The fuselage is built upside down in a jig.

The jig is a massive structure, apparently designed to withstand earthquakes. The side rails are 16 ft long 2x6, with 2x4 cross members. 2x4s on edge are fastened to the top. The position and height of these 2x4s is critical because they determine the location of the fuselage bulkheads. The main fuselage longerons rest on these 2x4s, so I carefully shimmed them to make the tops of the cross members all in the same plane, using taut lengths of dental floss as a reference to measure from.

The firewall will be bolted to the two uprights at the end of the jig.

Read on for more.

Here we are looking at the other end of the jig.

I had to take over the whole garage. I had hoped to only use one bay, but once the lawn mower, was moved into the other bay, there was no longer room to get a car in.