CASA EX52/23 – CRS and SM CRS Document to Cover Specialist Maintenance by a Class D AMO – Instrument 2023

Specialist maintenance is defined implicitly by the scope of the exemption: it is limited to non-destructive testing or welding carried out by a CAT D1 or D2 AMO. The instrument does not permit other forms of specialist maintenance (such as composite repairs, heat treatment, or coating work) to be covered through this mechanism.

CAT A AMO means a Category A rated approved maintenance organisation authorised to perform line and/or base maintenance on aircraft. Under the unmodified CASR, such an organisation must issue a CRS in accordance with regulation 42.760 and, critically, must ensure that all maintenance (including subcontracted specialist work) is performed and certified by its own employees or by persons under its direct control.

CAT D1 or D2 AMO means a Category D1 or D2 rated AMO. D1 ratings cover non-destructive testing; D2 ratings cover welding. These organisations hold specialised competence but typically do not hold the broader aircraft-level maintenance authorisations that a CAT A AMO holds.

CRS is the certificate of release to service that an AMO issues after completing maintenance on an aircraft, component, or part. It is the document that confirms the work is done in accordance with the applicable maintenance data and that the aircraft may be returned to service.

SM CRS document is a document created under the instrument by the CAT D1 or D2 AMO. It is not a full CRS in the sense of regulation 42.760; rather it is a specialist maintenance certificate of release to service that, when issued, allows the CAT A AMO to take the view that the specialist maintenance is covered by the CAT A AMO’s own CRS for the aircraft. The instrument requires the SM CRS document to include a detailed specialist maintenance record (clause 3 of Schedule 1) and to be signed by each certifying employee.

Adverse Matters Report is a mandatory report that the CAT D1 or D2 AMO must give to the CAT A AMO as soon as practicable when the specialist maintenance cannot be certified because it was not completed in accordance with the maintenance data, because there are defects or non-conformances outside the prescribed limitations, or because any airworthiness information indicates a risk to aviation safety. This report must include all the information recorded in the specialist maintenance record.

Approved procedures are written procedures that both AMOs must have, approved in writing by CASA, to ensure compliance with the Schedule 1 conditions and proper coordination and control of all maintenance activities whose certification will rely on the instrument.

Time limitation is a structural feature: the instrument repeals itself on 30 April 2026. Anyone relying on it must monitor whether a replacement instrument is made before that date.

The primary parties are the two classes of AMO that the instrument defines. A CAT A AMO that performs line or base maintenance on aircraft and wants to subcontract non-destructive testing or welding to a specialist provider is directly affected. It gains the ability to issue a CRS without holding a D rating or employing the relevant specialists, but it must also bear the compliance burden of obtaining CASA approval, maintaining approved procedures, entering into a written contract with specific terms, and retaining documents. The CAT D1 or D2 AMO is similarly affected: it gains a streamlined pathway to provide specialist services to a CAT A AMO under its own certification, but it must comply with record-keeping obligations that mirror parts of CASR Part 42 (regulations 42.745 and 42.760(1) as if they applied to it) and must issue the SM CRS document only when the conditions in clause 9 of Schedule 1 are satisfied.

The certifying employees of both AMOs are indirectly affected because the specialist maintenance record must identify each certifying employee by name, certification authorisation number, and signature, and the SM CRS document must be signed by each such person. The employees of the CAT D1 or D2 AMO are the ones who actually perform the non-destructive testing or welding; the exemption in section 5 relieves the CAT A AMO from having those employees treated as its own employees for the purposes of paragraph 42.760(1)(c) and related provisions.

The instrument also affects CASA as the regulator. It must process written applications for approval of both AMOs and for approval of their procedures. The instrument says that it is “unlikely” that the requirements of aviation safety could be achieved by a CAT D1 or D2 AMO without a permanent facility - a note that signals CASA’s likely expectation when assessing an application.

