Tue Nov 25 2008

Drilling F-719B clips and F-902 bulkheads

Well yesterday I worked in the shop all evening, but not doing work on the plane. The dang place was a disaster and needed some serious cleaning. You couldn't hardly see the tops of the work benches. I was tired of the mess and having to constantly look for parts and tools so I used the evening to get organized. Today I called in sick to work, but managed to make it down to the shop to put a few last items away. Here's a pic of one of my workbenches. How nice and clean! (I wonder how long that'll last? :-)

Anyway after taking it easy all day I was feeling better, so I headed down in the evening to do some work. I needed to get the F-719B clips drilled to the F-719 stiffeners as well as the firewall stiffeners. I clamped the clip in place, unclecoed the side skin near the top of the fuselage (near the floor) and used my long #40 drill bit to reach up between the skin and the longeron to drill these holes.

Hrm...the holes seem awefully close to the flange of the F-719 stiffener.

Since I had already drilled all three holes in this angle clip, I had to figure out a way to match drill through the clip into the firewall stiffener. After much head scratching, I decided to:

  1. Cleco the F-719 to the skin to get the correct vertical position of the F-719B clip.
  2. Use a c-clamp to clamp the F-719B clip to the firewall stiffener. Note that in this image I had to remove one of the clecos to make room for the c-clamp.
  3. Uncleco the skin from the upper longeron, most of the firewall, and this angle stiffener. This allowed me to peel the skin back and...
  4. ...use the angle drill to match drill through the angle clip and into the firewall stiffener.


While I had the skin peeled back, I noticed that one corner of the F-719B clip was contacting the firewall. Not wanting to get a dent in my firewall...

I sanded then filed it at a 6 degree angle. That looks better!

After repeating the process to drill the F-719B on the right side of the fuselage, I decided to match drill through the side skin through the lower longeron and into the firewall weldments. Again, I did the right side as well.

Next, I opened up the prepunched hole in the F-902 bulkheads to 5/8 inch diameter with a unibit to accept a snap bushing.

I also drilled and dimpled for some K-1000 nutplates that will eventually be installed here.

After that, I started fitting the F-7101L web plate between the auxiliary and lower longerons.

I used a sharpie to mark through the holes from the outside so I could check what edge distance I would end up with. I've heard that others have had edge distance problems here. Looks good, though.

I also noted that between the forward flange of the F-7101 and the F-902, there is a slight gap. I think I'll need to make a shim here.