RV-12 Anti-Servo Tabs

Reference: page 08-02, page 08-03; 2.5 hours

The Anti-Servo Tabs will be attached to the Elevator or Stabilator on the RV-12 airplane. Vans Aircraft designed the RV-12 so the horizontal stabilizer and elevator are one unit or flying tail. This helps to keep the parts count and weight down. The servo tabs are used to trim pitch control.

OK enough details let's build them!

Reference: page 08-02

Note: This section describes the Anti-Servo Tab (AST) construction for the left side. Construction for the right side is a mirror for the left, and should be done at the same time.

Step 1: Read all steps prior to construction.

Step 2: Remove the material shown hatched from the bottom half of the HS-1221-L AST Skin as shown in Figure 1.



Note: The tope surface and inboard end of the HS_121-L AST Skin can be identified by the AST Control Horn cutout, called out in Figure 4.

Step 3: Cleco the top and bottom flanges of the four HS-1222 AST Ribs to the inside of the HS-1221-L AST Skin. Orient the flanges of the three inboard ribs to point outboard. Orient the flanges of the outboard rib to point inboard as shown in Figure 2.



Step 4: Final-Drill #30 the HS-1222 AST ribs using the holes in the HS-121L AST Skin nearest to the trailing edge as a guide. Mark the rib locations to return them to the same position as drilled for final assembly.

Disassemble, deburr holes and remove any chips.



Step: 5 Held off until next entry.

Reference: page 08-03

Step1: Mark and separate the F-1220-LR AST Control Horn per call-outs in Figure 1>



Step 2: Machine countersink the HS-1220-L AST Control Horn for a 3/32 inch rivet per call-out in Figure 2.



Step 3 & 4: Holding off till next entry.

Step 5: Remove the hinge pin from one AN257-P3X6' (also known as MS20257-3) Piano Hinge. Cut eash of the hinge halves into two lengths per dimensions given in Figure 5.

Locate cuts so that there are hinge eyelets at both ends of all four hinge halves.

Two hinge half lengths will be the left and right HS_1218B AST hinges. The two other lengths will be the left and right HS-1218A Aft Stab Hinges. the aft stab hinges will be installed during Section 9. Stabilator Assembly. the Hinge pins will be installed during section 11, Empennage Attach.



Step 6: Position the HS-1223 Drill Guide per Figure 6, Detail A. Orient the notched edges of the drill guide adjacent to the eyelets of the AST hinge half, then clamp the drill guide on to the AST hinge half.

Note: Save the HS-1223 Drill Guide called out in figure 6 and 7, it will be used again during Section 9 Stabilator Assembly.



Step 7: Match-Drill #30 the Hinge Half, using the HS-1223 Drill Guide per Figure 7. Refer to Figure 6, Detail B to remove the drill guide. Repeat Step 6 and Step 7 until the entire hinge half has been drilled to make the HS-1218B AST Hinge Half.



Next time we will finish the Anti-servo tabs.Till then I will be getting the parts ready and prime them.

RV-12 Rudder (Finishing)

Reference: page 07-03, page 07-04, page 07-05; 3.5 hours

Today the rudder for the RV-12 will be completed. If you are just joining this blog I'm in the process of building a Vans Aircraft RV-12 airplane that fits in the E-LSA (Experimental Light Sport) Category. The idea is to follow through the builders manual and document each step with pictures. If you look at the Topics on the left you can reference a specific page of the plans. You will also information about my RV-10 as well.

Let's see, we left off after checking the Hinge spacing for fitting the rudder spar to the vertical stabilizer. The parts have been alodined and primed with zinc chromate primer.



Reference page 07-03

Step 2:


Remove the R-1205 Hinge Brackets and WD-1205 Rudder Horn. Rivet the R-1204 Spar Caps and the R-1203 Main Rib to the R-1202 Spar. Rivet only the four holes common to the main rib. See the rivet call-out in Figure 2. NOTE: On my kit these rivets were a half size too long (this makes the shop head want to "clinch" or go off side ways) so I ended up cutting them down to size before setting them. Your mileage may vary;)



Step 3: Rivet the R-1205 Hinge Brackets to the R-1204 Spar Caps and R-1202 Spar. Rivet the remaining holes in the spar caps to the spar. See the rivet call-outs in Figure 2. NOTE: I found it easier to set the rivets I'm pointing at in the picture below before installing the hinge.





Step 4: Completed on previous blog entry.

