ADs are enforceable FAA rules addressing unsafe conditions. Establish applicability for the aircraft and installed products, document the required action and evidence, and keep recurring next obligations current.
What are aircraft Airworthiness Directives?
Airworthiness Directives, or ADs, are legally enforceable FAA rules addressing unsafe conditions in products such as aircraft, engines, propellers and appliances. A buyer needs to know which directives apply to the equipment actually installed, what actions establish compliance and whether anything remains recurring or becomes due before delivery. “ADs complied with” in an advertisement is not that complete determination.
The FAA's FAA: what Airworthiness Directives cover explains the authority and product scope. Its FAA: AD compliance responsibilities identifies the owner and operator's compliance responsibility and the prohibition on operating a product contrary to an applicable AD. This guide provides an evidence workflow for purchase and ownership. It does not determine the AD status of a specific airplane or replace qualified maintenance review of the current directives and records.
Begin with the aircraft and installed equipment
Create an identity list containing the airframe model and serial number, engine and propeller models and serial numbers, and relevant installed appliances and modifications. Record the evidence source for each item. An old equipment list may no longer describe the airplane. If a component was exchanged during maintenance, a previous applicability review may need to be revisited for the newly installed unit.
The FAA's FAA: AD applicability and compliance says that finding applicable directives requires searches for the product, including aircraft, engines, propellers and installed appliances, and attention to model series. Applicability can depend on installed part numbers or modifications. Searching only the airframe's familiar marketing name risks missing a directive for a separate installed product. The professional review should reconcile records with the actual configuration.
Do not treat every search result as automatically applicable. Read the directive's applicability section and establish whether its model, serial, part or configuration conditions are met. Equally, do not reject a result merely because the aircraft's registration is absent from a generic search. Record a reason for nonapplicability that a later reviewer can evaluate, rather than leaving a blank box or writing “not our aircraft.”
Read required action, timing and evidence separately
The directive supplies the required actions and compliance timing. According to the FAA's applicability guidance, that timing relates to the effective date as specified in the AD. A statement that the owner intends to address it at the next annual is not sufficient if the actual directive requires earlier action. Some obligations involve one-time work; others require recurring inspections, replacements, restrictions or additional actions after a finding.
For each applicable directive, ask the reviewer to identify the method used, the supporting entry, the current status and any next required action. Section 91.417's 14 CFR 91.417: records, retention and sale transfer specifically addresses the AD number and revision date, method of compliance, and time and date of the next action when recurring. A worksheet can summarize those items, but the underlying entries and supporting evidence still matter.
Read all relevant conditions rather than isolating the most convenient paragraph. An initial inspection may lead to further work depending on results. An approved change may terminate one repetitive action only if the directive's conditions are met. Conversely, performing a task once does not prove a recurring obligation has disappeared. Ask the mechanic to document which paragraph or approved method supports the conclusion.
Use an applicability-to-evidence worksheet
| Field | Evidence or explanation | Question it resolves |
|---|---|---|
| Directive identity | AD number, revision, effective date and current status | Which exact rule was reviewed? |
| Affected product | Installed model, serial, part and configuration information | Does the applicability match the actual equipment? |
| Required action | Relevant directive paragraph and specified method | What must be done, and under what conditions? |
| Compliance evidence | Dated signed entry and supporting documents | What establishes the action actually accomplished? |
| Next obligation | Recurring threshold, units and calendar conditions | What remains due and when? |
| Reviewer and gaps | Review date, responsible professional and unresolved items | What still prevents a supported conclusion? |
The most useful output is a traceable status as of a specified date and aircraft time. A spreadsheet marked “current” without that reference point becomes stale as the airplane flies or new directives take effect. Keep separate lines for unresolved evidence and confirmed future requirements. Do not turn “record not supplied” into “complied with” simply because the seller says the work probably occurred.
Treat service bulletins and referenced documents carefully
Manufacturers issue service bulletins for safety, maintenance and product improvements. The FAA's FAA: service bulletins and the aircraft owner explains that compliance may or may not be mandatory and that safety information should not be ignored. Therefore, neither “all service bulletins are optional” nor “anything labeled mandatory by a manufacturer is automatically the same as an AD” is a reliable universal rule.
