This document establishes the legal framework and mandatory procedures for the issuance and compliance of Airworthiness Directives (ADs) within the United States aviation industry. The Government Printing Office provides this text as the official codification of Federal Aviation Regulations Part 39, which empowers the Federal Aviation Administration to identify and correct unsafe conditions in aircraft, engines, propellers, or appliances. The text serves as the primary regulatory authority for aircraft maintenance and safety compliance.

Experts and aviation professionals recognize this as a foundational regulatory text required for compliance in the aviation industry. Readers frequently note the technical density of the prose, which is written in formal legal language for use by certified mechanics, pilots, and aviation administrators.