CASA EX44/24 — Maintenance on Limited Category and Experimental Aircraft Exemption 2024

The instrument relies on a small number of tightly defined concepts. Understanding these concepts is necessary to work out the scope and trigger points for the exemption.

• Exempted aircraft. The term is defined to mean a limited category aircraft or an aircraft on which an experimental certificate is in force (s 3, definition). The instrument notes that certain terms retain their statutory meaning under the Civil Aviation Act 1988 and the regulations (s 3 note). The source text does not reproduce those external definitions; practitioners must cross‑check the CASR and the CASR Dictionary to confirm whether a particular airframe falls within “limited category” or has an active experimental certificate.

• Exempted aircraft maintenance. The instrument defines this by negative description. Exempted aircraft maintenance is maintenance on an exempted aircraft that is not any of the following: maintenance of instruments and equipment required by CASR, CAR or the Civil Aviation Orders; maintenance to comply with a condition on the special or experimental certificate; maintenance specified in an airworthiness directive or CASA direction; and maintenance to comply with an instruction specified in the aircraft’s approved maintenance data (s 3, definition of exempted aircraft maintenance). The definition therefore excludes a set of maintenance tasks from the exemption, preserving the operation of mandatory airworthiness requirements, certificate conditions, ADs/directions, and approved maintenance data obligations.

• Major design change. For exempted aircraft, a “major design change” is a design change that has a significant effect on weight and balance, structural strength, performance, operational characteristics, or other characteristics that may affect the validity of the aircraft’s special or experimental certificate (s 3). The definition is outcome‑oriented, linking the concept to safety‑relevant characteristics and certificate validity.

• Exemptions and conditions. The instrument grants exemptions from CAR regulation 42U and specified paragraphs of 42W (s 5(1)). For the registered operator, these are subject to the condition in s 6(1) where the maintenance involves a major design change. The condition requires written notice to and written acceptance by one of four named recipients before any further operation or flights (s 6(1)-(2)).

• Information requirement. The precise items of information that must be provided where a major design change has occurred are listed in s 6(2): description of the maintenance; photographs if the maintenance has been carried out; reasons for the change; analysis of effects against the major design change criteria; and explanation why safety will not be adversely affected (s 6(2)(a)-(e)). The text ties the operator’s authority to operate to receipt of written acceptance.

• Temporal limitation. The instrument is expressly temporary, commencing 1 August 2024 and ceasing on the earlier of commencement of specified Parts of new legislation or 31 July 2027 (s 2). The instrument therefore functions as an interim regulatory arrangement pending formal commencement of those Parts.

These core concepts create a framework where routine or non‑mandated maintenance on limited category and experimental aircraft can proceed without compliance with the cited CAR provisions, subject to preservation of mandatory ADs, certificate conditions and approved maintenance data requirements, and with an explicit reporting/acceptance gate where the maintenance amounts to a major design change.

The instrument identifies two classes of addressees (s 4). First, the registered operator of an exempted aircraft. Second, each person carrying out exempted aircraft maintenance. The exemptions and conditions therefore operate at both the operator level and the level of the individual or organisation performing the maintenance.

Registered operator. The registered operator is the entity responsible for operation of the aircraft. The instrument explicitly makes the exemptions available to registered operators (s 4; s 5(1)). For operators, the exemptions are conditional: if maintenance constitutes a major design change, the registered operator bears obligations before operation or permitting flight (s 5(2); s 6(1)). The operator thus has the decision responsibility to withhold operation pending compliance with the condition.

Persons carrying out maintenance. The instrument also exempts the person carrying out the exempted aircraft maintenance from compliance with the specified CAR provisions (s 5(1)). The text does not limit that category by qualification or licence within the instrument itself. The definition of exempted aircraft maintenance, however, excludes maintenance tasks that are already required under other statutory instruments (s 3). The instrument therefore affects both formally authorised maintenance providers and private individuals who might carry out maintenance tasks on limited category or experimental aircraft, subject to the exclusions.

Third parties with approval or authorisation roles. The instrument identifies a set of recipients to whom the registered operator must provide information if a major design change is involved (s 6(1)(a)(i)-(iv)). These are CASA’s Airworthiness and Engineering Branch, “an authorised person” who holds decision power under specified CASR provisions and Subpart 21.M, a person authorised to issue a certificate of airworthiness in the aircraft’s category, or an approved design organisation (s 6(1)(a)). These entities are placed in a decision role: the registered operator must obtain written confirmation from one of them that the major design change is acceptable before flying (s 6(1)(b)). The instrument therefore affects those organisations by making them potential adjudicators of acceptability.

