Which CFR part requires Airworthiness Directives and who issues them?

• A. 14 CFR Part 21
• B. 14 CFR Part 39; issued by the FAA
• C. 14 CFR Part 61
• D. 14 CFR Part 43

Answer: (B)

Airworthiness Directives are the mechanism the FAA uses to address unsafe conditions in aircraft, engines, propellers, or certain appliances. They are defined in 14 CFR Part 39, which establishes the requirement and process for issuing ADs. When the FAA identifies an unsafe condition, it issues an AD that mandates specific actions—such as inspections, modifications, or replacements—to correct the issue and restore airworthiness. Compliance with ADs is mandatory for owners and operators of the affected product. The other parts govern different regulatory areas—Part 21 deals with certification, Part 61 with pilot certification, and Part 43 with maintenance rules—so they don’t establish the AD process.