Installing the "Upgrade Package" to our Zodiac CH 601 XL

Since the FAA's Special Airworthiness Information Bulletin (SAIB) and AMD's Safety Alert / Directive were issued on Saturday, November 7, 2009, we've begun the job of updating our Zodiac XL demonstrator per Zenair Upgrade drawings. As the kit factory, we want to have this done as soon as possible while also documenting and verifying the drawings and developing detailed step-by-step assembly instructions for builders and owners.

We've spoken with many builders over the last couple of days, and we want to thank you for your overwhelming support! 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. We'll be providing details on availability (how to order, etc.) later this week.

I plan to post updates here of our progress as we install this Upgrade Package to our demonstrator Zodiac XL to give builders and owners a good idea of the job ahead:

First thing first: Removal of the wings.
As Zodiac builders know, this is a straightforward process: Empty the fuel tanks, disconnect the controls, wires and lines, and remove the spar bolts:

Despite its age, our demonstrator Zodiac XL appears to be in great condition, with expected normal "wear and tear" to the cabin interior and exterior paint. We've taken hundreds of folks flying in this aircraft, and it's been around the country (several times!), and hundreds (if not thousands) have sat in it trying it on for size at shows around the country and at the factory.

Here's a brief video clip of the wing removal:

Our next step will be to drill out the rivets for the nose skin and top rear skin...
I'll be documenting the process here as we complete the Upgrade Package installation. Click here to view Part 2.

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Comment by Jim Timm on November 13, 2009 at 4:35pm
I have close to 200 hours of very enjoyable flying in my airplane. Yes, the aileron control is a bit heavy and the pitch is responsive, but it isn't supposed to be an acrobatic airplane. Recognize it's flight characteristics and handle it accordingly. It's a very nice flying airplane the way it is. I do love flying it and I really hate the thought of tearing it apart and possibly screwing up what is now a very nice airplane. Having experience/knowledge of putting the wings on five 601XL airplanes, It will not be possible to add a .062 to the wing spar and get it to fit in the present center spar. Something will have to change, The tail dragger airplanes will have to have some special consideration on how to handle the forward fuselage skin reinforcement.
Comment by Phill Barnes on November 13, 2009 at 4:28am
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 Richard Simmons on November 12, 2009 at 7:49am
I am curious on the Aileron counter balance. Will this be here for the US and for the Hinge-less surfaces?
Are you putting these on the Demo plane?

Thanks for you efforts!
Rich Simmons
Comment by Mark Hubelbank on November 11, 2009 at 7:43pm
Given that the only "failure" documented in tests was the wing bolts and holes at the ultimate load (I know this is technically allowed) would this be a good time to also use a higher grade bolt and washer with higher torque? I can't see any down side but then I am not an aircraft designer.
Comment by Matt Archer on November 11, 2009 at 6:36pm
Thanks for all the support. Look forward to seeing it progress and getting started. I am also planning on cleaning up some items and making some mods while I have it apart. Looking forward to starting.

Thanks for the continued support.


Comment by Clarence K. Andrews on November 11, 2009 at 4:18pm
Looking forward to getting started on the mod. It will give me an opportunity to add brakes to the passenger side. An omission I regret.
Comment by Mack P. Kreizenbeck on November 11, 2009 at 2:25pm

Please continue posting the photo updates as you progress through the modifications.

I have been very apprehensive about flying the XL, because all the trash-talking, on the web.

I waited over a year after the DAR signed it off to fly the bird. Even had to due an annual before first flight.

I now have over 5 hours on it, but I'll gladly make the recommended modifications as it will put my mind at ease.

I spent a great amount of time studying all the available LSAs and still feel that I made the correct choice.

Thank you for the updates and postings.
Comment by Brad DeMeo on November 11, 2009 at 12:58pm

Thanks for the updates. I really appreciate hearing from the factory and seeing the photos.

With the wings off I might finally fit the wheel fairings, clean up the wing root rubber, and do a few other non-structural things to "clean up" those nagging "I wish I would'a put this over here, and that over there...and so on, and so forth", mostly cosmetic stuff.

Good luck with the installation and testing. I can't wait to get started on mine.
Comment by JG Ginther on November 11, 2009 at 12:16pm
I am with my friend Dr. Moody on this one. The FAA letter in typical bureaucratic double-speak pretty much makes the case for not tearing apart a perfectly good plane. My 2002 is one of the original Czech planes and has 400 trouble free hours. Here is the relevant quote from the FAA:

After the review we made a determination that these accidents did not clearly indicate a single root cause. Instead, it implicated the potential coupling of design and operational aspects of the aircraft.

Having flown my XL for seventy hours now, I think the more fruitful upgrade would be with the "operational aspects" rather than the design.
Comment by Louis Gallego on November 11, 2009 at 11:10am
Thank you for starting this post and these perfect pics. I agree, and am willing to pay for this kit, and really can't wait to get started. Once you get over having to do it, it seems straightforward enough. I think I will have to rebuild my 4' x 12' flat table for this. Keep up the good posts. One question I had was, if you add a doubler to the wing root, won't fitting the root into the center spar be difficult? When I attached my wings, the fit seemed pretty snug, perfect actually. Thanks

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