---
kind: "section"
citation: "14 C.F.R. § 21.77"
title: "14"
number: "21.77"
heading: "Duration."
url: "https://uscodex.org/cfr/14/21.77"
---

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- (a) Unless sooner surrendered, superseded, revoked, or otherwise terminated, provisional type certificates and amendments thereto are effective for the periods specified in this section.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

## Notes

### Amendments

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

### Source

Source: Docket No. 5085, 29 FR 14566, Oct. 24, 1964, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7572; 49 U.S.C. 106(f), 40105, 40113, 44701-44702, 44704, 44707, 44709, 44711, 44713, 44715, 45303.

### Amendments

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