Excluded stakeholders. The instrument does not alter obligations that are preserved by the definition of exempted aircraft maintenance. Specifically, maintenance that is required by CASR, CAR or Civil Aviation Orders, maintenance to satisfy certificate conditions, work specified in airworthiness directives or CASA directions, and maintenance required by approved maintenance data remain outside the exemption (s 3). Accordingly, entities who rely on those regimes , for example, holders of approvals related to AD compliance, certificate issuers and persons responsible for maintaining mandatory equipment , remain implicated by the broader regulatory framework even where the exemption applies.

Geographic and temporal scope. The instrument applies to exempted aircraft registered in Australia, as indicated by the use of “registered operator” (s 4) and its creation under CASA’s regulations (preamble). It is time‑limited and contingent on commencement of the Part 43 reforms (s 2), so the class of affected persons is implicitly transitional.

In sum, the instrument places obligations and reliefs on registered operators and maintenance performers for a defined set of aircraft and tasks, while allocating the final acceptability determination for major design changes to CASA or specific authorised/approved entities.

The instrument creates specific duties, preserves certain rights to exemption, and allocates decision responsibilities. The key duties and rights are as follows.

Exemption right for specified maintenance. Subject to the exclusions in the definition of exempted aircraft maintenance (s 3), the registered operator and the person carrying out the maintenance are exempted from compliance with CAR regulation 42U and paragraphs 42W(2)(b) and 42W(4)(a) and (c) in respect of exempted aircraft maintenance (s 5(1)). That is a conditional right to not comply with those parts of CAR for eligible maintenance work.

Duty to follow exclusions. The exemption does not apply to maintenance of instruments and equipment required by CASR, CAR or Civil Aviation Orders; maintenance to comply with a condition on the certificate; maintenance specified in an airworthiness directive or CASA direction; or maintenance to comply with approved maintenance data (s 3). The duty to comply with those excluded maintenance obligations remains in force.

Duty where major design change occurs. If the exempted aircraft maintenance involves a major design change, the registered operator has a proactive duty: they must not operate the aircraft or allow it to be flown after the maintenance until two cumulative requirements are satisfied (s 6(1)). First, the registered operator must provide specified information in writing to one of four named recipients (s 6(1)(a); s 6(2)). Second, the recipient must inform the registered operator in writing that the major design change is acceptable (s 6(1)(b)). Only when written acceptance has been given is operation permitted.

Content of the written submission. The instrument prescribes in detail the content of the information the registered operator must provide where a major design change is involved. This includes: a description of the maintenance involving the change (s 6(2)(a)); photographs that illustrate key steps if the work has already been carried out (s 6(2)(b)); the reasons for the change (s 6(2)(c)); how the maintenance may affect each of the factors in the major design change definition (s 6(2)(d)); and why the major design change will not adversely affect safety (s 6(2)(e)). These prescriptions allocate to the registered operator the burden of documenting and explaining the change.

Choice of recipient. The registered operator may choose which of the listed recipients to send the information to: CASA’s Airworthiness and Engineering Branch; an authorised person with decision power under certain CASR provisions and Subpart 21.M; a person authorised to issue a certificate of airworthiness in the category of the aircraft; or an approved design organisation (s 6(1)(a)(i)-(iv)). The right to select among these recipients gives the registered operator an element of choice in how to discharge the duty, and may affect timing and cost depending on which recipient is engaged.

Right to operate conditional on written acceptance. The registered operator’s right to fly the aircraft after maintenance involving a major design change is contingent on receiving written acceptance from the recipient (s 6(1)(b)). The instrument does not specify timeframes for the recipient’s response; it only requires that the recipient inform the registered operator in writing that the change is acceptable.

No new explicit penalties or enforcement mechanism in the instrument. The instrument creates duties and exemptions but does not itself prescribe civil or criminal penalties for breach within its text. The exemptions are expressed as conditions of compliance with CAR provisions (s 5(1)-(2)); failure to meet conditions would mean the claimed exemption is not in force. Any consequences beyond loss of exemption must be found in the broader statutory and regulatory framework, which the instrument does not recite.

