A list of lift strut suppliers (updated 12 Dec 2007)

[flyguy]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

Strange.

If there sre FAA instructions/documents that detail the paperwork steps required to install a PMA part, then that is what needs to be done. Nothing else. No matter what anyone "says." If not, we are all sc---ed because then it becomes a matter of opinion. (Substitute the word judgement if you want to be nice.) So the question is: what does FAA documentation (FARs?) say about the paperwork for PMA parts?
Meantime I will look it up myself. Y'all have piqued my curiosity.
DC

[Garry Crookham]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

Dave:
I agree with you on the confusion factor. After a lot of thought and research on this I think the reason for the STC may be because the vendor replacement struts are not identical in construction to the factory struts (the streamline tubing size is larger).
I've run into this on the Superor Millenium A-65 cylinders. They require an STC because the head casting was improved and is not identical to the factory cylinder.

Garry Crookham
N5112M
Tulsa

[flyguy]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

8110.42B
1.4a
Also PMA may approve the production of parts from a supplemental type certificate (STC). PMA applies to most replacement and modification parts. Only use an STC for the approval of parts that constitute a major change to the product.

Talk about abusing the English language. I think "major change" is the operative word here.

So far haven't seen anything that directly indicates what paperwork process is required for installing a PMA (ed) part. Still searching.
DC

[Guest]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

Dave:
I agree with you on the confusion factor. After a lot of thought and research on this I think the reason for the STC may be because the vendor replacement struts are not identical in construction to the factory struts (the streamline tubing size is larger).
I've run into this on the Superor Millenium A-65 cylinders. They require an STC because the head casting was improved and is not identical to the factory cylinder.

Garry Crookham
N5112M
Tulsa

Hey Garry thanks,

I think that would make sense to me if it didn't have PMA replacement part status but it does. According to McAnaul there is no need for an AMOC if it is a PMA approved replacement for the MA... part numbers in the AD. Otherwise it needs an AMOC according to him and he is the controlling office for AMOCs. BTW-FSDOs do not approve AMOCs, they are a channel for them to go to the McAnauls of the FAA**.

I am betting/guessing that the cylinders don't have a status as a PMA replacement part. The PMA replacements I normally use don't need STCs. The basis for this part's PMA certification as a replacement part is an STC (which seems odd to me). The cylinder kit that I found (which may not be the correct one, you say if its correct) has a PMA status but not a replacement part. Here's what I found;

cylinder PMA, not replacement parts, that's why stc/337;

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgpma.nsf/0/09389AD1880E85518525704D00544FA7?OpenDocument

Airframe's PMA is apparently a replacement part for MA-A815, that's why Andy says log entry only, what up with stc/337 I don't know;

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgpma.nsf/0/051C69D1E5C755FD86257387005E38EB?OpenDocument

Univair's PMA not a replacement part, that's why Univair needs an AMOC;

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgpma.nsf/0/E499064513487AC8852570500056BA9B?OpenDocument

I am still perplexed just showing you what I see, maybe it will lead to someting.
.
Thanks, Dave.



**§ 39.19 May I address the unsafe condition in a way other than that set out in the airworthiness directive?
Yes, anyone may propose to FAA an alternative method of compliance or a change in the compliance time, if the proposal provides an acceptable level of safety. Unless FAA authorizes otherwise, send your proposal to your principal inspector. Include the specific actions you are proposing to address the unsafe condition. The principal inspector may add comments and will send your request to the manager of the office identified in the airworthiness directive (manager). You may send a copy to the manager at the same time you send it to the principal inspector. If you do not have a principal inspector send your proposal directly to the manager. You may use the alternative you propose only if the manager approves it.

[flyguy]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

Dave,
I think I understand the STC part ok. AF PMA was developed using an existing STC for data. (see my entry above) The UV one was developed using new raw data. Both done under part 21. So much for the STC. So the 337 biz is the only thing that is a question to me. I see the Univair one as being a problem given the information we have presently.
Think we need some more information from UV or the FAA engineer. Question is: does a PMA precede a 337, making it unnecessary?
Edit: and what does a PMA as a "modified part" mean? Requires same paperwork as doing a splice (major repair--337), plus the AMOC?
Pictures multiple inspectors running screaming into woods, LOL.
DC

[jstall]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

This A/D was written to quickly, without enough info to get it in place.

