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LCP Wing Rib question

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dan.gagnon85

Member
Looking through the laser cut parts list, the wing ribs W-1011-x are marked as only being affected for the rib connected to the inboard flap bracket. I understand why the others might not be affected, but how is the outboard flap bracket not affected? It seems like they would be under the exact same loads.
 
Likely that the inboard bracket is loaded by the application of the flap motor force against the flap itself..?
 
That makes sense, thank you.

Looks like with the ribs I have, only 2 of them are on the replace list (the W-1011 inboard flap bracket rib, and the W-1010 inboard ribs. So I think I can make some progress on my wings at this point.

It looks like I can slide those 2 ribs in a bit later down the road, as long as I hold off on riveting the skins into place. Hopefully not too far down the road.

The only other LCP I have in the wings is one of the torque tube brackets (2/3 were punched)
 
Glad you caught it before you did the skins. My wing kit makeup seems quite similar to yours. Definitely most, if not all the ribs are LCP. But with one of those little 1000x USB microscopes, I cannot see any cracking at all, both on the unriveted lower skins and the riveted upper skins. The laser holes just don't look that bad at all. With the upper skin riveted, I guess you could basically cut out the ribs in question, but getting the new ones in looks a bit dicey. I'm thinking leave them be.
 
I have been sitting on them for about 6 months now, waiting to see what the next steps need to be, working on what ever I can with other non LCP I have (some fus kit, some wing) but I am out of progress I can make without starting these now. All of my ribs are for sure LCP, but they dont look bad, and the chart says they are acceptable, so I am putting some faith in Van's for the sake of progress. I have enough rework that will need to be done on my Emp kit (shipped Dec-22) I hope I am not shooting myself in the foot with this one.
 
Walt D said:
Glad you caught it before you did the skins. My wing kit makeup seems quite similar to yours. Definitely most, if not all the ribs are LCP. But with one of those little 1000x USB microscopes, I cannot see any cracking at all, both on the unriveted lower skins and the riveted upper skins. The laser holes just don't look that bad at all. With the upper skin riveted, I guess you could basically cut out the ribs in question, but getting the new ones in looks a bit dicey. I'm thinking leave them be.
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I think even more info will be coming out soon, but from all the engineering analysis and an AMAZING amount of testing, I would say that those ribs are just fine and will outlast other critical areas of the airframe, with service life of something like 50--100 normal airframe lifetimes.

I think leaving them be is a solid decision.
 
Just one data point but I took careful, magnified pictures of the dimples in those inner wing ribs that I had riveted to the upper skin but not the lower skin, sent them to Vans support who opined that they were punched, not LCP. So at least some “red” parts are not actually LCP. Does anyone know what percentage of “red” parts are actually supposed to be LCP? Not 100% I guess.

Greg Beckner
141283
Double dues paid gladly
 
Imagine47 said:
Just one data point but I took careful, magnified pictures of the dimples in those inner wing ribs that I had riveted to the upper skin but not the lower skin, sent them to Vans support who opined that they were punched, not LCP. So at least some “red” parts are not actually LCP. Does anyone know what percentage of “red” parts are actually supposed to be LCP? Not 100% I guess.

Greg Beckner
141283
Double dues paid gladly
Click to expand...

There's no part that was purely LCP. Pretty much all parts that could be LCP were a mix of that and punched.
 
No blue film.
George I interpret what are saying is that any given kit will have a mix of punched and LCP parts. Which seems reasonable. I do not infer from one punched part that any others are not LCP. I failed to mention that I sent pix of both root ribs and both were deemed punched. But insofar as the 14 wing is concerned no other parts were “red” and I’ve decided to live with blue and green. My unscientific impression from reading the various threads here is that lately there is shift toward acceptance of some LCP as the reality is that rigid refusal of all LCP means it might be years until you fly. Us old farts don’t have years. YMMV
Cheers
Greg
 
Agree, Greg. Some folks have taken the very strict stance that they will accept no LCP in their plane. And that's their prerogative. However well produced LCP are not distinguishable from punched. So to me, its about the quality of the part and its tolerance for dimpling without a crack.
 
georgemohr said:
Agree, Greg. Some folks have taken the very strict stance that they will accept no LCP in their plane. And that's their prerogative. However well produced LCP are not distinguishable from punched. So to me, its about the quality of the part and its tolerance for dimpling without a crack.
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I think that the initial laser cut parts were probably of high quality and carefully scrutinized by Van's when they chose to use this method. However, over time, it appears that these parts became lower quality. Whether this was a function of the same supplier cutting corners, or adding additional suppliers that weren't as high quality, we don't know. But I wouldn't be surprised to hear that early laser cut parts are all acceptable.
 
Stigaro, this was exactly my thought also. Our wing kit was delivered just after LCP went into production. I'm pretty confident we have some ribs that are LCP, but I can't be very sure. The quality of these parts were all excellent. I have an example left over because we screwed it up. If I look *really* closely, I can see some evidence that the holes are LCP on this part. But they dimpled and riveted perfectly, and required no special treatment to get that result.

I really wish Vans had been more clear about this early in the LCP process. I feel personally that they created a lot of this trauma by sending out red spreadsheets with little context about the quality of the specimens in question.

Edit: I should note that we got two really bad LCP parts in that kit. Not ribs, but shims that go on the tank support bracket. They had all the bad indicators, and they cracked like mad when dimpled. If you are interested, here's the thread from that time. I believe it was the first public post regarding cracked LCP.

https://vansairforce.net/community/showpost.php?p=1631948&postcount=1
 
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georgemohr said:
Stigaro, this was exactly my thought also. Our wing kit was delivered just after LCP went into production. I'm pretty confident we have some ribs that are LCP, but I can't be very sure. The quality of these parts were all excellent. I have an example left over because we screwed it up. If I look *really* closely, I can see some evidence that the holes are LCP on this part. But they dimpled and riveted perfectly, and required no special treatment to get that result.

I really wish Vans had been more clear about this early in the LCP process. I feel personally that they created a lot of this trauma by sending out red spreadsheets with little context about the quality of the specimens in question.

Edit: I should note that we got two really bad LCP parts in that kit. Not ribs, but shims that go on the tank support bracket. They had all the bad indicators, and they cracked like mad when dimpled. If you are interested, here's the thread from that time. I believe it was the first public post regarding cracked LCP.

https://vansairforce.net/community/showpost.php?p=1631948&postcount=1
Click to expand...

I received my wing kit prior to the laser cut parts with the exception of the leading edge ribs which were B/O'd. I received these just after the first LCP showed in inventory in Jan '22, so I suspect they may be LCP. While I don't recall if these had blue film and I don't have any photos of them, I don't recall anything out of the ordinary with these parts at all.
 
Walt D said:
Glad you caught it before you did the skins. My wing kit makeup seems quite similar to yours. Definitely most, if not all the ribs are LCP. But with one of those little 1000x USB microscopes, I cannot see any cracking at all, both on the unriveted lower skins and the riveted upper skins. The laser holes just don't look that bad at all. With the upper skin riveted, I guess you could basically cut out the ribs in question, but getting the new ones in looks a bit dicey. I'm thinking leave them be.
Click to expand...
Walt, same here. On my QB wings, I have not found any cracks but I have not looked at them all yet. Here are images of 3 consecutive dimpled holes on one of ribs where the bottom skin goes
 

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When I went through the RV14 list it showed W-1011 L/R x 10 (yellow), still looking for solution, recommend replacement, then the note only 2 affected. The RV-10 lists them as acceptable for use. I was thinking they may replace them all so I have just left them on the shelf.
 
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