14 CFR § 21.77 - Duration.

---
identifier: "/us/cfr/t14/s21.77"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 21.77 - Duration."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "21.77"
section_name: "Duration."
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"
---


# 21.77 Duration.

(a) Unless sooner surrendered, superseded, revoked, or otherwise terminated, provisional type certificates and amendments thereto are effective for the periods specified in this section.

(b) A Class I provisional type certificate is effective for 24 months after the date of issue.

(c) A Class II provisional type certificate is effective for twelve months after the date of issue.

(d) An amendment to a Class I or Class II provisional type certificate is effective for the duration of the amended certificate.

(e) A provisional amendment to a type certificate is effective for six months after its approval or until the amendment of the type certificate is approved, whichever is first.

[Doc. No. 5085, 29 FR 14566, Oct. 24, 1964, as amended by Amdt. 21-7, 30 FR 14311, Nov. 16, 1965]