Left flaperion hinge failure.

43 posts in this topic

Posted

The 140 doesn't have the piano hinge you see  on the 150/172. It has two metal ribtails similar to the kit fox. They go into the ailerons and are secured with a bolt and nylon lock nut. 

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Posted

The 140 doesn't have the piano hinge you see  on the 150/172. It has two metal ribtails similar to the kit fox. They go into the ailerons and are secured with a bolt and nylon lock nut. 

Yes, I remembered just after writing that - been too long away from older Cessnas.  Thanks,  EDMO

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Posted (edited)

I too wish you my regards.   I can't imagine how terrifying that must have been.  Divine intervention? Perhaps.  Major kudos  however are deserved; you were at the controls.

I'm rereading the Kitfox SB #9 and they make it clear that the standard rib tails will suffer side loads but to the extent 90lbs (12g's). That's pretty robust. The reinforcement is considered mandatory on each ribtail if "the rod type mass-balance is inserted in the leading edge of the flaperon".  Presumably thats the lead filled "2 tube.

It's reasonable to assume yours was subjected to a sideload of some kind. Some have been known to fail if rotten as someone else above pointed out.  

Thank you for sharing and hopefully you'll be flying again soon.

Edited by allonsye

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Posted (edited)

Man, thanks for joining up here and telling your story!  And I'm totally with you when it comes to the media!  When my dad dunked our KF2 on floats after the 532 dropped a cyl (he swam away safely) it was crazy to see the news stories and inaccuracies and "overcoverage" merely because it had wings.  One article even dramatized the "severe" nature of the damage with a photo of the "wings ripped off" as it sat on the trailer with the wings folded neatly at it's side! :lmao:

 

As to your accident, thank God for the outcome where no one suffered permanent injury or worse.  I agree, your "distress call" (prayer) was clearly answered!  It (God's hand of protection) becomes clear and undeniable when you witness it for yourself firsthand doesn't it!  I like the part of the cell phone laying in your lap when you woke up to an airplane that was NOT on fire!

And I am with the rest of the group here - rooting for you to get back in the air and put that day behind you.  That was truly a freak accident, but essentially no different than a countless many auto accidents.  Of course you (and your passenger) would get back in a car again right?

Take care, look forward, and get back up there again soon!

Edited by MN Kitfox 2
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Posted

Thanks for having the courage to share the details here, we all appreciate it.   Hopefully it's a very good reminder for us all to address un-reinforced rib tails!  

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Posted

Thanks for this post.  It motivated me to inspect the hinge points on the flaperon.  The wood was not rotting but the top part of the wood was delaminating.  I epoxied the wood and am fiber glassing the extensions.  Definitely something to pay attention to.  My plane has been inside for 99.9% of its life.  My guess is the dry wood getting wet one time and the drying again caused the delamination. 

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Posted

Yea, thanks! And so glad you both are okay. Before I bought mine I did a lot of reading. The only fatality I would find was from a flaperon hinge failure like yours. They said it was because of rot.

So that is one thing I really looked closely at before the purchase. I stripped all the paint off them, made sure they were solid, painted polyurethane on them then white paint. Mine has always been hangered, but I'll sure check them closely on preflight from now on.

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Posted

Holy buckets! I am really glad to read this and know you’re ok!

I would ask the forums help in understanding the reinforcement issue. I’ve checked and it would appear that my rib tips (AVID MKIV HH) are not reinforced but are simply the extension of the rib as originally designed. They are painted so I will be scrapping some paint, GENTLY, on my next trip outntonthe field. If I pm reading the SB correctly, that would look like the aluminum pieces are riveted to the top and bottom of then rib face...that about right? Could one just laminate some aluminum to the rib tip itself? Say JB WELD on a well prepped surface and the cross rivet it at odd intervals?

tia

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Posted

I just skimmed through the earlier posts, looking for the Kitfox SB.  Didn't see it, but this is my point.  The bottom of the Kitfox rib is not the same as the bottom of the Avid Flyer rib.  On the Kitfox, there is room for the aluminum doubler, but not on the Avid.,  Some how, my computer has been updated this morning by Microsoft (I think) and I can't figure how to access my photos so I can't right now post pictures to show you what I'm talking about.  On a side note, any advice on the computer would be helpful, I'm guessing I wasn't the only one.  JImChuk

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Posted

Exactly! My CFI has a KF4 (early model) with the wide hinge plates riveted to the upper and lower surfaces. No such material on the AVID hince my thought about making a lamination of aluminum on either side of the TE tips. 

 

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Posted (edited)

Tonight, I'll post some pictures of what I'm doing with my MK IV. I'm using a single piece of aluminum flat stock and had to Dremel a slot to insert the flat stock into the rib (beyond the tail).

Saw pictures of someone else who did this the same way, but can't find the post.

Edited by RobS

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Posted

That’d be awesome. I really DONT wanna have to recover the wings!

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Posted

Exactly! My CFI has a KF4 (early model) with the wide hinge plates riveted to the upper and lower surfaces. No such material on the AVID hince my thought about making a lamination of aluminum on either side of the TE tips. 

 

I cleaned and sanded all the rib ends and then fiberglassed.

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Posted

My solution probably won't work for you as I failed to remember your wings are already covered. I created a slot from the bottom side of the rib to insert the aluminum plate and plan to Hysol and rivet it in place - which requires access to the entire rib.

This post from another thread on this subject provides a reasonable solution for wings that are already covered. Look at the next to the last post by wypaul

http://www.avidfoxflyers.com/index.php?/topic/1061-broken-flaperon-pivot-point/#comment-4

 

 

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Posted

One thing to remember as well, is that the original design was plenty strong enough to handle flight loads.  Having  the ribs half rotted off or sudden and severe impact applied, goes beyond the original design.  Preflight well, and don't bang into to things goes a long way toward avoiding problems.  JImChuk

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Posted

Could someone post some photos of the ribtail reinforcements?

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Posted

Diagram for KF

IMG_0215.JPG

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Posted

Something looks a bit strange in the vids, in that the broken rib tails don't look to have been made from the high quality 10-layer birch plywood, but rather something a lot less strong.  I agree that this is a weak point in the design, and yet another point of vigilance.  One could argue ones self into a very long pre-flight inspection.  

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