Aircraft owners and operators are indirectly affected because the chain of certification becomes more complex. The CRS they receive from the CAT A AMO relies on a separate SM CRS document from a different organisation. If any condition of the instrument is not met, the CRS may be invalid, grounding the aircraft or exposing the operator to enforcement action.

Finally, the predecessor instrument EX60/20 and any approvals issued under it are directly affected: those approvals continue in force under this instrument, and references to EX60/20 in documents such as AMO expositions are deemed to refer to EX52/23.

Duty to obtain prior CASA approval. Both the CAT A AMO and the CAT D1 or D2 AMO must be approved in writing by CASA for the purposes of the instrument. This is a condition precedent - without approval, the exemptions do not apply.

Duty to have a written contract. There must be a written contract between the two AMOs with respect to the specific specialist maintenance (clause 2). The contract must specify that the specialist maintenance must be carried out in accordance with the relevant maintenance data and any prescribed limitations (clause 10(a)). It must also state that only a document fully complying with the instrument constitutes an SM CRS document (clause 10(b)). Critically, the contract must include terms requiring the CAT D1 or D2 AMO to give an Adverse Matters Report when the specialist maintenance cannot be certified (clause 10(c)). Each AMO must provide the other with a copy of its approved procedures (clause 10(d)). The contract is deemed to include the terms of each work order from the CAT A AMO (clause 11).

Duty to have approved written procedures. The procedures must be approved in writing by CASA and must ensure compliance with the Schedule 1 conditions and proper coordination and control of all maintenance activities whose certification will rely on the instrument (clause 8).

Duty of the CAT D1 or D2 AMO to create a specialist maintenance record. On completion of the specialist maintenance, the D-rated AMO must make a record that contains 13 categories of information, including aircraft registration, date and time, detailed description of the work, part numbers and serial numbers of parts installed, identification of maintenance data, results and airworthiness information, equipment used, certifying employee details, the AMO’s approval reference, a statement of whether all maintenance has been completed in accordance with the data, any prescribed limitations from the CAT A AMO’s work order, any known defects or non-conformances, and a statement identifying the document as a specialist maintenance record (clause 3).

Duty to issue an SM CRS document only when conditions are met. The CAT D1 or D2 AMO must issue the SM CRS document only if all specialist maintenance has been completed in accordance with the maintenance data, all known defects or non-conformances are within the prescribed limitations (if any), and there is no airworthiness information indicating a risk to aviation safety (clause 9). The document must include the specialist maintenance record and be signed by each certifying employee.

Duty of the CAT A AMO to issue a compliant CRS. The CRS issued by the CAT A AMO must comply with regulation 42.760 of CASR except for paragraph 42.760(1)(c) (the requirement that the CRS be based only on certification by the AMO’s own employees) (clause 4). The CAT A AMO may then issue the CRS even though the specialist maintenance was done by the D-rated AMO.

Direction to retain documents. Both AMOs must retain a copy of any document issued, given, or received under the instrument for at least 24 months after creation. This includes the contract, SM CRS documents, specialist maintenance records, and Adverse Matters Reports (section 7(2)). Additionally, each AMO must retain copies of its own and the other party’s approved procedures for at least 12 months after the contract expires or is terminated (section 7(3)). The CRS itself remains subject to the retention requirements in the Part 145 Manual of Standards.

Right of the CAT A AMO to rely on the SM CRS document. Provided all conditions are met, the CAT A AMO may take the view that its CRS covers the specialist maintenance even though it was not performed by its own employees.

Right of the CAT D1 or D2 AMO to be relieved from certain Part 145 MOS requirements. The exemption in section 6 relieves the D-rated AMO from the requirements of regulations 145.030(1)(a), 145.045(a)(v), and 145.070(1)(e) of CASR to the extent they require compliance with paragraph 145.A.50(a) of the Part 145 MOS (which deals with maintenance records). This allows the D-rated AMO to issue the SM CRS document in a form that may not fully conform to the Part 145 MOS record-keeping requirements, provided it meets the conditions of the instrument.

