14 CFR § 21.113 - Requirement for supplemental type certificate.
---
identifier: "/us/cfr/t14/s21.113"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 21.113 - Requirement for supplemental type certificate."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "21.113"
section_name: "Requirement for supplemental type certificate."
chapter_name: "FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "AIRCRAFT"
part_number: "21"
part_name: "CERTIFICATION PROCEDURES FOR PRODUCTS AND ARTICLES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7572; 49 U.S.C. 106(f), 40105, 40113, 44701-44702, 44704, 44707, 44709, 44711, 44713, 44715, 45303."
cfr_part: "21"
---
# 21.113 Requirement for supplemental type certificate.
(a) If a person holds the TC for a product and alters that product by introducing a major change in type design that does not require an application for a new TC under § 21.19, that person must apply to the FAA either for an STC, or to amend the original type certificate under subpart D of this part.
(b) If a person does not hold the TC for a product and alters that product by introducing a major change in type design that does not require an application for a new TC under § 21.19, that person must apply to the FAA for an STC.
(c) The application for an STC must be made in the form and manner prescribed by the FAA.
[Doc. No. FAA-2006-25877, Amdt. 21-92, 74 FR 53387, Oct. 16, 2009; Doc. No. FAA-2018-0119, Amdt. 21-101, 83 FR 9169, Mar. 5, 2018]