is not being released at this time. The Fort St. John R.C.M.P. will continue to assist both the Coroner service and the Transportation Safety Board in their respective investigations in determinng the cause of the crash. Originally released 08-05-30 at 14:14hrs by Sgt. GOODLEY of the Fort St. John RCMP. " Charles |
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Charles Vincent wrote:
cavelamb himself wrote: Clare, did YOU submit that "report"? Because the airplane went down in rough terrain and there were no witnesses cited. The RCMP report stated there were eyewitnesses, though I have not seen any report that credited an eyewitness with any opinion of what went wrong or description of the crash...... "2008-05-30 18:54 PDT Shortly after noon on the 30th of May, 2008, the Fort St. John R.C.M.P. received reports of a possible plane crash in the Charlie Lake area. Eye witnesses assisted police in narrowing the area to be searched. A small aircraft was located a short while later by first responders, in a heavily wooded area off of the Golf Course Rd., at Charlie Lake. The lone occupant of the aircraft was found deceased. The name of the deceased is not being released at this time. The Fort St. John R.C.M.P. will continue to assist both the Coroner service and the Transportation Safety Board in their respective investigations in determinng the cause of the crash. Originally released 08-05-30 at 14:14hrs by Sgt. GOODLEY of the Fort St. John RCMP. " Charles I haven't seen much more that this either. Keep an eye on it. -- Richard (remove the X to email) America has become thouroughly convinced that the lunatics are running the assylum and good idea or no, it will take more that George W Bush at a press conference to reclaim the public trust this administration has wantonly destroyed. John R. Corroll |
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On Jul 7, 2:00 am, cavelamb himself wrote:
You are coming off pretty snotty, VB. Show and tell time. Let's see the airplanes you have designed and built... I'm holding up my end of an argument, against three or four people who are being equally snotty. I would be delighted to raise the level of this "discussion" up to a more genteel level, but it would require the same commitment from others... who immediately came after me with both barrels right out of the gate. As for show and tell, I did not and do not claim to be an aircraft designer. I've sketched on paper, and head-scratched, and dreamed just like everyone else on the homebuilt newsgroup. However if you read the thread from the start I went out of my way to not masquerade as a structural engineer, and to compliment Chris Heintz on actually being one. I will claim only this: 1. After having built and tested and crashed and succeeded and failed with hundreds of balsa model airplanes, and after having owned 15 or 16 full size aircraft, and after having gone through A&P mechanic school, and after having listened and learned from several people with engineering knowledge far greater than my own, and after having tinkered good and bad with small sheet metal projects on several airplanes... I have a little better understanding of what I am talking about on this thread than (let's say) half of the people here. 2. There are some people who probably have a lot more engineering knowledge than I, there are some with a lot less, and there are a few with engineering degrees that I definitely do not have. 3. I looked at a CH-601XL and found a fairly obvious problem. I pointed it out to an Aerospace engineer / A&P in our EAA chapter and he said there was too much movement there but there might not be any assymetrical loads on it. 4. There have been now SEVERAL 601XL in-flight wing failures, one or two new ones since I made the comment that started this flame-fest. If my big mouth keeps a couple of people from burying their heads in the sand on this issue, then perhaps there is some good being done. 5. Although I know damned well there are people on this newsgroup with engineering degrees and greater sheet metal knowledge than mine by far, for some reason they have NOT participated and NOT explained if I'm wrong and NOT explained if anyone else is right. 6. I own a CH-701 mini-project (plans and a few tail parts built), and I would love to build it and fly it. I am a very strong supporter of Chris Heintz' designs for the most part. He has done something brilliant, made the airplanes easy to build, and extremely simple. 7. But if Kelly Johnson can make a mistake, and Ed Heinemann, and Kurt Tank, and Willy Messerschmitt, and Andrei Tupolev, and Matty Laird, and Igor Sikorsky, and Bill Stout, and even CG Taylor can make a mistake, then so the hell can Chris Heintz make a mistake. It is my GUESS that he took the original 601 Zodiac and tried to make a sexy low drag wing for it, at the same time as he was fighting like hell to get it light enough for the new LSA category. He had to push too hard on some engineering issue (or more likely several small ones), he had to go to a lighter skin gauge or thinner shear webs or spread a load across too few bolts or something I do not have the college degree to understand ... and the strength of the airplane fell between what was good enough on paper and what the real world of ASSYMETRICAL flight loads or gusts or sub-par workmanship requires. 8. If I'm being snotty I apologize, but I will return fire when fired upon. And as you can see I will fully substantiate my arguments, unlike some others here ! From a highly experienced airport bum and highly NON-engineering- degreed mechanic, I am telling you all that there is an issue on the tail mounting of the Zenair design. I don't know if it is a big problem, a fatal accident waiting to happen, hugely overbuilt, or something that will wiggle but never break. That is a question for the engineers to clarify but someone needs to look at it. I'm saying that there is a tragic problem with the CH601XL airplane design. There are too many catastrophic structural failures that cannot be swept under the rug of builder error or amateur aerobatics. If it is a design flaw by Heintz, then he is still a great designer and deserves the same respect, but he will have to find the problem and issue a repair or upgrade. Bill Berle |
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On 2008-07-28, Victor Bravo wrote:
