AD/PROP/4 - Overhaul Affected Propellers

The AD embodies several core legal and technical concepts that govern its application and compliance.

Issuing power and legal basis. The AD is issued under subregulation 39.1(1) of CASR 1998, as stated in the opening paragraph. That locates the instrument within the regulatory framework that permits CASA delegates to issue directives requiring action to correct unsafe conditions in aircraft or aeronautical products. The AD itself does not restate the full enforcement regime or penalties from CASR 1998; it uses that subregulation as its legal authority.

Applicability and scope. The AD is expressly limited to propellers of specified manufacturers (Hartzell, McCauley, Sensenich, Raytheon/Beech) that both (a) have a hub serial number listed in Table 1 and (b) were last released to service by T and W Propellers, Inc., of Chino, California. The text uses the conjunctive condition "and that have a propeller hub Serial Number (S/N) listed in Table 1 of this Directive." That conjunctive phrasing matters for identification: a hub S/N listed in Table 1 is not sufficient by itself unless the propeller was last released to service by T and W.

Mandatory corrective action. Requirement 1 prescribes the substantive work: disassembly, cleaning, inspection (for a detailed list of defects and maintenance failures), repair or replacement as necessary, reassembly and testing. The inspections must be "in accordance with the applicable manufacturers service documentation." The AD therefore delegates the precise technical methodology and acceptance criteria to the manufacturer's service documentation; CASA prescribes what must be done in broad terms and which defects to look for, but not the exact step‑by‑step procedure.

Installation prohibition. Requirement 2 is an immediate installation ban. It prohibits the installation of any listed propeller last released by T and W unless the actions of Requirement 1 have been complied with. The AD states that Requirement 2 is effective at the effective date of the directive.

Timing and Time in Service (TIS) thresholds. The AD sets different deadlines according to the propeller's Time In Service since last release by T and W. If TIS since release is less than 10 hours, Requirement 1 must be done "before further flight". If TIS is more than 10 hours, Requirement 1 must be completed "within 10 hours TIS." The AD does not further define how TIS is to be calculated beyond those terms; operators must rely on their maintenance and flight logs to determine applicability and deadlines.

Cross‑reference to FAA AD. The AD includes the single sentence "Note: FAA AD 2003-13-17 Amdt.13219 refers." That flags that the FAA has issued a companion or related directive. The AD nonetheless requires compliance under Australian authority and with manufacturers' documentation; the FAA AD is an informational pointer, not a substitute for compliance with this CASA AD.

Documented provenance. Table 1 lists affected hub serial numbers alongside manufacturer, propeller model, work order number and work order date. This provides a record linking particular propellers and specific maintenance actions performed by T and W Propellers, and it frames the AD's identification method as one that uses measurable identifiers rather than generic model lists alone.

Safety rationale. The background asserts that the AD responds to "a failure of a propeller blade returned to service by T and W Propellers, Inc." It asserts that failure to inspect and rework these propellers could "lead to failure of the propeller and loss of control of the aeroplane." That is the stated safety risk upon which the mandatory actions are premised.

Legal effectivity and notification. The AD is signed by the CASA delegate, dated 6 August 2003, and the AD note records that it was notified in the Commonwealth of Australia Gazette on 7 August 2003. The document’s effective date is 7 August 2003. Those formalities are the AD’s mechanism for signalling legal force and public notice.

The AD identifies three principal affected groups by plain text and structure: operators and owners of aircraft fitted with the listed propellers, maintenance providers and installers, and CASA/regulatory oversight entities. The language of the AD makes obligations flow primarily to the regulated parties that operate and maintain aircraft.

