Part 6: Installing the "Upgrade Package" to our Zodiac CH 601 XL: Installing the Top Rear Spar Angle doubler

Next we install the Top Rear Spar Angle 6-ZU-1-3 reinforcement doubler inside the rear (spar) channel 6W7-2.
Below is a view of the angle inside the top rear channel (inboard, over the rear channel doubler 6-ZU-1-5 previously installed):

This angle doubler sits inside the top rear spar channel.

Steve first clamps the doubler into position, and then back-drills from the top, and clecos it into position.

Here Steve drills through the top rear spar angle doubler into position.

The angle doubler is made up of two halves that are spliced together in the middle.

Now the doubler is drilled and clecoed horizontally to the rear channel (viewed from the back):

Next, we install the Aileron Rod Hole Doubler 6-ZU-1-4 to the rear spar channel over the existing aileron rod hole.

We back-drill it to position and cut out the aileron rod hole to match:

Video clip: Installing the Top Rear Spar Angle doubler:

I've just heard from Doug and Lori Dugger of Quality Sport Planes (in Cloverdale, California) that they will host a free "Upgrade Workshop" during the upcoming November 20-22 weekend. This is one more way for Zodiac XL builders, owners, and pilots to get assistance with the new upgrades required for their aircraft. For more information, contact Quality Sport Planes. RSVP to (707) 894-4084. Thanks Lori and Doug for hosting this workshop!

Also, please make sure to check out and contribute to brother Mathieu's "Zenair Q&A"
This will help answer many of your questions.

Next, we'll install the aileron bellcrank support channel inside the wing.

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Comment by Jake Reyna on November 15, 2009 at 10:15am
Robert, this and many other issues are addressed by Mathieu's Q&A - Safety Alert and SAIB

There are currently 7 pages and I believe Mathieu has answered every conceivable questions numerous times. One question that continues to be beat to death is hingeless ailerons, you don't need hinges, but you do need to add the counterweights along with the rest of the upgrades.
Comment by Louis Gallego on November 14, 2009 at 9:46pm
All the upgrades look very straightforward, appear to add minimal weight, but all look like they will strengthen suspected weak areas greatly. I should be able to complete this in a few weeks. Thank you for the very helpful pics/blogs.
Comment by Robert Reinero on November 14, 2009 at 4:20pm
Will the spar roote doubler fit into the carry through when added to the wing spar?

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