Temporal limits on rights. The right to rely on the exemption exists only while the instrument is in force, between its commencement on 1 August 2024 and its repeal trigger (s 2). Once the Parts of the Part 43 reforms commence, the exemption lapses at that point even if before 31 July 2027 (s 2(b)(i)).

In practical terms, the instrument transfers some compliance discretion to operators and maintenance performers for non‑excluded work, while imposing a documented, recipient‑based gatekeeping step where the work changes the aircraft in ways captured by the major design change definition.

The instrument itself does not introduce new penalties or specific enforcement procedures. It grants limited exemptions and prescribes a condition where a major design change is involved, but it does not include standalone sanctioning provisions in its text.

What the instrument does specify is that certain CAR provisions will not apply to exempted aircraft maintenance (s 5(1)). For the registered operator, those exemptions are expressly subject to a condition (s 5(2)). The practical enforcement implication is that failure to satisfy the condition in s 6 will mean the operator cannot rely on the exemption. The instrument therefore creates a compliance gate: if a major design change occurs and the operator continues to operate without providing the s 6(2) information and obtaining written acceptance, the operator would be operating contrary to the instrument’s condition and, consequently, would not be in the exempted posture described in s 5.

The instrument has been made under regulations 11.160 and 11.205 of CASR (preamble). Enforcement action for breaches of CASR or CAR generally sits within the existing regulatory and enforcement framework administered by CASA, but the instrument does not itself set out how CASA will proceed in instances of non‑compliance with the exemptions or related duties. The instrument does not specify administrative penalties, infringement notices, suspension authorities, or criminal offences in its text.

Because the instrument disapplies specific CAR provisions for certain maintenance activities, determining enforcement outcomes in any particular case requires checking the broader regulatory regime outside the instrument. For example, if an operator claims the exemption but the maintenance is in fact one of the excluded categories in the definition of exempted aircraft maintenance (s 3), the operator would remain subject to the underlying CAR or CASR obligations that the instrument leaves intact. Conversely, where a registered operator fails to observe the s 6(1) prohibition on operating after a major design change, any enforcement authority or sanctioning power would derive from the overarching legislative and regulatory framework rather than from this instrument itself.

In short, the instrument creates duties and conditional exemptions but delegates enforcement and sanctions to the existing legal framework. Practitioners should not assume the instrument provides independent penalty provisions; instead, failure to comply with the instrument’s conditions will remove the operator’s entitlement to the exemption and expose the operator and maintenance provider to whatever enforcement mechanisms apply under CAR, CASR or the Civil Aviation Act, which are not restated in the instrument.

The instrument is tightly cross‑referenced to other parts of the aviation regulatory framework and to a separate legislative reform package. It interacts with other laws and regulatory instruments in several concrete ways.

Foundation in CASR. The instrument is made under provisions of the Civil Aviation Safety Regulations 1998, namely regs 11.160 and 11.205 (preamble). It therefore sits as an instrument exercising powers conferred by CASR. The instrument also notes that certain terms have the same meaning as in the Civil Aviation Act 1988 and the regulations (s 3 note). Those cross‑references mean that definitions (for example, approved design organisation, certificate of airworthiness, experimental certificate, special certificate of airworthiness, and limited category aircraft) are sourced from the broader statutory scheme rather than redefined in the instrument (s 3 note). Practitioners must therefore read the instrument against the CASR and the Civil Aviation Act to determine who and what is captured.

Interaction with CAR. The immediate effect of the instrument is to exempt the registered operator and the person carrying out exempted aircraft maintenance from CAR regulation 42U and certain paragraphs of 42W in relation to exempted aircraft maintenance (s 5(1)). The instrument does not reproduce the content of those CAR provisions, so interpreting the practical effect of the exemption requires consulting CAR regs 42U and 42W to see which duties are being suspended. At the same time, the instrument preserves other CAR/CASR/Ops obligations by excluding from the exemption maintenance required by CASR, CAR or Civil Aviation Orders, maintenance to satisfy certificate conditions, maintenance specified in airworthiness directives or CASA directions, and maintenance to comply with approved maintenance data (s 3). Thus, the instrument selectively disapplies parts of CAR while leaving other statutory duties in place.

Link to Part 43 reforms. The instrument is expressly transitional in relation to the Civil Aviation Legislation Amendment (Part 43,Maintenance of Aircraft) Regulations 2024. It will be repealed either on commencement of Parts 1 and 2 of Schedule 1 to that instrument or on 31 July 2027, whichever is earlier (s 2(b)). That linkage indicates the instrument is designed as an interim arrangement pending the new regime under Part 43. Once Part 43 Parts 1 and 2 commence, this exemption lapses automatically (s 2(b)(i)), and the new maintenance rules then in force will govern.

