Part 145 Manual of Standards (MOS)

The MOS content operates using a small number of recurring regulatory concepts and cross-references. Understanding those concepts is essential for applying the instrument.

• Category A certifying employee, Part 66. The MOS assumes the reader knows the Part 66 Category A licence classification. Operationally the Appendix binds AMOs: they may authorise Category A employees to perform and certify the specific tasks enumerated in the list (paras 1-3). Many tasks are "minor", "simple defect rectification", or "routine". The MOS therefore draws a lines-based distinction between line/minor tasks and more complex maintenance that sits outside Category A scope.

• AMO authorisation scope. The Appendix frames the list as the "scope of authorisations that an AMO may issue" for Category A employees, so the AMO is the decision-maker that issues authorisations within the permitted envelope. The MOS delimits rather than prescribes every case: for components or tasks not explicitly listed, the instrument allows for CASA-approved "simple tasks" to be authorised (paras 3(q), 3(p)).

• CASA approval and guidance dependencies. Several entries require active CASA decisions: the weekly-check-equivalence determination is a CASA decision and is referenced to Part 66 guidance material (para 1(b)); MEL implementations are permitted only where the MEL application is one CASA approves as a simple task (para 3(p)); replacement of "any other component" is allowed if CASA approves the task as simple (para 3(q)). The conditions for non-Part 66 certifying employees also require equivalence of training to Part 66 human factors and airworthiness regs training, which will in practice be assessed by an AMO or CASA against Part 66 MOS standards (condition (c)). Thus the MOS delegates substantive discretion to CASA and relies on external guidance.

• Scope limitations and cross-references. The MOS repeatedly cross-references other instruments: Part 66 of CASR 1998 for Category A licencing and Appendix III of the Part 66 MOS for type training levels (condition (e)), and paragraph 145.A.30(k) of CASR (for the regulatory pathway to use non-Part 66 personnel). The MOS therefore functions as a subordinate, operational standard tied into an interconnected regulatory framework.

• Experience and training thresholds for non-Part 66 staff. The MOS sets quantitative experience thresholds (5 years line, 8 years base; reduced to 3 years for Category A-equivalent tasks) and qualitative training equivalence obligations (human factors and airworthiness regs) plus task/type training requirements aligned to Appendix III (conditions (d)-(e)). These impose measurable, verifiable qualifications for non-Part 66 staff to be used in certifying roles.

• Helicopter-specific allowances. The Appendix contains a set of helicopter-only items (para 3(r)(i)-(v)), indicating that certain tasks for rotary-wing aircraft are expressly covered. These include removal/installation of certain external fittings, chip detector handling, rotor blade folding/inspection/deployment procedures (subject to handling instructions and ground equipment), and certain minor repairs to acrylic windscreens. This signals that the instrument applies discretely to fixed-wing and rotary-wing contexts where tasks differ materially.

• Simple task concept. The instrument repeatedly relies on a "simple task" label that is not defined within the excerpt. Where tasks are not enumerated, the authority to perform them rests on CASA's approval of the application as a "simple task" (paras 3(p) and 3(q)). Operationally, this creates an open-ended but administratively gated route for tasks to be added to the Category A authorisation envelope.

Collectively, these concepts show the MOS delivering a prescriptive list (for certainty) together with a controlled expansion mechanism (CASA-approved simple tasks) and a pathway for non-Part 66-qualified nationals to be used under specified, verifiable conditions. Implementation depends on AMO authorisations, CASA approvals and cross-instrument training and type standards.

The MOS text identifies four principal affected parties and spells out discrete decision or cost-bearing roles for each.

• Aircraft Maintenance Organisations (AMOs). AMOs are the immediate addressees of the authorisation scope. The Appendix opens with "the scope of authorisations that an AMO may issue" to Category A Part 66 certifying employees. Practically this means AMOs must structure their internal authorisation processes, personnel rosters, and maintenance manuals to reflect the enumerated list and any CASA-approved simple tasks. The AMO decides which employees to authorise, but only within the legal envelope the MOS describes. Consequently AMOs bear compliance costs: documenting authorisations, ensuring employees meet license/experience/training standards, and ensuring AMO procedures mirror the MOS and any CASA approvals referenced.

