Flap nose ribs

[Jetmart]

All of my flap nose ribs have this bump in the flange. Is this supposed to be like this or should I be straightening this?

 

[543TB]

The skin won't lie flat on the rib if you don't reduce the rise there. We used fluting pliers to flatten it out.

 

[Jetmart]

That’s what I figured, but with every rib looking identical, it appeared that they made the effort to make it that way. I have not pulled the skins out yet and before I flattened them all I wanted to confirm.

Thank you

 

[543TB]

That’s what I figured, but with every rib looking identical, it appeared that they made the effort to make it that way. I have not pulled the skins out yet and before I flattened them all I wanted to confirm.

Thank you

I'm guessing it was just a byproduct of the part shape-stamping. Flattening the flange didn't appreciably distort the line for the rivet holes.

 

[MCA]

Whenever there is curvature, you must flute.

 

[Alphalpha]

Mine did too. So I fluted between holes and worked the bump down a little - times 28...

 

[aturner]

Fluting is necessary both the straighten the rib but also to create proper spacing between holes. If you are just flattening, you may want to measure hole spacing on your skin and compare it to what you have on the rib. You may be surprised.

A related issue...my nose skins have small bumps associated with the corner of the top front tab on the noseless ribs. If I had it to do over again, I would trim the edge of those front tabs back a bit.

 

[GaryK]

Fluting is necessary both the straighten the rib but also to create proper spacing between holes. If you are just flattening, you may want to measure hole spacing on your skin and compare it to what you have on the rib. You may be surprised.

A related issue...my nose skins have small bumps associated with the corner of the top front tab on the noseless ribs. If I had it to do over again, I would trim the edge of those front tabs back a bit.

View attachment 114778

I remember that edge needing more work than I thought to eliminate the small bumps. The General instructions covers this early on

 

[deene]

These waves you see is the result of the factory forming a curved flange where the outside edge starts with more metal than the inside edge. Thus the resulting waves. Two classic solutions are fluting and cutting the flange into small fabs each of which deals with the excessive metal without damaging the flange. A third approach which is not normally used in in aircraft metal structures uses a crimper tool to force the metal together often damaging the metal.

Vans generally recommends the fluting approach. You may notice that several types of fluting tools are sold by metal tool suppliers and are easy to use. A good approach is to lay the flange on a flat surface and start to flute until the flange is straight.