Part 3: Installing the "Upgrade Package" to our Zodiac CH 601 XL: Drilling out the top inboard main wing spar

In our third installment, we drill now drill out the conventional bucked rivets of the top inboard main wing spar, starting where we left off with the top rear skin removed and the top of the nose skin opened:

Remember, I am posting this info to show you how we installed the Upgrade Package to our Zodiac CH 601 XL. This is not a set of instructions or a teaching aid. I only recommend that you attempt drilling out the solid rivets if you have some experience working with bucked (conventional) rivets. They require some special tools and skills. Your local A&P mechanic or an EAA chapter member may be able to help you and guide you.

Some good reference materials to read and study are:
Construction Standards for Zenair Light Airplanes
Standard Aircraft Handbook
AC 43-13 Acceptable Methods, Techniques, and Practices...
The Online Builder Resources are available exclusively to builders and owners, including a 41-page checklist to help you thoroughly pre-flight your Zodiac aircraft.

To install the top spar extrusion angle reinforcement (6-ZU-1-1) we'll first need to drill out the top spar rivets 1680 mm. from the inboard end (the first 5.5 feet of the spar).

First, we drill out the rivet head:
(See the video clip below for a better view of this):

Then we knock-off the head:

Then, we hammer the punch to push the rivet out:

The spar is quite thick here and it takes time and effort to push the rivet out:

Using the pneumatic rivet hammer really quickens the process of pushing the rivets out. Note that we have not enlarged the holes in the process.

Here's a video clip of us drilling out the solid rivets:

Upgrade Package availability:
As many of you know, we're also really busy getting the Upgrade Package kit together: We're making excellent progress on this and we will be ready to announce availability soon. Check the Zenith website update page for details on obtaining your Upgrade Package.
This shows most of the Upgrade Package kit parts:

Over the last several days we have spoken to and have heard from many Zodiac XL builders, owners and pilots from around the world, and again, we need to thank you for your overwhelming support during this difficult period! We are working very hard to complete the Upgrade Package kit and to make it available to all so that it can be installed as soon as possible and at minimum inconvenience and cost.

I apologize if I have not yet responded to your email message or inquiry - I plan to as soon as I have the chance to. Please rest assured that your questions are not falling on deaf ears.

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Comment by Garlen Mikolichek on December 2, 2009 at 6:10pm
To get the rivets out without using an air hammer , I made a small press to push out the rivets. It looks like a "c" clamp and works good. I took two plates of steel,spaced them 1/2" apart, notched them to a "c" shape then welded a 1/2" nut on one end. I drilled a 3/16" hole in the end of a 1/2" bolt and placed a 3/16" bolt with the threads ground off into the the 1/2" bolt for the punch.
Comment by Robert Pelland on November 14, 2009 at 7:25pm
Wendll, They are called " Wing nut draw Cleco's " and can be found at most of the aircraft tool suppliers. They have a much stronger holding, and clamping capicity, however they are rather expensive. You can count on paying anywhere between 2.25$ to 3.50$ deoending on the clamping length.

The 701 & 750 scratch
Comment by Wendell D. Sullivan on November 14, 2009 at 10:48am
What are the tools that look like special clecoes? How many will be needed and where can they be purchased?
Comment by Clarence K. Andrews on November 13, 2009 at 9:22pm
After just a cursory glance at the proposed drawings. it appears that the installation will be somewhat labor intensive, and is something that sometimes will require help from at least tow helpers. The good news is that there doesn't seem to be a lot of material added, which is good in that the added weight is not significant. It's just that where the material is added will require a lot of labor to get it there. Since the amount of material is small, hopefully that will be reflected in a reasonably low cost for the parts and drawings.
Comment by Dan Dempsey on November 13, 2009 at 10:55am
At one point during building my wings (the first time) I messed up the bottom spar cap and had to remove it. I found the rivets almost impossible to drive out with a hammer. I solved this problem by making a little jack. Pictures can be seen here:
Comment by Robert Pelland on November 13, 2009 at 6:32am
Not that it's any of my business, but in seeing the work involved in knocking out the solid rivets, there is a way it might be done more effectivlly. Once the head is removed, and some one get's out the hammer, you might want to think about supporting the rear of the spar with some weight. I would use a half inch drive deep socket around the protruding rivet, backup up with a small heavy weight of sorts, somethng akin to a bucking bar. This way there would be much less mouvement of the spar, and a much quicker, and easier removal of the rivet. This would resemble the rivet's initial installation process by being backed up at the rear.
Just a thought,,,

The 701 & 750 scratch
Comment by Phill Barnes on November 13, 2009 at 4:30am
Hi all
Sebastien asked me to send questions to his email and not to this blog but feel free to leave comments. Fare enough. Mathieu Heintz also has a Q&A forum here and is doing a pretty good job at answering questions thoroughly. Well done Heintz boys. Keep up the pics & vids. We all wanted a stronger plane, now we've got it. So long as we get all the infomation that we need or request, who can really complain.

Comment by Taylor Ogden on November 12, 2009 at 9:39pm
I'm not building a Zodiac, but I'm keenly interested just to see the quality of support, in both directions. Zenith supports us, and we support you!
Thanks to all involved.
Comment by Matt Archer on November 12, 2009 at 9:23pm
Thanks for these Blogs. They are very valuable in answering a lot of questions.

I really appreciate your efforts and customer support.



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