National Aeronca Association Bulletin Board

Hi Burl,

Thanks for taking the time this afternoon to help me through a simple-yet-tricky regulatory question on the Pawnee tailwheel Service Bulletin. As you know, I'm restoring 1241H as I work through A&P school and since the fabric was off anyway, I decided to be one of the first to go for the Pawnee tailspring. This is a simple question and simple answer, thanks to your work with the Anchorage ACO, but the student-instructor relationship I have at school makes it a little hard to put my foot down and insist that I know what I'm talking about (for once).

If it's ok with you, I'm going to ask you the question again for everybody to see, in hopes that other Sedan owners don't get into a similar quagmire with a well-meaning FBO doing the work, as I did with the instructors at school this week. Everybody's on the same side, of course, and the A&P school instructors are doing their job at making the important point that this isn't the Wild West of Experimental; there are rules to be followed and you can't just start hacking away willy-nilly at an airframe.

- - -

The question came up in one of the classes: "Under what authority did Eric cut the longerons out of his airplane and replace them with doubled-up tubing--isn't that a Major Alteration? Won't that have to get inspected by an IA, and won't Form 337 have to be submitted to FAA because the longeron is a major structural member of a semi-monocoque airframe?"

That's certainly a valid question by the student in that class. Even though I thought I'd explained this Service Bulletin to the instructors at school, the instructor answered something to the effect of, "Absolutely. Regardless of whatever drawings and instructions he's following from the TC holder, the second Eric cut a longeron, he invoked the process by which a 337 gets filled out, Major Repair/Alteration, A&P with Inspection Authority, etc, end of discussion."

I showed the instructor the text of your Service Bulletin, where you state that since this is Factory Approved Data, no further approval is necessary, just a logbook entry.

The response that finally trapped me was, "A factory can issue any Service Bulletin they feel like on any sort of topic, but that doesn't make it FAA Approved Data. Nowhere in this SB does it say that this modification is FAA Approved Data--only factory approved data, therefore your new tailwheel must be a Field Approval prior to starting the work, and the longeron welding must be a Major Alteration. Until it's on the TC (Aircraft Specification in our case), in an STC, or a one-off Field Approval, what you did was unapproved."

Crap. And that's when I phoned you.

- - -

So that I don't get it wrong, would you be willing to take a minute and explain on this forum what you explained to me regarding the tailwheel Service Bulletin and the authority by which I cut & welded longerons with only a logbook entry?

Eric
I feel a sense of Deja VU here. I replied to some of your posts about this a while back, So I will try not to repeat myself here. The thing that sticks out to me from your post is this "A factory can issue any Service Bulletin they feel like on any sort of topic, but that doesn't make it FAA Approved Data. Nowhere in this SB does it say that this modification is FAA Approved Data--only factory approved data," This statement is completly incorrect.

If a service bulletin pertains to an approved type certificate then it absolutley is FAA approved data. Burl cannot just draw this stuff up and then start handing it out, he needs to go to the FAA with engineering data, test data, installation instructions, instructions for continued airworthiness, etc... The FAA then approves the data which becomes part of the Type Certificate Data, just like the rest of the drawings that pertain to the aircraft.

The service bulletin can now be installed on the aircraft with just a log book entry, because all of the engineering and testing has already been done. The factory and/or the T.C. holder of any aircraft is always under the watchful eye of the FAA, any changes to the T.C. data must be approved.

I am not a certified mechanic or lawyer, this is just knowledge that I have gained from being around aviation my entire life. Now maybe Burl can chime in with the official word.

Tom, thanks for your comments. It wasn't my hope to stir controversy and raise blood pressures and I'll feel badly if that's the outcome. Mostly what I wanted to do was humbly request that Burl explain to the group what he explained to me so that everyone can benefit from his authority and hard work. I can't possibly be the only owner (or mechanic) that's going to find themselves answering to someone who has seemingly incomplete regulatory information.

I feel a sense of Deja VU here. I replied to some of your posts about this a while back

Must be a glitch in the matrix. I think this is the first time I've mentioned Service Bulletins & Approved Data wrt the Pawnee tailwheel.

The thing that sticks out to me from your post is this "A factory can issue any Service Bulletin

Just to clarify, -I- wasn't claiming that a Factory can issue any SB it wants...; I was recounting what the IA at my A&P school told me, correct or otherwise. His view is that unless the SB actually reads "FAA Approved Data", it's not necessarily FAA Approved Data and can't be automatically inferred by the fact that it was issued by the Factory. To be FAA Approved Data [again, recounting what I was told], it needs to be described in the Type Certificate, an STC, or a Field Approval. Anything outside of those three is merely Acceptable Data (eg, AC43.13).

I personally am not making any claim, other than that Burl generously took 30 minutes out of his afternoon to talk me through a slippery regulatory question in such a way that probably saved me from stopping work on my fuselage until I got a Field Approval for the tailwheel work I've already performed.

Please--let Burl weigh in on this if he's so inclined, he'd be the one to speak with authority.

I ask for your attention to the following:


Engineering Change Order (ECO) 0209-1 February 20, 2009

Type Certificate No. A-802
Rogers (Aeronca) Model 15AC Sedan
Ref. 7-842A Alternate Tail Gear Installation

This document describes changes that have been made to the descriptive data and documentation of the Type Certificate listed above.

Descriptive Data
The descriptive data has been updated to reflect the following design changes:

General
Installation Drawings and Installation Instructions have been added to the descriptive data set in order to describe the addition of alternate parts and installation of a replacement tail gear installation for model 15AC Series airplanes. The original tail gear is no longer being manufactured due to extremely high costs associated with the original design material call-out.

Descriptive Data
This conversion was done in accordance with data contained in the Descriptive Data List No. 15ACTW1, dated February 20, 2009.

Test Data
. On 02-20-09 a drop test was performed with FAA Engineers Michael Heusser, David Swartz and Dave Meekers observing. That test resulted in a 3.35 G load with a 5.52” + 2.0”added correction factor using effective weight factor We =232.5 lbs.

In accordance with CAR 3, May 15, 1956, Section 3.353 and 3.354 the tests demonstrated compliance.

Drop test was conducted using the Scott 3200-8” tail wheel since it represented the
most conservative choice for the test.


The above referenced Engineering Change Order is, for the most part complete. The actual formula data numbers and identification of the test aircraft have been left out.

This means that the installation of the Pawnee tail spring and all the data, parts, references, etc. i.e., SB15ACTW1, are now part of the FAA Approved Design Data for the 15AC Sedan. Burl's Aircraft, LLC holds PMA for the entire airplane. Any additional data that is added is FAA Approved before it can be added.

Since it is part of the Design Data on the Type Certificate the installation is Approved and no further approval is required or needed. These are factory parts with factory designed and, by way of the TC and the PMA, are FAA Approved.

I hope this clears up any misunderstandings.

Blue skies and strong tail winds to all,

Burl

Thanks Burl.

I can't believe I'm the only person that's going to get cornered by someone in authority who insists that welding==major alteration, regardless. Having this information regarding the tailwheel in the public domain will make it easier for anyone else who finds themselves in the same predicament I was in.

Best regards,
Eric

Eric,

Email your IA's the link to this page and it should help.

When the Type Certificate holder says its ok, that lends a lot of weight to what you are doing. After all, it is "approved data" so to speak.

Joe A