Reference: page 07-04

Step 1: Rivet the R-1203A. trimmed Rib to the WD-1205 Rudder Horn. Flange orientation and rivet call-outs are shown in Figure 1. Refer to this assembly as the Rudder Horn Assembly. NOTE: Not sure if the two LP4-3 should be installed from the top or bottom, so I installed them from the top as it was a much better clearance for the rivet puller.



Step 2: Rivet the Rudder Horn Assembly to the R--1202 Spar, as shown in Figure 2.



Step 3: Rivet the three remaining R-1203 Main Ribs to the R-1202 Spar. Flange orientation and rivet call-outs are shown in Figure 3> Refer to this assembly as the Rudder Skeleton Assembly.



This completes page 07-04.

Reference: page 07-05

Step 1: Remove the material shown hatched from the lower end of the R-1201 Main Skin shown in Figure 1.



NOTE: I "broke" the leading edge of the left skin to help it lay flat and not pucker after riveting. This is not called for in the plans, just something I did.



Step 2: Position the R-1201 Main Skin oner the Rudder Assembly. Check for main skin hole alignment with the Rudder Skeleton Assembly. Cleco the entire main skin to the Rudder Skeleton AAssembly.



Step 3: Star nearest to the trailing edge rivet the R-1201 Main Skin to the Rudder Skeleton Assembly per call-oust in Figure 2. Leave open the top row of holes in the main skin.



Step 4: Close, and rivet the R-1201 Main Skin on the forward side of the R-1202 Spar. the main skin must overlap onto itself as shown in Figure 3.





This completes the rudder and section 07.

RV-12 Rudder

Reference: page 07-02, page 07-03; 4.5 hours

Today I'm starting the rudder on the RV-12 airplane.


Step1: Read all steps in manual prior to construction.

Step 2: Separate the R-1204 Spar Caps by removing the material shown hatched in Figure 1. Deburr all the edges of both caps.



Step 3: Mark both of the R-1204 Spar caps with a centerline on the surface that will nest against the R-1202 Spar web as show in Figure 3.



Step 4: Final-Drill #30 the 1/8 inch holes in the R-1205 Hinge Brackets as called out in Figure 2.



Step 5: Final-Drill #12 the 3/16 inch holes in the R-1205 Hinge Brackets as called out in Figure 2.



Step 6: Separate the R-1205 Hinge Brackets by removing the material shown hatched in Figure 2. Deburr all the edges and drilled holes of both hinge brackets.



Step 7: Position the R-1204 Spar Caps between the flanges of the R-1202 Spar so the center shows through the middle set of holes in the spar web as shown in Figure 3. Adjust the bend of each spar cap, as necessary, to nest against the inner surface of the spar web and flange as shown in Figure 3. Detail A-A.



Clamp the spar caps in place. Mark the spar caps left or right so they can be installed in the same position as drilled.



Step 8: Match-Drill #30 the holes from the R-1202 Spar into the R-1204 Spar Caps per call-out in Figure 3. Cleco each hole before drilling the next. First match-drill the holes in the spar web, unclamp and clear away any chips, cleco the spar caps back in place.





Then match-drill the holes in the spar flanges. Remove the spar caps, deburr holes, and clear away any chips.



Step 9: Final-Drill the holes in the WD-1205 Rudder Horn as shown in Figure 4.



Step 10: Cleco the R-1204 Spar Caps, the R-1205 Hinge Brackets and the WD-1205 Rudder HOrn to the R-1202 Spar. Position clecos on the web of the spar as shown in Figure 4. Hereafter refer to this assembly as thew Rudder Spar Assembly.



Reference: Page 07-03

Step 1: Check the rudder hinge alignment by temporarily attaching the Lower Hinge Assembly to the V-Stab Assembly. Temporarily attach the Rudder Assembly to the V-Stab Assembly as shown in Figure 1.

When installing the hinge hardware, use one washer between the bolt head and R-1205 Hinge Bracket, one washer between nut and hinge bracket, and only one washer between each hinge bracket and upper hinge assembly. Begin with the same hardware order for the Lower Hinge Assembly. AN960-10L Washers may be substituted for AN960-10 Washers to adjust clearance between the hinge brackets.

Once a fit is confirmed, make note of the washers used. Detach the Rudder Spar Assembly.

NOTE: I made some washer holders out of tongue depressors to make it easier to place the washers.









Step 4: Remove the forward flange from one R-1203 Main Rib, per dimension in Figure 3. Deburr the trimmed edge. Hereafter refer to this trimmed rib as the R-1203A Trimmed Rib.