When an AD directs use of particular service information, have the reviewer identify the document and revision required or permitted by the directive. A newer bulletin should not be assumed acceptable merely because its publication date is later. Other controlling requirements can also affect maintenance obligations. The buyer needs a task-specific explanation of which authority applies, not a slogan about all private or all commercial aircraft.
Keep referenced documents linked to the compliance record when needed to understand the work. Access to a manufacturer's current library helps, but it does not prove that a particular earlier action used the required method. Our detailed AD compliance guide expands the review of applicability, records and next actions without making a finding for an individual aircraft.
An alternative method needs actual approval
Section 39.19, 14 CFR 39.19: approved alternative methods, allows a proposal for an alternative method of compliance or a changed compliance time that provides an acceptable level of safety. The proposed alternative can be used only if the responsible FAA manager approves it. An owner's preference, an available part or an email requesting consideration does not itself authorize the change.
If a seller relies on an AMOC, request the approval and have the maintenance professional verify its scope, conditions and applicability to the aircraft and action in question. A document approved for another situation is not automatically transferable. Keep the actual basis with the records so a buyer, future shop or other reviewer can understand why the stated method meets the obligation.
Price the work without confusing price and permission
An AD-related cost can include records research, access, inspection, parts, corrective work, outside services, documentation and downtime. Obtain a scope-specific proposal rather than using a dramatic example from another model as a price benchmark. The required action and actual findings determine the project; a generic national AD-cost allowance cannot establish it.
For an invented budgeting example, suppose a written inspection proposal is $900 and a separately quoted corrective option, if needed, is $3,600. Inspection alone is $900; the combined scenario is $4,500. If $2,000 is already allocated, the latter scenario has a $2,500 funding gap before any additional excluded costs. These numbers are arithmetic examples, not prices, probabilities or a prediction that a real directive requires either task.
Keep the cost decision and operating decision separate. Available cash does not establish compliance, and lack of cash does not extend an AD's time limit. Ask appropriate professionals about lawful storage, transport and next steps where status is unresolved. Do not assume a purchase contract, lender approval or current annual permits operation contrary to an applicable directive.
Make the purchase handoff current
During the pre-buy, ask an independent qualified reviewer to evaluate the applicability list against the records and installed configuration. Agree what evidence is needed before releasing contingencies. If a gap exists, identify the research or inspection required and the party responsible. The FAA's FAA AC 43-9D: maintenance record guidance notes that reconstructing missing AD evidence can require significant effort and sometimes repeating work to establish compliance.
Update the review before delivery if the airplane has flown, equipment has changed or new requirements have arisen. Record remaining recurring tasks and their next thresholds in the receiving owner's maintenance plan. Transfer the required continuing-status records under section 91.417 rather than handing over only a clean-looking summary. Pair the review with our records handoff FAQ.
Continue the review after ownership changes
The FAA's FAA: directive resources and notifications links to directive resources and offers notification of new ADs and Special Airworthiness Information Bulletins. Notifications can support awareness, but subscription settings do not establish a complete applicability determination for every installed product. Assign responsibility with your shop for reviewing new information and updating records, particularly after component changes or maintenance events.
Keep the owner-facing schedule understandable: what is due, the controlling units, the evidence supporting the last action and the person coordinating the next one. Do not rely on the next annual as the sole review point. A maintained evidence trail helps purchase and financing discussions, but it does not guarantee collateral value, insurance acceptance, lender approval or future serviceability.
AD questions
Is AD compliance mandatory?
An applicable AD is legally enforceable, and a product must be operated in accordance with its requirements. Determine applicability, action and timing from the actual directive and current evidence. A pending alternative-method request, seller assurance or current annual is not a substitute for compliance.
Can ADs be expensive?
The cost depends on the required action, aircraft configuration, access and findings. Obtain a complete written scope and consider conditional corrective work and downtime. This guide does not assign a universal price or use another model's experience as your estimate.
How do I check an aircraft's AD status?
Have qualified maintenance personnel reconcile current applicable directives for the aircraft and installed products with signed records, methods used and recurring next actions. Document gaps and the review's date and time reference. A seller's list is an input to that investigation, not a complete independent finding.