 Today, FAA Advisory Circular 43.18 provides guidance for the fabrication of parts to be consumed purely during a maintenance operation, and additional guidance is expected to be released in the near future.One of the key features of FAC 43.18 is that it recommends implementation of a quality assurance system quite similar to the fabrication inspection systems that PMA manufacturers are required to have.The trade association representing the PMA industry is the Modification and Replacement Parts Association (MARPA).