I'm holding up my end of an argument, against three or four people who are being equally snotty. I would be delighted to raise the level of this "discussion" up to a more genteel level, but it would require the same commitment from others... who immediately came after me with both barrels right out of the gate. Put yourself in my position. You make comments about an airplane on which I just spent a large sum of money and invested a lot of personal emotion into, using your experience with one part of the aircraft to "explain" that another, completely unrelated part of the aircraft that's been implicated in accidents is somehow underdesigned, yet not backing up your comments beyond that - and especially when my experience with your complaint on my aircraft turns out to be quite different? Just what kind of a reaction were you expecting? 4. There have been now SEVERAL 601XL in-flight wing failures, one or two new ones since I made the comment that started this flame-fest. If my big mouth keeps a couple of people from burying their heads in the sand on this issue, then perhaps there is some good being done. Nobody I know of in the Zodiac community is burying their head in the sand. With a couple of exceptions, nobody's running around in Chicken Little mode, either. We're watching the situation and doing what we can to minimize the risks inherent in flying, just as any prudent pilot would do. One of the Heintz brothers (I think it was Mathieu, but I could be misremembering) has said that there is no one common factor among the accidents that are under investigation. Since he's involved in the investigation, he can't say any more than that until the NTSB has released its findings. 6. I own a CH-701 mini-project (plans and a few tail parts built), and I would love to build it and fly it. I am a very strong supporter of Chris Heintz' designs for the most part. He has done something brilliant, made the airplanes easy to build, and extremely simple. Great! Build it and fly it! Even if your scaremongering about the 601XL were on target, that would not apply to the 701 - as that's a different aircraft, with a different flight profile, and a safety record even you shouldn't be able to find fault with. 8. If I'm being snotty I apologize, but I will return fire when fired upon. And as you can see I will fully substantiate my arguments, unlike some others here ! Fine. Let me know when you do substantiate your arguments. So far, you have utterly failed to explain how the one piece of concrete data you have - that you were able to flex the horizontal stabilizer mounting by moving the stabilizer tip - has anything at all to do with inflight structural failure *of* *the* *wings*. Until you do, you're just blowing smoke. From a highly experienced airport bum and highly NON-engineering- degreed mechanic, I am telling you all that there is an issue on the tail mounting of the Zenair design. I don't know if it is a big problem, a fatal accident waiting to happen, hugely overbuilt, or something that will wiggle but never break. That is a question for the engineers to clarify but someone needs to look at it. This is not borne out on my aircraft. Further, it has never once been implicated in any accident, fatal or otherwise, of the 601XL. Therefore, why, exactly, is it relevant? I'm saying that there is a tragic problem with the CH601XL airplane design. There are too many catastrophic structural failures that cannot be swept under the rug of builder error or amateur aerobatics. That remains to be seen. I do think there's a problem somewhere. There are enough possibilities, and enough factors that can interact, that I do not believe there is an inherent design flaw sufficient to cause structural failure of an aircraft that is properly built, well maintained, and conservatively flown. That there has been no common factor found in the accidents in the type tends to bear out that opinion. Until the problem is found, I intend to maintain my aircraft to the highest standards of airworthiness possible, and fly it well within its performance envelope and my capabilities as a 225-hour, non-instrument-rated private pilot. That's all I can do. -- Jay Maynard, K5ZC http://www.conmicro.com http://jmaynard.livejournal.com http://www.tronguy.net Fairmont, MN (FRM) (Yes, that's me!) AMD Zodiac CH601XLi N55ZC (got it!) |
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On Jul 29, 7:16 am, Jay Maynard
wrote: using your experience with one part of the aircraft to "explain" that another, completely unrelated part of the aircraft that's been implicated in accidents is somehow underdesigned, yet not backing up your comments beyond that - and especially when my experience with your complaint on my aircraft turns out to be quite different? What I brought up is two separate issues with the 601, one of which also applies to the 701. The tail movement has not caused any accidents to my knowledge, it was simply something that bothered me about the design, and something that could eventually cause some inappropriate wear or cracking. If I left you with the opinion that I was associating the tail flexing with the wing issues I apologize. They have nothing to do with each other to my limited knowledge. Nobody I know of in the Zodiac community is burying their head in the sand. One guy on this newsgroup thread said the 601XL is the safest airplane in the sky bar none, and apparently got irritated at my mere mention of a potential problem. His head is buried in something, although it may not be sand ![]() With a couple of exceptions, nobody's running around in Chicken Little mode, either. There are only three 601XL people I know personally. The 3/4 completed Quick Build kit project with a Jabiru 3300 has been put up for sale by the builder because of the wing issues. The factory built fly-away LSA airplane has been put in the back of the hangar until this same issue is sorted out to his satisfaction. The XL that was built and flown crashed on the first flight, due to something that had nothing to do with the wing or tail. One of the Heintz brothers ... said that there is no one common factor among the accidents that are under investigation. Let me get this straight... you're saying there is no one common factor in the structural inflight failure crashes