The instrument itself does not create new criminal or civil penalties. It operates as an exemption from existing CASR requirements, and the enforcement consequences flow from the underlying regulations. If any condition in Schedule 1 is not satisfied - for example, if the AMOs do not have a written contract with the required terms, or if the CAT D1 or D2 AMO issues an SM CRS document when the conditions in clause 9 are not met - then the exemptions in sections 5 and 6 do not apply. This means the CAT A AMO would be in breach of the provisions from which it was purportedly exempted, including subregulations 42.725(1) and (2), regulation 42.730, paragraph 42.745(a), and paragraph 42.760(1)(c). Those provisions carry their own enforcement liabilities under CASR Part 42, which may include infringement notices, enforceable undertakings, or civil penalty proceedings under the Civil Aviation Act 1988. Similarly, the CAT D1 or D2 AMO would lose its exemption from the Part 145 MOS requirements.

The direction to retain documents (section 7) is a direction made under the instrument. Failure to comply with the direction may constitute a breach of a condition of the exemption, because the direction is part of the instrument and the exemptions are expressly subject to the conditions in Schedule 1. Non-compliance with the retention direction would likely mean the AMO is not meeting the conditions, triggering the same loss of exemption.

CASA has ongoing oversight: it must approve the AMOs and their procedures in writing. CASA may withdraw or refuse approval at any time, and the instrument does not limit CASA’s discretion. The note in Schedule 1 about the unlikelihood of a CAT D1 or D2 AMO without a permanent facility being approved signals that CASA will scrutinise the operational capability of the specialist AMO.

Because the instrument is time-limited (repeal on 30 April 2026), any reliance on it after that date without a replacement instrument would also be a breach of the underlying CASR provisions.

The instrument is made under regulations 11.160, 11.205, and 11.245 of CASR. Regulation 11.160 is the general power to grant exemptions; regulation 11.205 allows CASA to impose conditions; regulation 11.245 allows CASA to give directions. The instrument therefore sits as a subordinate legislative instrument within the CASR framework.

The instrument interacts directly with CASR Part 42 (aircraft airworthiness requirements). It exempts a CAT A AMO from subregulations 42.725(1) and (2) (which require records and certification for maintenance), regulation 42.730 (which deals with the content of maintenance records), paragraph 42.745(a) (which relates to the CRS and the persons who may sign it), and paragraph 42.760(1)(c) (which requires a CRS to be based on certification by the AMO’s employees). However, the exemption is limited: the CAT A AMO’s CRS must still comply with the rest of regulation 42.760 (clause 4 of Schedule 1). Similarly, the CAT D1 or D2 AMO is exempted from the same subregulations 42.725(1) and (2) to the extent necessary to issue an SM CRS document, and clause 6 of Schedule 1 requires the D-rated AMO to comply with subregulation 42.750(1) (keeping a record of defects) as if it applied to the AMO and as if the reference to a CRS were a reference to an SM CRS document.

The instrument interacts with Part 145 of CASR and the Part 145 Manual of Standards (MOS). The CAT A AMO is exempted from paragraph 145.030(1)(a), subparagraph 145.045(a)(v), and paragraph 145.070(1)(e) to the extent they require compliance with subparagraph 145.A.55(c)1 of the MOS (maintenance records), but only with respect to the specialist maintenance records covered by section 7(2). The CAT D1 or D2 AMO is exempted from the same three Part 145 provisions to the extent they require compliance with paragraph 145.A.50(a) of the MOS (also maintenance records).

The instrument replaces CASA EX60/20. The savings provision (section 9) ensures continuity: approvals under EX60/20 continue as approvals under this instrument, and references to EX60/20 in other documents (such as AMO expositions or CASA publications) are automatically read as references to this instrument.

The instrument does not affect the operation of the Civil Aviation Act 1988 or other Commonwealth laws, but the underlying CASR penalties derive from that Act.