• Category A Part 66 certifying employees. These employees gain a defined scope of permissible certifying functions: minor scheduled line maintenance, pre-flight/transit/overnight checks, replacement of specific components, MEL implementation where CASA approves, and a list of example tasks (paras 1-3). A Category A certifying employee’s right to sign a certificate of release to service is constrained by the MOS list and by any AMO internal restriction. The MOS therefore shapes daily duties for Category A workers and sets what actions they can certify.

• Non-Part 66 certifying employees from other National Aviation Authorities (NAA). The MOS creates a conditional pathway for NAA-licensed personnel to be used in Australian certifying roles, provided five conditions (a)-(e) are met. Affected individuals must hold an NAA-issued ICAO Annex 1 AMEL (condition (a)), must have the specified experience (d), and must receive the human factors, airworthiness regulation, and type/task training required (c, e). This affects international recruitment, contractors, and operators who hire foreign licence-holders: they now have a textually defined compliance route but also a non-trivial training and evidence burden.

• Regulator (Civil Aviation Safety Authority, CASA) and its guidance apparatus. The MOS repeatedly assigns CASA the role of approver and judge of equivalence: CASA determines what it considers equivalent to a weekly check and lists that in Part 66 guidance material (para 1(b)); CASA approves whether an MEL application is a "simple task" for Category A implementation (para 3(p)); CASA approves other "simple tasks" (paras 3(q)); and implicit CASA assessment is required for training equivalence. The regulator decides and certifies equivalence and simple-task status and thus shapes the practical envelope beyond the explicit list.

Secondary affected parties include registered operators (who set aircraft maintenance programs referenced in para 1(a) and whose MEL entries can be implemented under para 3(p) if CASA approval exists), helicopter operators (due to helicopter-specific allowances), and certifying employees’ home NAAs (because the MOS requires an ICAO Annex 1 licence). Downstream, airline operations and scheduling teams may be affected by the kinds of line maintenance available under Category A authorisations.

Who pays: AMOs and operators will pay for additional training, record-keeping, CASA approvals where required, and internal administrative controls. Individual employees may face costs linked to obtaining type/task training and demonstrating experience equivalence. CASA bears administrative decision costs in assessing and approving equivalence and simple-task applications.

Who decides: AMOs decide to authorise and manage employees within the MOS envelope; CASA decides equivalence and approves "simple tasks"; registered operators determine maintenance program content and MEL entries. Employees decide whether to obtain or demonstrate the training/experience required for authorisation under either the Part 66 route or the non-Part 66 conditional route.

The MOS establishes specific duties and limited rights tied to authorisation, certification, training and evidence.

Duties on AMOs and operators

• Limit authorisations to the MOS envelope. AMOs that issue authorisations to Category A Part 66 employees must do so within the scope provided by the Appendix. That list is explicit (paras 1-3) and includes broad categories such as "minor scheduled line maintenance" and enumerated component replacements. If an AMO authorises tasks beyond this list, that authorisation will be outside the MOS-specified scope unless CASA has approved the task as a "simple task" (paras 3(p), 3(q)).
• Ensure MEL implementation approvals align with CASA approvals. If an operator’s MEL allows deactivation or component deactivation, the MOS permits Category A certifying employees to implement MEL actions only where the MEL application is one that CASA approves as a simple task (para 3(p)). AMOs and operators therefore must ensure CASA approval precedes Category A certification for MEL items.
• For non-Part 66 certifying employees used under paragraph 145.A.30(k), ensure all five conditions (a)-(e) are met and documented. This includes verifying licences (condition (a)), scope limits (b), training equivalence (c), maintenance experience (d), and task/type training requirements (e).
• Maintain evidentiary records. While the MOS does not prescribe record formats, the conditions in (a)-(e) implicitly require documentation of foreign licences, training evidence, experience records and type/task training records for audit or regulatory review.