Decision‑making and approvals under Subpart 21.M and certificates of airworthiness. The condition in s 6 places CASA’s Airworthiness and Engineering Branch, persons authorised to make decisions under regs 21.006A and 21.009 and Subpart 21.M, persons authorised to issue a certificate of airworthiness in the aircraft’s category, and approved design organisations into roles where their written acceptance must be obtained for major design changes (s 6(1)(a)). Those references tie the instrument to existing approval and certification pathways under Subpart 21.M and the certificate issuance regime. The instrument therefore overlays the exemption with a requirement that existing competent authorities or organisations confirm acceptability before an aircraft with a major design change is flown.

Preservation of airworthiness directives and CASA directions. By excluding maintenance specified in an airworthiness directive or CASA direction from the scope of “exempted aircraft maintenance” (s 3), the instrument confirms that ADs and CASA directions continue to operate irrespective of the exemption. This preserves the usual regulatory levers for mandatory corrective or safety actions.

No change to certificate validity rules within this instrument. The instrument’s definition of major design change links to “characteristics that may affect the validity of the special certificate of airworthiness or the experimental certificate” (s 3). The instrument treats those certificate validity concerns as a trigger for the s 6 process but does not itself change the grounds on which certificates may be issued, suspended or revoked. Interaction with certificate regimes therefore takes place through the existing certificate rules rather than through new certificate provisions in this instrument.

In short, CASA EX44/24 operates as a temporary, partial disapplication of identified CAR provisions for certain maintenance on limited category and experimental aircraft, while anchoring that disapplication within the broader framework of CASR, CAR, airworthiness directives, certificate processes and the forthcoming Part 43 maintenance reforms.

The instrument records its making and commencement and provides a single explicit trigger for repeal. The record in the instrument shows it was made by Daniel Bernard O’Hagan, Manager, Legislative Drafting, Legal, International & Regulatory Affairs Division, as a delegate of CASA, and signed on 29 July 2024 (preamble and signature block). The instrument’s own name clause designates it as CASA EX44/24 , Maintenance on Limited Category and Experimental Aircraft Exemption 2024 (s 1).

Commencement. The instrument commences on 1 August 2024 (s 2(a)). That fixed commencement date establishes when the exemptions and conditions take effect.

Repeal triggers. The instrument will be repealed at the earlier of two events (s 2(b)): (i) the commencement of Parts 1 and 2 of Schedule 1 to the Civil Aviation Legislation Amendment (Part 43,Maintenance of Aircraft) Regulations 2024 (s 2(b)(i)); or (ii) the end of 31 July 2027 (s 2(b)(ii)). Thus the instrument is transitional and contingent on the separate Part 43 legislative process.

No further amendments recorded in the instrument. The text provided does not include any subsequent variations, revocations, or amendments. The instrument as printed contains the original making and commencement information and the built‑in expiry mechanism described above. Any future amendment, extension or early repeal would need to be effected under the powers in the governing regulations or by replacing instruments.

Implication for future amendment. Because repeal is tied to the commencement of Parts 1 and 2 of Schedule 1 to the Part 43 legislative instrument, practitioners should monitor progress of that legislative instrument to know whether and when the exemption will lapse earlier than the hard date of 31 July 2027. The instrument does not itself provide a mechanism for extension beyond that hard date, nor does it set out a procedure for modification prior to repeal.

In summary, the instrument is a single, time‑limited measure made on 29 July 2024, commencing 1 August 2024, with a built‑in expiry linked to the Part 43 reforms or to 31 July 2027.

The instrument contains no litigation history. Its text does not record any judicial consideration, challenges, or interpretations. It was made and signed on 29 July 2024 and commences on 1 August 2024 (preamble; s 2). Given those dates and the instrument’s recent origin, there is no record in the instrument of any legal proceedings, appeals, or judicial decisions concerning its validity, application or construction.

