Service Bulletin 14-01-31 (5)


Tonight was my first time working on the project in over a month. I finished my MBA program in December and began a Master’s in Engineering in late January. My undergrad is in electrical engineering, but I guess I had chosen to forget that engineering is far more difficult and requires a greater commitment to studying. You can’t BS or fall behind in an engineering degree! As a result, the plane has been put on the back burner while I’ve worked to brush up on topics that are considered pre-requisite knowledge, but aren’t not areas I’m well versed in, such as programming with C.

Anyways, back to the plane. The first two photos are photos I completed in the last session. I don’t believe I had taken good photos previously. The relief notches are complete as is the removal of the spar corners. Tonight I cleaned up all the edges with sand paper and scotch-brite.


I also cleaned up a few rough spots on the reinforcement angles.

I removed the forward flange of the HS-405 ribs. These will be replaced with an piece of angle. With the addition of the spar doublers, the HS-405 will no longer fit, necessitating this change.

Here is the result. It is also necessary to radius the outer edge to rest against the attaching angle. 

Next I deburred the spar reinforcement angles. Then I drew the rivet lines. These lines run through the centerline of the pre-punched rivet holes. The offset rivet marks the top side of the HS-00001 doubler. The line will be used to align with the holes in the spar (shown below).

Here are both side by side. The top side of each doubler will rest against the intersection of the web and flange on the front spar, and it is necessary to radius the edge here as well. 

Here you can see how the line I drew is used to align the doubler.

And finally, on a completely separate note, I recently made a hardware order from Aircraft Spruce. While doing so, I did not immediately notice that they have both the AN-XXXA rivets on the same page as the AN-XXXAD rivets. The -A rivets are SOFT and are NOT for use in structural components. I accidentally ordered two sets, shown here. Why ACS would put them on the same page is beyond me. I’m willing to bet I’m not the only person who has made this mistake. Luckily it was only 2 types. I already mixed them with the ones I have, so I’ll need to replace them all.

Hopefully, I’ll be able to find some time in the coming weeks for the project, but the next 3 months are going to be slow. I will not take as many classes next term as I am this term, thats for sure!

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