Duties on certifying employees

• Work within authorised scope. Category A certifying employees may certify only those minor or simple tasks listed or CASA-approved simple tasks. Non-Part 66 employees authorised under 145.A.30(k) must not exceed their national licence scope (condition (b)).
• Hold and maintain qualifying licences/trainings. Category A employees must hold Part 66 Category A licences; non-Part 66 certifiers must hold an NAA ICAO Annex 1 AMEL (condition (a)) and must have completed human factors and airworthiness regs training equivalent to Part 66 (condition (c)). They also must have the experience (d) and type/task training (e) required.

Rights conferred

• Right to certify release to service for listed tasks. The MOS gives Category A certifying employees the operational right to issue certificates of release to service for the enumerated tasks and checks, subject to AMO authorisation and CASA approvals where required (paras 1-3).
• Conditional right for non-Part 66 licence-holders. Provided conditions (a)-(e) are met, non-Part 66 licence-holders can be used as certifying employees under paragraph 145.A.30(k). That is a conditional right: the MOS sets the gates to be cleared before the AMO/operator may rely on such certifiers.

Specific procedural duties and limits

• Training alignment with Appendix III. Condition (e) requires maintenance certifying employees to receive type training at a level corresponding to Appendix III of the Part 66 MOS for every aircraft they are authorised to certify. For persons restricted to Category A-equivalent tasks, task training may substitute for full type training. This establishes an explicit training-grade duty tied to another MOS instrument.
• Experience proof thresholds. Condition (d) sets quantifiable experience thresholds: 5 years maintenance experience for a line maintenance certifying employee, 8 years for a base maintenance certifying employee, with a reduction to 3 years if the individual's authorised tasks do not exceed Category A. AMOs and operators must therefore verify and retain those experience records before using such employees in certifying roles.

What is not assigned in the MOS

• The MOS does not specify the form of certification statements, nor does it specify the administrative process for CASA approvals of "simple tasks" within this extract. It also does not specify penalty amounts or enforcement mechanisms; it relies on the CASR legal framework for enforceability (note to Part 145 MOS). To determine enforcement action or sanctions you must consult the relevant provisions of CASR 1998 and associated enforcement policies.

In short, the MOS creates discrete duties to restrict certification to the listed tasks and to verify licences, experience and training where non-Part 66 personnel are used. It confers rights to certify within those bounded categories and makes CASA the gatekeeper for equivalence and "simple task" approvals.

The MOS extract itself does not prescribe fines, civil penalties or criminal liabilities. The text expressly notes that the Manual of Standards is "in force under the Civil Aviation Safety Regulations 1998", which indicates that the MOS operates as a standards instrument subordinate to CASR 1998 (note to Part 145 MOS). However, within the provided excerpt there are no express penalty clauses, enforcement procedures, or administrative sanctioning powers described.

What the MOS does do in enforcement terms is set mandatory technical and documentary conditions that will be used by the regulator and by AMOs as the benchmark for compliance. For example, the conditions (a)-(e) set out verifiable criteria (licence type, training equivalence, years of experience, type training) that are objective compliance markers an auditor or CASA inspector can examine. The MOS therefore creates an evidentiary framework that supports enforcement under CASR 1998, even if the specific enforcement powers are not located in the MOS text.

Implications for enforcement practice, based on the MOS content

• Enforcement will rely on CASR authority. Because the MOS is the standard instrument under CASR 1998, enforcement action for non-compliance with the MOS is likely to be pursued through the powers available under the CASR and the Civil Aviation Safety Act framework. Those enforcement mechanisms and penalties are not contained in the MOS extract and must be sought in the enabling legislation and regulations.
• Inspectors and AMOs will need to check documentary evidence. The MOS prescribes documentaryly verifiable criteria (licences, training and experience). CASA or delegated inspectors exercising enforcement functions will thus rely on records and training logs when investigating compliance.
• CASA approvals as compliance preconditions. Several permissions in the MOS depend on CASA decision-making (equivalence of weekly checks, CASA approval of MEL simple tasks and other simple tasks). Failure to obtain required CASA approvals where the MOS requires them will be a clear compliance breach in any enforcement assessment.