Operators and owners. The AD applies to "All Hartzell Propeller, Inc., McCauley Propeller Systems, Sensenich Propeller Manufacturing Company, Inc., and Raytheon Aircraft Company (formerly Beech Aircraft Corporation) propellers last released to service by T and W Propellers, Inc. of Chino, California USA and that have a propeller hub Serial Number (S/N) listed in Table 1 of this Directive." In practice owners and operators of aircraft must identify whether any propeller fitted to their aircraft satisfies both conditions: manufacturer/model and hub S/N in Table 1, and last release to service by T and W. If both conditions hold, the owner/operator must ensure the Requirement 1 overhaul is carried out within the stated compliance window and must not install any such propeller unless the overhaul has been performed (Requirement 2).

Maintenance organisations and certifying staff. The AD mandates overhaul work "in accordance with the applicable manufacturers service documentation." That places technical responsibility on maintenance organisations and licensed personnel to perform disassembly, inspection for an enumerated set of defects, repair or replacement with serviceable parts, reassembly and testing. The AD highlights specific inspection items that require technical awareness: chemical conversion coatings, paint applied over corrosion, lack of paint on internal surfaces, shot peening, torqueing of bolts, incorrect parts or incorrect installation, and one‑time use parts being reinstalled. Maintenance providers need to check for these conditions and to interpret manufacturer service documentation to apply the AD's requirements.

Installers and airworthiness release authorities. Requirement 2 bars installation of listed propellers unless Requirement 1 has been complied with. That creates a direct obligation on whoever signs the propeller or aircraft release to service or performs installation work. Installers must confirm compliance with Requirement 1 before installation or they risk non‑compliance with the AD.

Aircraft registrants and recordkeepers. Determining whether a propeller is “last released to service by T and W Propellers, Inc.” requires administrative records: release to service documentation, work order numbers and dates, maintenance logs and TIS tracking. Table 1 includes work order numbers and work order dates for each listed hub S/N. Operators and registrants therefore must reconcile their records against Table 1 to determine applicability and to establish TIS since last release.

CASA and inspectors. CASA issued the AD under an express regulatory power and will be the enforcing authority for compliance with the AD. The AD’s signature by the CASA delegate and Gazette notification establish formal regulatory action that CASA may enforce under CASR 1998, though the AD text itself does not set out enforcement procedures or penalties.

Ancillary stakeholders. Insurers, lessors and lessees of aircraft with listed propellers are affected indirectly. The AD’s prohibition on installation and the timing constraints for overhaul carry operational and insurance implications, such as grounded time and the need for maintenance approvals. The AD also references FAA AD 2003-13-17, which indicates parallel foreign regulatory action that may affect international operations or maintenance performed under foreign approvals.

Geographic and manufacturer specificity. Although the AD lists many hub S/Ns and multiple manufacturers, the AD only applies where the last release to service was by T and W Propellers, Inc. of Chino, California. Propellers with the same hub S/N but released to service by another organisation are not captured by the AD as written. That condition will be a key determinant of who is in or out of scope.

Immediate effect on installations. Requirement 2 is effective as at the AD effective date, so anyone attempting to install a listed and T and W released propeller on or after 7 August 2003 must ensure Requirement 1 has first been complied with. For propellers with less than 10 hours TIS since the T and W release, the AD requires compliance "before further flight", which means owners cannot lawfully operate the aircraft without completing the inspection and overhaul first.

The AD organises duties as mandatory obligations (expressed as Requirements 1 and 2) and leaves procedural detail to manufacturer documentation. It does not enumerate rights in the form of appeals or waivers within the text, but it does establish duties with timing, scope and reference documentation.

Primary duties

• Identification duty. Operators, owners and maintenance organisations must identify whether any propeller on their aircraft is both (a) of the manufacturers named and (b) has a hub S/N listed in Table 1 and was last released to service by T and W Propellers, Inc. The AD uses those criteria as the gate for applicability.

• Overhaul and inspection duty (Requirement 1). For propellers captured by applicability, the AD requires disassembly; cleaning; inspection for a specified set of defects and conditions; repair and replacement with serviceable parts as necessary; and reassembly and test. The AD directs that these actions be done "in accordance with the applicable manufacturers service documentation." The AD therefore requires maintenance organisations to consult and follow the manufacturer instructions when performing these steps.