Because the instrument cross‑references external provisions (for example CAR regs 42U and 42W, and CASR provisions cited in s 6(1)(a)(ii)), disputes about its practical operation could arise in future over the meaning of terms such as “exempted aircraft maintenance” or “major design change” and over whether a particular activity falls within an exclusion. Any such disputes would be resolved by application of the instrument in conjunction with the primary legislation and regulations that it references. The instrument itself does not set out dispute resolution, appeal rights or adjudicative processes beyond vesting written acceptability decisions with named authorities or authorised persons (s 6(1)(a)-(b)).

Practitioners should therefore not assume existing case law applies specifically to this instrument without checking whether courts or tribunals have considered it. The instrument’s text contains no citations to precedents and no history of judicial treatment.

Several practical pitfalls and points of legal ambiguity arise directly from the instrument’s wording. The instrument is compact, but small drafting choices produce consequences that require careful attention.

Exemption by reference to external provisions you must read. The instrument exempts persons from compliance with CAR regulation 42U and paragraphs of 42W (s 5(1)). The instrument does not reproduce the contents of those provisions. To know what obligations are actually suspended, practitioners must read CAR regs 42U and 42W in full. Assuming the exemption covers particular tasks without checking those provisions risks misapplication of the instrument.

Narrow negative definition of permitted maintenance. “Exempted aircraft maintenance” is defined by what it is not (s 3). The definition excludes maintenance required by CASR, CAR or Civil Aviation Orders; maintenance to comply with certificate conditions; ADs or CASA directions; and maintenance required by approved maintenance data. Those exclusions capture many safety‑critical tasks. A common mistake would be to assume that all maintenance on limited category or experimental aircraft is exempt; the instrument says the opposite for those categories. Confirming whether a particular task falls into the excluded categories is essential.

Ambiguity in “major design change” threshold. The definition of major design change speaks of a design change that has a “significant effect” on listed items (s 3). The instrument does not quantify “significant” or specify assessment criteria or thresholds. Whether weight and balance changes, structural modifications, or performance impacts cross that threshold will depend on technical and regulatory judgment. Where operators and maintainers disagree about whether a change is “major”, the safe approach under the instrument is to treat it as a major design change and trigger the s 6 process.

Timing and operation prohibition without a definitive timeframe for written acceptance. If a major design change occurs, the registered operator must not operate or allow flight until the information has been provided and the recipient has informed the operator in writing that the change is acceptable (s 6(1)). The instrument contains no service standard or statutory timeframe for the recipient’s response. That gap creates potential operational delay that could be commercially significant if the recipient takes time to consider the materials. Operators should anticipate possible delays and select a recipient with capacity to respond in a timeframe that aligns with operational needs.

Choice of recipient affects cost and timing. The registered operator has four different options for who to send the information to (s 6(1)(a)(i)-(iv)). The choice matters. An approved design organisation or authorised person under Subpart 21.M may charge fees or require formal technical substantiation. CASA’s Airworthiness and Engineering Branch has institutional processes. The instrument does not specify the consequence where two recipients reach different conclusions; the operator must obtain written acceptance from the party it approached.

Photographic evidence limited to "if the maintenance has been carried out". The instrument requires photographs that provide supplementary explanation only if the maintenance has been carried out (s 6(2)(b)). If work is proposed but not yet executed, the instrument does not require photographs. Preparing sufficient documentary and technical material where the work is only proposed may therefore be more demanding in other respects.

No record retention or evidence rules included. The instrument demands written submissions and written acceptance (s 6(1)-(2)) but does not prescribe retention periods, format, or evidentiary standing. Practitioners should record and preserve the written exchanges, but the instrument does not specify how long.

Interplay with certificate validity. The major design change definition includes “other characteristics that may affect the validity of the special certificate of airworthiness or the experimental certificate” (s 3). That wording places certificate validity considerations at the heart of the trigger, but the instrument does not alter certificates themselves. Operators must therefore check certificate conditions and certificate‑issuer expectations before assuming the exemption permits otherwise restricted work.

Temporal cliff‑edge. The exemption is transitional and will lapse on Part 43 commencement or by 31 July 2027 (s 2). Operators undertaking multi‑stage projects must monitor the Part 43 timetable to avoid being caught mid‑project by a change in the applicable regime.

No express enforcement or penalty text. The instrument does not itself create new sanctions. Non‑compliance will remove the operator’s entitlement to the exemption, but the instrument does not describe enforcement steps. Practitioners must assume consequences derive from the broader legal framework.

In summary, the principal gotchas are: the need to read the external CAR provisions being suspended; the exclusions that preserve many mandatory obligations; the indeterminate “significant effect” threshold for major design change; potential delay and cost in obtaining written acceptance; and the instrument’s temporal, procedural and evidentiary gaps.

