Cracked Dimple F-1029R

I am in the process of verifying all work by the previous builder of my RV-10 empennage kit. So far everything is good, except when I did a close inspection of F-1029-R, the right-hand bellcrank rib. I found one dimpled hole with cracks, as seen in the photo below:



The previous builder had already assembled the rib to the F-1037B Bellcrank Angle after priming the pieces. The crack looks like it developed after priming (the reason I noticed it was that there was bare aluminum visible in the crack).

Is there an acceptable way of correcting this without having to order a new bellcrank rib, drilling out rivets and separating the original part from the F-1037B, and priming and reassembling? Can this dimple be drilled out and a doubler placed over the hole? This way I might place a dimpled spacer in the drilled out hole and then rivet through the spacer into the doubler, which would be attached to the adjacent rivets?

Or would it be safer to replace the whole part? I've read some other threads about cracked dimples and haven't made a decision either way yet. The part only costs $13.30 plus shipping. I just received an order last week from them and the shipping costs seem to outweigh the part costs most of the time for onesie-twosie orders.

It would help to know the section so I could look at the specific part, but I would drill out to the next size up and see if that clears the cracks. Then you can put in an oops rivet or just a bigger standard 426.

Jesse said:

It would help to know the section so I could look at the specific part, but I would drill out to the next size up and see if that clears the cracks. Then you can put in an oops rivet or just a bigger standard 426.

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It's on Page 10-5. Your suggestion makes sense for sure, but I'm not sure that an oops rivet will fill it. I'll give it a try. Thanks!
ETA: I got the rivet size wrong. They are indeed AN426AD3 rivets. I will try drilling it out and using the appropriate NAS1097 rivet.

Looks wierd

No help really, just a comment as I'm not a -10 builder, but looks like a replace situation to me if you can relatively easy.

Also looks odd to me to see a shop head in a dimple. To me it makes a whole lot of sense why it cracked - the dimple is supposed to spread the squeeze load of a 426 mfg 100deg head, and of course the metal is stretched and thinned there. With a shop head, the localized compression would have a propensity for cracks. Strength wise, once you get those radial cracks, not much strength left in that joint IMHO.

If its a critical area, then I'd drill out the existing completely eliminating the cracks, leave it open, and put more holes and rivets in around there to compensate.......or best replace entirely if possible.

Just my .02.

Mani

It looks like maybe that hole wasn't drilled to full size before it was dimpled, or maybe it was dimpled crooked, causing the crack. The suggestion of drilling it out and leaving it open, putting an extra river on either side, is also a good one.

Thanks for the replies, guys!

Mani, there is no rivet in that dimple yet--am I misunderstanding what you're saying about seeing a shop head in the dimple?

1001001 said:

Thanks for the replies, guys!

Mani, there is no rivet in that dimple yet--am I misunderstanding what you're saying about seeing a shop head in the dimple?

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Oh. haha - it looks like a shadow created by a shop/rivet tail (which is really the hole). I see it now though. Kinda like the famous old lady and the young woman painting.
http://www.grand-illusions.com/opticalillusions/woman/