To further muddy the waters!
What an “STC” is and what it is not:
STC is not a word it is an acronym: Supplemental Type Certificate
It supplements the original Type Certificate.
It is not an approval for manufacturing Parts. That is a PMA another acronym: Parts Manufacturing Authority. A replacement part manufactured under an FAA PMA does not require a form 337 to be installed, as it must fit (replace) the original part in Form Fit and Function. Do Rosen sun visors meet that qualification? (Maybe) A manufacture cannot manufacture a part and sell it to another person for use in a Type Certificated Aircraft without a PMA. That does not necessarily mean that the part is TSO’d another acronym: Technical Standard Orders (TSO) TSO is a minimum performance standard for specified materials, parts, and appliances used on civil aircraft. When authorized to manufacture a material, part, or appliances to a TSO standard, this is referred to as TSO authorization. Receiving a TSO authorization is both design and production approval. But a part having TSO part is not an approval for you to install it in your aircraft. It would still need to be installed by an authorized individual with the proper rating and or licenses and the appropriate log entry made. Many aircraft parts are manufactured that do not have TSOs
A part manufactured under PMA and sold as an STC is a way that an STC holder can sell and ensure and along with the FAA be sure a part is installed under proper guide lines by qualified people on type certificated aircraft. The part will have a PMA but probably not a TSO.
However an owner operator may manufacture a part as an owner produced part for use in his own aircraft if manufactured with Acceptable Techniques and Practices such as those contained in AC 43.13-1B. He may not install that part in the type certificated aircraft unless it falls under the Category under Appdx A, "Preventive Maintenance" otherwise it would have to be installed as either a Minor alteration and an entry made in the Log book by an A&P (Airframe & Power Plant rated technician). Or as an Major Alteration which would require being installed by and A&P or properly supervised individual and inspected by an IA (Inspection Authorization), DER (Designated Engineering Representative) or field approved by and FAA maintenance Inspector and installed by those approved individuals. And then the appropriate log entry made or if required form 337..
An STC holder (the person who owns the STC) may not even manufacture the part or parts. He may only have drawings of the parts which he then may give an approval in writing and supply the drawings to the owner of the aircraft who then may manufacture the part or parts, must document and have inspected by the criteria in the previous paragraph. But it is Still a Major Alteration if performed in accordance with the STC instruction.
An STC may be issued as a one-time only STC which then is only applicable to the aircraft in which it was originally installed. In fact a FAA Field Approved Modification done on a form 337 is actually a one-time STC although it will not be given an STC number, and the form 337 shows that the aircraft was modified in accordance with the instructions as written in Block 8 of the Form 337. And will require instruction, for continued airworthiness and other items be included in Block 8 of the form and must meet the criteria of this AC: AC No: 21-47
http://www.faa.gov/documentLibrary/medi ... 021-47.pdf
The Rosen Sun visor example: if a log book entry was made stating that they were installed in accordance with the STC in whatever manor the entry was worded then it is required that the installation be performed by and A&P or properly supervised individual inspected by and IA and an MAJOR ALTERATION FORM 337 needs to be filed out. If the installation instructions mention in any paragraph the STC. Then the installation would drive that it is not a Minor Modification and would require that if you made an entry stating you followed the manufactures installation instructions to install it becomes MAJOR. The Maybe part comes if you install a set of ROSEN sun visors and do not install them per the STC or the manufactures installation instructions. And if you mention the manufactures name in the log entry the part then becomes an illegally installed part. If you installed the Rosen sun visors as an Owner Produced Part and you considered it as an item that falls under the Appdx A, "Preventive Maintenance" then you could sign it off as the owner operator of the aircraft. But I have to ask why would you do that? Simply to not have to pay that damned A&P I guess. No insult intended.
Installation of an STC by the owner operator of an aircraft would not necessarily have to be installed by an A&P if the instructions in the STC said that it could be performed by the owner operator. However as it is a supplement to the original Type Certificate of the aircraft it would still need to be inspected by and A&P and IA and the FORM 337 and log entry made. Or the work can be performed under the direct supervision of an A&P and then inspected by an IA and the FORM 337 and log entry made.
All of this is why people build experimental aircraft! It takes the A&P partially out of the question. And it takes the IA completely out of the question as an IA’s only job is to make certain that the aircraft conforms to its Type Certificate or properly altered condition. This is what an IA’S function is at the annual inspection or when he signs the bottom of a Form 337. (Read the small blue paragraphs on the Standard Airworthiness Certificate in your aircraft). READ IT! Experimental aircraft do not have a Type Certificate. They have an Airworthiness certificate that comes with a letter of Limitations which outline in accordance with whatever types of experimental category the aircraft is listed in how it will be operated and Maintained and how it will be signed of at its “conditional inspection”. And the Letter of Limitations must reside with the Airworthiness certificate in the aircraft when it is operated. An experimental inspection can be performed by any licensed A&P mechanic, an FAA Approved Repair Station, or by the builder of the airplane provided the builder obtains a "Repairman's Certificate" from the FAA. Note that unlike an annual for a type certificated aircraft, the A&P mechanic does NOT have to have his/her "Inspection Authorization". There are many different categories of experimental aircraft. Take a look at a 8130-6 form from the FAA web site and you will see what I mean. Found here:
http://www.faa.gov/forms/index.cfm/go/d ... 19145.Note that the 8130-6 is also the form for applying for a standard airworthiness certificate and if you were requesting a new airworthiness certificate or ferry permit it is the form you would use.
In my job I fill out some 50 or so Airworthiness applications a year for both Standard Category and Experimental category aircraft. except for Ferry permits the FAA comes and inspects these aircraft every time.
It sounds to me that you may have made you aircraft so that it does not conform to its airworthiness certificate and may not be signed of buy an IA as airworthy. However it is up to the owner operator to make that determination. But an IA may not agree with you
I had a guy call me up at the shop one time and asked me to perform his annual inspection under the table so that he would not have to pay shop fee's that he hated A&P's and that he performed all of the work on his own airplane and had an IA sign it off at annual, other wise no log entries were made by him. I told him we would not be able to work together. Some time later I was asked to perform a pre-purchase inspection on this aircraft for an interested buyer not knowing it was the same guy. The list of unapproved modifications on this aircraft were mind boggling. I presume he eventually sold the aircraft to someone but not my customer.
