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kitfox spar damage

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occom(at)ns.sympatico.ca
Guest

Posted: Sun Jun 25, 2006 7:30 am Post subject: kitfox spar damage

I have two damaged spars which I'm still  working on removing. The previous owner started repairs and the workmanship is  good, I'm just doubtful of the whole concept. 

  

 The rear spar in one wing is cut and spliced just a  bit before the insert stops between ribs 7 and 8. The front spars  appears fine. I've attached a photo of the splice. It has a sleeve over it  and I think it has an extension of the insert inside. It looks like they riveted  a plate on the insert web and used part of another insert as an extension. No  photos of that, it's hard enough to decide  what I'm looking at down there.  

  

 Does anyone think this would work?

  

 The second spar is dented at the jury strut attach  point. There's a slight bend to the spar starting at this dent, I've not yet  measured it, it looks like about 1/2" bow. I expect the only advice I will get  is that it must be replaced, but I'll ask anyway. Pictures are attached I hope.

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dave(at)cfisher.com
Guest

Posted: Sun Jun 25, 2006 7:51 am Post subject: kitfox spar damage

Dave G, 

  

 Unreal is all I have to say. 

  

 Splicing spars like that is very Mickey Mouse   to say the least. 

  

 If you have any dents in the spars and you say at  the wing atach point the integrity and strength has been comprized.  

 I would replace any spar tube that has damage as  well as anything else that has been damaged.   

  

 I cannot comprehend what one was thinking to make  those repairs in the photos.   I would suggest getting an expericend  builder to look over your entire Kitfox. 

  

  

 Dave 

  

  

  

 [quote]   ---

occom(at)ns.sympatico.ca
Guest

Posted: Sun Jun 25, 2006 8:42 am Post subject: kitfox spar damage

The original builder did an exceptional job, and  flew the plane many hundreds of hours as far as I know. It was sold when he  built another, The incident that damaged the wings occured for the third owner.  I've looked over the whole aircraft and the wings appear to be the major damage.  There was slight damage to the tailpost but it's been repaired well. Nothing  else is dented, wrinkled, cracked or bent as far as I've been able to find.  The only irritation is the aerothane paint job, it's hard to sand off for  patching small spots. I'll be using polytone for the wings. 

 [quote]   ---

ddsyverson(at)comcast.net
Guest

Posted: Sun Jun 25, 2006 9:40 am Post subject: kitfox spar damage

Dave G.



The rear spar of a Kitfox carries a larger load than the front spar. Based on 

the photos, I don't see how the damaged rear spar in the photo could possibly 

carry the design loads. I don't see how a person could even guess at what 

load it COULD carry - or for how long.   



FYI - I threw away two brand new spars supplied by Skyclinker because of dents 

and radial scratches in the surface - also had a DC-9 mechanic (familiar with 

lots of aluminum) look at them before I decided. 



Your comments;  "I'm just doubtful of the whole concept."  & "...it's hard 

enough to decide  what I'm looking at down there..." tells me you know the 

answer. I would suggest that you go with your better judgment - you are 

looking at the parts more directly than we ever can through a photo.



Anytime a person is dealing with a damaged aircraft, A person will only know 

the entire aircraft is safe if a complete disassembly is done, every part of 

the aircraft is inspected, assesssed, and either A) re-used if within 

acceptable service limits; or B) replaced if: 1) not within acceptable 

service limits; or, 2) replaced if not in original condition and the service 

limits are unknown.



There are probably three real good ways to handle this. 1) Stick with the 

specifications of the kit manufacture for the model you have; 2) Have a 

competent Airframe mechanic look it over; 3) Make sure the repair or 

replacement is complete and in reasonable agreement with the procedures laid 

out in the FAA's Advisor Circular on acceptable repairs.



My comments may be a bit of overkill for some; however, there has not been a 

structural failure of a wing spar on a 

kitfox............yet.................. 



Sincerely,



Dave S

St Paul, MN



On Sunday 25 June 2006 10:27 am, Dave G. wrote:

 	  Quote: 	
		   I have two damaged spars which I'm still working on removing. The previous

 owner started repairs and the workmanship is good, I'm just doubtful of the

 whole concept.