of... five 601XL type aircraft ??? Jay, 601XL IS the common factor ! Even if your scaremongering about the 601XL were on target, Scaremongering !?!? Kindly explain where you would draw the line between intelligently discussing a potential problem (that has resulted in several tragedies) and "scaremongering". Would you prefer to just not allow any discussions about a potential problem with a specific airplane? that would not apply to the 701 - as that's a different aircraft, with a different flight profile, and a safety record even you shouldn't be able to find fault with. The 701 has an excellent safety record, good design features, and a very clever balance between engineering for strength and engineering for simplicity. The unique tradeoff between exceptional STOL ability and cost to build/fly/own is indeed why I am interested in it. So far, you have utterly failed to explain how ..... the horizontal stabilizer ..... has anything at all to do with inflight structural failure *of* *the* *wings*. Until you do, you're just blowing smoke. Once again, I did not and do not believe there is a direct connection between moving the tail too much with hand pressure and wing failures. I hope this is not a big surprise... we may be talking about more than one issue ! The 601 and 701 have an issue which may be a design flaw or may be a design compromise. I personally didn't like the fact that you can move the tail in a manner which you cannot on ANY other similar airplane. So far this has NOT caused any problems or crashes but I stand by that it was worth mentioning. The "concrete evidence" that you forgot to mention is that there have been several fatalities on only one particular variant (XL) of an otherwise very robust and safe design (Zodiac). For the third and final time, I am NOT associating these wing failures with the horizontal tail rigidity... I am associating these wing failures with the possibility that there is not enough metal in the XL wing. You sound like the people who stand out in front of a courthouse screaming "racism !" because the guy who shot four innocent people and is on trial for murder happens to be a different skin color than the people on the jury. That has nothing to do with whether he shot the people or not. Because I have the nerve to hold up an argument and make people talk about a possible design issue, does not make me a scaremonger. (tail movement) This is not borne out on my aircraft. Good. At least you looked at it, considered my point, and made your own decision. That's all I wanted out of the tail argument anyway. Further, it has never once been implicated in any accident, fatal or otherwise, of the 601XL. Therefore, why, exactly, is it relevant? The same reason a warning about Salmonella contamination on some food product is relevant to an automobile recall for bad brakes. You check your brakes AND you check where your friggin' tomatoes came from, because you could have, exactly, two separate unrelated problems that could cause you to get hurt. If you're not getting this concept (of more than one thing going on at the same time) you might not be an ideal candidate for aircraft ownership or operation. I do think there's a problem somewhere. Ahhh... the dull yellow light of higher brain function flickers briefly... I do not believe there is an inherent design flaw sufficient to cause structural failure of an aircraft that is properly built, well maintained, and conservatively flown. ....and just as quickly is extinguished. In aviation, particularly experimental aviation, we have to be far more suspicious than complacent. We have to be utterly suspicious of everything that can affect safety, and ever vigilant. We have to do a pre-flight inspection assuming that something on the airplane will try to kill us this day, and it is our job to find it before it does. Guilty until proven innocent on all matters concerning mechanical safety. We have to fly knowing the engine IS about to fail, and be looking for emergency landing areas at all times. There is a very large burden we have to carry, which makes every flight equally nerve wracking as it is enjoyable. It is this burden that makes me willing to argue with and infuriate a total stranger like you, so that perhaps your anger at me will force you to take that one extra look at a problem from a different angle. You say there are no common factors in the failures... which SHOULD prove that at least one of them was well built and being flown within its limits. The most recent one was a formation flight, so it can be assumed that pilot was flying in level flight and not maneuvering excessively. Until the problem is found, I intend to maintain my aircraft to the highest standards of airworthiness possible, and fly it well within its performance envelope and my capabilities as a 225-hour, non-instrument-rated private pilot. That's all I can do. Sorry Jay, I can't let you off the hook. The "highest standards of airworthiness possible" means you would load test the wings (sandbag test) to verify structural integrity... at various torsional moments (wing twisting due to air loads). "Within its performance envelope" means that you KNOW what the real performance envelope is. If other 601XL aircraft have failed inflight operating within or even near this envelope, it means the published envelope is really not fully proven out. Changing my personalities for a moment, and assuming the role of someone less antagonistic who only wants you to be able to fly safely, I will turn off the smart-ass switch and turn on the "help this guy live to enjoy his airplane" switch. Until a real engineer has determined the full problem and figured out a real solution, I sincerely advise you to implement a temporary set of restrictions in your flight envelope to increase your structural margins. Reduce your turbulent air penetration speed and VNE speed by 25% each. Reduce the allowable gross weight of your airplane by 10%. Reduce the maximum G loading by one or two G. Limit aerobatics to low G barrel rolls. Reduce or eliminate maneuvers that put rolling (wing twisting) loads on at the same time as G loads. Taking these precautions WILL greatly reduce the loads on your structure, until a qualified engineer figures this all out. Bill Berle |
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