Operational documents
MEL and CDL records review
A MEL and CDL records review confirms that the operator's minimum equipment list and configuration deviation list are current, approved, and consistent with the aircraft's configuration. It is used before a purchase or an operator transition. It checks the MEL against its master source and approval, the operational and maintenance procedures the MEL relies on, and the configuration items the CDL covers. You receive a MEL and CDL status record, the items out of step with the source or the configuration, and what is needed to close each gap.
When this review is needed
- An aircraft will move to a new operator and the MEL and CDL must be confirmed before use.
- A buyer wants the MEL and CDL approval and currency verified before relying on them.
- The master minimum equipment list has revised and the operator MEL may not reflect it.
- A configuration change affects which CDL items apply and the list needs reconciling.
The problem
The MEL lets an operator dispatch with specific items inoperative, and it has to stay aligned to its master source, its approval, and the procedures it depends on. A MEL can lag the latest master revision, carry an item the aircraft is not configured for, or rely on a procedure the records cannot produce. The CDL is similar for missing external parts, and a list that reads as authoritative can be a revision or a configuration behind the aircraft it covers.
What gets reviewed
- The operator MEL against its master minimum equipment list and revision
- The MEL approval and its applicability to the aircraft and operation
- The operational and maintenance procedures the MEL items reference
- The CDL against the aircraft configuration and the items it covers
- MEL and CDL items that no longer match the installed configuration
- Items present in the current master or source but missing from the operator list
Scope this review
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What gets validated
- The operator MEL reflects the current applicable master minimum equipment list revision
- The MEL is approved for the aircraft type and the intended operation
- Each MEL item references a procedure the records can produce
- The CDL items match the aircraft configuration they are meant to cover
- Source-added items appear in the operator MEL and CDL
Evidence normally required
- The operator minimum equipment list and its revision record
- The master minimum equipment list and its current revision
- The MEL approval and operations specification reference
- The operational and maintenance procedures the MEL relies on
- The configuration deviation list and the aircraft configuration
Common discrepancies
- An operator MEL lagging the current master revision
- A MEL item the aircraft is not configured to carry
- A referenced MEL procedure the records cannot produce
- A CDL covering parts that do not match the configuration
- A master-added item missing from the operator MEL or CDL
What is at stake
A MEL out of step with its master or its approval can permit a dispatch condition the source no longer allows, and a CDL that does not match the configuration can address parts the aircraft does not have or omit ones it does. On a transition, an unverified MEL and CDL cannot be relied on by the receiving operator, and re-establishing approval after the move takes time.
Move from findings to resolution
Move from findings to a documented resolution path.
How the work runs
Match MEL to its master
Compare the operator minimum equipment list against the current applicable master revision and note where it lags.
Confirm approval and scope
Check that the MEL is approved for the aircraft type and the intended operation and tied to the right operations specification.
Test items against configuration
Verify each MEL and CDL item matches the installed configuration and that referenced procedures can be produced from the records.
List items out of step
Record master-added items missing from the operator list and items the aircraft is not configured for, then set an alignment path.
What the buyer receives
- A MEL and CDL status record against source, approval, and configuration
- A list of items out of step with the source or the aircraft
- A recommended closure path for each gap with the source or procedure to align
Who uses the output
- Flight operations relying on the MEL for dispatch decisions
- Continuing-airworthiness teams confirming the documents are current
- Acquisition and transition teams confirming the operational document set
How the work fits into the transaction or program
The review supports a pre-purchase or an operator transition by confirming the MEL and CDL are approved, current, and matched to the aircraft. It complements the deferred-maintenance review, since MEL items become tracked deferrals once an aircraft dispatches against them.
Jurisdiction-specific considerations
MEL approval is specific to the authority and the operator's approval basis, and a MEL approved for one is not portable to another. Where the aircraft changes operators or authorities, the review identifies what the receiving operator will need to re-establish.
Regulatory limits
The review confirms that the MEL and CDL records are complete, consistent, and traceable to their source and approval. It does not approve a MEL, grant a dispatch condition, or make an airworthiness determination.
What this review does not cover
- Approval of the MEL or CDL
- Authorising any dispatch condition
- Any airworthiness determination on the aircraft
Specific to this review
- A MEL is only valid against its master source and its approval, so a MEL a revision behind can permit a condition the source has since removed.
- MEL items reference operational and maintenance procedures, and a list whose procedures cannot be produced is incomplete even if every item looks correct.
- MEL approval is tied to a specific operator and authority, so it does not transfer with the aircraft and has to be re-established by the receiving operator.
Sources
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
How do the MEL and a deferred-maintenance record relate?
The MEL defines what may be deferred and under what conditions. When an aircraft dispatches against a MEL item, that becomes a tracked deferral, so the two reviews look at the same items from the rule side and the tracking side.
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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