What the document does not provide

• The MOS does not define the consequences of non-compliance (suspension, fines, remedial directions). It does not set appeal pathways or administrative review within this excerpt. It also does not list inspector powers or procedural mechanisms for enforcement. Those matters lie in CASR 1998 and the Civil Aviation Safety Act, which are outside the MOS excerpt provided.

Actionable takeaway for compliance and risk management

• Treat the MOS provisions as mandatory operational standards and expect enforcement to be documentary and standards-based. AMOs and operators should maintain clear records showing licences, type/task training, human factors and airworthiness regs training equivalence, and experience logs, because these are the precise elements the MOS makes mandatory or conditional. Where CASA approvals are required, do not rely on internal interpretation; obtain express CASA approval and retain the approval documentation.

For precise penalty structures and enforcement powers, the MOS user must consult CASR 1998 and the Civil Aviation Safety Act; the MOS provides the normative standards but not the enforcement apparatus in this text.

The MOS extract is explicitly a subordinate standards instrument operating within the CASR 1998 framework and the broader international aviation regulatory system. The text contains multiple express cross-references that determine how it interacts with other legal instruments and administrative processes.

Interaction with CASR 1998 and Part 66

• Part 66 of CASR 1998 is the primary licencing regime referenced. The Appendix authorises AMOs to issue authorisations to employees "qualified under Part 66 of CASR 1998 as Category A" (opening line). The MOS therefore implements operational detail for the Part 66 licencing categories; it sets what Category A licence-holders may be authorised to do within an AMO environment. Part 66 MOS materials are also referenced for type-training levels (Appendix III of the Part 66 MOS) in condition (e). The MOS content therefore relies on both the regulatory licencing definitions in CASR Part 66 and the higher-level MOS material for training standards.

Interaction with paragraph 145.A.30(k) of CASR 1998

• The conditions section is expressly intended to operationalise paragraph 145.A.30(k) , "Conditions for the use of employees not qualified to Part 66 of CASR 1998 in accordance with paragraph 145.A.30 (k)". In effect the MOS specifies the conditions under which the statutory provision at 145.A.30(k) may be implemented. This is a direct subordinate-to-parent relationship: the MOS supplies the technical conditions for the statutory exception or permission.

Interaction with ICAO standards and NAAs

• Condition (a) requires that the individual hold "an appropriate licence issued by an NAA under the country’s national regulations that is an ICAO Annex 1 aircraft maintenance licence". The MOS therefore imports an international standard (ICAO Annex 1) as a normative requirement and links domestic acceptance of foreign licences to the ICAO regime. This creates an interaction between Australian CASR/MOS requirements and the licensing regimes of other NAAs to the extent those licences are ICAO Annex 1-compliant.

Interaction with MELs and operator maintenance programs

• Paragraph 1(a) allows Category A tasks that are "specified in the registered operator’s approved aircraft maintenance program", and paragraph 3(p) permits implementation of an operator’s MEL "if the MEL application is one that CASA approves as a simple task". Thus the MOS requires alignment between the operator's maintenance program/MEL and the AMO authorisations, with CASA as the approving authority for what counts as a simple MEL task. In practice this binds operator maintenance programs and MEL content into the MOS operational envelope, subject to CASA approval.

Interaction with other MOS instruments

• Condition (e) requires type training at a level corresponding to Appendix III of the Part 66 MOS. Therefore compliance depends on reading this MOS extract alongside the Part 66 MOS Appendix III for training grade requirements. The MOS extract cannot be applied in isolation; it prescribes interactions across MOS documents.

Interaction with CASA guidance material

• Paragraph 1(b) expressly relies on CASA judgment and Part 66 guidance material when it permits "minor scheduled line maintenance" tasks not specified in an operator’s maintenance program but which "CASA considers is equivalent to a weekly check and lists in Part 66 guidance material." This creates a dynamic interaction where CASA guidance material and its judgments are an operative part of whether a particular task sits within the MOS-authorised network.