 The rear spar in one wing is cut and spliced just a bit before the insert

 stops between ribs 7 and 8. The front spars appears fine. I've attached a

 photo of the splice. It has a sleeve over it and I think it has an

 extension of the insert inside. It looks like they riveted a plate on the

 insert web and used part of another insert as an extension. No photos of

 that, it's hard enough to decide  what I'm looking at down there.



 Does anyone think this would work?



 The second spar is dented at the jury strut attach point. There's a slight

 bend to the spar starting at this dent, I've not yet measured it, it looks

 like about 1/2" bow. I expect the only advice I will get is that it must be

 replaced, but I'll ask anyway. Pictures are attached I hope.

Jim Shumaker

Joined: 09 Jan 2006
Posts: 106

Posted: Sun Jun 25, 2006 9:40 am Post subject: kitfox spar damage

Dave

   

  The hang glider industry uses round spars and splices tubes with sleeving.  But what I see in the photo is absolutely unacceptable in any form.  There is NO way to save that spar.  Sleeving with over sized or undersized tube works but a split tube scabbed over a break is not acceptable by any either the Hang gliding industry or the Aviation industry as detailed in publication 43.13-1A/2A.

   

  Any permanent bend in the spar is reason for rejection.  No need to quantify it.  It is evidence of failure.

   

  Jim Shumaker

  



"Dave G." <occom(at)ns.sympatico.ca> wrote:

   	  Quote: 	
		          I have two damaged spars which I'm still  working on removing. The previous owner started repairs and the workmanship is good, I'm just doubtful of the whole concept. 

   

  The rear spar in one wing is cut and spliced just a bit before the insert stops between ribs 7 and 8. The front spars appears fine. I've attached a photo of the splice. It has a sleeve over it and I think it has an extension of the insert inside. It looks like they riveted a plate on the insert web and used part of another insert as an extension. No photos of that, it's hard enough to decide  what I'm looking at down there. 

   

  Does anyone think this would work?

   

  The second spar is dented at the jury strut attach point. There's a slight bend to the spar  starting at this dent, I've not yet measured it, it looks like about 1/2" bow. I expect the only advice I will get is that it must be replaced, but I'll ask anyway. Pictures are attached I hope.

_________________
Jim Shumaker

iworonko(at)cox.net
Guest

Posted: Sun Jun 25, 2006 10:22 am Post subject: kitfox spar damage

Dave,

 ditto to all the other comments about that spar  repair.

 You say the workmanship is good but I guess you  forgot to include a picture of that part because what I see in these pictures is  an absolute disaster. That split tube repair wouldn't be acceptable on a farm  tractor.

 For that doubler repair to be even remotely  effective it would require many more high quality fasteners properly placed and  spaced throughout the patch, not just a few pop rivets randomly placed here and  there. All that is beside the point since this kind of repair has no business on  a tubular wing spar.

 Whoever flew this airplane after that repair is  extremely lucky that he has not reached a G load that would have shown him , in  a very unpleasant way, what a poor repair this is.

 I vote for a new spar.

 Eric

  

  

 [quote]   ---

smokey_bear_40220(at)yaho
Guest

Posted: Sun Jun 25, 2006 10:36 am Post subject: kitfox spar damage

Hi Dave,



 	  Quote: 	
		   Does anyone think this would work?


	


No!!!



 	  Quote: 	
		   The second spar is dented at the jury strut attach

 point. There's a slight bend to the spar....


	


SkyStar didn´t even allow scratches on the spar, and

with good reason.  The spars flex like bending coat

hangars.  If undamaged, they will flex a long time

without breaking.  But if damaged, even scratched,

they will fail much sooner, like a coat hangar would.



If you took an empty can and stacked bricks on it, the

can would hold up quite a few without crunching.  But

if you cut open one side, only a few bricks would

flatten it.  Same with that spliced spar.  A very weak

fix.  It is doomed!



Sorry,



kurt S.



