In Reply to Parent Post by PHANTOM
1. I'm trying to understand what it really takes to earn a TSOA. Its not just about getting design approval and being able to throw together a part you can sell. Does the FAA look at say, material control, MRB, quality system, the qualification of your workers perhaps? How much scrutiny comes from the FAA or do they simply say "Your paperwork looks good, your test data is good, call us when your done".
2. I am guessing OEMs want to be quite particular about who is holding PMA for their necessary parts. Does the OEM have any say in who gets PMA or is it strictly an FAA decision? Does the manufacturer have to satisfy both? Is it common for a manufacturer to receive design data from the OEM?
1. There is a lot that goes into earning the TSO Authorization letter. After all of the work with the ACO for certifying the design, the ACO will request the local MIDO to oversee the production. This includes multiple audits with a frequency and type depending on your risk level. I would recommend reading FAA Orders 8120.22 and 8120.23 to start with. The RGL is your best friend and all of the current orders can be found there. http://rgl.faa.gov/
Ensure that you have a good relationship with both the ACO and the MIDO during the application process and while you maintain the Production Approval.
2. As for PMA, The easiest way to obtain approval is through the airframer (OEM). All it takes is to request the letter of technical assistance from the Type Certificate holder and then apply to the MIDO. It really depends on the OEM if they will provide this letter. Some of the larger airframers will give them to the supplier with no problem, others will refuse the request. If you hold the TSO for the part you do not also need PMA. For the less friendly way to get PMA, you would need to show identically through an alternate route such as test and computation. This eliminates the OEM from the equation and you would apply to the ACO. For more information research FAA Order 8110.42D (also on the RGL).