Instructions for continued airworthiness
ICA development and review for modifications and equipment
ICA development and review builds or checks the instructions for continued airworthiness that a modification or item of equipment must deliver, so an operator can actually maintain the installed change. It is used by avionics, equipment, and modification teams who owe an ICA as part of an approval. It covers the maintenance and inspection tasks, the life limits and intervals, the airworthiness limitations section, and the trace from each instruction back to the design and safety basis. You receive drafted or reviewed instructions, a usability and completeness assessment, and a list of tasks that lack substantiation or detail.
When this review is needed
- A modification or installation owes an ICA and the document has to be written from the design and safety basis.
- An existing ICA reads as a template and needs the maintenance and inspection content that makes it usable.
- The airworthiness limitations section has to be separated out and substantiated against the analysis behind it.
- An operator has flagged that the instructions cannot be performed as written and they need correcting.
The problem
An ICA is often the last deliverable and gets the least attention, so it ships as a structure with thin content. Tasks are described without the access, tooling, or acceptance criteria a technician needs, intervals appear without the analysis that set them, and the airworthiness limitations are mixed into ordinary maintenance text. The operator then cannot maintain the change the way the approval assumed.
What gets reviewed
- The maintenance and inspection tasks the modification or item requires
- Intervals, thresholds, and life limits and their substantiation
- The airworthiness limitations section as a distinct, controlled element
- Access, tooling, and acceptance criteria a technician needs to perform each task
- The trace from each instruction back to the design and safety basis
- Format and structure appropriate to how the operator will use the document
Scope this review
Tell us the asset, the event, and the evidence in scope, and we will outline a focused first engagement.
Identify what is missing against the means of compliance.
What gets validated
- Each task states the access, tooling, and acceptance criteria needed to perform it
- Intervals and life limits trace to the analysis or testing that set them
- The airworthiness limitations section is separated and clearly identified
- Inspection criteria are objective enough to give consistent results
- Every instruction traces back to a design feature or safety requirement
- The document fits the operator's maintenance program structure
Evidence normally required
- The design definition for the modification or equipment
- The safety assessment and any limitations it drives
- Existing maintenance or inspection data for similar installations
- Life-limit and interval substantiation
- The operator's maintenance program structure if known
Common discrepancies
- Tasks written without the access, tooling, or acceptance criteria to perform them
- Intervals or life limits stated with no traceable analysis behind them
- Airworthiness limitations buried inside routine maintenance text
- Subjective inspection criteria that produce inconsistent results
- Instructions with no trace to a design feature or safety requirement
What is at stake
An ICA that cannot be performed does not protect the installed change in service. Operators raise questions back to the holder, inspections get skipped or improvised, and the gap between what the approval assumed and what the fleet actually does widens over time.
How the work runs
Anchor to the design
Work from the design definition and safety assessment to identify what must be maintained and limited.
Write the tasks
Draft or check each task with the access, tooling, intervals, and acceptance criteria a technician needs.
Isolate the limitations
Separate and substantiate the airworthiness limitations section as a controlled element.
Confirm usability
Assess the instructions for completeness, trace, and whether the operator can perform them.
What the buyer receives
- Drafted or reviewed instructions for continued airworthiness
- A usability and completeness assessment of the tasks and limitations
- A list of tasks lacking substantiation, detail, or trace
Who uses the output
- Continued-airworthiness leads owning the ICA deliverable
- Maintenance engineers who will execute or audit the tasks
- Certification leads confirming the ICA supports the approval
How the work fits into the transaction or program
The work produces or validates the one continued-airworthiness document the operator works from day to day. It sits inside the broader deliverables review when the whole in-service set is in question, and it draws on the design and safety basis so each instruction is anchored rather than generic.
Start with a single asset
Reduce finding cycles by checking the package first.
Regulatory limits
Endeavor Elements develops and reviews the applicant's instructions for continued airworthiness. It does not approve the ICA, make compliance findings, or determine that the instructions satisfy the authority. Acceptance of the ICA rests with the authority and the approval holder.
What this review does not cover
- Approving the ICA or its airworthiness limitations section
- Making compliance findings or issuing any approval
- Performing the maintenance or inspection tasks in service
Specific to this review
- The airworthiness limitations section is treated as a distinct, controlled element because it carries mandatory limits separate from ordinary maintenance text.
- A task is judged usable only when a technician could perform it from the page, with the access, tooling, and acceptance criteria stated.
- Every interval and life limit is traced to the analysis or testing that set it, since an unsubstantiated interval is the first thing an audit questions.
- Subjective inspection wording is a recurring defect, because criteria that read differently to two technicians do not protect the installed change consistently.
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.
U.S. Government (eCFR). Maintenance recordkeeping content and approval-for-return-to-service requirements, including 43.9, 43.11, and Appendix B.
European Union / EASA. Continuing airworthiness, maintenance records, CAMO responsibilities, and the airworthiness review process in the EASA system.
Frequently asked questions
Can you write the ICA from scratch?
Yes. Working from the design definition and safety assessment, we can develop the instructions, including the tasks, intervals, and the airworthiness limitations section, and trace each one back to its basis.
What makes an inspection task usable?
A task a technician can perform from the page: it names the access, the tooling, the method, and objective acceptance criteria, so two technicians reach the same result.
Relevant glossary terms
Related pages
Where this fits
Talk to an engineer who has done this work
We will walk through your current state, the records or evidence involved, and a scoped first engagement.
Walk through your situation with an engineer who has done this work.