There were not enough suppiers out there at the time and the "Factory
Bandit was the only game in town, to the point of 7 million in sales"

See GAN article

Why would they go to this extreme?" Ingram wrote. "Greed. If the factory wasn't in business they could create an environment very similar to the Piper Cub lift strut Airworthiness Directive. Let's do some math: 3,000 Taylorcrafts, $2,500 for a new set of lift struts equals $7,500,000."

This A/D was issued and constructed for Monitary reasons only, there were no evidence of failures, the Wiley accident was not "struts" but the A/D was written before the investigation was done. Lots of money here, How many are involved is yet to be found but I will assure you the process is starting.

JS

[flyguy]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

Is that article still there, can't find it. Assume General Aviation News--right? Found it, more or less, but I don't see anything on the Ingram "quote."
DC

[Ed O'Brien]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

I'd agree that it looks like a factory born infection caused most of the FAA puss. Interesting thing is: The factory seems unable to take advantage of it... due to poor customer service, bad mangement, incompotent manufacturing, inability to clear FAA hoops (take your pick or come up with your own)... on and on. I've worked for a couple of manufacturers with a clean sheet of paper and from-scratch-built planes that are closer to getting their final FAA flight test and manufacturing approvasl... while building much more complicated airplanes than the factory. These companies have been in business about the same time as the new Taylorcraft factory... The Taylorcraft factory already had an approved and airworthy craft to begin with.

Your conclusions to these tribulations are your own. BUT, if bulls@$t had wings it could have gotten FAA approval by now.
Meaning -- some BS flies and some dosen't.
With regards; ED OBRIEN

[Guest]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

Dave,
I think I understand the STC part ok. AF PMA was developed using an existing STC for data. (see my entry above) The UV one was developed using new raw data. Both done under part 21. So much for the STC. So the 337 biz is the only thing that is a question to me. I see the Univair one as being a problem given the information we have presently.
Think we need some more information from UV or the FAA engineer. Question is: does a PMA precede a 337, making it unnecessary?
DC

Hi Darryl,

I think I get that UV one. UV has a PMA for a part so its a legal installation requiring log entry only (under part 43 and its appendices). They have no STCs. But they need an AMOC approval from McAnaul's office because their part does not replace the new MA... sealed struts. They do have an AMOC, I have a copy of it so that fits together for me. There is nothing that one does when installing a UV strut that makes it a major repair per part 43 appendix A so no 337 needed and they have no STC so no 337 needed for that.


Why AF needed an STC still perplexes me but it would seem that the mere presence of the STC makes a 337 required as Terry said earlier. Its a tangled web then because if I follow this correctly you have a PMA approved replacement part that requires at 337 because its also a major change to the type design. Seems a contradiction.

Thanks for the help, Dave

I am hoping the light will come on for me soon and I 'll get all of this!

[flyguy]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

I think the STC was the basis of the data for the PMA so it is irrelevant as far as the end user is concerned. You would be installing it under the PMA, not the STC.
I believe the UV AMOC would satisfy the FAA for AD compliance, but it would still require a 337 to install them legally on the plane as they are a "modified part" which would be the same as repairing (as in splicing) them, which is a major repair. But I am assuming a lot on a couple of words, which is often not a wise thing to do.
DC

[Guest]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

I think the STC was the basis of the data for the PMA so it is irrelevant as far as the end user is concerned. You would be installing it under the PMA, not the STC.
I believe the UV AMOC would satisfy the FAA for AD compliance, but it would still require a 337 to install them legally on the plane as they are a "modified part" which would be the same as repairing (as in splicing) them, which is a major repair. But I am assuming a lot on a couple of words, which is often not a wise thing to do.
DC

hmm...

in that case where would you get the approved data from for the 337?

[flyguy]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

Reference the PMA? Must be in the FAA data base, right? On the AMOC? Copy of PMA from UV?
Good question.
DC

[Guest]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

I pay good money for taxes to the Feds, I am calling the FSDO Monday and let them earn it, and explain!

My PMI is good at figuring this stuff out and has helped in the past when I wanted to do something unusual, maybe he will get this one.

Gonna give it a whirl.

[flyguy]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

That should offer them a little challenge. Am looking forward to hearing their conclusions on all of the above. Hope the guys at your FSDO are a lot more capable....well, that is all I am going to say about that.
DC

[Gary Snell]

Re: A list of lift strut suppliers (updated 10 Nov 2007)

It's a new one on me. Always thought a 337 got filed with an STC. Seems the STC is superfluous paper in this case. Maybe we will hear from others on this.