---------------------------------------------------------- Kitfox-List Digest Archive --- Total Messages Posted Fri 06/12/09: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:57 AM - Re: Adding wheel pants. (Boilermaker2000) 2. 01:24 PM - Bungee gear limit cables (was) Re: model 5 gear pictures (Lowell Fitt) 3. 04:29 PM - Re: model 5 gear pictures (Joel) 4. 10:23 PM - Re: Bungee gear limit cables (was) Re: model 5 gear pictures (bjones@dmv.com) 5. 11:45 PM - Re: model 5 gear pictures (akflyer) ________________________________ Message 1 _____________________________________ Time: 04:57:54 AM PST US Subject: Kitfox-List: Re: Adding wheel pants. From: "Boilermaker2000" Yodaone, Did you ever get any info or pics on how to install the wheel pants? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=247785#247785 ________________________________ Message 2 _____________________________________ Time: 01:24:08 PM PST US From: "Lowell Fitt" Subject: Kitfox-List: Bungee gear limit cables (was) Re: model 5 gear pictures Hi Bob, What advice are you having trouble with? I stated a fact - I do have friends that removed the limit cables - and then made a suggestion. For the Limit Cable fans, I did some research and made a drawing or two and made some calculations. First, Mil-C-5651D Load Specifications for our Type III Bungee cord call for a load range at 100% elongation of between 90 lbs. and 150 lbs. A minimum stretch at 140% and an ultimate breaking load of 300 lbs. For those concerned with the 300 lbs, remember that we have six turns and 12 lengths of bungee supporting our landing gear. Using the drawings, it appears that a stretch of 140% would drop the height of the fuselage at the gear, about 7" or maybe 9" at the prop in the three point or the original 7" wheel landing. (It has been a long time since I had a Model IV on the original bungee gear, but pictures I have of numarous airplanes show the ground clearance in the three point to be well over half a prop blade length.) Given a load at the100% stretch to be at the low end - 90 lbs multiplied by 12 would be 1080 lbs. Per gear leg or close to 2 Gs if all the max gross wt. was on the mains. This would result in a bungee cord drop of about 3 inches or a nose drop of about five inches. (Mayabe this is where the manual illustration measurement comes from - see below). Calculating at the high end of 150 lbs. the 100% stretch load would be 1800 lbs. at max gross and all weight on the mains or 3Gs. to get the same drop. It is likely that the bungees we have - if relatively fresh would give a load somewhere between these figures. Most of this stuff is meaningless except regarding the length of the limit cables. The manual - my manual - calls for a length of 4.5 to 5 inches. The drawing shows 3 inches. The drop at the bungees at the 140" stretch would be closer to six inches. If your limit cables are in the 4.5 to 5 inch range, or worse yet, installed at the 3 inches in the drawing, you are cutting the bungees effective spring action to a fraction of what it is designed to handle and the sudden stop of "spring" movement focused on the bungee bulkhead has in the past and likely will in the future, cause damage to the most difficult to repair structural element. I mentioned that some have removed the limit cables. I don't recall recommending that as was asserted, but I did recommend lengthening them. Frankly with a little bit of effort, I think I can now fairly safely suggest that removing them would result in minimal risk to the prop, but can't say much about the wing tips if someone manages to put 3gs of force on one gear leg, but I think I would strongly recommend that they be long enough to allow for at least six inches of downward movement of the bungee attachment tube. If someone else wants to do the work and comes up with different numbers, I am willing to listen. Better landings? Definitely good advice. Lowell Fitt Cameron Park, CA Model IV-1200 R-912 UL Covering. ----- Original Message ----- From: "AKFLYERBOB" Sent: Thursday, June 11, 2009 8:31 AM Subject: Kitfox-List: Re: model 5 gear pictures > > > Thats bad advice > The cables are to keep the prop and "WING" from hitting > the ground. Even with broken bungees and bent gear > you can still fly home on the safety cable. > What should be eliminated is the HARD LANDINGS if possible. > Bob > > -------- > Bob Wolfe..Soldotna, Alaska > KF Mod I and III > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=247687#247687 > > > ________________________________ Message 3 _____________________________________ Time: 04:29:44 PM PST US Subject: Kitfox-List: Re: model 5 gear pictures From: "Joel" A few more model 5 landing gear pix -------- Joel Mapes Kitfox 5 912 ULS Aerocomp amphibs Read this topic online here: http://forums.matronics.com/viewtopic.php?p=247891#247891 Attachments: http://forums.matronics.com//files/dscf0005_558.jpg http://forums.matronics.com//files/dscf0004_712.jpg http://forums.matronics.com//files/dscf0003_160.jpg http://forums.matronics.com//files/dscf0002_114.jpg http://forums.matronics.com//files/dscf0001_674.jpg ________________________________ Message 4 _____________________________________ Time: 10:23:47 PM PST US From: bjones@dmv.com Subject: Re: Kitfox-List: Bungee gear limit cables (was) Re: model 5 gear pictures Lowel I have heard about three failures of relatively NEW bungees in Kitfox installations. In one instance the gear safety cable failed after the bungee failed. The result was a ground loop and wing damage. Apparently there was no structural damage caused by the safety cables in those three cases although we have heard of it in other cases. I don't know what caused the bungee failures but suspect fraying, installation error or bungee end failure. If there is a moral here, it may be that Murphy can show up in a variety of "unexpected" ways in addition to the expected hard landing