Regulations - Airworthiness Directives | Training Blog

What are airworthiness directives (ADs), and when are they issued?

AI-generated editorial illustration created for Green Castle Aero Club using the Club's official N84455 fleet photo as an aircraft reference and the permanent GCAC wings logo as a branding reference. The people, checklist, and maintenance scene are illustrative rather than documentary.

When the FAA Requires Corrective Action
An Airworthiness Directive, or AD, is a legally enforceable FAA rule used to correct an unsafe condition in an aircraft product. Under 14 CFR § 39.3, a product may be an aircraft, aircraft engine, propeller, or appliance.

​The FAA issues an AD when both findings in § 39.5 are met:

• An unsafe condition exists in a product.
• The condition is likely to exist or develop in other products of the same type design.

An AD is a rule, and the FAA must make both findings in § 39.5 before issuing one. Source: Electronic Code of Federal Regulations, 14 CFR Part 39.

The AD itself identifies the affected product and states what must be done and when. Depending on the unsafe condition, it may require an inspection, repair, replacement, modification, operating limitation, or recurring action. The exact applicability, required action, and compliance time in the AD control; a familiar model name or a maintenance-shop summary is not enough.

Applicability also extends beyond the airframe. An airplane can have separate ADs for its engine, propeller, and installed appliances. The FAA therefore directs owners and operators to search each product and to check the precise model, series, part number, serial number, and modification details stated in the AD.

Checking AD Status for a Club Airplane
The owner or operator is primarily responsible for keeping an aircraft airworthy, including compliance with Part 39. No person may operate a product that does not meet an applicable AD. Maintenance records must show the current status of applicable ADs, the method of compliance, the AD number and revision date, and the next required time and date when an action recurs.

For practical review, ask four questions:

• Does it apply? Match the AD against the exact aircraft, engine, propeller, appliance, and configuration.
• What does it require? Read the rule's required actions and any incorporated instructions.
• When is it due? Identify the effective date and compliance time, including any recurring interval.
• Is compliance documented? Confirm the maintenance record shows how and when the action was completed and, if recurring, when it is due again.

At Green Castle, CrewChief Systems provides Club members access to aircraft status, squawks, and airworthiness and maintenance records. For N84455, members can review the active AD and service-bulletin list, open the AD Compliance Report from Aircraft Logs, and view the full report last completed by a certificated mechanic.
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The related training blog post on required aircraft inspections explains where AD status fits beside inspection currency, while another post explains why effective registration and airworthiness certificates alone do not prove the airplane is airworthy today.

CrewChief gives Club members access to N84455's active AD list as well as the complete AD Compliance Report from the Aircraft Logs menu. The screenshots are a point-in-time example; use the current CrewChief record, applicable AD, and supporting maintenance logbook entries to verify compliance.

​The pilot does not need to memorize every AD. However, they should know where current status is recorded, recognize when something is unresolved, and stop before flight until the proper maintenance answer is clear.

FAA Sources and References
14 CFR Part 39, Airworthiness Directives
14 CFR § 91.417, Maintenance records
FAA Airworthiness Directives
FAA AD Applicability and Compliance
FAA Dynamic Regulatory System

​Next Week
Plane & Pilot - Left-Turning Tendencies

What are the four left-turning tendencies of an aircraft?
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Four aerodynamic and mechanical effects can make a propeller-driven airplane yaw or roll left, especially when power is high and airspeed is low. Next week, we will separate those effects and connect each one to what the pilot sees and corrects during takeoff and climb.