Sunday, December 31, 2017

Wings, Rear Spar (Part 2)

I took a Christmas break to study the plans and Service Bulletin 16-03-28 to determine my next steps in the building process.  Now that I understand what to do.....let’s do it!

Essentially, the assembly instructions (and parts) in the SB are to be substituted for the instructions in the plans (as they are currently written NOW).

The plans say that the manfacturing process leaves the W-1013 Aileron Hinge Bracket Spacers slightly warped or bowed and have to be straightened.  My pieces were very slightly bowed, so I followed the directions and used firm hand pressure on the pieces while they were clamped in a bench vice.  This process worked out fine and they are now pretty straight.  The Spacers are shown below after being straightened as described above.  The two Spacers on the right are for the Inboard Aileron Hinge (supplied in SB 16-03-28) and the two on the left are for the Outboard Aileron Hinge (supplied with the normal kit). 

The next step was to prepare the the Aileron Attach Doublers.  It came in one long piece and had to be divided into four individual pieces as described in the excerpt of the Service Bulletin below.  I used my band saw to separate the four parts.  These pieces will be attached on the forward side of the Rear Spar opposite the Aileron Hinge Brackets.  

According to the SB, RV-14’s now skip to Step #20.  Below is the figure associated with Step #20.  The W-1013FG Aileron Angle Bracket also has to be separated into four pieces as shown below. The angle is separated at the three holes that are offset from the flange holes.  There is a note that specifically describes the edge distance of two holes and their orientation in the assembly.

This is the raw piece of angle supplied with the SB.

You can see the offset holes described above and the blue perpendicular cut lines I have drawn using a square.  The instructions say to cut perpendicular to the part and trim away any material the width of the holes across the entire part.

After cutting the pieces with my band saw, you can see where the offset holes were “cut in half” and will need to be filed and/or grinded smooth. 

Here are the four finished pieces.  I used a combination of a 6” Scotch-Brite wheel on a bend grinder, a fine hand file, and 220 grit sand paper.  Once the pieces are all clecoed together with the Aileron Hinge Bracket, I can fine tune any edges that might need a little more sanding.

With the exception of some minor edge work, all the pieces that make up the Aileron Hinge Brackets have been prepared.  Now, all the pieces are clecoed together.....keeping in mind the specific holes mentioned above requiring the appropriate edge distance.

Below are the two Inboard Aileron Hinge Brackets clecoed together.  Like I said, a few of the pieces will need some additional edge work and two of the braces will need to be trimmed according to the excerpt above.  After that, the pieces can be primed and riveted together.