The instrument prescribes discrete steps and documentary items for operators and maintenance providers. Compliance requires a mixture of advance planning, careful categorisation of the maintenance task, and documentary discipline.

1. Confirm aircraft and maintenance categorisation. Before relying on the exemption, determine that the aircraft is indeed a limited category aircraft or has an experimental certificate in force (s 3, definition of exempted aircraft). Cross‑check the aircraft’s registration and certificates against the Civil Aviation Act and the CASR definitions referred to in the instrument’s note (s 3 note).

2. Analyse the maintenance task against the exclusions. Determine whether the proposed maintenance is captured by the definition of “exempted aircraft maintenance”. If the work is maintenance of instruments and equipment required by CASR, CAR or Civil Aviation Orders; required to comply with a condition on the certificate; specified in an airworthiness directive or a CASA direction; or required by an instruction in the aircraft’s approved maintenance data, then the exemption does not apply (s 3). If any of those apply, do not rely on the s 5 exemption.

3. Decide whether the work involves a major design change. Evaluate whether the maintenance is a design change having a significant effect on weight and balance, structural strength, performance, operational characteristics, or other characteristics that may affect certificate validity (s 3). Where doubt exists about whether the effect is “significant”, adopt a conservative approach and treat the work as a major design change so as to trigger the s 6 process.

4. If no major design change, document the ground for that view. If you conclude the maintenance is exempted aircraft maintenance and does not involve a major design change, maintain contemporaneous records demonstrating why the task falls outside the excluded categories and why it does not meet the major design change definition. Although the instrument does not prescribe retention periods, the submission and receipt documentation required by s 6 in major change cases suggests written records will be important if challenged.

5. If a major design change applies, do not operate the aircraft. The registered operator must not operate or allow the aircraft to be flown after the maintenance until the required steps under s 6(1) are satisfied.

6. Prepare the s 6(2) submission. Assemble the written information required by s 6(2): a description of the maintenance involving the major design change (s 6(2)(a)); photographs providing supplementary explanation of the key steps if the maintenance has been carried out (s 6(2)(b)); the reasons for making the major design change (s 6(2)(c)); an analysis of how the maintenance may affect each of the matters listed in the major design change definition (s 6(2)(d)); and an explanation of why the major design change will not adversely affect safety (s 6(2)(e)). Ensure the submission is precise, technical where necessary, and addresses the five enumerated items.

7. Choose an appropriate recipient and submit in writing. Send the s 6(2) materials in writing to one of the four authorised recipients identified in s 6(1)(a)(i)-(iv): CASA’s Airworthiness and Engineering Branch; an authorised person holding decision power under regs 21.006A and 21.009 and Subpart 21.M of CASR; a person authorised to issue a certificate of airworthiness in the category; or an approved design organisation. Select the recipient with regard to speed, expertise and cost. Keep evidence of the time and manner of delivery.

8. Obtain written acceptance before resuming flight. Do not operate the aircraft until the addressee has informed the registered operator in writing that the major design change is acceptable (s 6(1)(b)). Retain that written acceptance as the operative authorisation to fly post‑modification.

9. Preserve records and correspondence. Although the instrument does not state retention periods, maintain records of the submission, the recipient’s acceptance, and any technical reports, photographs, or test data relied upon, in case an enforcement inquiry arises or the operator needs to prove compliance with the instrument’s condition.

10. Monitor Part 43 commencement and the instrument’s expiry. Note that the exemption ends on the earlier of the Part 43 commencement specified or 31 July 2027 (s 2). If the Part 43 rules commence during a project, assess how the new rules affect work in progress and whether additional approvals, compliance steps, or documentation will be required under the new regime.

11. Where in doubt, engage competent assistance. Because the instrument ties major design change assessment to elements affecting certificate validity and safety, involve technical advisers, approved design organisations, or authorised persons where appropriate to prepare the s 6 submission and to help select an efficient recipient.

Following these steps maps directly to the duties and rights created by the instrument. The operative compliance obligations are: (a) to ensure the work falls within the exemption’s scope; (b) to withhold operation where a major design change applies; (c) to prepare and lodge the information specified in s 6(2) with one of the named recipients; and (d) to obtain written confirmation of acceptability before returning the aircraft to service (s 3; s 5; s 6).