Deferred maintenance
Boeing 777 family deferred maintenance records review
This review examines the deferred-maintenance position of a specific Boeing 777: what is carried open, on what basis, for how long, and whether cleared items were actually closed with evidence. It is run for a lessor, operator, or buyer who needs the carry-forward list understood before a transaction, an induction, or a program handover. The work checks each deferral against its MEL or CDL basis, confirms the raising and clearing entries, and surfaces items that have carried past their intent. You receive a reconciled deferral list, a supported exception list, and a closure plan scoped to this tail.
When this review is needed
- A 777 is changing hands and the buyer needs the open deferral list and its basis understood before closing.
- The aircraft is due for induction and the carry-forward items must be sorted into what closes at the check.
- A lease return requires the deferral log to be clean, with cleared items evidenced rather than assumed.
- The tail is moving between operators and the raising operator's MEL basis will not carry to the new program.
The problem
Deferred items on a 777 accumulate quietly, and the log rarely shows the whole story. A deferral is raised against an MEL category but the interval that category allows was passed weeks ago. A cleared item shows a closing reference that points to a work card no one can produce. An item repeats every few months under a new number because the underlying defect was never fixed. The records manager sees a tidy open list and a much messier reality behind it.
What gets reviewed
- Open deferrals reconciled against the current deferral log and technical log entries
- Each open item checked to its MEL or CDL category and the interval that category allows
- Cleared deferrals confirmed against the work that closed them
- Repeat and chronic items grouped to show defects that were deferred rather than resolved
- Deferrals tied to AD or SB requirements flagged for their compliance impact
- Items that will not carry across a program change identified for the receiving operator
Scope this review
Tell us the asset, the event, and the evidence in scope, and we will outline a focused first engagement.
Send a representative, redacted record set and we will scope the review.
What gets validated
- Each open deferral shows an MEL or CDL basis and remains within the interval that basis allows
- Cleared items trace to the specific work card or task that closed them
- Repeat items are grouped so a recurring defect is not read as several unrelated deferrals
- Deferrals that touch AD or SB compliance are cross-checked to the compliance status
- The open list agrees between the deferral log, the technical log, and the maintenance system
Evidence normally required
- The current deferred-maintenance log and open-item list for the serial number
- Technical log pages or extracts covering the raising and clearing entries
- The MEL and CDL in force, with any operator-specific interval definitions
- Work cards or task references cited when items were cleared
- AD and SB status where deferrals interact with compliance requirements
Common discrepancies
- Open items carried past the interval their MEL category allows
- Cleared deferrals whose closing reference points to a work card that cannot be produced
- A recurring defect reappearing under new deferral numbers instead of being resolved
- Deferrals raised on an MEL basis that will not transfer to the receiving operator's program
What is at stake
A deferral position that is not understood before a transaction turns into inherited liability the moment title moves. Items that carried past their MEL interval or cleared without evidence can reopen airworthiness questions after the aircraft is operating, and a receiving operator can find itself holding defects it never priced because the carry-forward list was taken at face value.
Move from findings to resolution
Move from findings to a documented resolution path.
How the work runs
Reconcile the open list
Align the deferral log, technical log, and maintenance system into one current view of open items for the tail.
Test basis and interval
Check each open item against its MEL or CDL category and confirm it remains within the allowed interval.
Verify clearances and repeats
Confirm cleared items were closed with evidence and group recurring defects that were deferred rather than fixed.
Plan the closures
Deliver a sequenced list of the items needing action before the transaction or induction.
What the buyer receives
- A reconciled deferral list showing open items, their basis, and their age
- A supported exception list for items past interval or cleared without evidence
- A closure plan that sequences the items needing action for this tail
Who uses the output
- Asset managers pricing the open deferral position into a transaction
- Maintenance planners sorting carry-forward items into the induction work scope
- Continuing-airworthiness staff confirming which deferrals survive a program change
How the work fits into the transaction or program
The deferred-maintenance review connects the day-to-day technical log to the transaction and induction plans. Its output tells the induction planner what must close at the next check and tells the AD-status review which open items carry a compliance consequence, so it usually runs alongside those two rather than in isolation.
Aircraft-specific considerations
A 777 records review relies on careful engine-module trace, structural-repair history, ETOPS-related evidence, and heavy-check work-package closure. Deferrals matter for ETOPS because an item that is acceptable for domestic flying can restrict extended operations, so the review flags any open deferral that touches ETOPS-significant systems on this serial number.
Regulatory limits
This review reports the recorded status and basis of each deferral. It does not raise, extend, or clear any deferral, does not make an MEL determination, and does not issue an airworthiness determination on the aircraft's fitness to fly with the items open.
What this review does not cover
- Raising, extending, or clearing any deferred item
- Physical rectification of a deferred defect
- Production of a new MEL or operator-specific interval definitions
Specific to this review
- The most common deferral defect is an item carried past its MEL interval because the clock was tracked in a system separate from the deferral log.
- A recurring defect deferred under successive numbers hides in an open list that shows only current entries, so the review reads the raising history rather than the snapshot alone.
- On a 777, an ETOPS-significant deferral can be legal for one operation and disqualifying for another, which is why the review flags the operation as well as the item.
Sources
U.S. Government (eCFR). Maintenance recordkeeping content and approval-for-return-to-service requirements, including 43.9, 43.11, and Appendix B.
U.S. Government (eCFR). Records an owner or operator must keep, including total time in service, current status of life-limited parts, and AD compliance.
European Union / EASA. Continuing airworthiness, maintenance records, CAMO responsibilities, and the airworthiness review process in the EASA system.
International Civil Aviation Organization. International standards for aircraft operation, including maintenance program and recordkeeping expectations.
Frequently asked questions
Why review cleared deferrals rather than only the open list?
A cleared item that was closed without evidence is a records gap that surfaces later as an unresolved defect. Reviewing clearances confirms the closing entries are real and stops a recurring problem from being read as a series of separate, resolved items.
Relevant glossary terms
Related pages
Where this fits
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We will walk through your current state, the records or evidence involved, and a scoped first engagement.
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