---
kind: "section"
citation: "14 C.F.R. § 121.1109"
title: "14"
number: "121.1109"
heading: "Supplemental inspections."
url: "https://uscodex.org/cfr/14/121.1109"
---

# §121.1109. Supplemental inspections.

- (a) **Applicability.** Except as specified in [paragraph (b)](#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)](#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)](#c-1) and [(c)(2)](#c-2) of this section, and any later revisions to these changes, must be submitted to the Principal Maintenance Inspector for review and approval.

## Notes

### Amendments

[Docket FAA-1999-5401, 70 FR 5532, Feb. 2, 2005. Redesignated by Amdt. 121-336, 72 FR 63412, Nov. 8, 2007; Amdt. 121-337, 72 FR 70508, Dec. 12, 2007; Docket FAA-2018-0119, Amdt. 121-380, 83 FR 9173, Mar. 5, 2018]

### Source

Source: Amdt. 121-336, 72 FR 63411, Nov. 8, 2007, unless otherwise noted.

### Authority

Authority: 49 U.S.C. 106(f), 40103, 40113, 40119, 41706, 42301 preceding note added by Pub. L. 112-95, sec. 412, 126 Stat. 89, 44101, 44701-44702, 44705, 44709-44711, 44713, 44716-44717, 44722, 44729, 44732; 46105; Pub. L. 111-216, 124 Stat. 2348 (49 U.S.C. 44701 note); Pub. L. 112-95, 126 Stat. 62 (49 U.S.C. 44732 note); Pub. L. 115-254, 132 Stat. 3186 (49 U.S.C. 44701 note).

### Amendments

[Docket FAA-1999-5401, 70 FR 5532, Feb. 2, 2005. Redesignated by Amdt. 121-336, 72 FR 63412, Nov. 8, 2007; Amdt. 121-337, 72 FR 70508, Dec. 12, 2007; Docket FAA-2018-0119, Amdt. 121-380, 83 FR 9173, Mar. 5, 2018]