When Does FAA Issue Airworthiness Directives?

14 CFR § 39.5 sets the two findings the FAA must make before it issues an airworthiness directive: an unsafe condition exists in a product, and that condition is likely to exist or develop in other products of the same type design.

It is the "trigger" section of Part 39 — it does not tell you to do anything. It tells the FAA when it is allowed to act. Your obligations live in the sibling sections: § 39.7 makes operating a non-compliant product a violation, § 39.9 makes every single flight a separate violation, and § 39.11 spells out the inspections, conditions, limitations, and actions an airworthiness directive can demand. Think of § 39.5 as the on-switch and § 39.7, § 39.9, and § 39.11 as the consequences.

14 CFR § 39.5 applies to you the moment you fly an aircraft, even though it is written as a rule about the FAA's authority.

The section itself describes when the FAA issues an airworthiness directive — that is an agency action. But once an airworthiness directive is issued against a product you operate, § 39.7 and § 39.9 reach straight to the person operating the aircraft. Per AC 39-7D, Airworthiness Directives, the owner or operator is responsible for complying with applicable airworthiness directives and for recording that compliance in the maintenance records. And § 91.403(a) makes the owner or operator "primarily responsible for maintaining that aircraft in an airworthy condition, including compliance with part 39." So the mechanic signs the work off — but the legal exposure for flying out of compliance is yours.

This is why "is there an open airworthiness directive on this airplane?" belongs in your preflight diligence, not just on your A&P's bench. You cannot delegate § 39.7 away by assuming someone else handled it.

14 CFR § 39.5 has two operative findings — (a) and (b) — and both must be satisfied; there is no compliance time, altitude, or distance in this section because § 39.5 is a trigger, not an action item.

The hard numbers in Part 39 — compliance times, inspection intervals, recurring deadlines — live in each individual airworthiness directive and in § 39.11, not here. The numbers that matter for § 39.5 itself are regulatory-history numbers:

The reason § 39.5 reads like a plain-English question-and-answer ("When does FAA issue airworthiness directives?") is the 2002 rewrite: the final rule in Docket No. FAA-2000-8460 (Amdt. 39-9474), published July 22, 2002 and effective August 21, 2002, pulled the boilerplate that used to clutter every individual airworthiness directive up into Part 39 and recast the whole part in question-form sections. That is why every section heading in Part 39 is literally a question.

Once the FAA issues an airworthiness directive under 14 CFR § 39.5, operating the affected product without meeting that airworthiness directive's requirements is a violation — and under § 39.9, you violate § 39.7 every single time you operate the aircraft or use the product.

Section 39.5 is the trigger; § 39.7 supplies the prohibition: "Anyone who operates a product that does not meet the requirements of an applicable airworthiness directive is in violation of this section." Section 39.9 then removes any "I only flew it once" defense — each flight is a fresh, separately chargeable violation. Stack a week of flying on an overdue airworthiness directive and you have not one violation but one per flight.

The most common mistake is treating a manufacturer's service bulletin as if it carried the same legal force as an airworthiness directive issued under 14 CFR § 39.5 — it does not.

A service bulletin is the manufacturer talking. An airworthiness directive is the FAA talking, and only the airworthiness directive is a legally enforceable rule under Part 39 (§ 39.3). The two often look alike — same part numbers, same fix — and an airworthiness directive frequently references or incorporates a service bulletin by reference. But for a Part 91 operator, complying with a service bulletin is generally optional; complying with an applicable airworthiness directive is mandatory. The second common mistake is assuming a one-off failure on a single airframe will produce an airworthiness directive. Under § 39.5(b), the FAA also has to find the condition is likely to exist or develop in other products of the same type design. No fleet-wide likelihood, no airworthiness directive.

14 CFR § 39.5 connects to your aircraft's type design because prong (b) reaches "other products of the same type design" — and per AC 39-7D, the FAA generally uses type-certificate and airworthiness-certification data, including the Type Certificate Data Sheet (TCDS), to identify exactly which products an airworthiness directive covers.

"Same type design" is what scopes an airworthiness directive to a model, a serial-number range, or a specific configuration. That is also why § 39.5 ties into the broader airworthiness chain: § 91.7 prohibits operating a civil aircraft that is not in an airworthy condition, and an aircraft with an overdue airworthiness directive is, by definition, not airworthy. So a § 39.5-triggered airworthiness directive that you have not complied with does not just violate § 39.7 — it also puts you crosswise with § 91.7 and § 91.403. They reinforce each other.

In practice, the FAA almost always issues an airworthiness directive through a Notice of Proposed Rulemaking (NPRM) with a public comment period — that is the normal path.

When the unsafe condition is urgent and there is no time to wait out a comment period, the FAA can skip ahead and issue the airworthiness directive immediately as a final rule (the "immediately adopted rule," often issued as an Emergency Airworthiness Directive). Either way, the § 39.5 two-prong finding is the legal foundation underneath it. For the day-to-day mechanics of tracking, planning, and managing airworthiness directive compliance across a fleet, AC 39-9, Airworthiness Directives Management Process is the companion guidance to AC 39-7D.