Recurring ADs: Verify the Next Due Date and Supporting Records

Start With the Directive and the Last Completed Action

A next-due value in a maintenance tracker should be traceable to the applicable Airworthiness Directive (AD), the completed work, and the calculation of the next interval. If those sources disagree, resolve the discrepancy before using the tracker to plan an operation.

Check these four items first:

The AD and revision that apply to the product and configuration.
The last completed action and its recorded date, hours, or cycles.
The compliance threshold and repeat interval specified by the AD.
Any approved alternative, terminating action, or other applicable provision.

A recurring AD has no implied tolerance borrowed from another maintenance task. Compliance times and authorized alternatives come from the directive and the applicable approval. ADs are legally enforceable under 14 CFR Part 39.

Maintenance-Program Tolerance Does Not Automatically Transfer

Some inspection programs and task controls include task-specific tolerances. Their availability, amount, direction, and conditions depend on the approved or accepted program and the operator’s authority.

A tolerance attached to one scheduled task does not automatically apply to:

An AD.
An airworthiness limitation.
A life limit.
A certification maintenance requirement.
A task governed by a different program or operating rule.

The same tracking screen displays all of them as next-due dates, but the legal source and available flexibility differ. Each due item should retain a link to its controlling authority.

One-Time, Recurring, and Terminating Actions

ADs require a one-time action, repetitive actions, or both.

A recurring requirement usually establishes:

An initial compliance threshold.
A repeat interval.
A measurement basis such as hours, cycles, landings, or calendar time.
The affected product or configuration.
The action and method required.

Some directives provide a terminating action that ends specified repetitive work. Others are amended, superseded, or rescinded. Applicability also changes when the product or configuration changes.

That is why “complied with” is not always enough. The records and status system should show whether the action was one-time, whether another interval remains open, which revision controls, and whether an approved terminating action or AMOC applies.

Establish the Exact Compliance Point

For each applicable recurring AD:

Confirm product and configuration applicability.
Identify the directive and current revision.
Read the compliance paragraph, not only the referenced service document.
Determine the initial threshold and repeat interval.
Identify the measurement source.
Calculate the last-complied and next-due values.
Record the method of compliance and any approved AMOC.
Confirm whether a terminating action, superseding AD, or configuration change affects status.

If the AD uses “not to exceed” language, treat the stated interval as a ceiling unless an authorized provision changes it. Do not round hours, cycles, or dates to create convenience.

Check the Scope of an Approved AMOC

14 CFR 39.19 permits a person to propose an alternative method of compliance or adjustment of the compliance time when the proposal provides an acceptable level of safety.

An operator cannot self-approve an AMOC merely because its maintenance program permits engineering deviations. Confirm:

Who approved the AMOC.
Which AD and paragraphs it covers.
Which aircraft, products, or configurations it applies to.
Any reporting, inspection, or notification conditions.
Whether the approval transfers or must be re-established.
How the alternative changes the next-due calculation.

Keep the approval with the AD status evidence. A note in tracking software is not a substitute for the underlying authorization.

Special Flight Permits Are Not a General Extension

Under 14 CFR 39.23, the FAA may issue a special flight permit to operate a product to a location where the AD requirements can be accomplished, unless the AD states that the permit is not allowed.

The permit is a separate authorization with conditions. Nothing about it is automatic. The operator should coordinate with the FAA and qualified maintenance personnel, review the AD, and obtain the permit before operating.

Other operations-specific authority may also matter. The correct pathway depends on the directive, aircraft, operator, and proposed operation.

A Hypothetical Overdue Finding

Assume an aircraft returns from a trip and its recorded time is above the next-due value for a recurring structural AD. The tracking system shows no AMOC or terminating action.

Pause ordinary scheduling and verify the governing record:

Stop ordinary scheduling while status is verified.
Confirm actual accumulated time and applicability.
Review the AD for compliance provisions and special-flight limitations.
Search for completed but unposted work or an approved AMOC.
Coordinate with qualified maintenance personnel and the FAA as required.
Document any inspection, authorization, correction, and return to service.
Investigate how the due calculation or reconciliation failed.

The aircraft may need the required work before further operation. A special flight permit may be available. Qualified maintenance personnel should verify the applicable requirements and any authorization before operation.

What an Audit-Ready AD Record Shows

A useful current-status record includes:

AD number and revision date.
Product and configuration applicability determination.
Method of compliance.
Date and aircraft time or cycles when accomplished.
The next recurring due time or date, when applicable.
The signed maintenance entry and supporting work reference.
Any AMOC, terminating action, or supersedure evidence.

This aligns with the current-status requirements in 14 CFR 91.417.

Sources and Further Reading

Talk with Radar to compare your maintenance status report with its source records.