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United States Department of Transportation United States Department of Transportation

Advisory Circulars (ACs)

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Advisory Circulars (ACs) search results
Number Title Status Office Date
33.67-1 Engine Fuel Systems

This advisory circular (AC) provides guidance for demonstrating compliance with the
requirements of Title 14, Code of Federal Regulations (14 CFR) Section 33.67, Fuel
system.

Active AIR-625 2024-05-20
33.70-4 Fatigue Life of Nickel Powder Rotating Life-Limited Parts

This advisory circular (AC) provides guidance that may be used to demonstrate compliance with Title 14, Code of Federal Regulations (14 CFR) 33.70 for rotating life-limited engine parts made of nickel powder.

Active AIR-625 2023-08-15
20-29C Approval and Use of Fuel System Icing Inhibitors (FSII)

This advisory circular (AC) describes an acceptable method to demonstrate compliance with Title 14, Code of Federal Regulations (14 CFR) §§ 23.2620(a)(1), 25.1583(b)(1), 27.1583(b)(1), 29.1583(b)(1), 33.7(b)(2), and 33.7(c)(2) regarding the requirements for the approval and use of Fuel System Icing Inhibitors (FSII) in engines and aircraft.

Active AIR-625 2024-03-27