Started center fuselage

February 27, 2014 – Today I opened up the center wing spar, or F704 bulkhead. This package came with my wing kit back in 2010, so it was nice to finally open this package. This center part of the wing spar is match-drilled to the outer wing spars. There are two large spar structures that will sandwich together to create one large beam that the wings will attach to, so this structure is big, heavy and important.

The first thing to do is to enlarge (or drill) holes for snap bushings. These holes will accommodate wiring or cables that will run through this structure. They will all be 5/8″.

Some of these holes are started:

…and some you have to drill. The plans call for two holes to be drilled on both the forward and aft bulkheads.

There are two blocks or spacers (F704G) that are match-drilled to the aft bulkhead. They come with bolt holes already drilled, so I just had to temp-install them with bolts and drill the rivet holes. The instructions say to cleco the vertical plates to each bulkhead, then place the large wing attach bolts so make sure everything is precisely lined up. The large bolts are the bolts that will eventually hold the wings on. The smaller bolts you see below with the washer stack and the castle nuts are holding these blocks in place for drilling.

You only drill two (#30) rivet holes, but these blocks are 3/4″ or so thick, so I had to use some BoeLube. The holes get countersunk for flush rivet installation on the forward side, so I marked these holes.

Time: 1:35