Practical legal interaction effects

• The MOS acts as the technical gating instrument. Compliance analysis requires cross-referencing: (1) the CASR statutory provisions (Part 66, paragraph 145.A.30(k), and enforcement parts); (2) the Part 66 MOS (Appendix III for training and Part 66 guidance material for weekly-check equivalence); (3) registered operator maintenance programs and MEL approvals; and (4) CASA approvals and guidance. Failure to align across these instruments will generate non-compliance even where one element alone might appear compliant.

Limits on unilateral interpretation

• Because the MOS defers to CASA for key determinations, AMOs and operators cannot unilaterally expand the Category A authorisation envelope by internal interpretation alone. CASA approval or the presence of explicit entries in the operator maintenance program are needed for several categories of action. That operational tie-in is both a compliance control and a source of administrative friction.

In summary, the MOS is a technical sub-instrument that requires the user to map its provisions across Part 66 licencing, Appendix III training standards, CASA guidance and approvals, registered operator maintenance programs and international licence recognition under ICAO Annex 1. Legal and operational compliance therefore entails systematic cross-referencing across those instruments.

The MOS compilation includes a table of registration and commencement dates, and a Table of Amendments that records which provisions were amended, repealed, substituted or added in successive MOS instruments. The key recorded entries from the table are:

• MOS 145 2011: Registered 18 February 2011 (F2011L00281) and commenced 27 June 2011. This is the base instrument in this compilation.
• MOS 145 2011 Amendment No. 1: Registered 22 June 2011 (F2011L01192), commenced 27 June 2011 (entry shows "," under application/saving or transitional provisions).
• MOS 145 2012 Amendment No. 1: Registered 5 April 2012 (F2012L00794), commenced 6 April 2012.
• MOS 145 2012 Amendment No. 2: Registered 25 June 2012 (F2012L01326), commenced 26 June 2012.
• MOS 145 2014 Amendment No. 1: Registered 2 October 2014 (F2014L01316), commenced 3 October 2014, with a note that this amendment was disallowed by the Senate on 18 March 2015 at 17:57 (the table explicitly notes the disallowance).

The Table of Amendments identifies specific provisions and the manner in which they were affected. Selected entries include:

• s. 1: replaced (rs.) by MOS 145 2011 No. 1.
• s. 2: amended (am.) by MOS 145 2011 No. 1.
• s. 3: repealed (rep.) by MOS 145 2011 No. 1.
• MOS title, Schedule heading and other items are marked as repealed or amended across the listed instruments.
• Numerous MOS sections are recorded as amended by MOS 145 2011 No. 1 and subsequent amendments, and multiple sections are recorded as amended by MOS 145 2014 No. 1 but annotated "disallowed".
• Appendix IV is recorded as added (ad.) by MOS 145 2014 No. 1 but flagged as disallowed.

The effect of the recorded disallowance is that amendments registered and commenced on 3 October 2014 under MOS 145 2014 No. 1 were subsequently disallowed by the Senate on 18 March 2015. The table lists many provisions with the annotation "MOS 145 2014 No. 1 (disallowed)", indicating that the changes proposed or adopted in that amendment instrument were not sustained by the parliamentary disallowance process.

What the amendment table means in practice

• The MOS has undergone iterative change since its 2011 inception, with frequent amendments in 2011 and 2012. The attempted 2014 amendment had wide-ranging effects across many sections but was disallowed by the Senate and thus has a special status in the amendment record. The table records which sections were affected and how (added, amended, repealed, replaced), so a compliance practitioner must read the MOS in the context of the final operative instruments (i.e., the versions that remained in force after any disallowance).

Limitations of the amendment record provided

• The table provides register and commencement dates and amendment mechanics (am., ad., rs., rep.), but it does not provide legislative history reasons or explanatory memoranda in this extract. It also does not show the text of the amendments themselves. To determine the substantive change effected by each amendment, one must consult the full text of the relevant MOS amendment instruments and the FRLI registered versions referenced in the table identifiers (e.g., F2011L00281, F2014L01316).

