Wing Flap 22-4-2 to 22-5-6

After finishing deburring the remaining rib and nose skin edges, I was ready to continue fitting and drilling the flaps as documented in the plans.

Flap skeletons formed after clecoing ribs and hinge brackets to flap spars

Skins were clecoed to the skeletons in the following order

1. Bottom skin
2. Nose skins bottom side
3. Top  skin
4. Nose skins top side

I trimmed the flanges of the nose ribs as needed to remove any faceting that remained visible through the nose skins, and also filed the edges of the nose skins where they met in the center of the flaps as there was a slight overlap there.

Bottom skin and nose skins clecoed to the skeleton. The nose skins overlap the bottom skin along the spar flange

Flap flipped over to allow the top skin to be clecoed in place before completing clecoing of the nose skins

Trailing edge wedges being attached. I used wood blocks to hold up the trailing edge of the flap so that it would be more level. The leading edge of the flap was held higher by the hinge subassemblies resting on the bench 

Next I installed and trimmed the trailed edge wedges to length, making sure to debur the ends of the wedges and round over the sharp corners.

Trimming the trailing edge to rough size using a metal blade hacksaw

Inboard trailing edge after trimming. The trailing edge wedge extends about 1/32" past the flap skin edge. I did not see this on the rudder or elevators, but it should not be an issue.

Two trailing edge wedges are required along the 8ft length of the flap. Here is where they meet under the skin. I rounded the sharp corners to remove any future stress points.

Flap trailing edge wedge trimmed to fit at the outboard end

With everything trimmed and fitting nicely together, I match drilled the two nose skin to (missing) rib holes in each nose rib flange. I also final drilled (with a reamer) the trailing edge holes along the trailing edge using a guide block to make sure I was drilling perpendicular to the wedge chord.

Using a small guide block cut at an 83 degree angle to ensure that I drilled trailing edge holes perpendicular to the chord of the trailing edge wedge

Right flap assembled for match/final drilling

Finally, I match drilled the four holes in the flanges of each hinge subassembly.

Outboard hinge subassembly flanges were easy to drill with no interference from clecoes holding the flap together

Center and inboard hinge subassemblies took a little more time as I had to reposition some clecoes to have access for drilling. Short stubby clecoes worked well here as I was able to clear the drill bit over them. However, the bottom hinge flange hole had to be match drilled after removing the hinge subassembly as it was just too close to the skin.

With all the match/final drilling done, I took apart and labelled all the pieces, and started deburring all holes.

After drilling, I checked that the holes in the square angle lined up with the trailing edge wedge holes, and then deburred the drilled holes.

These aluminum supports will be used to cleco the flap trailing edge after prosealing, and help maintain a straight trailing edge.

Holes within the nose skins were deburred by rotating a deburring bit by hand

After deburring all parts, I dimpled all the ribs and skins as called out in the plans. 

I used the close quarters dimpling tool to dimple aft rib holes in the tight space between the flanges

The plans call out for countersinking the non-mating flange holes in the hinge bracket halves which will then be double flush riveted later, This was not too hard to do manually using the countersink bit in a cordless drill, as the hinge flange prevented easy use of a standard countersink cage.

Nose skin holes near the leading edges were dimpled using the pop rivet dimpling tool. An LP 4-3

rivet worked well to create a nice dimple without breaking the mandrel

After dimpling, I disassembled and labelled the hinge brackets and ribs prior to priming.

All parts deburred, dimpled, and labelled as needed

Time Taken:     23.6 hours

Dates:                June 18 - July 14 2024

Wing Flap Total Time:        41.0 hours

RV-10 Build Total Time:   765.8 hours

Priming Total Time:                     83.6 hours (not included in build time totals)