RV12 Vertical Stabilizer (completed)

Reference: page 06-07 2 hours

Todays work will finish off the vertical stabilizer for the RV-12. Next I build the rudder. What has amazed me with this experimental aircraft kit is how few parts there are compared to the RV-10. The engineering department at Vans Aircraft has done a great job designing this E-LSA.

Step 1: Cleco the VS-1201 Main Skin to the V-Stab Skeleton Assembly as shown in Figure 1. First cleco one side of the skin, then check that the narrow end of the VS-1202 Front Spar, VS-1205 Tip Tib, and VS-1206 Mid Rib will not deform the leading edge of the main skin. If any of the ribs deform the leading edge of the main skin, radius the marrow ends of the ribs (See Page 6-05, Step 1.) Next, check the main skin hole alignment with the ribs on the side not yet cleoed. If holes do not align, remove the skin and adjust the ribs by additional fluting of lessening existing flutes (Section 5N) until the rib holes align with the skin holes. When all of the holes align, celco the rest of the main skin.





The idea is to not have deformation of the skin as you see in the two pictures below. To correct this I ended up removing the skin a couple of times and reworking the radius on the end of the Front Spar and the Middle Rib.





This is what I was hoping for, below.



Step 2: Start nearest to the leading edge of the VS-1201 Main Skin, remove one cleco and rivet that hole before moving on to the next hole. Continue until all of the main skin holes are riveted to the corresponding holes in the V-Stab Skeleton Assembly per call-out in Figure 1.





Step 4: Screw the VS-1204 Fwd Skin to the nutplates at the front of the V-Stab Assembly using the hardware called out in figure 1. the bottom eight holes in the Fwd Skin are left open until the V-Stab Assembly is installed to the Tailcone Assembly.



Step 5: Bolt the Upper Hinge Assembly to the V-Stab Assembly using the hardware called out in Figure 1. NOTE: After I finish torque bolts down, I like to make them with a spot of Torque Seal (the orange stuff on the bolt head.) This way 6 months or a year from now when I come back to working on a part I know whether or not I have torque those bolts or not.



Step 6: tie the Lower Hinge Assembly to the V-Stab Assembly through the bolt holes that will be used to attach the Lower Hinge Assembly and tape a bag of the hinge hardware to the tie. The Lower hinge Assembly will be installed when the V-Stab Assembly is installed to the Taicone Assembly. NOTE: If you read a head you will see it need to be attached temporarily during construction of the rudder.

RV12 Vertical Stabilizer (continued)

Reference: page 06-04, page 06-05, page 06-06 hours 4

Step 5: Rivet the VS-1212-B-R Upper Spar Cap to the VS-1203 Rear Spar as shown in Figure 2. Leave open the spar flange rivets for this step. Install the VS-1212B-L Upper Spar Cap as a mirror of the right. (The rivet wedge tool fabricated at the beginning of this section may be useful here for the rivets closest to the rear spar flange.)





Step 6: Rivet the nutplates to the VS-1203 Rear Spar and VS-1212B-R & -L Upper Spar Caps as shown in Figure 2.



Step7: Rivet the nutplates to the VS-1202 Front Spar per call-out in Figure 3. This completes page 06-04.



Reference: page 06-05

Step 3: Rivet the VS-1202 Front Spar, the VS-1208 Lower Main Rib, and the nutplates together. Orient rib flanges as shown in Figure 2. Flush rivet on the previously counter sunk side of the front spar.



Step 4: Rivet the VS-1207 Upper Main Rib to the VS-1202 Front Spar. Hardware call-out and rib flange orientation shown in Figure 2.

NOTE: I ran into a possible GOTCHA in this step. The front two flange tabs (on the VS-1207) had rivet holes that were under sized and needed to be drilled out to #30 size. As best as I can tell if this isn't done the tab would not be riveted during the final riveting of the skins.





Step 5: Rivet the VS-1212A-L & -R Lower Spar Cap to the VS-1203 Rear Spar using the rivets called out. Place tape over the holes to be left open. Leave open all rear spar flange holes and the rib attach holes for this step.





Step 6: Rivet the VS-1207 Upper and VS-1208 Lower Main Rib to the VS-1203 Rear Spar and VS-1212A-L & -R Lower Spar Caps.

Step 7: Rivet the VS-1206 Mid Rib to the VS-1203 Rear Spar.

Step 8: Rivet the VS_1205 Tip Rib to the VS-1203 Rear Spar.

Refer to this sub-assembly as the V-Stab Skeleton Assembly.
This completes page 06-05.



Reference: page 06-06.

Step 9: Rivet the previously dimpled K1100-08 Nutplates, to the VS-1201 Mai Skin per call-outs in Figure 4. This completes page 06-06.