Operational guidance from the amendment history

• Because several entries are marked "disallowed", practitioners should verify the operative MOS text by reference to FRLI or the statutory instrument register to confirm which amendments are in force currently. The table itself is an index; it flags that change is possible and has occurred, but it does not substitute for reading the operative MOS as currently in force.

The provided MOS excerpt contains no case law, no judicial decisions, and no references to litigation. The annotation table and notes record administrative amendment events (including a Senate disallowance of MOS 145 2014 No. 1), but there are no court cases quoted, no tribunal determinations, and no litigation outcomes referenced in the text.

Consequences of the absence of litigation references

• Lack of recorded litigation in the MOS extract indicates that the MOS serves primarily as an administrative technical standard rather than as a product of judicial interpretation in the text provided. Legal questions about the interpretation of "simple task", "equivalent to a weekly check", or the boundaries of 145.A.30(k) are therefore not resolved by any case law within this document. Practitioners should be aware that statutory and regulatory disputes arising from application of these provisions would need to be located in judicial or tribunal databases external to this MOS extract.

Operational implication for lawyers and compliance officers

• Because the MOS contains discretionary elements that invite administrative decisions by CASA (e.g., approval of simple tasks, equivalence determinations), disputes about those decisions could in principle be litigated or administratively reviewed, but no such cases are reported in this excerpt. In the absence of precedent in the text, regulatory ambiguity around CASA discretion or the interpretation of training equivalence will need to be managed administratively through seeking explicit CASA approvals or by developing robust documentary evidence to support internal compliance decisions.

Note on the Senate disallowance

• The only adjudicative-like event recorded is a parliamentary (Senate) disallowance of MOS 145 2014 No. 1 on 18 March 2015. That is a political-administrative mechanism, not a court decision, but it affects the legal status of those amendments. The MOS table records the disallowance; there is no commentary or litigation record about the disallowance in this excerpt.

For legal certainty in contentious matters, the MOS user must therefore look beyond this document to CASR 1998, the Part 66 MOS, CASA decisions, administrative review pathways, and any judicial decisions that have since interpreted these instruments.

The MOS text contains multiple operational and interpretative traps that create compliance risk if not handled carefully. Below are concrete "gotchas" drawn from the text and the mechanism by which each risk arises.

1. Dependence on CASA approval for unspecified tasks

• Several key permissions hinge on CASA approving an application as a "simple task" (paras 3(p) and 3(q)) or determining equivalence to a weekly check and listing it in Part 66 guidance (para 1(b)). If an AMO or operator assumes that a task is "simple" without express CASA approval, the AMO may be operating outside the MOS-authorised scope. The mechanism of risk: reliance on internal classification instead of obtaining a definitive CASA approval.

2. "Simple task" is not defined in the extract

• The text repeatedly mentions "simple task" but does not provide a definition in this extract. That leaves room for differing interpretations between AMOs and CASA. The compliance implication: AMOs should not self-certify tasks as simple; they should obtain CASA confirmation or ensure the task falls squarely within the enumerated list.

3. MEL implementation requires CASA-approved MEL application

• Category A implementation of an operator’s MEL is conditional on CASA approval of the MEL application as a simple task (para 3(p)). Operators may wrongly assume that because an MEL item is minor it can be implemented by Category A staff. The MOS requires CASA approval. The mechanism is a cross-approval gate: a plausible operational shortcut will not satisfy the MOS.

4. Use of non-Part 66 employees requires multiple verifiable items

• Condition (a)-(e) together create a bundle of documentary requirements: NAA-issued ICAO Annex 1 licence, scope alignment with national licence, equivalent human factors and airworthiness regs training, quantified experience thresholds, and type training aligned to Appendix III (para Conditions (a)-(e)). The gotcha: failure to document any one element invalidates the pathway under 145.A.30(k). Practically, the evidence trail must be robust and stored.

5. Experience thresholds vary by role and task

• Condition (d) sets 5 years for line certifiers, 8 years for base certifiers, but allows a 3-year threshold for those whose authorized tasks do not exceed Part 66 Category A. The gotcha: misclassification of the employee's role or authorised task set can lead to under-provisioning of experience requirements. AMOs must ensure authorised task sets are tightly defined to permit reliance on the lower threshold where intended.