• Installation prohibition (Requirement 2). From the effective date, no propeller that has a hub S/N listed in Table 1 and that was last released to service by T and W may be installed unless Requirement 1 has been complied with. This is an affirmative prohibition that applies at the point of installation.

• Compliance timing duty. The AD contains time limits tied to Time In Service since the last release by T and W. If TIS is less than 10 hours, the overhaul/inspection must be performed before further flight. If TIS exceeds 10 hours, the required work must be completed within 10 hours TIS. Those timings provide a short window of operational tolerance for some propellers, and an absolute pre-flight requirement for others.

Implied duties and operational consequences

• Maintenance record reconciliation. The AD’s applicability criterion depends on being able to show last release to service by T and W and the hub S/N recorded in Table 1. This creates an implicit duty to examine maintenance release documentation, work order numbers and dates, and propeller serial number records.

• Use of manufacturer documentation. The AD delegates the technical details to "applicable manufacturers service documentation." Maintenance providers must have access to and apply the correct manufacturer service instructions, revisions and acceptance criteria to comply substantively.

Rights and absence of explicit procedural protections

• No rights-of-refusal or waiver language in the AD. The AD text does not set out a process for seeking a variation, exemption or alternative method of compliance. The AD’s legal basis (subreg 39.1(1) of CASR 1998) is cited, but the AD does not itself include a right of appeal or a waiver mechanism. Any such procedures, if available, would be those provided under CASR or CASA administrative processes, not the AD text.

• No explicit compensation or cost-sharing provisions. The AD does not provide any payment, subsidy or compensation for parties who must perform the inspections and repairs. Costs of labour, parts, ground time and potential aircraft downtime are therefore borne by operators, owners or maintenance providers as determined by their commercial arrangements.

Delegation and decision-making

• CASA delegate as decision-maker. The AD is signed by a CASA delegate and is expressed to be issued by the CASA delegate under the CASR power. The AD sets out what the delegate "considers necessary to correct the unsafe condition" (first paragraph). The delegate has made the decision to require these actions; the AD does not provide for on‑its‑face delegation of the decision to other bodies.

• Use of manufacturers’ judgement for technical actions. While CASA prescribes the inspection tasking and defect list, the AD directs adherence to manufacturers’ service documentation for how to perform the work and to determine acceptability. That transfers technical judgement to manufacturer-approved procedures and to the certifying maintenance staff who apply them.

Who is responsible for compliance

• Owners/operators are ultimately responsible to ensure the propeller is not operated or installed contrary to the AD. Maintenance organisations and certifying staff are responsible to perform the work in accordance with the manufacturer's documentation and to provide the appropriate release to service. Installers are responsible to confirm Requirement 1 has been complied with before installing a listed propeller.

The AD itself establishes mandatory requirements but does not specify monetary fines, criminal penalties or the enforcement process within its text. The AD is issued "under subregulation 39.1 (1) of CASR 1998," which provides the issuing authority; enforcement and penalty details are therefore to be located in CASR 1998 and other regulatory instruments rather than in the AD text. The AD does, however, state the safety consequence it seeks to avoid: "Failure to do this could lead to failure of the propeller and loss of control of the aeroplane" (Background).

What the AD does state

• Mandatory compliance. The AD contains two mandatory requirements. The language of the AD is prescriptive: Requirement 1 requires specific actions; Requirement 2 forbids installation unless Requirement 1 has been complied with. The compliance timings are set out clearly.

• Effective date and notification. The AD becomes effective on 7 August 2003. It was signed on 6 August 2003 and notified in the Commonwealth of Australia Gazette on 7 August 2003. Those steps are how CASA gives legal notice and triggers enforceability under the CASA regulatory regime.