and in bungee failures not caused by hard landings the safety cables could be valuable. As an aside, I too installed longer cables during my last bungee replacement. BJ N154K N626NR bjones@dmv.com 443-480-1023 Quoting Lowell Fitt : > > Hi Bob, > > What advice are you having trouble with? I stated a fact - I do have > friends that removed the limit cables - and then made a suggestion. > > For the Limit Cable fans, I did some research and made a drawing or two and > made some calculations. > First, Mil-C-5651D Load Specifications for our Type III Bungee cord call > for a load range at 100% elongation of between 90 lbs. and 150 lbs. A > minimum stretch at 140% and an ultimate breaking load of 300 lbs. For those > concerned with the 300 lbs, remember that we have six turns and 12 lengths > of bungee supporting our landing gear. > > Using the drawings, it appears that a stretch of 140% would drop the height > of the fuselage at the gear, about 7" or maybe 9" at the prop in the three > point or the original 7" wheel landing. (It has been a long time since I had > > a Model IV on the original bungee gear, but pictures I have of numarous > airplanes show the ground clearance in the three point to be well over half > a prop blade length.) > > Given a load at the100% stretch to be at the low end - 90 lbs multiplied by > 12 would be 1080 lbs. Per gear leg or close to 2 Gs if all the max gross wt. > > was on the mains. This would result in a bungee cord drop of about 3 inches > > or a nose drop of about five inches. (Mayabe this is where the manual > illustration measurement comes from - see below). Calculating at the high > end of 150 lbs. the 100% stretch load would be 1800 lbs. at max gross and > all weight on the mains or 3Gs. to get the same drop. It is likely that the > > bungees we have - if relatively fresh would give a load somewhere between > these figures. > > Most of this stuff is meaningless except regarding the length of the limit > cables. The manual - my manual - calls for a length of 4.5 to 5 inches. The > drawing shows 3 inches. The drop at the bungees at the 140" stretch would be > > closer to six inches. If your limit cables are in the 4.5 to 5 inch range, > or worse yet, installed at the 3 inches in the drawing, you are cutting the > bungees effective spring action to a fraction of what it is designed to > handle and the sudden stop of "spring" movement focused on the bungee > bulkhead has in the past and likely will in the future, cause damage to the > most difficult to repair structural element. > > I mentioned that some have removed the limit cables. I don't recall > recommending that as was asserted, but I did recommend lengthening them. > Frankly with a little bit of effort, I think I can now fairly safely suggest > > that removing them would result in minimal risk to the prop, but can't say > much about the wing tips if someone manages to put 3gs of force on one gear > leg, but I think I would strongly recommend that they be long enough to > allow for at least six inches of downward movement of the bungee attachment > tube. If someone else wants to do the work and comes up with different > numbers, I am willing to listen. > > Better landings? Definitely good advice. > > Lowell Fitt > Cameron Park, CA > Model IV-1200 R-912 UL > Covering. > > ----- Original Message ----- > From: "AKFLYERBOB" > To: > Sent: Thursday, June 11, 2009 8:31 AM > Subject: Kitfox-List: Re: model 5 gear pictures > > > > > > > > Thats bad advice > > The cables are to keep the prop and "WING" from hitting > > the ground. Even with broken bungees and bent gear > > you can still fly home on the safety cable. > > What should be eliminated is the HARD LANDINGS if possible. > > Bob > > > > -------- > > Bob Wolfe..Soldotna, Alaska > > KF Mod I and III > > > > > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=247687#247687 > > > > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------------------------ This message was sent using Delmarva Online's Webmail. http://www.delmarvaonline.com/ ________________________________ Message 5 _____________________________________ Time: 11:45:53 PM PST US Subject: Kitfox-List: Re: model 5 gear pictures From: "akflyer" One suggestion based on personal experience. Dont put the safety cable on the end of the gear leg like yours is now. Put it inside the cluster where the rear kicker comes in. My Avid, and my Brothers kitfox BOTH had a gear failure from cracking that started at the toe of the weld where the rear tube comes in. With the bungies on you cant see the cracks starting. On my Avid the result was the leg broke off and the cable had nothing to hold up so over he went (but I did get a damn good deal on a bent airplane because that was the second time it had happened and he was not able to repair it the second time). On my brother KF II the exact same thing happened but we were both in it. bounced a little but not bad, when he came back down the gear folded and over we went. Kinda ruined the day for us both and cost a few bucks for him to fix. It could have been prevented in both cases if the safety cable was located in an area that was not prone to breaking. If you have to change the gear, you would have to cut the cables, but that is a very small price to pay to keep the bird in one piece in the event of a gear failure. -------- DO NOT ARCHIVE Leonard Perry aka SNAKE Soldotna AK Avid "C" / Mk IV 582 IVO IFA Full Lotus 1260 #1 snake oil salesman since 1-22-2009 hander outer of humorless darwin awards Read this topic online here: http://forums.matronics.com/viewtopic.php?p=247920#247920 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kitfox-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kitfox-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/kitfox-list Browse Digests http://www.matronics.com/digest/kitfox-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.