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United States Department of Transportation United States Department of Transportation

AC 20-53C - Protection of Aircraft Fuel Systems Against Vapor Ignition Caused by Lightning

Document Information

Protection of Aircraft Fuel Systems Against Vapor Ignition Caused by Lightning
Date issued
Office of Primary Responsibility
AIR-600, Policy and Innovation Division

This advisory circular (AC) provides applicants with guidance for obtaining Federal Aviation Administration (FAA) approval of compliance pursuant to title 14, Code of Federal Regulations (14 CFR) 23.954, 27.954, and 29.954, Fuel system lightning protection. This AC recommends how to protect an aircraft’s fuel system from lightning strikes that may ignite fuel vapors.

For guidance on compliance pursuant to 14 CFR 25.954, Fuel system lightning protection, for transport category airplanes, see AC 25.954-1, Transport Airplane Fuel System Lightning Protection, dated September 6, 2018 (83 FR 47548, September 20, 2018).

This AC is not mandatory and does not constitute a regulation. This AC describes an acceptable means, but not the only means, to obtain certification for fuel system lightning protection. However, if you use the means described in this AC, you must follow it in all important respects. The term “must” is used to indicate mandatory requirements when following the guidance in this AC. The term “should” is used when following the guidance as recommended, but not required to comply with this