6. Type training vs task training distinction

• Condition (e) requires type training corresponding to Appendix III of the Part 66 MOS, but allows task training instead of complete type training where authorised tasks do not exceed Category A. The gotcha: AMOs must be precise in documenting why task training suffices. Without clear records mapping the authorised tasks to task training curricula, oversight will find the AMO non-compliant.

7. Operator maintenance program coupling

• Paragraph 1(a) ties certain Category A tasks to what is specified in a registered operator's approved aircraft maintenance program. The gotcha: tasks performed under an operator contract must be reconciled with both the AMO authorisations and the operator's maintenance program. Discrepancy between operator program entries and AMO authorisations will create non-compliance.

8. Helicopter-specific allowances have preconditions

• Rotor blade folding/deploying is permitted "if handling instructions permit folding for storage" and "ground support equipment is available" (para 3(r)(iii)(A)-(B)). The gotcha: having an employee authorised to fold blades without confirming both the specific handling instructions and the availability of approved ground support equipment will breach the MOS.

9. International licence acceptance is conditional on ICAO Annex 1 status

• Condition (a) requires NAA licences to be ICAO Annex 1 aircraft maintenance licences. The gotcha: not every foreign licence or endorsement will meet Annex 1 standards or the AMO's expectations. Relying on a foreign licence without confirming Annex 1 compliance risks regulatory breach.

10. Amendment history and disallowance risk

• The amendment table shows MOS 145 2014 No. 1 was disallowed by the Senate. The gotcha: practitioners relying on older or draft MOS amendment texts might be misled about current operative provisions. Always confirm the operative instrument as registered and not later disallowed.

11. No penalties in MOS , enforcement lies elsewhere

• The MOS does not state penalties though it operates under CASR 1998. The gotcha: organisations may mistakenly assume permissive status if no penalty text is present. The proper approach is to treat the MOS as mandatory operational standards enforceable via CASR mechanisms.

12. Cross-instrument reading required

• The MOS depends on Part 66 MOS Appendices and CASA guidance; failure to read those cross-referenced instruments is a compliance pitfall. The gotcha: reading the Appendix in isolation will not give the full picture of training levels, definitions, or CASA guidance lists.

In every instance the mechanism of risk is documentary misalignment, administrative assumption, or insufficient CASA approvals. The practical mitigation is procedural: obtain explicit CASA approvals where the MOS requires them, document licences/training/experience, map authorised tasks to training curricula, and reconcile operator maintenance programs with AMO authorisations.

Compliance with the MOS requires a structured, document-first approach that maps personnel, tasks, and approvals to the MOS’s enumerated list and CASA-dependent approvals. Below are concrete steps an AMO/operator should take, linked directly to the MOS provisions.

1. Map Category A task authorisations to the MOS list

• Prepare an inventory of all Category A certifying activities undertaken by your AMO and cross-check each against the MOS enumerated tasks in paras 1-3. For items not explicitly listed, identify whether the task might qualify as a CASA-approved "simple task" under paras 3(p) and 3(q). Do not assume membership; either rely on explicit MOS listing or obtain CASA approval.

2. Reconcile operator maintenance programs and MEL entries

• For any Category A task that an operator’s approved maintenance program specifies, keep a clear cross-reference in the AMO maintenance control and authorisation records (para 1(a)). For MEL-related actions, ensure the MEL application has a CASA-approved "simple task" status before allowing Category A employees to implement MEL items (para 3(p)). Retain CASA approval documentation tied to each MEL item.

3. Implement an approval-seeking process for "simple tasks"

• Where an AMO wishes to authorise a task not on the enumerated list, submit the relevant task documentation to CASA for determination as a "simple task". Establish a tracking register of CASA determinations and ensure the task scope authorised to Category A employees aligns exactly with the CASA approval.