What the AD does not state

• The AD does not enumerate a particular penalty amount, infringement notice regimen or a criminal sanction within its text. It also does not detail the enforcement procedure that CASA will use in case of non‑compliance, such as suspension of an air operator's certificate or the imposition of a civil penalty. Those enforcement mechanisms, if available, derive from CASR 1998 and broader aviation enforcement powers.

How enforcement is likely to be framed (as stated or implied)

• Enforcement under CASR. Because the AD is issued under a specific subregulation of CASR 1998, non‑compliance with the AD would place an operator or maintenance provider in breach of CASA regulatory requirements. Practical enforcement mechanisms could include audit findings, directives to ground aircraft until compliance, administrative penalties, or other regulatory actions under the Civil Aviation Safety Regulations and Aviation Safety Act frameworks. The AD does not itself specify which of those mechanisms CASA will use.

• Safety connection to enforcement. The background explicitly links non‑compliance to an increased risk of propeller failure and potential loss of control. That stated safety risk is the basis for CASA taking regulatory action and would inform the enforcement priority assigned by CASA inspectors and safety investigators.

Practical consequences of non‑compliance

• Operational: Aircraft may be grounded or prohibited from flying until Requirement 1 has been complied with where the AD requires action prior to further flight.

• Liability: The AD’s specification of the unsafe condition and its corrective action may be cited in post‑incident or civil liability settings as establishing the regulator’s non‑discretionary expectation of compliance. The AD itself does not adjudicate liability, but the AD’s requirements frame standard of care expectations.

• Insurance and commercial: Non‑compliance with an AD could have implications for insurance coverage if an insurer requires compliance with airworthiness directives as a condition of cover. The AD text does not address insurance, but the existence of the AD imposes an operating constraint that commercial parties will need to manage.

Recordkeeping and proof of compliance

• The AD does not specify records that must be lodged with CASA, nor a specified form of compliance report. That absence means proof of compliance will rely on the operator’s and maintenance organisation’s standard maintenance release documentation, manufacturers’ service documentation records, and internal maintenance logs.

The AD is framed and issued within the CASA regulatory scheme, and the document itself references other regulatory and foreign instruments. The text establishes relationships and delegations, and leaves a number of interactions to be governed by existing regulatory and manufacturer systems.

Primary statutory interaction

• CASR 1998. The AD is explicitly issued under subregulation 39.1(1) of CASR 1998. That locates the AD within Australia’s Civil Aviation Safety Regulations. The AD therefore functions as a regulatory instrument created under that authority. The AD does not reproduce the content of CASR 1998; it uses the subregulation as the legal basis for issuing mandatory requirements.

Administrative interaction

• CASA delegate authority. The AD is signed by a CASA delegate, demonstrating the exercise of statutory delegation under CASR. The AD states that it requires the action that "the delegate considers necessary to correct the unsafe condition." The act of delegation and decision to require these actions are thus administrative in nature and are part of the CASA enforcement and safety regulation apparatus.

Interaction with manufacturer documentation and approvals

• Manufacturer service documentation. Requirement 1 directs that the work be carried out "in accordance with the applicable manufacturers service documentation." That requires integration between the AD’s mandatory tasks and the technical, procedural and acceptance criteria set in manufacturers' instructions, service bulletins or manuals. Where a manufacturer provides a detailed procedure, that procedure will be the operative technical method for satisfying the AD’s inspection and repair obligations.

• Release to service and maintenance approvals. Because the AD deals with release to service history and work order records, it interacts with the legal framework for maintenance approvals, certifying staff privileges, and release to service documentation. The AD does not specify changes to those approval regimes; it requires compliance in line with existing authorised maintenance processes.

Interaction with FAA AD and foreign regulation

• FAA AD reference. The AD includes the sentence "Note: FAA AD 2003-13-17 Amdt.13219 refers." That indicates that the FAA has issued a related directive. The AD’s inclusion of this note signals international regulatory parallelism and provides an information link for operators or maintainers who may want the FAA's text or procedures. The CASA AD, however, is operative in Australia and its requirements do not rely on the FAA AD for legal force.

