Q&A - Zodiac 601XL -650 for the latest upgrade drawings of November 24 2009

This Q&A is for the upgrade kit of the Zodiac 601XL & 650 based on drawings of Nov. 24, 2009 and AMD Safety Alert of November 7. 2009

New drawings:
Nov. 24, 2009: We've updated the draft Drawings 6-ZU-1, 6-ZU-2, 6-ZU-3 and 6-ZU-4, and LAA Aileron Balance.

For very detailed questions (or if you must complain or vent), email me at newplane@gmail.com

Please post all your questions on the last page.

Views: 4008

Replies are closed for this discussion.

Replies to This Discussion

I like to use a Ingersol Rand 4X. It has a very nice teasing trigger and if you have a regulator on it, you can do #3 rivets all the way up to 1/4" with no problem.
try here:
this is the IR brand but there are others...this is just my personal prefrence. Stay away from the ACAT though..they are junk.
Hope this Helps!
Tim Mix
I have completed the spars, bell cranks and skin stiffners upgrades on both wings. However, after reading CH's comments about the mass balance on the ailerons for the 601XL, I am not sure that this is what I want to do to my a/c. After 400 hours of flight and after inspecting my wings I see no evidence of vibration or flutter anywhere in my a/c. In addition, CH commented on the mass balance as untested and the results are unknown. Can you bring more clarity to the mass balance discussion? Are there any other options such as spades or dams? Has anyone tested the mass balance recently? Thank, Mark, N200BE
FWIW, my current inclination is to not balance the ailerons.
The UK CAA did test the mass balance and we did get confirmation from the German flutter expert that the mass balance will not have a negative impact on the design. The FAA and NTSB also seemed to like the mass balance design, as we have not heard any negative comments from them on the upgrade kit.
The mass balance was added to the upgrade kit as we are trying to eliminate any and all possibilities of vibration and or flutter. Mass balance, flap stops, aileron bellcrank strengthening, wing skin reinforcing, rear spar reinforcing etc. are all for minimizing vibrations.
The German expert who did the most flutter testing on the aircraft clearly stated that the aircraft does not have a flutter problem, but The NTSB stated the opposite. Some customers have reported flutter (Large vibrations in my opinion as once a wing starts to flutter, there is probably damage withing seconds).
So to satisfy the NTSB, we added the mass balance but also because we do not know how well each and every homebuilt aircraft is built. In the name of continued airworthiness, its a good idea that everyone adds the mass balance, especially for the second owner who will have no idea on how to maintain the aircraft (tight control cables etc.).
Its important that the aircraft regain its reputation. The upgrade will help significantly but pilots will also have to respect the limitations such as Va.
Once you are ready to fly your upgraded aircraft, PLEASE go over your aircraft by using the 41 page check list. Once you fly, PLEASE calibrate your ASI properly so that anyone who flies the aircraft will be doing so safely.
I still have trouble adding a second hole to the rear spar when Chris and the German expert clrearly state there is NO flutter problem if the aircraft is maintained and flown within limits. Did the NTSB do other flutter testing to prove their statement or how do they justify it? Can we use the German data as justification to the FAA as to why we did not do the aileron balance mod to get our airworthiness ticket?

IS anyone planning to go down that road?

The rest of the Mods make sense but not this last part..
I am not aware of any way to get aileron flutter without resonance. The German tests pretty much ruled that out. If I already had my aircraft licensed, I would probably omit the balance mod, and do most or all of the other mods.

However, it looks to me as though I will need to do all the mods to get it licensed. If that indeed is the case, I will do the mod, even though it adds weight needlessly.
Adding the second hole in the rear spar for the mass balance bar is not an issue as it is at the tip of the wing where the loads are very low.
Yes, it is frustrating for everyone to do the upgrade especially when experts are stating that the aircraft does not have a flutter problem. However, the NTSB continues to state that there is a flutter problem and they are the accident experts. Maybe there can be flutter and or vibrations if the aircraft is not built to the drawings or maintained correctly. Because of this unknown, its best that we all do the upgrade.
thanks Mathieu
I will go as per the plans with the ailerons. and some of the Ausies are already getting their air mailed mod kits.
Thanks for the follow up. I will add the Mass........
When Are Mod Kits Going To Be Delivered ????

Hi Mathieu,
I've been in contact with Allan, our Oz Zenair representative this morning. He tells me there is no definite date from you as to when our kits will be delivered. I'm sitting, as it seems so are lots of Oz builders, with a heap of dismantled aircraft. It's halfway through January now so when do you anticipate we will get some kits????
The situation is far from satisfactory. Over here it seems we are the poor relations. Your tarnished reputation is not being assisted by this appalling customer service. Sorry for the rant, but I feel it's very justified.

A VERY pi%%ed off customer,
Paul Toone
I definatly feel your frustrations on this one Paul!!!!! Zac has not been very forth coming on the progress of our kit delivery. I keep getting empty promises and can only watch the lucky few who have received a kit rebuild there aircraft and there hopes and dreams!!! This has been my first build and will def be my last. When I go to my shop and see the pyle of pieces laying around that was an airplane it almost turns me against flying all togather!
If you have something to complain about, call us. Anita at Zenair coordinates all the shipping. 705-526-2871. You may also want to call Allan and see if he actually ordered upgrade kits, and paid for them.
You, like anyone else can order direct from Zenith or Zenair. Zenair will be shipping quite a few upgrade kits to New Zealand this week. Zenair has no other others right now. Zenith is shipping out 10-15 per day. To date, both Zenith and Zenair have shipped more than 300 (includes Europe).


New from Zenith:

Zenith Planes For Sale 

Classified listing for buying or selling your Zenith building or flying related stuff...


Weather Maps

Custom Instrument Panels
for your Zenith

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, power distribution panel, Approach Fast Stack harnesses, Dynon and Garmin avionics, and more.

Custom Upholstery Kits for your Zenith Aircraft:

Zenith Vinyl Upholstery Kits

Zenith Apparel from EAA:

Zenair Floats

Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz

Builder & Pilot Supplies:

How to videos from HomebuiltHELP.com

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.

Aircraft Insurance:


West Coast USA:

Pro Builder Assistance

Pro Builder Assistance

Aircraft Spruce & Specialty for all your building and pilot supplies!

© 2019   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service