Continued airworthiness
Instructions for continued airworthiness evidence review for modifiers
An ICA package evidence review checks that the instructions for continued airworthiness delivered with a modification actually match the configuration the STC approves. It is run for a modifier before submittal, during a finding response, or when a design change ripples into maintenance, by or for the team that owns the data package. The work reads the maintenance tasks, airworthiness limitations, illustrated parts data, and configuration coverage against the approved design, then flags where the ICA describes a part, task, or interval the modification no longer carries. You receive a gap list, an evidence map from each ICA element back to the approved configuration, and a closure sequence the STC team can execute.
When this review is needed
- A late design change removed or repositioned a component the ICA still lists a maintenance task against.
- An airworthiness limitation derived from the safety analysis has not made it into the limitations section of the ICA.
- The illustrated parts data references part numbers that the current modification drawing no longer uses.
- An operator or authority has questioned whether the ICA covers every configuration the STC is effective on.
The problem
ICA is written to describe a design that keeps moving, so the maintenance manual, the limitations section, and the parts data drift apart from the configuration as the program matures. A task survives against a part that was deleted, a limitation from the safety case never reaches the document, or an interval is stated without the analysis that justifies it. The modifier ends up shipping instructions that read complete but describe an aircraft slightly different from the one the STC actually approves.
What gets reviewed
- Maintenance tasks reconciled to the components and systems the approved modification installs
- Airworthiness limitations checked against every life, inspection, and limit the safety analysis derives
- Illustrated parts data reconciled to the current modification drawing and part numbering
- Configuration coverage confirmed across all effectivity the STC applies to
- Task intervals traced to the analysis or precedent that sets them
- Cross-references between the ICA and the base aircraft manuals checked for orphaned callouts
What gets validated
- Every maintenance task addresses a component the approved configuration actually installs
- Each airworthiness limitation in the safety analysis appears in the limitations section of the ICA
- Part numbers in the illustrated parts data match the current released modification drawing
- The ICA states coverage for each effectivity the STC is approved on, with no configuration left undocumented
- Every stated interval traces to an analysis, test, or accepted precedent rather than being asserted
Evidence normally required
- The full ICA set: maintenance instructions, airworthiness limitations, and illustrated parts data
- The approved modification drawing tree and effectivity list
- The safety assessment that derives life and inspection limitations
- The STC effectivity and the base aircraft maintenance data the ICA supplements
- The change history for design revisions that touched maintainable hardware
Common discrepancies
- A maintenance task retained against a component a later design change deleted
- An airworthiness limitation derived in the safety analysis but absent from the limitations section
- Illustrated parts data citing a part number the current modification drawing has superseded
- An STC effectivity the ICA does not explicitly cover
What is at stake
ICA that lags the approved configuration is a finding waiting to surface, either at the authority's review or later when an operator cannot follow a task against hardware that is not installed. A missing airworthiness limitation is the sharpest exposure, because it is mandatory content and its absence can hold up approval or, worse, leave a life or inspection limit uncontrolled in service.
Move from findings to resolution
Identify gaps against the means of compliance.
How the work runs
Map tasks to hardware
Reconcile every maintenance task to a component the approved modification actually installs.
Trace the limitations
Confirm each life and inspection limit from the safety analysis reaches the limitations section.
Check parts and coverage
Match illustrated parts data to the current drawing and confirm every effectivity is documented.
Order the fixes
Sequence the ICA corrections against the submittal and delivery schedule.
What the buyer receives
Who uses the output
- STC program managers confirming the ICA is complete before the package is submitted
- Certification leads checking that mandatory limitations content is present and derived
- Engineering owners reconciling the maintenance data to the design they actually approved
How the work fits into the transaction or program
ICA is the modification's handoff to the operating world, so it has to close the loop between the approved design and the maintenance program that will keep it airworthy. Reviewing it before submittal catches a drifted task or a missing limitation while the design data is still open, and the evidence map ties the ICA back to the same configuration the conformity and compliance evidence already rest on.
Start with a single asset
Confirm requirements trace through verification.
Jurisdiction-specific considerations
FAA and EASA both treat the airworthiness limitations section as mandatory, approved content, but they differ on how the rest of the ICA is accepted and on where limitations must physically reside. Where a modification is certified under both, the review notes where a limitation or task presentation acceptable to one authority needs restructuring to satisfy the other.
Regulatory limits
The review confirms the ICA is complete and consistent with the approved configuration. It does not author maintenance instructions, set an airworthiness limitation on the authority's behalf, or determine that the ICA is approvable or that the aircraft is airworthy.
What this review does not cover
- Writing the maintenance tasks or illustrated parts data from scratch
- Deriving new airworthiness limitations or the analysis behind them
- Any determination that the ICA satisfies the authority
Specific to this review
- The airworthiness limitations section is approved, mandatory content, so a limitation missing from it is a harder finding than an incomplete maintenance task.
- Maintenance tasks outlive the parts they service, because deleting a component in a design change rarely triggers a matching edit in the manual.
- An ICA gap surfaces twice: once at the authority review and again years later when an operator tries to follow a task against hardware that is not there.
Sources
U.S. Government (eCFR). Type certificates, STCs (Subpart E), TSO authorizations (Subpart O), PMA (Subpart K), and export airworthiness approvals (Subpart L).
Federal Aviation Administration. STC application process, certification basis, and continued airworthiness obligations of an STC holder.
European Union / EASA. EASA design and production certification, STCs, ETSO authorizations, and EASA Form 1 release.
Frequently asked questions
Why treat the airworthiness limitations section differently from the rest of the ICA?
The limitations section is approved content and its items are mandatory in service, so a limit that the safety analysis derives but the section omits is both a certification finding and an uncontrolled risk once the aircraft is operating. The review checks that section against the safety case first.
Relevant glossary terms
Related pages
Where this fits
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