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Broken Flaperon pivot point

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Posted

I have a Avid Model A I just bought. It is acually #6 from Avid and was built by the creators of this plane. Anyway I just bought it and in transport two of the flaperon poviot points at the end of the wing rib broke. Does anyone know the quick and proper way to fix these. It has new fabric on the wings so I would prefer not to have to recover the whole wing.

See attached picture

Thanks

Craig

post-409-13287411567721_thumb.jpg

post-409-13287411754086_thumb.jpg

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Posted

I don't have a painless procedure for an easy repair. On my Kitfox III we laminated a thin aluminum sheet to the plywood on either side of the flaperon hanger using Hysol to give it extra strength. these laminations went back inside the wing about eight inches.

On yours, I'd first remove the flaperons and carefully inspect the other hangers. I'm wondering if your plane was stored outside. The breaks look like the plywood may have lost some strength.

-- Paul S

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Posted (edited)

Kitfox published an article on this repair. I will have to see what the site is. Believe it involved slitting fabric on each side back a ways, and splicing new wood hangers in and then a tape job on fabric. There was also an article about reinforcing the hangers with aluminum angles because Britain or the UK said it was not strong enough for certified aircraft standards. I have 1/16" aluminum glued with 9460 and riveted to mine from spar to tip of rib with 1/4 inch rivets. Probably overbuild, but I have 14" Flaps and Ailerons.

Will get back on this in a day or so if no one else posts it.

Try <www.sportflight.com> or the Kitfox Builder.

Ed in MO

Scan0317.jpg

Scan0318.jpg

Scan0319.jpg

Edited by EDMO

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Posted

I don't have a painless procedure for an easy repair. On my Kitfox III we laminated a thin aluminum sheet to the plywood on either side of the flaperon hanger using Hysol to give it extra strength. these laminations went back inside the wing about eight inches.

On yours, I'd first remove the flaperons and carefully inspect the other hangers. I'm wondering if your plane was stored outside. The breaks look like the plywood may have lost some strength.

-- Paul S

It would be nearly impossible to fix without opening up the wings. I also agree that wood looks almost rotten. I re-glassed mine when I redid the wings. Here's a pic to give you an idea of what they look like when totally exposed.

IMG_3564.jpg

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Posted

Look at Avid Catlina post on this site and at post #23 page two

you will see a picture of replacing all hinge rib tails

Their are quite a few pictures in that thread to follow the wing rebuild

actually the whole airplane,

not finished,

it got side tracked

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Posted

Here's a link to the refernced post: Avid.Catalina Post 23

-- Paul S

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Posted

Here's a link to the refernced post: Avid.Catalina Post 23

-- Paul S

Thank you for all the suggestions. I have heard the two pieces of aluminum on either side. I have done tons of metal fabrication so I think this I will beef all of them up.

This plane was actuall #6 from Avid in 1983 and was used a oshgosh for a demo to see the plane. It had tricycyle gear and tail dragger so I am trying to put it back in original configuration in a tricycle gear format with the original 2si motor.

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Posted

Thank you for all the suggestions. I have heard the two pieces of aluminum on either side. I have done tons of metal fabrication so I think this I will beef all of them up.

This plane was actuall #6 from Avid in 1983 and was used a oshgosh for a demo to see the plane. It had tricycyle gear and tail dragger so I am trying to put it back in original configuration in a tricycle gear format with the original 2si motor.

Whenever you can, I would sure like to see some photos of the nose gear and attach points.

I am cooking my own, but anything might help.

Ed in MO

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Posted

I have a Avid Model A I just bought. It is acually #6 from Avid and was built by the creators of this plane. Anyway I just bought it and in transport two of the flaperon poviot points at the end of the wing rib broke. Does anyone know the quick and proper way to fix these. It has new fabric on the wings so I would prefer not to have to recover the whole wing.

See attached picture

Thanks

Craig

Craig,

I am in the building process so the method that I am describing is not proven but what I am doing. I bent some aluminum channels 8" long, cut them to fit the rib tails that the flaperons attach to, with Hysol glued them on and then installed one hard rivet through them. I am attaching some photos that may make this clearer. In your case, glue the broken tail on with some epoxy first and then clad the tip as described.

post-267-13303955703845_thumb.jpg

post-267-13303956282439_thumb.jpg

post-267-13303959092942_thumb.jpg

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Posted

Craig,

I am in the building process so the method that I am describing is not proven but what I am doing. I bent some aluminum channels 8" long, cut them to fit the rib tails that the flaperons attach to, with Hysol glued them on and then installed one hard rivet through them. I am attaching some photos that may make this clearer. In your case, glue the broken tail on with some epoxy first and then clad the tip as described.

Iv'e been having similar thoughts. what material did you use for this. how thick is it. and where did you get it.

Thanks

-Robert-

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Posted

My Catalina suffered some similar cracks in the rib tails at the flaperon attachment points while I was trailering her from Florida to Seattle.  Wish I understood better exactly how it happened, because the plane was shrink wrapped pretty well and the control surfaces secured.   I suspect some sort of flutter or long-term vibration damage, because there was additional damage found on the flaperons themselves- the rivets securing the flaperon skin to the flaperon spars were all loose and showing powdered metal. 

 

Anyway, the Catalina's brackets sandwich the rib tail pretty well- it just moved the crack point further up and pulled the rib tail away from the rib top cap.   I'm thinking of making a new bracket that not only sandwiches the rib tail, but also extends up over the top cap.  

 

I'll post some pictures tomorrow when I get home. 

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Posted

Said pictures of Catalina rib tail cracks at flaperon hangers.  http://imgur.com/a/vtt1T#0  

 

How did your repairs turn out?  