__________________________________________________

occom(at)ns.sympatico.ca
Guest

Posted: Sun Jun 25, 2006 11:21 am Post subject: kitfox spar damage

I think you misunderstand, the aircraft was never  flown this way. My comment that the workmanship was good on this repair reflects  the fact that there are no spaces, chips or gaps. All the rivets reflect exactly  the specified pattern for the original construction, and all edges are radiused  and relieved. All the replaced ribs are in the correct position, vertical, and  the spar is straight as a die. So the work is fine, it's the concept that's  flawed. I was never in doubt that the spliced spar required replacement.  

  

 I was never in a great deal of doubt about the  dented one, but the damage is not severe and there is/was a shred of doubt about  that one. 

  

  

 [quote]   ---

mike
Guest

Posted: Sun Jun 25, 2006 2:56 pm Post subject: Re: kitfox spar damage

This is my thoughts on the whole thing.  Call John and order two new spars.  Pull off all the ribs and build a new wing.  When your up at altitude you will feel muuuuch better knowing you have a good wing.  Better to be taking the time to have it right now than to be wishing you did while in a spiral going into the ground.

occom(at)ns.sympatico.ca
Guest

Posted: Sun Jun 25, 2006 3:16 pm Post subject: kitfox spar damage

Oh, I've been slowly peeling off epoxy for a week now. Still have a way to 

go. Been emailing Sportplane about parts but I'll have to wait until they 

are apart before I know how much to order. The best way I've found to remove 

the epoxy without damaging ribs is with a hot blade.

---

wliles(at)bayou.com
Guest

Posted: Sun Jun 25, 2006 3:20 pm Post subject: kitfox spar damage

Salvage what you can but replace both of those spars.  There is no way 

the rear spar repair would be airworthy and the front spar dent and 

bowing render it unacceptable.



Jerry Liles



Dave G. wrote:



 	  Quote: 	
		   I have two damaged spars which I'm still working on removing. The 

 previous owner started repairs and the workmanship is good, I'm just 

 doubtful of the whole concept.

  

 The rear spar in one wing is cut and spliced just a bit before the 

 insert stops between ribs 7 and 8. The front spars appears fine. I've 

 attached a photo of the splice. It has a sleeve over it and I think it 

 has an extension of the insert inside. It looks like they riveted a 

 plate on the insert web and used part of another insert as an 

 extension. No photos of that, it's hard enough to decide  what I'm 

 looking at down there.

  

 Does anyone think this would work?

  

 The second spar is dented at the jury strut attach point. There's a 

 slight bend to the spar starting at this dent, I've not yet measured 

 it, it looks like about 1/2" bow. I expect the only advice I will get 

 is that it must be replaced, but I'll ask anyway. Pictures are 

 attached I hope.



 ------------------------------------------------------------------------

 ------------------------------------------------------------------------

 ------------------------------------------------------------------------

mike
Guest

Posted: Sun Jun 25, 2006 5:38 pm Post subject: Re: kitfox spar damage

You will need to sawsall the old spars to get the ribs out, have fun.

mike
Guest

Posted: Sun Jun 25, 2006 5:46 pm Post subject: Re: kitfox spar damage

lets see here, you can keep the ribs to cross pipes together for the most part. You know, tear it down is sections and basically slip them right over the new spars.  drill out all the rivets match them in place to the new spars and rivet.  Should be pretty easy.  You will need to figure what your going to do with the center thing amagigies in the spars at mid way. You could remove the old ones and turn them around and reinstall in the new spars or just buy new ones.  Other than that, the wing is pretty simple to build.  Get the latest on the plans for building the wings.



I would say the only things you need to buy are the spars, rivets, and maybe the inserts, and some hysol.  build some saw horses for construction.

lcfitt(at)sbcglobal.net
Guest

Posted: Sun Jun 25, 2006 6:24 pm Post subject: kitfox spar damage

Not to disparage any of the previous posts on the spar repair - I am in 

agreement with the "bad repair" group.  As previously posted,  but I 

attended a Rans fly-in in Utah over the weekend at a build assist center 

there, and I was amazed at the number of holes drilled through the spars 

etc. - big holes.  I sure like the kitfox - avid design.



