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Zodiac Zenair AMD models?

Posted: Fri Nov 25, 2022 10:00 pm
by Sundancer
Hello All,

I found a Wikipedia page that SEEMS to cover the Zodiac/Zenair/AMD models - except for Zenith 601 XLB. What's the "B", as opposed to just Zenith 601XL? The wing mod??

https://en.wikipedia.org/wiki/AMD_Zodiac

Re: Zodiac Zenair AMD models?

Posted: Fri Nov 25, 2022 11:41 pm
by drseti
The B indicates that the Airworthiness Directive has been complied with, modifying the wing to prevent the failures that were believed to have caused several accidents, circa 2010.

Re: Zodiac Zenair AMD models?

Posted: Sat Nov 26, 2022 10:34 am
by Sundancer
Thanks! Hey, are you the guy who did the EAA presentation on taking an S-lSA to E-LSA?

Re: Zodiac Zenair AMD models?

Posted: Sat Nov 26, 2022 10:45 am
by drseti
Yes

Re: Zodiac Zenair AMD models?

Posted: Sat Nov 26, 2022 12:00 pm
by Sundancer
My thanks, then - you answered all my questions about moving an aircraft from S-LSA to E-LSA. Got me shopping for E-LSA that is (or can be) equipped for IFR/IMC use. The DAR confirming "zero changes" before the move to E-LSA scares me some, so I'm inclined to seek out a plane already registered as E-LSA.

Re: Zodiac Zenair AMD models?

Posted: Sat Nov 26, 2022 12:32 pm
by drseti
If you plan to purchase an ELSA, and contemplate IFR operation, be sure to check out the Operating Limitations closely. They need to authorize "day and night, VFR and IFR". If the original DAR didn't specify that, it's going to be very difficult to change it. The Operating Limitations will also specify that the aircraft must be equipped in accordance with FAR 91.205 (c) for night operation, and 91.205 (d) for IFR opetation.

If taking an SLSA to ELSA, the DAR doesn't have to confirm "zero changes", just that all modifications were done with a Letter of Authorization, and none would take the aircraft out of SLSA compliance.

Re: Zodiac Zenair AMD models?

Posted: Sun Nov 27, 2022 9:47 am
by Sundancer
Got it, check the limitations on the pink slip. My uninformed concern on a S-LSA not yet moved to experimental is whether I'd recognize changes made without a LOA - I'd have to have a real certain knowledge of the type. But I could check with the folks who own them, via user forums, etc.

Is it possible for one DAR to prohibit IFR/IMC while another allows it? On identical aircraft? That would seem pretty sketchy on the FAA's part. . . .

Re: Zodiac Zenair AMD models?

Posted: Sun Nov 27, 2022 12:45 pm
by drseti
Sundancer wrote: Sun Nov 27, 2022 9:47 am My uninformed concern on a S-LSA not yet moved to experimental is whether I'd recognize changes made without a LOA - I'd have to have a real certain knowledge of the type.
That's one thing that a mechanic checks for during a prebuy examination. For details on prebuys, see my video "how to buy a used LSA" at:

https://avsport.org/webinars/videos/prebuy.mp4
Is it possible for one DAR to prohibit IFR/IMC while another allows it?
Some will feel more comfortable with authorizing it than others. My video "IFR in an LSA" touches on this:

https://avsport.org/webinars/videos/IFR_LSA.mp4

Re: Zodiac Zenair AMD models?

Posted: Sun Nov 27, 2022 1:29 pm
by drseti
Found this language in an FAA document describing ELSA Operating Limitations (http://www.faa-aircraft-certification.c ... ating.html) :
Experimental LSA Operating limitations must be designed to fit the specific situation encountered. As mentioned before, the FAA/DAR may impose any additional limitations they deem necessary in the interest of safety.
That would appear to give the DAR discretion regarding IFR authorization.

Re: Zodiac Zenair AMD models?

Posted: Sun Nov 27, 2022 11:17 pm
by Sundancer
That is uhhh, lame language. Identical aircraft, and S-LSA,whether factory or homebuilt, must be identical per the regs - at least when the AW cert was first granted. . .I read "discretion" and hear "capricious".

I get it, that's the reality - but it's gonna be weird to find different limitations for identical aircraft because one DAR was more (or less) "comfortable" with the "situation."

I guess one must "shop" for a DAR when moving a S-LSA to E-LSA for IFR/IMC use.

Re: Zodiac Zenair AMD models?

Posted: Mon Nov 28, 2022 1:25 am
by Type47
Shopping for a Dar is definitely the way to go.
When I was looking to go experimental with my slsa, a few seemed to be looking for every reason to find an issue.
Also, one seemed to want to come up with the most restrictive limitations possible.
I call it savior of the world complex.
The Dar I went with has done many conversions and used limitations that will allow for the least restrictions and the most possibilities.
Let’s face it. Digging deep to make sure there weren’t any of the smallest modifications since new on a currently in annual aircraft will help no-one. Especially when you have carte blanche to make any changes except major modifications on your experimental Elsa literally 5 minutes later.

Re: Zodiac Zenair AMD models?

Posted: Mon Nov 28, 2022 9:24 am
by JimParker256
The thing with E-LSA is that the vast majority of FAA folks don't really know and understand it very well. I went through an almost year-long hassle with my local FSDO just to get the test flight area changed (originally built in Montana, now operating in Texas). The guy was very apologetic and all that, but just had no clue about how to make it happen. Eventually, he consulted with someone at FAA HQ who told him how to make it happen, and I received an entire new special airworthiness certificate, with the newer-style "Conditions and Limitation" section.

And here's where it ties back into your question... After Phase I (test flight period), the document specifies:
Kinds of operations authorized:
Day VFR operations are authorized.
Night flight operations are authorized if the instruments specified in § 91.205(c) are installed, operational, and maintained per the applicable requirements of part 91.


Note that there is no "IFR" permitted for my airplane. I don't know if this is because my FSDO guy didn't know any better, or because my original "Operating Limitations" document was worded the that way and he didn't want to second-guess the FAA Inspector who signed off the original Certificate (yeah, it had to be an FAA inspector back then - no LSA DARs yet).

I don't really care about not being able to bring the aircraft into IFR-approved status. I have no interest in IFR flying at this point in my life. If the weather is bad, I'm driving or taking the airlines. To me, this type of airplane (100-115 mph cruise, 27 mph stall, 3 hours range with comfortable reserve) isn't something I'd want to be flying in IMC - bumping around in the clouds. Adding all the stuff to make it IFR legal would take away a good bit of useful load, and there was no provision in the design for adding an autopilot (and no real good way to do so, either, as others have found out). I cannot imagine hand-flying this "sports-car handling" airplane for hours on end solely by reference to instruments, with no autopilot to assist.

Then there's the whole practicality challenge of fuel reserves... By the time you factor in the reserve fuel needed to make the missed approach, hold, fly to alternate, and shoot that approach, I'd only be able to file about a 1-hour leg. And our typical "flyable IFR" here in Texas would likely mean viable alternates would be more than an hour's flight away... Just totally impractical, in my opinion.