Legal Interpretations
Thompson-ANM-113 2011
Summary
The Question
Does SFAR No. 13 permanently limit the certification basis for changes to a Douglas DC-3 to 1954 standards, preventing the FAA from requiring a later basis under 14 CFR 21.101?
Background
The FAA's Standardization Branch (ANM-113) asked whether SFAR No. 13, which in 1954 raised DC-3 certification standards above pre-World War II requirements, caps the type certification basis for later DC-3 changes.
The FAA’s Interpretation
No. Under 14 CFR 21.101(a), as revised in 2000, an applicant for a change to a type certificate must show compliance with the airworthiness requirements in effect on the date of application for the change, with exceptions in paragraphs (b) and (c). SFAR No. 13 was meant to keep DC-3 changes from falling back to pre-war safety levels; treating it as a permanent 1954 limit would negate 14 CFR 21.101.
- Requester
- Thompson
- Organization
- ANM-113
- Issued
- April 1, 2011
- Subject
- Aircraft & Parts Certification
Regulations Cited
- 14 CFR 21.101
- 14 CFR Part 34
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Federal Aviation
Administration
Memorandum
Date: APR - 11011
To: Mi~el T. Thompson, Standardization Branch, ANM-113
From: te~~. ~~:lf~ant Chief Counsel for Regulations, AGC-200
John King, Staff Attorney, AGC-210Prepared by:
Subject: Request for Interpretation - 14 CFR §§ 21.101 and SFAR 13
This memorandum responds to your September 8, 2010, e-mail request for a legal interpretation of whether Special Federal Aviation Regulation (SFAR) No. 13 places a limit on the type certification basis for changes made to a Douglas DC-3, or whether the FAA can later require a later type certification basis imposed under 14 CFR § 21.101. The answer is found in the language of§ 21.101 (a), which was revised by the 2000 rulemaking Type Certification Procedures for Changed Products [65 FR 36244, June 7, 2000).
§ 21.101 Designation ofapplicable regulations.
(a) An applicant for a change to a type certificate must show that the changed product complies with the airworthiness requirements applicable to the category of the product in effect on the date of the application for the change and with parts 34 and 36 of this chapter. . Exceptions are detailed in paragraphs (b) and (c) of this section. The date of application for the change to the type certificate determines which airworthiness requirements are applicable. Special Civil Air Regulation No. SR-398 (I 8 FR 6448), which was superseded by Special Civil Air Regulation No. SR-407 (19 FR 5039), and is now codified as SFAR 13, raised the standards for the certification basis for the Douglas DC-3 in
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1954. The purpose ofSFAR 13 was to raise the certification standards from pre-World War II requirements and to ensure that future changes to the DC-3 did not reduce the level of safety back to pre-World War II standards. SFAR 13 is not a permanent limitation to 1954 requirements on certification standards affecting the DC-3. To conclude that every change to a DC-3 is forever limited to 1954 standards would negate the 2000 rulemaking provisions of§ 21.101. Paragraph (a) of§ 21.101 clearly articulates the method of selecting the appropriate airworthiness standards and paragraph (b) clearly specifies when an applicant can choose an earlier standard.
We trust that these answers will be of assistance. If you have any questions, please contact my staff at 202-267-3073. This response was coordinated with the Aircraft Certification Service, Certification Procedures Branch.
Regulations Referenced
Snapshot retrieved August 6, 2026.