Service Bulletin 14-01-31 (4)

Lots of time in the hangar, without a ton to show for it. Today was challenging.

First I set about cleaning up a small nick I had placed in the spar. The drill had slipped during drilling of the rivets, and I wanted to clean up that surface. Unfortunately it was in a difficult position on the corner of the web and flange. I had to remove additional skin rivets and then slowly sand the area down. This was very slow going with limited space to maneuver. You can see the end polished result below.  

I also made the relief notches. Here you can see the start. The red lines mark the width and depth of the notch. 

You can see a completed notch at the bottom of this photo next to the first spar corner I removed. The process here is to wedge the stainless steel between the spar and the skin and then use a dremel to make the cut. Still space is difficult and getting a perfectly clean line is difficult.

I used a two by four to wedge the skin open to help file the rough edges and round the corners. Very slow going as my hands and arms don’t contort the right way and space was very limited.

Here’s a good picture of a completed relief notch and spar modification. Of note, the RV-7 plans explicitly call out the relief notch, whereas there is not mention of the relief notching the RV-8 plans (diagrams or instructions). 

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