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Posted (edited)

And this builder is going with heavier metal than the KF mod....No such thing as "too strong", IMO.

EDMO

Edited by Ed In Missouri

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Posted (edited)

Just for future readers, here's the link to the aforementioned kitfox article on reinforcing the rib tails with aluminum angle.   http://www.kitfoxaircraft.com/support/service_bulletins/sb9.htm   

Here is the copy of the Kitfox British required hanger rib reinforcement.   It was right here in Technical Tasks.   But I cant get it to open.    I should have a printed copy in my files to scan tomorrow. 

But NOTE:  This was for new, structurally sound ribs - NOT for repairing broken ones!   

OK - Here are 3 pages about Kitfox SB9 scanning again now.     EDMO

Scan0317.jpg

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Scan0319.jpg

Edited by EDMO

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Posted

This reinforcement is a lot easier to do on the Kitfox than an Avid Flyer.  If you look at the pictures in the last page, you see how the bottom cap strip stops about 2 1/2" from where the top cap strip does.  On the Avid, the bottom cap strip comes back to the same point as the top one does.  That bottom cap strip has a slot cut in it so that it goes on both sides of the rib tail.  It's all glued together so there is no hole there to put the aluminum reinforcement in without cutting on the bottom cap strip.  JImChuk

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Posted

This reinforcement is a lot easier to do on the Kitfox than an Avid Flyer.  If you look at the pictures in the last page, you see how the bottom cap strip stops about 2 1/2" from where the top cap strip does.  On the Avid, the bottom cap strip comes back to the same point as the top one does.  That bottom cap strip has a slot cut in it so that it goes on both sides of the rib tail.  It's all glued together so there is no hole there to put the aluminum reinforcement in without cutting on the bottom cap strip.  JImChuk

Jim,  Seems like the easiest thing to do is cut the bottom Avid capstrip about 2 1/2" short and make it like the Kitfox?   EDMO

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Posted

Ed,  in my opinion, the trouble with that is you end up with nothing to glue that last 2 1/2" of fabric to.  When it's shrunk, it wants to pull away.  When I recovered the Kitfox 1 wing, I put some small angels of aluminum there to hold the fabric.  I would think that Avids cap strip going out to the end made for a stronger rib tail than Kitfox's cut off cap strip.  JImChuk

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Posted (edited)

Ed,  in my opinion, the trouble with that is you end up with nothing to glue that last 2 1/2" of fabric to.  When it's shrunk, it wants to pull away.  When I recovered the Kitfox 1 wing, I put some small angels of aluminum there to hold the fabric.  I would think that Avids cap strip going out to the end made for a stronger rib tail than Kitfox's cut off cap strip.  JImChuk

Then I guess the second-best thing to do is to cut the slot in the lower capstrip wide enough to insert the aluminum sandwich thru it?   Or, like you said, "put some small aluminum angles there".   Lots of Kitfoxes were built with that short capstrip on the hanger ribs - none of my Kitfoxes showed any pulling away, but I haven't covered wings as much as you have.  I would put extra tapes there.   I think the tips break just behind the trailing edge anyway.   EDMO

Edited by EDMO

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Posted

Ed,  in my opinion, the trouble with that is you end up with nothing to glue that last 2 1/2" of fabric to.  When it's shrunk, it wants to pull away.  When I recovered the Kitfox 1 wing, I put some small angels of aluminum there to hold the fabric.  I would think that Avids cap strip going out to the end made for a stronger rib tail than Kitfox's cut off cap strip.  JImChuk

Then I guess the second-best thing to do is to cut the slot in the lower capstrip wide enough to insert the aluminum sandwich thru it?     EDMO

That's what I did. Some other pics that may be helpful HERE

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Posted

I have a Avid Model A I just bought. It is acually #6 from Avid and was built by the creators of this plane. Anyway I just bought it and in transport two of the flaperon poviot points at the end of the wing rib broke. Does anyone know the quick and proper way to fix these. It has new fabric on the wings so I would prefer not to have to recover the whole wing.

 

See attached picture

 

 

Thanks

Craig

 

 

Craig,

 

I am in the building process so the method that I am describing is not proven but what I am doing. I bent some aluminum channels 8" long, cut them to fit the rib tails that the flaperons attach to, with Hysol glued them on and then installed one hard rivet through them. I am attaching some photos that may make this clearer. In your case, glue the broken tail on with some epoxy first and then clad the tip as described.

post-267-13303955703845_thumb.jpg

post-267-13303956282439_thumb.jpg

post-267-13303959092942_thumb.jpg

Just a quick follow up.After Over 500 hours the rib tail reinforcement is provei with some heave abuse,  Sorry High Country I guess I missed your posted questions 5 years ago.

I have a Avid Model A I just bought. It is acually #6 from Avid and was built by the creators of this plane. Anyway I just bought it and in transport two of the flaperon poviot points at the end of the wing rib broke. Does anyone know the quick and proper way to fix these. It has new fabric on the wings so I would prefer not to have to recover the whole wing.

 

See attached picture

 

 

Thanks

Craig

 

 

JustCraig,

 

I am in the building process so the method that I am describing is not proven but what I am doing. I bent some aluminum channels 8" long, cut them to fit the rib tails that the flaperons attach to, with Hysol glued them on and then installed one hard rivet through them. I am attaching some photos that may make this clearer. In your case, glue the broken tail on with some epoxy first and then clad the tip as described.

post-267-13303955703845_thumb.jpg

post-267-13303956282439_thumb.jpg

post-267-13303959092942_thumb.jpg

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Posted

Just a follow up after 500 hours the repair/reinforcement is working great and it has been well tested.  Sorry High Country I guess I missed your post and questions all those years back.

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