This instrument has not been amended since its commencement on 1 May 2023. It is a self-contained reissue of a previous instrument, CASA EX60/20, which it replaces via the savings provision. The instrument has a scheduled repeal date of 30 April 2026, meaning it has a fixed three-year lifespan. No amending instruments have been published as of the date of this analysis. If CASA considers that the exemption should continue beyond April 2026, it will need to make a new instrument (or amend this one to extend the repeal date, though the current wording provides for automatic repeal).

No litigation involving CASA EX52/23 has been reported in publicly available Australian aviation law decisions. Because the instrument is a legislative exemption that establishes a permissive regime, it is unlikely to be the direct subject of court proceedings. Legal challenges, if any, would more likely arise from enforcement actions where an AMO relied on the exemption but did not satisfy all conditions, leading to a dispute about whether the exemption applied. No such cases have been identified. The predecessor instrument EX60/20 also appears not to have been litigated. The instrument has not been the subject of a merits review or judicial review application as of the date of this analysis.

The exemption only applies to non-destructive testing and welding. The instrument does not extend to any other specialist maintenance task (e.g., composite bonding, heat treatment, shot peening, or specialist electrical testing). If a CAT A AMO tries to rely on the instrument for other specialist work, it will be in breach of the underlying CASR provisions.

Both AMOs must have prior written approval from CASA. This is not optional. A contract between the AMOs is not enough. Without CASA’s written approval for both parties, the entire exemption collapses. The application process carries both time and cost, and CASA may refuse approval if it is not satisfied about coordination and control, particularly if the D-rated AMO lacks a permanent facility (as the instrument notes).

The SM CRS document can only be issued if all three conditions in clause 9 are met. If the specialist maintenance is not fully completed in accordance with the data, or if there are any defects outside the prescribed limitations, or if there is any airworthiness information indicating a safety risk, the D-rated AMO must not issue the SM CRS document. Instead, it must issue an Adverse Matters Report as soon as practicable. A CAT A AMO that receives an Adverse Matters Report cannot rely on the instrument to cover that specialist maintenance; it must either rectify the issues or find another way to certify the work (such as by performing the work itself or using a different exemption path). The requirement to report adverse matters “as soon as practicable” is deliberately tight.

The specialist maintenance record (clause 3) is detailed and mandatory. All 13 categories of information must be included. Missing any one item - for example, the identity of the certifying employee or a reference to the maintenance data - means the record is not compliant, and the SM CRS document is not properly issued. The CAT A AMO then cannot rely on the exemption.

Document retention periods are not symmetrical. Documents issued, given, or received under the instrument must be retained for 24 months. But the approved procedures must be retained for at least 12 months after the contract expires or terminates - which could be well beyond 24 months if the contract runs for several years. An AMO that discards procedures too early may breach the direction.

The instrument repeals itself on 30 April 2026. Any contract or workflow that extends beyond that date needs to account for the possibility that the exemption will no longer be available. Work orders placed in early 2026 may not be completed and certified before the repeal. The instrument does not contain a transitional provision for work in progress at the time of repeal, so the unmodified CASR would apply from 1 May 2026.

The written contract must include very specific terms. Clause 10 lists mandatory specifications: the requirement to follow maintenance data and prescribed limitations, a statement about what constitutes an SM CRS document, an adverse matters reporting clause, and an obligation to exchange approved procedures. A standard commercial maintenance contract will almost certainly need to be amended to include these terms. The contract is also deemed to include each work order, meaning the work order becomes part of the contract and must be consistent with its terms.

The approved procedures must cover coordination and control. Clause 8 requires procedures for coordination and control of “all maintenance activities whose certification will rely on this instrument.” This is not just the specialist maintenance itself; it includes the CAT A AMO’s line or base maintenance activities that the CRS will cover. The procedures must be approved in writing by CASA. Developing and gaining approval for such procedures is a non-trivial cost.

The CAT A AMO remains responsible for the overall airworthiness of the aircraft. Even though the specialist maintenance is done by another AMO and certified via the SM CRS document, the CAT A AMO is the one that issues the CRS for the aircraft. If the specialist maintenance later turns out to be deficient, the CAT A AMO cannot simply blame the D-rated AMO - its own CRS is on the line.

