This morning, Kerin and I had plans to head up to Cleveland for my grandmother's 86th birthday. Before we got on the road, though I was able to sneak in a couple hours working on the step.

Here I've marked some short tick marks along the vertical row of rivets in the F-770 side skin. Only the center one is close to matching up and it is about 1/16 inch too high (actually too low in this image since the fuselage is upside down). I decided to use the die grinder to enlarge the torque tube hole towards the bottom of the fuselage by 1/16 inch.

After doing that, I made some marks at the corners of the step flange and asked Kerin to hold the step in position while I back drilled the center hole from inside the fuselage using the angle drill. You can see that this now lets me hold it one with a single cleco.t

Next, I pulled the step out, laid out the remaining rivet pattern, and drilled all except the lower aft hole in the step flange. Note that I needed to modify the row spacing in the forward-aft direction to result in 3/8 inch edge distance for the outermost holes.

You can't really tell in this image, but the fit of the step at the lower aft corner is pretty much crap. I've done a bunch of research and pretty much everybody ends up filling this gap with proseal or RTV or whatever. I suppose I'll probably end up doing the same.