ICA in Aviation Maintenance: If You’ve Got It — Use It!

In Australian aviation, few documents are as misunderstood — or as neglected — as much as Instructions for Continued Airworthiness (ICA). Every aircraft, component, and modification comes with an ICA, yet many operators and maintainers fail to use them properly. The result? Repeated audit findings, inconsistent maintenance, and unnecessary operational risk.

At Jotore, we see this all the time. ICA does exist, but they’re buried, ignored, or misinterpreted. This blog explains what they are, why they matter, and how they should be managed across both CAMO and AMO environments.

What is ICA?

Instructions for Continued Airworthiness are the technical instructions required to keep an aircraft, system, or modification in an airworthy condition over its operational life.

An ICA typically includes:

• Maintenance instructions

• Inspection intervals

• Special checks or tests

• Required tooling or equipment

• Drawings, diagrams, or part lists

• Recommended servicing practices

• Component life or overhaul limits

If you’re maintaining or operating an aircraft, you must follow the ICA exactly as written — unless a regulatory approval has been issued for an alternative.

Where Do ICAs Come From?

ICA can come from multiple sources:

1. Type Certificate (TC) Holder

For the base aircraft, the ICA is published in the AMM, CMM, SRM, IPC, WDM, and other OEM manuals.

2. Supplemental Type Certificate (STC) Holder

Any modification (e.g., avionics, interiors, structural changes) must include a set of ICA that is specific to that STC.

3. Part 21 Design Organisations

In Australia, design changes approved under CASR Part 21 Subpart M or Subpart O must include ICA documentation.

4. Repairs and Approvals

Major repairs require ICAs issued by a Part 21 design approval holder.

If a design change is approved, the ICA must be supplied — and it must be used.

Who Approves ICA?

Approval depends on the source:

• OEM manuals → approved by their National Aviation Authority, accepted by CASA.

• STC ICA → approved by the STC holder’s issuing authority (FAA, EASA, CASA).

• Australian design changes → approved by a CASA-authorised Part 21 design organisation.

• Repairs in Australia → approved by the same.

Once approved, the operator must incorporate the ICA into their maintenance program.

Regulatory References (Australia)

ICA is referenced throughout the regulatory framework:

CASR Part 42 – Continuing Airworthiness Management Organisations

CASR Part 21 – Certification

MOS for Part 42 and Part 145

• Requires CAMOs/AMOs to control current versions of ICA documents used during maintenance.

Why does ICA Matter

1. They Are Legally Required

Failure to follow the ICA is a breach of the CASRs. CASA audit teams routinely raise findings where ICAs are missing or not incorporated.

2. They Ensure Safety

A modification without its ICA is essentially “unsupported engineering.” Even minor equipment additions can introduce:

• electrical load changes

• structural implications

• new failure modes

ICAs explain how to monitor and maintain them safely.

3. They Protect Operators and Maintainers

Using the ICA demonstrates compliance with approved data — critical for investigations or insurance claims.

4. They Standardise Maintenance

Everyone works to the same instructions, regardless of shift, base, or engineer.

How ICA is Managed in the CAMO

The CAMO (or operator under Part 42) is responsible for:

1. Receiving and Reviewing ICA

Every modification must come with ICA. The CAMO must review it and ensure suitability.

2. Incorporating It into the Maintenance Program

ICAs are added to:

• AMP / AMP Variation

• MPDs

• Work instructions

• Reliability or tracking programs

If the ICA introduces new tasks, they must be scheduled.

3. Controlling the Master Set

The CAMO holds the controlled copy of all ICA.

4. Communicating Requirements to the AMO

Work orders must refer to the correct ICA sections, revisions, and references.

How ICA is Managed in the AMO (Part 145)

The AMO is responsible for:

1. Accessing Current ICA Data

They must have the correct version controlled by the CAMO, not their own old copy.

2. Following the ICA Exactly

Tasks must be completed and certified strictly in accordance with the approved ICA.

3. Documenting Deviations

If an ICA cannot be followed, it must be escalated — the AMO cannot improvise. Only the CAMO (or operator) can assess and seek design approval for variations.

4. Feeding Back Issues

Discrepancies, unclear tasks, or tooling conflicts must be reported so the CAMO can review with the design organisation.

How to Store ICA Properly

A good storage system ensures ICAs are:

• Controlled

• Current

• Accessible

• Traceable

Best Practices

✔ Store ICAs with the modification or repair record (STC folder, design change file).

✔ Maintain a central ICA register linked to the aircraft.

✔ Use a document management system (e.g., TRAX or Ramco).

✔ Ensure the AMO always accesses the CAMO-controlled copy.

✔ Label ICA documents with revision status and effective date.

✔ Retain superseded versions for audit traceability.

✔ Back up digitally and avoid relying on paper-only data.

The Jotore Bottom Line: If You’ve Got It — Use It.

ICA is not an optional add-on. It’s a mandatory part of keeping your aircraft compliant and safe. Whether it’s an OEM manual, STC, or local design approval, there must be a robust process so it can be:

• Captured.

• Reviewed.

• Incorporated into the maintenance program.

• Followed.

• Reported on any anomalies

Missing or ignored ICA is one of the most common — and easily avoidable — audit findings across Australia. If your organisation needs help building an ICA register, integrating ICA into your AMP, or ensuring your AMO uses the correct data, Jotore can help.

Stay Safe,

Craig