Lowell



---

roncarolnikko(at)hotmail.
Guest

Posted: Sun Jun 25, 2006 7:11 pm Post subject: kitfox spar damage

Dave I'm the guy that would do or fly anything to save a buck, BUT....   I 

vote replacing the spars.   While flying my Avid a model which is the 

predeccessor to the Kitfox, I often tell the passenger to watch the leading 

edge.  When I pull back on the stick it bends up, and then down on the 

negative g.   Then they understand the concept of the wing removal tool.   

That spar would not tolerate the way I fly, or the unexpected turbulance 

often encountered.  Sorry  Ron NB Ore.

 	  Quote: 	
		  From: "Dave G." <occom(at)ns.sympatico.ca>

Reply-To: kitfox-list(at)matronics.com

To: <kitfox-list(at)matronics.com>

Subject: kitfox spar damage

Date: Sun, 25 Jun 2006 12:27:30 -0300



I have two damaged spars which I'm still working on removing. The previous 

owner started repairs and the workmanship is good, I'm just doubtful of the 

whole concept.



The rear spar in one wing is cut and spliced just a bit before the insert 

stops between ribs 7 and 8. The front spars appears fine. I've attached a 

photo of the splice. It has a sleeve over it and I think it has an 

extension of the insert inside. It looks like they riveted a plate on the 

insert web and used part of another insert as an extension. No photos of 

that, it's hard enough to decide  what I'm looking at down there.



Does anyone think this would work?



The second spar is dented at the jury strut attach point. There's a slight 

bend to the spar starting at this dent, I've not yet measured it, it looks 

like about 1/2" bow. I expect the only advice I will get is that it must be 

replaced, but I'll ask anyway. Pictures are attached I hope.


	




 	  Quote: 	
		  << wing004r.jpg >>


	




 	  Quote: 	
		  << wing7r.jpg >>


	




 	  Quote: 	
		  << wing010.jpg >>


	


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dpremgood(at)aol.com
Guest

Posted: Sun Jun 25, 2006 8:55 pm Post subject: kitfox spar damage

Dave,

  

 If you were seriously considering  keeping that wing, get help from a structural engineer. The engineer would then have to do a load analysis on that section of  wing, determine what kind of repair/material is needed and then determine if the present repair is adequate. (I can see the dollar signs)

  

 Personally, I would be ordering new spars right about now.

  

 Bonne Chance,

  

 Doug Remoundos

 Montreal

 

--

occom(at)ns.sympatico.ca
Guest

Posted: Mon Jun 26, 2006 2:32 am Post subject: kitfox spar damage

Thanks to all for the replies. I had talked to Sportplane about the repair a 

couple of weeks ago, when I thought only one spar needed replacing, and we 

had determined that the chance of sucessfylly reusing the insert was poor. I 

didn't want the spliced rear spar but posted the pictures because I didn't 

definitively know that it wouldn't work.



I am still curious about the other rear spar. I will take another, clearer, 

picture when it stops raining. I expect you could get by with this for some 

time, if the wing had not been uncovered it would not be noticable except 

for the deformation of the mounting tabs. Since the wings are both without 

fabric at this time, it makes sense to replace it. I expect I'll have the 

technique of removing the spar after the other wing is done.



Just because the epoxy removal is a slow and difficult job, I asked 

Sportplane about a whole wing kit. I'll decide how much to order when I have 

this spar out.

occom(at)ns.sympatico.ca
Guest

Posted: Mon Jun 26, 2006 2:42 am Post subject: kitfox spar damage

---

dave(at)cfisher.com
Guest

Posted: Mon Jun 26, 2006 2:55 am Post subject: kitfox spar damage

Dave,



I agree that entire wings would be best most likely. Tubing is all standard 

but when you buy it comes in 20 foot lengths.

Shipping can be abusive to alum sheeting and tube. Dented materials is not 

an option.

Ribs -  you might need a few when you are done and I would ask Sportplane 

what cost is for Ribs etc.  depeneds on what your hours are worth to you. 

Actually more like days or weeks to get apart.



And like i said before,  I wold find a experienced builder to come look over 

this plane as after seeing those repairs, well who knows else was messed 

up.



When all said and done you want a plane that you can feel safe in.

Dave

---

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