The UK CAA released the third edition of CAP 2153 in March 2026. This is a major revision to the Part CAMO CAME User Guide, and the changes go beyond editorial housekeeping. For Continuing Airworthiness Managers and compliance teams, there are specific new requirements that need to be reflected in your exposition.
We have reviewed the full document. Here is what has changed, what it requires, and where to focus your attention.
Task Optimisation: The most significant addition in this edition
Section 1.2.9.4 introduces formal CAA guidance on Task Optimisation for Part-M aircraft. This is not an entirely new concept; M.A.302(e) has long permitted organisations to deviate from recommended maintenance task intervals. But until now, there was no published framework within the CAME structure for how this should be documented, justified, and controlled.
That gap has now been closed.
Definition: For the purposes of this guidance, "optimisation" means the escalation or de-escalation of scheduled maintenance task intervals, supported by a formal reliability programme or substantiated in-service data.
Task categories and their optimisation eligibility:
The guidance establishes three distinct categories:
Mandatory tasks include those contained within the Airworthiness Limitations Section (ALS) and Airworthiness Directives (ADs). These constitute changes to the approved type design and may only be amended through an Article 71(1) exemption. They are explicitly excluded from optimisation. Certification Maintenance Requirement (CMR) tasks should continue to be managed strictly in accordance with the TCH instructions contained within the Maintenance Planning Document for the specific type.
Safety-related tasks are those required to ensure the continued safe operation of the aircraft. For MSG-3 developed aircraft, these are typically classified as:
· Evident Safety (FEC 5)
· Hidden Safety (FEC 8)
Optimisation of safety-related tasks requires support from the Type Certificate (TC) holder, Supplemental Type Certificate (STC) holder, or another appropriately approved design organisation. This support must take the form of approved design data, in addition to the justification required for non-safety tasks.
Non-safety (operational or economic) tasks are those introduced to manage operational risk to an acceptable level or to achieve economic benefit. Under MSG-3, these are categorised as:
· Operational (FEC 6)
· Economic (FEC 7)
· Hidden Operational/Economic (FEC 9)
These may also arise from Service Bulletins, Service Letters, vendor recommendations, or other manufacturer guidance.
Justification requirements:
Optimisation of non-safety tasks must be justified through either:
· A formal reliability programme (as required by M.A.302(g) or voluntarily implemented per AMC M.A.302(d) point 6)
· The collection and analysis of in-service experience
The CAA notes that voluntary programmes can vary in scope from a component defect monitoring system for a small CAMO to an integrated maintenance management programme for a larger organisation.
What your CAME section needs to describe:
· The method for determining whether a task is safety-related or non-safety-related
· Whether the aircraft is subject to MSG-3/MRB methodology or another maintenance development process
· The analytical approach used for interval escalation or de-escalation
· How each proposed optimisation is justified through documented analysis, supported by data from your reliability programme or in-service experience
· How the analysis is maintained through continuous monitoring to ensure the optimised interval remains appropriate for the nature and environment of the operation
Data and analysis standards:
The data used to support optimisation should include those elements listed in Paragraph 1.5.1 of CAP 2153. The analysis must be at individual task level, with assurances of:
· Data Quality - the underlying data is accurate and complete
· Data Integrity - the data has not been corrupted or selectively filtered
· Suitable Data Analysis (engineering/statistics) - sufficient to demonstrate a 95% confidence level in the optimised task intervals
This is a high bar, and it should be. Organisations without a mature reliability programme or a structured approach to in-service data collection will need to build that capability before Task Optimisation can be meaningfully pursued.
Used Aircraft Imported From the EU: A new desktop route
Section 4.4.5 is entirely new and addresses a practical gap that has existed since the UK's departure from the EU regulatory framework.
The new process allows used Part 21 aircraft previously holding a valid CofA and ARC from an EU Member State to be eligible for UK CofA issue, and where applicable an ARC, through a desktop assessment. This means a CAA physical survey may not be required, provided the application is supported by a complete and credible Declaration/Recommendation (Form AW-AIR-FM-027).
Key procedural points:
· The organisation follows the standard import process (Section 4.4.4) for preparing records, compliance reports, and the airworthiness review
· Instead of presenting the aircraft and records to the CAA for physical survey, the organisation completes the CAA Declaration/Recommendation form
· The organisation is fully responsible for the accuracy and credibility of all information submitted
· The CAA will not review aircraft records or conduct a physical survey unless discrepancies, quality concerns, oversight history, or intelligence from AW/GAU indicate the need for referral to the standard process
· Where the last flight on the previous ARC exceeds 60 days before application, referral to the standard survey process may apply
· For Part-ML aircraft, the CAMO/CAO issues the ARC itself (CAA Form 15c), with the CAA issuing the CofA and Noise Certificate
· Aircraft processed under this desktop route will be scheduled for an ACAM survey within 12 months of CofA issue
Practical considerations: This is a welcome streamlining, particularly for organisations regularly importing EU-registered aircraft. However, the CAA has made clear that the burden of proof sits entirely with the CAMO. A weak or incomplete declaration will trigger referral to the full survey process. Organisations should ensure their airworthiness review process for imported aircraft is thorough and well-documented.
CAMO Complexity Matrix: New dynamic complexity item
Section 5.9 has been updated with a new question (item 18 in Dynamic Complexity): "Does the managed fleet use penalty factors?"
This reflects the CAA's interest in understanding how organisations are managing maintenance interval adjustments across their fleet, which connects directly to the Task Optimisation guidance above. If your fleet uses penalty factors, your Complexity Matrix needs to reflect this at the next CAME amendment.
What you should do now
1. Review your CAME against Section 1.2.9.4. If your exposition does not currently address Task Optimisation, you will need to add a procedure. Even if you are not actively pursuing interval optimisation today, the CAA now expects this to be addressed in the exposition structure.
2. Assess your data readiness. Task Optimisation requires either a formal reliability programme or structured in-service data collection. If you do not have this in place, consider what building blocks are needed: defect tracking, component removal analysis, task finding data, and fleet utilisation records.
3. Update your import procedures if you handle EU-origin used aircraft. Section 4.4.5 introduces a new pathway that should be reflected in your CAME.
4. Update your Complexity Matrix. Add the response to item 18 (penalty factors) and submit with your next CAME amendment.
5. Brief your airworthiness team. The Task Optimisation section in particular requires a clear understanding of task categorisation (mandatory vs. safety-related vs. non-safety), MSG-3 Failure Effect Categories, and the statistical requirements for justification.
How Baines Simmons can help
As TrustFlight's training and consulting capability, Baines Simmons provides specialist CAMO management, airworthiness advisory, and exposition development services. We support organisations with:
· CAME development and amendment to reflect CAP 2153 Edition 3 requirements
· Task Optimisation procedure development, including reliability programme design and data analysis frameworks
· EU aircraft import process implementation
· Airworthiness review staff training and competency assessment
· Regulatory compliance audits and gap analysis
If you need support interpreting these changes or updating your CAME, contact our airworthiness team at hello@bainessimmons.com.
CAP 2153 Third Edition (March 2026) is published by the UK Civil Aviation Authority and is available at www.caa.co.uk/CAP2153.