Now that the dry assembly of the fuselage is disassembled, I moved on to the scariest job so far: drilling the holes in C2 and C3 for the wing pins. A great deal of the documentation is dedicated to this topic, but in the end the process is not that complicated.

Ultimately, this is how I did the job:

1. I decided to keep C2 and C3 clamped together as they were, with the 65 mm spacers in place. In other words, exactly as they had been positioned on the strongback.
2. I drilled 22 mm holes because I am going to make brass or bronze bushings. Yes, I know that is heavier, but I do not want direct aluminium-to-steel contact.

This is how I set up and checked the reference system:

1. The strongback was perfectly levelled, and I verified it again.
2. I checked that C3 and C2 were level in the assembly. They were perfect. That gave me a straight line to use as a reference, so if the holes were drilled from that reference, the wing would sit level in the fuselage.
3. I checked and marked the centreline on C3 and C2.

After these checks, I finally removed the C2/C3 assembly from the strongback and marked the holes on C3, as stated in the plans. I used the 93 mm dimension from the plan and drilled the holes at a 940 mm spacing, equidistant from the previously marked centreline. Before drilling, I double checked the marks with my false spar assembly.

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