Gaps and potential conflicts

• No conflict clause. The AD does not include language to resolve conflicts if, for example, a manufacturer's service documentation appears to differ materially from the AD’s listed inspection items or timing. The AD requires action "in accordance with the applicable manufacturers service documentation" but also prescribes specific inspection items. Maintenance organisations may need to reconcile instructions where manufacturer documentation does not include precisely the same enumerated items; the AD requires them to ensure all AD-listed items are checked.

• Concurrent regulatory obligations. The AD does not displace other regulatory obligations such as maintenance release procedures, reporting duties under occurrence reporting rules, or continuing airworthiness requirements. Those obligations continue to apply alongside the AD.

Publication and notice

• Gazette notification. The AD was notified in the Commonwealth of Australia Gazette on 7 August 2003. That notification is the formal means by which CASA provided public notice and integrated the AD into the larger legal framework where other statutory or administrative actions may refer to it.

Practical cross‑checks

• Records and work order numbers. Table 1 provides work order numbers and dates which will help operators, maintainers and regulators cross‑check whether a propeller was released by T and W and therefore subject to the AD. That table establishes a documentation link between specific maintenance actions and the AD’s applicability.

The AD text before you contains no amendment history beyond its initial issuance and notification. The document identifies itself, records the signature of the CASA delegate and records the effective and notification dates, but it does not record any subsequent amendments, supersessions or revocations.

What the AD records

• AD identifier and date. The AD is recorded as "AD/PROP/4 Overhaul Affected Propellers 10/2003", it was signed by the CASA delegate on 6 August 2003 and it became effective on 7 August 2003. The AD is also stated as notified in the Commonwealth of Australia Gazette on 7 August 2003. Those are the only dates and provenance markers contained in the AD text.

• No amendments or versioning lines. The AD does not present any "Amendment" lines, instrument history table or subsequent effective dates. There is no text in the instrument indicating changes after initial issue, nor any express statement that the AD supersedes or replaces a prior AD or is provisional.

Implications of the absence of amendment data

• Single‑version status in-document. For any reader relying only on this AD text, the document is the original 7 August 2003 directive and there are no in‑text amendments. That does not preclude that CASA or another authority may have issued subsequent amendments, superseding ADs or exemptions after the AD was published. Those would not be visible in this primary document.

• Need to consult CASA current database. Because the AD itself contains no amendment history, anyone needing the current legal position must consult CASA's active AD database, current CASR instruments, or other official publications to determine whether the AD has been amended, superseded, or withdrawn since 7 August 2003. The AD’s lack of recorded amendments means the document should be cross‑checked against later regulatory material for up‑to‑date compliance.

Reference to FAA AD. The AD includes a reference to FAA AD 2003-13-17 Amdt.13219. That reference may be a lead to related foreign amendments or procedures, but it does not constitute an amendment to the CASA AD itself.

Record of notification. The AD records that it was "notified in the Commonwealth of Australia Gazette on 7 August 2003." That provides a published starting point for any timeline of administrative actions or for parties tracing the AD’s legal life. Any later changes should, in practice, be recorded in subsequent Gazettes or CASA updates, but no such entries are present in this document.

The AD text does not include any litigation history. It contains no references to judicial decisions, appeals, disputes, or administrative review cases. No cases are named, and there are no citations to court or tribunal rulings in the AD. The only legal provenance cited within the AD is its statutory issuing power: subregulation 39.1(1) of CASR 1998.

What the AD does and does not record

• No recorded disputes or appeals. The AD does not report any challenges to its issuance, nor any prior legal determinations concerning the specific propellers or the maintenance actions of T and W Propellers, Inc.

• No mention of enforcement actions taken following the AD. The AD asserts the unsafe condition and prescribes corrective action, but it does not describe any enforcement steps taken against T and W Propellers, Inc., any maintenance provider, or any aircraft operator. There is no administrative or judicial record contained in the AD.

