---------------------------------------------------------- KIS-List Digest Archive --- Total Messages Posted Thu 04/14/11: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:57 PM - Re: Re: TR-1 Spar Repair Choice (Richard Trickel) 2. 06:57 PM - Re: Re: TR-1 Spar Repair Choice (Richard Trickel) 3. 08:43 PM - Re: Re: TR-1 Spar Repair Choice (Scott Stearns) ________________________________ Message 1 _____________________________________ Time: 06:57:30 PM PST US From: Richard Trickel Subject: Re: KIS-List: Re: TR-1 Spar Repair Choice Alfred I have been reading the post regarding the wing.- the pictures were not s o good so there is some question.- also there were no rear spar photos. - Both scott and Mark are on the right path.- They should be since both are engineers and have a lot of experience with the kis a/c.- So heed their advice.- I would say that after a good exam of the damage area why not do a limit load test on the wing... It would take a little work but I would r epair the shear web panel and then do the load test. Mark if yopu read this could you tell him the best way to do this.- I wou ld be cheaper than buying a new wing.- I doubt that Pulsar will be able t o make one. Rich --- On Wed, 4/13/11, BlueSkyFlier wrote: From: BlueSkyFlier Subject: KIS-List: Re: TR-1 Spar Repair Choice You are right Mark.- There is some damage to the spar cap at the top rear of the C-section. The question uppermost in my mind is the following: Cons idering that damage resulted from compression, does damage to the resin mat rix necessarily imply that the carbon fibres are broken? And even if the fi bres are intact, could the resin matrix be repaired/strengthened effectivel y? The intended repair method involves claving (I think that's the right word? ) in new fibres with the old with a large overlap after cutting a very shal low V notch (3 feet slope on each side) at the crack location and then also repairing the shear web. Sounds similar to the repair job Rich supervised. The front half of the spar cap and the integrity of junction to the spine o f the C-section will remain uncompromised, because the damage is limited to the rear half of the top spar cap . Naturally, repairing a main spar is anomalous to us in the GA world and we do tend to look on it with suspicion. It does however seem that it is par f or the course in the sailplane world and the main contenders for the job ha s been doing main spar repairs for more than thirty years. Apparently the LAA (PFA) here will look kindly on the repair provided it is done by such a reputable sailplane repair outfit. I am trying to make cont act with the LAA official in charge of such affairs who apparently expresse d this opinion to a fellow KIS owner in Scotland, but establishing contact seems to be more difficult than making a call and leaving a request for a r eturn call - an experience some of the UK guys may have shared when dealing with the LAA :o) I must admit the option to walk away is tempting, but I'll make the final d ecision after considering all relevant information. - Alfred -------- _________________________________________ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=336867#336867 le, List Admin. ________________________________ Message 2 _____________________________________ Time: 06:57:46 PM PST US From: Richard Trickel Subject: Re: KIS-List: Re: TR-1 Spar Repair Choice --- On Wed, 4/13/11, Mark Kettering wrote: From: Mark Kettering Subject: Re: KIS-List: Re: TR-1 Spar Repair Choice The damage is very small BUT (and this is a very big but) there seems to be a small notch in the edge of the carbon fiber spar cap. If this was from c ompression then I would suspect the whole spar cap.- There is also the mi ssing paint on the top (bottom?) of the spar.- This also makes me suspect the spar cap.- If this is the case then it may not be a good idea to try to repair the spar but it can be done by an expert.- The fibers do not n eed to run from one end to the other but the repair will require a large ar ea to properly bond.- For example Rich supervised (or maybe did) the repa ir on the center spar of a TR4 that went to China. If the missing paint and notch were caused by other things like abrasion ov er time then maybe the spat cap is ok.- But without looking at it in pers on I can not tell. Mark -----Original Message----- >From: BlueSkyFlier >Sent: Apr 13, 2011 10:05 AM >To: kis-list@matronics.com >Subject: KIS-List: Re: TR-1 Spar Repair Choice > > > >Thank you for all the contributions so far. Good food for thought :o) > >Much obliged for the pointer to the wing information Scott! Attached a hi- res photo of the damaged area which will allow you to see where it is on th e spar - hopefully it won't be stripped off by the moderator. I'm hoping th at we will find that the carbon fibers on the top web of the c-section are intact. If so, the repair cost will drop by an order of magnitude. > >In case the carbon is damaged I am also looking at the option to have- a n entirely new wing built. For this I am working with people who routinely design and built huge hydro-electric turbine blades ... actually aircraft d esigners/builders who diversified into the turbine (wind and water) busines s. > >I'm thinking that the cost to build new would be about the same as an exte nsive repair, given the simple wing construction of the KIS and that we can re-use the flaps and ailerons. > >I already know of at least one other person who also requires a new wing. By building two wings we could at least split the non-recurring engineering costs. (While we are at it we'll obviously improve on the original.) > >Anyone else out there who requires a new wing?- The more the merrier :o) > >--**-- > >-------- >_________________________________________ > > >Read this topic online here: > >http://forums.matronics.com/viewtopic.php?p=336822#336822 > > >Attachments: > >http://forums.matronics.com//files/tr_1_spar_damage_162.jpg > > le, List Admin. ________________________________ Message 3 _____________________________________ Time: 08:43:45 PM PST US From: Scott Stearns Subject: Re: KIS-List: Re: TR-1 Spar Repair Choice It would break my heart if it were my airplane, but I'd take the money and walk away and find a new toy.- Maybe Mark will sell you his. - Scott- - --- On Wed, 4/13/11, BlueSkyFlier wrote: From: BlueSkyFlier Subject: KIS-List: Re: TR-1 Spar Repair Choice You are right Mark.- There is some damage to the spar cap at the top rear of the C-section. The question uppermost in my mind is the following: Cons idering that damage resulted from compression, does damage to the resin mat rix necessarily imply that the carbon fibres are broken? And even if the fi bres are intact, could the resin matrix be repaired/strengthened effectivel y? The intended repair method involves claving (I think that's the right word? ) in new fibres with the old with a large overlap after cutting a very shal low V notch (3 feet slope on each side) at the crack location and then also repairing the shear web. Sounds similar to the repair job Rich supervised. The front half of the spar cap and the integrity of junction to the spine o f the C-section will remain uncompromised, because the damage is limited to the rear half of the top spar cap . Naturally, repairing a main spar is anomalous to us in the GA world and we do tend to look on it with suspicion. It does however seem that it is par f or the course in the sailplane world and the main contenders for the job ha s been doing main spar repairs for more than thirty years. Apparently the LAA (PFA) here will look kindly on the repair provided it is done by such a reputable sailplane repair outfit. I am trying to make cont act with the LAA official in charge of such affairs who apparently expresse d this opinion to a fellow KIS owner in Scotland, but establishing contact seems to be more difficult than making a call and leaving a request for a r eturn call - an experience some of the UK guys may have shared when dealing with the LAA :o) I must admit the option to walk away is tempting, but I'll make the final d ecision after considering all relevant information. - Alfred -------- _________________________________________ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=336867#336867 le, List Admin. ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kis-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/KIS-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/kis-list Browse Digests http://www.matronics.com/digest/kis-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.