Sunday, February 27, 2011

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.