Potential areas for litigation or dispute arising from the AD (based on the AD’s content)

• Applicability disputes. The AD’s applicability condition depends on whether a propeller was "last released to service by T and W Propellers, Inc." Determining who last released a propeller to service depends on release paperwork, work order numbers and dates. Disputes could arise where records are incomplete, ambiguous, or in conflict. The AD includes work order numbers and dates in Table 1 which assist reconciliation; nonetheless, factual disputes over whether a given propeller meets the "last released" criterion could give rise to litigation.

• Interpretation of compliance timing. The AD distinguishes between propellers with less than 10 hours TIS since release and those with more than 10 hours, prescribing different compliance deadlines ("before further flight" versus "within 10 hours TIS"). Questions could arise over how TIS is to be calculated for the purpose of the AD, or about what constitutes "before further flight" in edge cases such as multi-leg operations or ferry flights. The AD does not interpret these terms further.

• Sufficiency of manufacturer documentation as compliance. The AD requires work "in accordance with the applicable manufacturers service documentation." A dispute could arise if an operator or maintenance organisation relies on a manufacturer document that a regulator later finds was an incorrect revision or otherwise insufficient to address the AD‑listed inspection items. The AD does not provide a specific mechanism to resolve differences between the AD's enumerated inspection items and the manufacturer's documentation.

• Liability for prior release. The AD is premised on "a failure of a propeller blade returned to service by T and W Propellers, Inc." Although the AD does not assign legal liability, the background fact may be used in subsequent civil litigation if a propeller failure results in damage or injury. The AD is an administrative statement of required corrective action and of the safety risk; it does not adjudicate tortious or contractual liability.

Absence of case law. Because no litigation history is recorded in the AD, readers must not assume the AD has been litigated or that courts have interpreted its provisions. Any legal disputes arising after the AD would be found in court or tribunal records outside this document.

Practical step to avoid disputes. The AD’s inclusion of hub S/Ns, work order numbers and dates in Table 1 provides a concrete evidentiary basis to determine whether a particular propeller is in scope. Meticulous record‑keeping and retention of maintenance release documents are therefore practical ways affected parties can reduce the risk of future disputes.

The AD is short on procedural detail in some places but prescriptive in others. That combination produces a number of practical pitfalls for owners, maintainers and installers. Below are specific "gotchas" rooted in the AD’s text that practitioners should note.

Conjunctive applicability criterion. The AD applies to propellers that (a) are of the listed manufacturers and (b) have a hub S/N in Table 1 and (c) were last released to service by T and W Propellers, Inc. A hub S/N appearing in Table 1 does not, by the AD’s wording, automatically capture all propellers with that S/N; the propeller must also have been "last released to service by T and W Propellers, Inc." Verify release documents. Do not assume Table 1 equals universal applicability without confirming release provenance.

Work order numbers and dates as evidence. Table 1 lists work order numbers and dates for each hub S/N. Those entries are the AD’s built‑in cross checks. Operators must reconcile their maintenance records against these work order numbers/dates. Failure to use the work order/date data when reconciling may produce incorrect applicability determinations.

Ambiguity in Time In Service (TIS) windows. The AD sets two timing rules: if TIS since last release is less than 10 hours, the overhaul must be completed "before further flight"; if TIS is more than 10 hours, it must be done "within 10 hours TIS." The AD does not state the reference point for the "within 10 hours TIS" deadline in clearer terms. Practitioners must rely on maintenance and flight logs to calculate TIS since the last release. Ambiguities over partial hours, multi-leg operations, or ferry frames can complicate compliance. Document calculations carefully and retain supporting logs.

"Before further flight" has immediate operational force. For propellers with less than 10 hours TIS since the T and W release, the AD forbids flying the aircraft further until Requirement 1 is completed. That is operationally disruptive. Ensure maintenance slots and parts availability are arranged before attempting to operate the aircraft.

