AD/PHS/10 Amdt 2 - Hydromatic Propeller - Aluminium Blades

Applicability and exclusions. The AD applies only to Hamilton Standard Hydromatic aluminium-bladed, non-counterweighted propellers that use engine oil for pitch control, listing 16 specific type numbers. The directive explicitly excludes propellers with integral oil control and steel blades (Applicability). This focuses the obligation narrowly on a well-defined technical population of propellers.

Mandatory inspection method. The inspection mandated is removal of blades and a visual inspection targeted at corrosion in the blade fillet and shank area, "particularly under the Teflon friction reduction strip and the resin corrosion barrier" (Requirement 1). The required standard operating procedure is the Hamilton Standard Aluminium Blade Overhaul Manual No. 130B dated 1 March 1980, "as in force at the date of this AD" (Requirement 1). That cross-reference binds the inspection to a specific overhaul manual and its procedural content as it stood at the AD date.

Two compliance tracks. There are two discrete compliance regimes. For the generic population of affected propellers the inspection interval is "at periods not exceeding 6 years calendar time in service" (Compliance 1). For a subset , propellers fitted to Limited Category aircraft for which AWAL is the administering authority under Part 132 of CASR 1998 , operators may comply with AWAL Maintenance Direction No. 16-001, "as in force from time to time" (Requirement 2). The AD records that AWAL Maintenance Direction No. 16-001 contains additional annual inspection requirements and that, notwithstanding those annual items, "the blade removal inspection must be completed at periods not exceeding 12 years calendar time in service" (Compliance Note 1). The AWAL Maintenance Direction does not apply to aircraft that have been flown off salt water (Compliance Note 3).

Calendar-time definition. The AD specifies that calendar periods "are deemed to commence from the time the propeller is first installed on an aircraft following reconditioning or inspection in accordance with the AD and shall be uninterrupted including all subsequent service and storage periods" (Compliance Note 2). This ties the interval framework to the moment of first installation after compliance and treats storage as counting towards the interval.

Background causal framing. The AD cites FAA advice regarding the possibility of fatigue cracking leading to blade separation caused by severe corrosion around the shank and fillet, particularly under the Teflon friction strip. It references FAA AD 81-13-06 R2 and notes prior amendments that altered inspection periods (Background). AWAL provided maintenance reports asserting that inspections at 6-year intervals had not revealed significant corrosion, prompting consideration for an alternate schedule for AWAL-administered Limited Category aircraft.

Delegation and dynamic content. The AD authorises compliance through an AWAL maintenance direction "as in force from time to time" for certain aircraft, thereby delegating the content and any future amendments of that maintenance direction to AWAL for the Limited Category cohort (Requirement 2). The AD also binds inspection practice to a named overhaul manual "as in force at the date of this AD", tying the technical method to a historical document rather than an evergreen manual.

Operational start date and signature. The AD states a commencement date of 20 February 2017 and bears a delegate signature dated 15 February 2017 (commencement, signature).

Overall, the core concepts are a targeted inspection mandate for a specific set of aluminium-bladed Hydromatic propellers, calendar-based inspection intervals, narrowly framed exceptions, and a delegated alternative compliance pathway for a defined Limited Category subset administered by AWAL.

Aircraft operators with the specified Hamilton Standard Hydromatic aluminium-bladed propellers are the primary parties affected. The AD applies to propellers of the listed type numbers: 22D30; 22D40; 23D40; 23E50; 23E60; 24D50; 24E60; 33D50; 33E60; 34D50; 34D51; 34E60; 43D50; 43D51; 43E60; and 43H60, as installed on an aircraft (Applicability). Operators must determine whether their installed propellers are among these types, and whether the blades are aluminium and use engine oil for pitch control. The AD explicitly excludes propellers with integral oil control and steel blades (Applicability). Therefore operators of propellers outside these physical attributes are not required to comply.

