January 08, 2020

sasadmin

Sofema Aviation Services considers the design & certification process by which

PMA Approval is a combined FAA design and manufacturing process.

Note: Only minor changes or improvements from the original OEM part are allowed in a PMA design. (Significant changes require a Supplemental Type Certificate.)

Determination of Criticality

The PMA Applicant will have to determine the criticality of the part by means of a failure modes and effects analysis (both for the part & next higher assembly (NHA).

Based on this analysis the part is classed as critical (possibly affecting airworthiness of the aircraft), important (possibly affecting the performance of the aircraft or engine), or not critical or important (all the rest).

Note: Most PMA parts are neither critical nor important.

FAA Approval

Two FAA Organisations are involved in the Oversight & Certification Process & only when both the design and production system are approved will the Parts Manufacturer Approval be issued by the FAA.

Aircraft Certification Offices (ACOs) – The ACOs are responsible for determining that a PMA applicant’s part meets the airworthiness standards that apply to the type-certificated product (aircraft, engine, or propeller) on which the part is to be installed.

Manufacturing Inspection District Offices (MIDOs) – The MIDOs are the Manufacturing Inspection District Offices who audit the manufacturing facility that will produce a PMA part to ensure that it has the production and quality systems necessary to reliably produce an aerospace quality part per the design.

The PMA Certification Process

The PMA process is the primary legal basis for approved replacement parts.

The PMA applicant must identify the applicable airworthiness standards to the FAA.

Note: The certification standards for the PMA part are essentially the same as for the original OEM part.

Once the applicable airworthiness requirements are identified the applicant must identify the basis for design approval.

The FAA has three standard paths that can be selected.

Note: Most PMA parts and virtually all complex parts now use test and computation for design substantiation. (Could also be considered a form of reverse engineering.)

a) Identicality with a license agreement – The OEM can license another firm to produce the part and notify the FAA that they are doing so. (These applications go straight to the appropriate MIDO for approval of the production and quality control processes)

b) Identicality without license agreement – A PMA applicant taking this path demonstrates to the FAA that the PMA part is identical in all respects to the OEM part.

c) Test and Computation – The applicant uses analyses and tests to prove the PMA part is equal to or better than the approved original part.

Further Guidance

Sofema Aviation Services (SAS) and SofemaOnline (SOL) are pleased to offer a range of EASA compliant regulatory training courses in support of Multiple Regulatory Compliance and Competence Development. For details please see www.sassofia.com, www.sofemaonline.com or email: office@sassofia.com or online@sassofia.com.

Tags:

Airworthiness, FAA Parts Manufacturer Approval, OEM, PMA