Deferred maintenance history checked against redelivery binder sources

When this review is needed

• The lease requires zero open deferrals at return and the log still shows items awaiting parts or hangar access.
• A deferral was cleared in the maintenance system but the acceptance inspector wants the task card and release signature.
• Mid-lease changes in deferral practice, for example a new MEL revision, left older entries misaligned with the current log format.
• Repetitive inspections created by deferred defects must be shown as terminated or transferred to the next operator's program.

The problem

A deferral log is maintained for daily operations, and its habits are operational rather than evidential. Entries get closed with a system status change while the physical sign-off lives on a task card the binder team must hunt down. Extensions approved through operations control leave thin trails, and a log that flew perfectly well for six years suddenly has to prove itself line by line to an acceptance inspector reading it cold.

What gets reviewed

• Every open deferral on the log reconciled with the lease's return-condition requirements
• Cleared deferrals traced to the corrective action, task card, and certifying signature that closed them
• MEL and CDL deferrals checked for category, applied interval, and any extension approvals
• Repetitive inspections raised by deferred defects followed through the task records for the deferral period
• Log entries cross-checked against discrepancy registers and technical log extracts in the binder
• Watch items and acceptable deferred defects reviewed for consistent carry-forward across log revisions

What gets validated

• Each cleared entry has corrective-action evidence naming the work performed, the part fitted where applicable, and the release signature
• Deferral intervals match the MEL category or program allowance in force at the time, including any documented extension
• No deferral was closed by administrative rollover, meaning a status change with no maintenance record behind it
• Repetitive inspection tasks tied to deferrals show accomplishment at each due point until termination
• Items open at the return date appear on the acceptance notes with an agreed disposition instead of vanishing between log revisions

Evidence normally required

• The deferred maintenance log or ADD list across the lease period, including superseded revisions
• Technical log pages and task cards for deferral raise and clearance events
• MEL and CDL references applicable during the lease, with extension approvals
• The binder's discrepancy registers and return-condition evidence
• The lease annex language on deferrals at redelivery

Common discrepancies

• A deferral shown cleared in the system while the clearing task card was never filed into the binder
• Extensions granted near the interval limit with no record of who approved them or on what basis
• A repetitive inspection trail that stops cold after a fleet software migration
• Items removed from the log between revisions with no clearance event on any technical log page

What is at stake

Each unsupported clearance reads to an acceptance team as a defect that may still be open. Return dates slip while cards are recovered, items genuinely open at return convert into financial adjustments, and a deferral whose interval control cannot be shown invites questions about the airworthiness oversight that overlapped it.

How the work runs

What the buyer receives

• A dispositioned deferral log with each entry marked supported, evidence pending, or open at return
• An exception list formatted for the redelivery acceptance file, one line per unsupported clearance
• A short recovery plan naming the likely holder of each missing card or approval
• Carry-forward notes for items the incoming operator will inherit

Who uses the output

• Redelivery managers negotiating which items are cleared, compensated, or carried
• Technical-records staff at the returning operator chasing the missing sign-offs
• The lessor's technical team assessing the asset before remarketing

How the work fits into the transaction or program

Deferral review lands late in binder assembly because the log keeps moving until the aircraft stops flying. Its results go straight into the acceptance meeting, where open items become financial or workscope discussions, and the verified log then travels forward as part of the delivery binder to the next lessee.

Jurisdiction-specific considerations

The two registries frame deferrals differently. FAA operations lean on the approved MEL and the operator's procedures, while EASA-context returns bring Part-M and CAMO oversight expectations into how extensions and repetitive inspections should be evidenced, with ICAO Annex 6 setting the baseline both build on. An acceptance inspector trained in one system will look for artifacts the other system does not naturally produce, so the review notes which evidence conventions the log actually follows.

Regulatory limits

This work does not authorize, extend, or clear any deferral, does not interpret MEL provisions on behalf of an operator, and makes no airworthiness or dispatch determination. It establishes the evidential status of the log so the responsible parties can act on facts.

What this review does not cover

• Performing or certifying the maintenance that clears an open deferral
• MEL interpretation or category disputes with the authority
• Assessment of the operator's reliability program or deferral culture

Specific to this review

• Deferral logs fail evidentially at their edges: the raise event is usually well documented, while the clearance is the record that goes missing.
• System migrations during a lease are a predictable break point; entries closed in the old system often reappear in the new one carrying a migration date instead of a maintenance event.
• A deferral cleared during a heavy check is often signed inside the check package rather than on a discrete card, so proving clearance means cross-referencing the check itself.
• Return-condition annexes rarely define what evidence clears a deferral, which is why agreeing the evidence standard early prevents acceptance-week disputes.
• Deferrals raised in the final weeks before return deserve their own pass, because clearance work competes with return preparation and paperwork is the first thing squeezed.

Sources

Frequently asked questions

Relevant glossary terms

Related pages

Where this fits