Reliance on "applicable manufacturers service documentation." The AD directs compliance in accordance with the applicable manufacturer service documentation. There are multiple practical issues here: which document(s) are "applicable" for a particular propeller model and serial number; whether the correct revision of a service bulletin or manual is used; and how to reconcile manufacturer procedures with the specific list of inspection items the AD contains. Maintenance organisations must ensure they apply the correct manufacturer instructions, including revision level, and must interpret any gaps between manufacturer detail and AD items in a way that fulfils the AD’s inspection list.

Inspection items that are not trivial to detect. The AD lists items such as "chemical conversion coat or paint or both applied over corrosion," "lack of chemical conversion coating," "lack of paint on internal surfaces," and "lack of proper shot peening." These are technical features that may require specialised inspection techniques, destructive or non‑destructive testing, or manufacturer guidance to evaluate. Do not treat these items as superficial visual checks only.

"Reinstallation of parts intended for one-time use." The AD calls out reinstallation of single‑use parts. Maintenance organisations must be able to identify one‑time use parts and ensure they are not reinstalled. That requires access to parts lists and manufacturer guidance.

Bolts incorrectly torqued and incorrect installation. The AD directs inspection for incorrectly torqued bolts and incorrect installation. Torque evidence may be difficult to detect after the fact. Where torque stamps or witness marks are absent, a conservative approach (replacement of suspect hardware) may be required to satisfy the AD’s requirement to repair and replace as necessary.

Installation prohibition effective immediately. Requirement 2 is effective at the AD’s effective date. From that date, any installer who fits a listed and T and W released propeller before Requirement 1 compliance will be in breach of the AD. Ensure installers and signing personnel are aware and have access to the necessary documentation proving compliance.

FAA AD cross‑reference. The AD notes that FAA AD 2003‑13‑17 Amdt.13219 refers. That FAA AD may contain specific procedural detail not replicated in the CASA AD. Practitioners should check the FAA AD for procedural or inspection specifics that the AD hints at but does not include. Do not assume the FAA AD replaces CASA obligations.

Recordproof is decisive. Because applicability and timing hinge on last release to service and TIS since that release, operators must keep accurate release and flight time records. Missing or inconsistent records make it difficult to satisfy the AD and will increase enforcement or litigation risk.

No explicit reporting requirement. The AD does not require a mandatory report to CASA once the inspections are complete, nor does it prescribe a form of compliance reporting. Nevertheless, maintain thorough records of the actions taken, service documentation used, parts replaced, test results and release to service entries, to evidence compliance should that be queried later.

Potential multiple stakeholders on a single propeller. A listed propeller might have been released by T and W but subsequently maintained by other organisations. The AD’s focus on the "last release" by T and W is a snapshot in time; maintenance history after that release does not remove the AD’s applicability unless the overhaul/inspection required by Requirement 1 has been completed. This can complicate tracing chains of custody for parts and may require coordination among several entities.

The AD sets out a specific sequence and timing for compliance. Below is a practical, stepwise checklist for operators, maintainers and installers based on the AD’s text. This does not add obligations not present in the AD, but organises the AD’s requirements into an operational plan consistent with the AD’s instructions.

1. Identify candidate propellers

• Cross‑check your aircraft's propeller hub serial number against Table 1 in the AD. Table 1 lists manufacturer, propeller model, propeller hub S/N, work order number and work order date for each affected unit.
• Confirm whether the propeller was "last released to service by T and W Propellers, Inc. of Chino, California USA." This requires locating and reviewing release to service documentation and maintenance work orders. Both the hub S/N and the release provenance must be present to trigger AD applicability.

2. Determine Time In Service (TIS) since last T and W release

• Using maintenance and flight logs, determine the TIS since the propeller was last released to service by T and W. The AD distinguishes two deadlines depending on whether that TIS is less than 10 hours or greater than 10 hours.

