Supplemental type certificate

In the United States issuance of such certificates is under the purview of the Federal Aviation Administration (FAA).

The determination of whether a proposed change in design, power, thrust, or weight to an existing type certified aircraft, engine, or propeller is acceptable under a STC is proposed by the design holder, and subjected to the approval of the local civil aviation authority.

In this case, a substantially complete investigation of compliance with the applicable regulations will be required.

In 2010 at the US/Europe International Aviation Safety Conference, Eurocopter discussed concerns about potential risks with, and incompatibilities in, STCs.

In response the Modification and Replacement Parts Association (MARPA) highlighted the success that the Parts Manufacturer Approval (PMA) industry had experienced in implementing Continued Operational Safety (COS) programs for the prediction and proactive addressing of hazards.