Section 21.310 - Inspections and tests(a) Each applicant for or holder of a PMA must allow the FAA to inspect its quality system, facilities, technical data, and any manufactured articles and witness any tests, including any inspections or tests at a supplier facility, necessary to determine compliance with this subchapter.(b) Unless otherwise authorized by the FAA, the applicant or holder- (1) May not present any article to the FAA for an inspection or test unless compliance with § 21.303(b)(2) through (4) has been shown for that article; and(2) May not make any change to an article between the time that compliance with § 21.303(b)(2) through (4) is shown for that article and the time that the article is presented to the FAA for the inspection or test.