3. Assess timing constraints and immediate actions

• If TIS since the T and W release is less than 10 hours: Requirement 1 actions must be completed "before further flight." Do not operate the aircraft again until the overhaul/inspection and any necessary repairs are finished and the propeller is reassembled and re‑tested in accordance with the manufacturer's service documentation and the AD.
• If TIS since the T and W release is more than 10 hours: Requirement 1 actions must be completed "within 10 hours TIS." Plan maintenance slots and parts acquisition to ensure completion within that 10‑hour window.

4. Plan the overhaul and inspections (Requirement 1)

• Obtain and confirm the "applicable manufacturers service documentation" for the specific propeller model and serial number. Confirm the correct revision level of the manufacturer service bulletin or maintenance manual to use for the work.
• Prepare to perform the following steps, in accordance with the manufacturer instructions:
  • Disassemble the propeller to the extent required by manufacturer documentation and to enable the listed inspections.
  • Clean components thoroughly to allow accurate inspection for the listed conditions.
  • Inspect for: cracks; corrosion; nicks; scratches; blade minimum dimensions; chemical conversion coat or paint or both applied over corrosion; lack of chemical conversion coating; lack of paint on internal surfaces; bolts incorrectly torqued; incorrect parts; incorrect installation of parts; reinstallation of parts intended for one‑time use; and lack of proper shot peening.
  • Document inspection findings and measure blade dimensions and other acceptance criteria as required by the manufacturer.
  • Repair and replace with serviceable parts as necessary, using parts approved or acceptable per manufacturer documentation and regulatory requirements.
  • Reassemble and test the propeller following manufacturer procedures and test criteria.

5. Record and certify the work

• When the overhaul/inspection is complete, document the maintenance actions carried out, list parts replaced, attach the manufacturer's service documentation references and revision numbers used, and record test results and acceptance checks.
• Issue the appropriate maintenance release or return‑to‑service documentation in accordance with existing maintenance approval procedures. The AD does not specify a separate CASA compliance form; rely on standard maintenance release practices to evidence compliance.

6. Installation and release (Requirement 2)

• Do not install any propeller with a hub S/N listed in Table 1 that was last released to service by T and W Propellers, Inc. unless Requirement 1 has been complied with and documented.
• Before installation, verify again that the maintenance release and required documentation evidencing compliance with Requirement 1 are available. Sign the release to service only after ensuring the AD requirements have been met.

7. Retain proof of compliance and cross‑reference FAA AD if needed

• Retain copies of the maintenance records, manufacturer service documentation used, work order numbers, and release to service entries. These records will be important for audit, enforcement or insurance queries.
• Consider consulting FAA AD 2003‑13‑17 (referenced in the AD) for additional inspection procedures or clarifying technical guidance that may assist in meeting the AD’s inspection list. Any FAA material should be used in conjunction with the CASA AD and manufacturer instructions.

8. Communicate internal controls and warnings

• Update your maintenance tracking and procurement systems to flag any propeller in your fleet that matches a Table 1 hub S/N. Ensure maintenance planners understand the "before further flight" and "within 10 hours TIS" requirements.
• Notify maintenance staff and certifying personnel that Requirement 2 prohibits installation unless the overhaul has been completed.

9. Where ambiguity exists, document the conservative choice

• If there is any ambiguity over whether the propeller was last released to service by T and W, or ambiguity in TIS calculations, document the evidence used, your interpretation, and any conservative operational decisions taken to avoid flying until compliance can be proved.

10. Check CASA for updates

• Because this AD document does not include amendment history, check CASA’s official AD registry or contact CASA for any subsequent amendments, supersessions or additional guidance relating to AD/PROP/4. Do not rely solely on the printed AD text as the final or current statement if some time has passed since the effective date.

Following the above steps will allow an operator or maintainer to align operational and maintenance activity with the AD’s mandatory requirements as they are set out in the directive. The AD prescribes the scope of inspection items, the use of manufacturers’ procedures for the method, and concrete timing and installation prohibitions that must be respected in practice.