An AMO wishing to use this exemption should follow a structured process:

1. Determine eligibility. Confirm that the specialist maintenance is limited to non-destructive testing or welding performed by a CAT D1 or D2 rated AMO. Confirm that the CAT A AMO holds a Category A rating and performs line or base maintenance on aircraft.

2. Obtain CASA approval in writing for both AMOs. Each AMO must apply to CASA for approval under the instrument. CASA will likely require evidence that the D-rated AMO has a permanent facility. The application should reference the specific scope of specialist maintenance expected.

3. Develop written procedures. Each AMO must prepare written procedures covering compliance with all conditions in Schedule 1 and coordination and control of all maintenance activities whose certification will rely on the instrument. These procedures must be submitted to CASA for written approval. The procedures should detail how the specialist maintenance will be ordered, how the specialist maintenance record will be created, how the SM CRS document will be issued and reviewed, how adverse matters will be reported, and how documents will be retained.

4. Enter into a written contract. The contract must be in place before any specialist maintenance is commenced. It must include the mandatory terms in clause 10 of Schedule 1: specification of maintenance data and prescribed limitations; a clause stating that only a document fully complying with the instrument is an SM CRS document; an adverse matters reporting clause requiring the D-rated AMO to give a detailed report as soon as practicable; and an obligation for each AMO to provide the other with a copy of its approved procedures. Each work order will be deemed part of the contract, so work orders must also be consistent.

5. Perform the specialist maintenance. The D-rated AMO performs the non-destructive testing or welding in accordance with the relevant maintenance data and any prescribed limitations provided by the CAT A AMO.

6. Create the specialist maintenance record. On completion of the specialist maintenance, the D-rated AMO must prepare a record with all 13 items listed in clause 3 of Schedule 1. This must include the registration mark, date and time, detailed description, part numbers and serial numbers, maintenance data identification, results and airworthiness information, equipment used, certifying employee identities (name, certification authorisation number, signature), the AMO’s approval certificate reference, a statement of completion, any prescribed limitations, any known defects or non-conformances, and a statement identifying the document as a specialist maintenance record.

7. Assess whether the SM CRS document can be issued. The D-rated AMO must check the three conditions in clause 9: all specialist maintenance completed in accordance with the data; any known defects or non-conformances within all prescribed limitations; and no airworthiness information indicating a risk to aviation safety. If all three conditions are satisfied, proceed to issue the SM CRS document. If any condition is not satisfied, the D-rated AMO must issue an Adverse Matters Report to the CAT A AMO as soon as practicable, including all the information from the specialist maintenance record.

8. Issue the SM CRS document. The SM CRS document must be in an approved form (either as contained in the D-rated AMO’s exposition or another form approved in writing by CASA and treated as an approved form). It must include the specialist maintenance record and be signed by each certifying employee (clause 9(f) and clause 7).

9. Issue the CRS for the aircraft. The CAT A AMO may now issue its own CRS covering the overall line or base maintenance, including the specialist maintenance, provided the CRS complies with regulation 42.760 except for paragraph 42.760(1)(c). The CAT A AMO must reference the SM CRS document as supporting certification.

10. Retain documents. Both AMOs must retain a copy of the contract, SM CRS documents, specialist maintenance records, Adverse Matters Reports, and any other documents issued, given, or received under the instrument for at least 24 months after the document is created. Additionally, each AMO must retain copies of its own and the other party’s approved procedures for at least 12 months after the contract expires or terminates. The CRS itself is subject to the retention requirements in the Part 145 MOS.

11. Monitor the instrument’s life. The instrument is repealed on 30 April 2026. Before that date, AMOs should check whether CASA has made a replacement instrument. If not, the exemption will cease, and any new specialist maintenance arrangements must comply with the unmodified CASR. Work in progress at the time of repeal may face a gap in the legal basis for certification.