§ 121.1109 – Supplemental inspections.
(a) Applicability. Except as specified in paragraph (b) of this section, this section applies to transport category, turbine powered airplanes with a type certificate issued after January 1, 1958, that as a result of original type certification or later increase in capacity have—
(1) A maximum type certificated passenger seating capacity of 30 or more; or
(2) A maximum payload capacity of 7,500 pounds or more.
(b) Exception. This section does not apply to an airplane operated by a certificate holder under this part between any point within the State of Alaska and any other point within the State of Alaska.
(c) General requirements. After December 20, 2010, a certificate holder may not operate an airplane under this part unless the following requirements have been met:
(1) Baseline Structure. The certificate holder's maintenance program for the airplane includes FAA-approved damage-tolerance-based inspections and procedures for airplane structure susceptible to fatigue cracking that could contribute to a catastrophic failure. For the purpose of this section, this structure is termed “fatigue critical structure.”
(2) Adverse effects of repairs, alterations, and modifications. The maintenance program for the airplane includes a means for addressing the adverse effects repairs, alterations, and modifications may have on fatigue critical structure and on inspections required by paragraph (c)(1) of this section. The means for addressing these adverse effects must be approved by the responsible Aircraft Certification Service office.
(3) Changes to maintenance program. The changes made to the maintenance program required by paragraphs (c)(1) and (c)(2) of this section, and any later revisions to these changes, must be submitted to the Principal Maintenance Inspector for review and approval.