The plans for this step have some changes to accommodate Service Bulletin SB-16-03-28. The SB deals with cracking of the aft wing spar web at the inboard aileron hinge bracket attach rivets and bracket flanges in all of the RV models except the RV-12. The SB replaces the original inboard hinge brackets with newly designed hinge brackets, and the new brackets are installed with additional doublers on the spar web. The SB was intended to repair flying airplanes with the cracking problems and to prevent the issue with new builds. The SB replaces step 3 on this page, which is the build-up of the inboard aileron hinge bracket assemblies (W-1013-L & R). The original design is still used for the outboard hinge bracket assemblies (W-1014-L & R). Step 4 on this page stays the same to build-up the outboard hinge bracket assemblies, and steps 5 – 6 apply to both inboard and out-board. The other thing to note on this page is that the aileron stop tab on hinge bracket spacers for the outboard assemblies is trimmed off, and it remains in place for the inboard assemblies. Steps 15-28 in the SB contain the details on preparing, building, and installing the inboard aileron hinge brackets.
Initial Prep (Debur, Trim, Drill, and Cut)
1/23/22 – 2.9h
1/24/22 – 1.8h
3/13/22 – 1.3h
The aileron hinges are built up from relatively thick parts with a lot of tool marks on the edges to debur. The parts have mainly long straight edges, which makes the deburring process easier. The plans call for final drilling all of the holes common to the hinge parts, which are all easy to access. The inboard aileron hinges have long and short sections of aluminum “L” channel that form the flanges of the parts. The long piece extends above the inboard hinge parts, which is trimmed along the angle of the hinge bracket and deburred. The outboard hinges have three pieces sandwiched together, and the aileron stop is cut off.
[Hole and Edge Deburring Tools, Dremel with Metal Cutting Disk, #30 Drill]
Final Prep (Dimple, Countersink, and Shape)
1/6/22 – 1.3h
1/7/22 – 3.5h
1/25/22 – 1.6h
The hinge bracket spacers can warp slightly when they are manufactured. I straightened them as well as I could using a combination of hand pressure and pressure from a table clamp. The clamp method works by elevating the piece off the table with small wood blocks at each end, and then using the table clamp in the center of the piece to bow it down. The hinge bracket spacers are short parts, and very sensitive to the amount of pressure used in the center to straighten them. They are also triangular-shaped parts, so I straightened each edge in turn until the whole part would lay flat on the smooth marble surface.
Each aileron hinge – both inboard and outboard – has holes near the hinge point that are countersunk for flush rivets. The holes are countersunk on the sides that will face the aileron to provide clearance when the aileron is installed. The microstop countersink cage with the #30 countersink cutter works well until you get to the flanges of the inboard hinges. The countersink cage is too large for that area, and I ended up “free handing” those holes. They actually came out pretty good by going slow and checking the depth often. I made one countersink about .003 - .005 too deep, but that should still be useable.
[Wood Blocks, Table Clamps, Flat Marble Surface, Flat File, Band Saw, Bench Grinder with 6” Scotch Brite Wheel, Microstop Countersink Cage, #30 Countersink Cutter]
Prime
2/16/2022 – 1.2h
2/20/2022 – 1.7h
3/13/22 – 0.7h
[Grey Scotchbrite Pads, Bon-Ami Cleanser, Dupli-Color Degreaser, Dupli-Color Self-Etching Automotive Primer (Green – Rattle Can)]
Assemble
2/21/22 – 3.2h
3/14/22 – 0.7h
The outboard hinge brackets are essentially a thick center piece sandwiched between two thinner edge pieces. The thick center piece also holds the aileron attach bearing. The bearing is pressed into the center piece with a bench vise and a couple of sockets, then the outer layers of the sandwich are riveted into place. Assembly of the outer hinge brackets went well, and the brackets are on the shelf to be attached to the rear spar in a later section of the plans.
The inboard hinge brackets didn't go quite as planned. The inboard brackets are made from two thick parts that hold the aileron attach bearing between them, and then two “L” brackets which make the flanges to attach the hinge bracket to the rear spar. The two primary pieces went together very well with the squeezer, and the ends holding the aileron bearing are tight against each other. I then attached the long “L” bracket to the top of each hinge bracket. Everything to this point came out fine, but somehow I swapped the left and right short “L” brackets which make the inboard flanges. I noticed the mistake when I tried to test fit the completed hinge brackets to the rear spar, and the holes did not line up! I drilled out the six (three on each assembly) AN426AD4-11 rivets and removed the short “L” brackets. These are very long rivets, and I damaged the ”L” brackets when I removed them. The rest of the assemblies look fine, but I need to order new “L” brackets to finish the assembly (sigh). I received the new “L” brackets from Van's, which I successfully prepped and attached to the hinge brackets correctly.
[Pneumatic Squeezer, 1/8” Cupped Squeezer Set, Flat Squeezer Set, Bench Vise, 7/16 and 9/16 Sockets]