4. Verify and document licence and experience for non-Part 66 employees

• If the AMO intends to use certifying employees who do not hold Part 66 licences, confirm their NAA licence is an ICAO Annex 1 AMEL (condition (a)). Verify that the scope of their national licence does not exceed the scope you will authorise them to exercise (condition (b)). Collect and retain documented evidence of maintenance experience: 5 years for line, 8 years for base, or 3 years if tasks do not exceed Category A-equivalent (condition (d)).

5. Implement human factors and airworthiness regs training equivalence

• Condition (c) requires evidence that the individual has received training on human factors and airworthiness regulations equivalent to that detailed in Part 66. Conduct a gap analysis between the foreign training curriculum and the Part 66 MOS human factors/airworthiness training requirements. Where gaps exist, provide bridge training and retain signed training records and assessment outcomes to evidence equivalence.

6. Provide and document type or task training consistent with Appendix III

• For each aircraft type on which a certifying employee will be authorised, ensure type training is provided at the level corresponding to Appendix III of the Part 66 MOS, unless the person is confined to Category A-equivalent tasks, in which case task training may be used instead (condition (e)). Map training records to the authorised task list and retain training completion certificates, syllabi and competency assessments.

7. Ensure helicopter-specific prerequisites are met

• For helicopter tasks listed in para 3(r), ensure handling instructions specifically permit folding if folding rotor blades are to be handled (para 3(r)(iii)(A)), and confirm ground support equipment availability (para 3(r)(iii)(B)). For chip detector handling and visual inspections, maintain documentation showing the specific inspection criteria and decisions permitted (para 3(r)(ii)-(iv)).

8. Maintain an auditable authorisation and competency register

• Keep a centralised register showing for each certifying employee: licence type, licence number and issuing NAA (where applicable), authorised task list, training records (human factors, airworthiness regs, type/task training), experience logs with employment history dates, and CASA approvals for relevant tasks/MEL items. This register will support CASA inspection and any enforcement or audit processes.

9. Update AMO procedures and manuals

• Amend the AMO exposition and other internal procedures to reflect the precise MOS-authorised task sets, training requirements, and CASA approvals. Ensure the AMO's quality system requires sign-off that employees are authorised only after all MOS conditions are met, and that records are uploaded to the quality management system.

10. Institute a CASA-approval checkpoint prior to operationalising new tasks

• Before operationalising any task not explicitly in the MOS list, route the task through a CASA approval checkpoint. Document the application, CASA response, and tie that approval to the employee authorisation record.

11. Monitor amendment status and FRLI entries

• Given the amendment history and the disallowance of MOS 145 2014 No. 1, periodically check the Federal Register of Legislation (FRLI) or CASA notices to confirm the operative MOS version. Do not rely on draft or superseded amendment texts for compliance determinations.

12. Prepare for CASA inspections focusing on documentary evidence

• Anticipate that CASA inspectors will focus on documentary evidence demonstrating compliance with the MOS’s objective conditions. Ensure records are precise, dated and readily retrievable. Where equivalence is asserted (weekly-check equivalence, training equivalence), retain the rationale and documentation that supported the AMO’s position and, where applicable, CASA confirmations.

13. Train compliance and quality staff on MOS interdependencies

• Because the MOS depends on other instruments (Part 66 MOS Appendix III, Part 66 guidance materials), ensure compliance personnel understand these cross-references. Maintain a compliance checklist that includes each cross-reference and the evidence required for it.

14. Seek early clarification from CASA for ambiguous items

• Where the MOS text leaves interpretative gaps (definition of "simple task", scope of "equivalent weekly check"), seek formal clarification from CASA and retain the response. Administrative clarity from CASA reduces enforcement risk.

15. Limit delegation and internal authorisation to trained signatories

• Ensure that only designated AMO signatories who have training in the MOS requirements and CASA processes can issue authorisations to Category A or non-Part 66 certifying employees. Maintain a list of authorised signatories and their competence evidence.

By aligning operational processes to the MOS’s enumerated tasks, CASA approval requirements, experience and training thresholds, and the documentary evidence regime, AMOs and operators can create a defensible compliance posture. The central compliance mechanism the MOS demands is documentary alignment: licences, training, experience, CASA approvals and operator program coherence must be explicit and readily auditable.