 During this time period, though, many manufacturers failed to obtain PMA approvals from the FAA.In the 1990s, the FAA engaged in an "Enhanced Enforcement" program that educated the industry about the importance of approval and as a consequence a huge number of parts were approved through formal FAA mechanisms.Under this program, companies that had previously manufactured aircraft parts without PMAs could apply for PMAs in order to bring their manufacturing operations into full compliance with the regulations.