Limited Category aircraft and AWAL. A subset of operators flying Limited Category aircraft administered by the Australian Warbirds Association Ltd under Part 132 of CASR 1998 are affected by the alternative compliance pathway. For those aircraft, the AD permits compliance by following AWAL Maintenance Direction No. 16-001, "as in force from time to time" (Requirement 2). The AD thereby imposes an obligation on both the AWAL-administered operators to follow AWAL’s maintenance direction and on AWAL to maintain such a direction. The AD also places a substantive qualification on AWAL’s exemption: AWAL Maintenance Direction does not apply to any aircraft that has been flown off salt water (Compliance Note 3).

Maintenance personnel and overhaul facilities. The requirement to "remove blades and visually inspect" in accordance with a named overhaul manual implicates maintenance organisations and certified personnel capable of performing blade removal, reinstallation, and the specific visual inspection steps included in Hamilton Standard Aluminium Blade Overhaul Manual No. 130B dated 1 March 1980 (Requirement 1). These organisations must have access to the manual as in force at the AD date and follow those procedures. The inspection work will typically be carried out by the operator’s maintenance organisation, approved overhaul facility or a suitably qualified team.

Record keepers and compliance managers. The AD’s calendar-time counting rules mean that whoever maintains the aircraft’s maintenance and installation records must track the date the propeller was first installed after reconditioning or inspection in accordance with the AD, and ensure the inspection schedule is observed uninterruptedly, including during storage (Compliance Note 2). For AWAL-administered aircraft, record-keeping must also show compliance with AWAL Maintenance Direction No. 16-001 where applicable.

Regulatory actors. The AD was issued by the Civil Aviation Safety Authority, with the delegate signature shown in the document. The AD references FAA findings and previous FAA ADs in its background, but the instrument itself is a CASA directive and its commencement and operation are governed by CASA’s administrative processes as reflected in the document (Background, commencement).

Suppliers of parts and manuals. Overhaul manual compliance ties affected parties to Hamilton Standard Aluminium Blade Overhaul Manual No. 130B dated 1 March 1980, "as in force at the date of this AD" (Requirement 1). Entities that supply or hold the relevant manual, spare blades, or Teflon friction strip materials may be indirectly affected because inspections will require removal and possibly replacement of components found corroded.

In summary, operators of aircraft that have the listed aluminium Hydromatic propellers, their maintenance organisations, AWAL-administered Limited Category operators and AWAL itself, and the personnel that maintain installation and maintenance records, are the affected parties identified by the AD. The AD narrows the affected population by material and control system type and provides an explicit alternative compliance track for a defined subset of Limited Category aircraft.

Key duties

• Inspective duty: Operators must remove blades and visually inspect for evidence of corrosion in the blade fillet and shank area, paying particular attention to the area under the Teflon friction reduction strip and the resin corrosion barrier (Requirement 1). The inspection must follow Hamilton Standard Aluminium Blade Overhaul Manual No. 130B dated 1 March 1980, "as in force at the date of this AD" (Requirement 1). This binds the inspection method to that manual as it existed on the AD date.

• Timing duty for general fleet: For propellers other than those covered by the AWAL alternative, the blade removal inspection is required "at periods not exceeding 6 years calendar time in service" (Compliance 1). Operators must ensure that the interval between required inspections does not exceed six calendar years.

• Alternative compliance duty for AWAL-administered Limited Category aircraft: For propellers described in Requirement 2 (Limited Category with AWAL administering authority under Part 132 of CASR 1998), operators must "Comply with the requirements in AWAL Maintenance Direction No: 16-001, as in force from time to time" (Requirement 2). AWAL-administered operators therefore have the duty of complying with AWAL MD No.16-001 in lieu of the standard six-year interval.

• Calendar time accounting duty: Calendar periods "are deemed to commence from the time the propeller is first installed on an aircraft following reconditioning or inspection in accordance with the AD and shall be uninterrupted including all subsequent service and storage periods" (Compliance Note 2). Operators have a duty to account for calendar time that includes storage, and to start the clock from the first post-reconditioning installation.

• AWAL-specific duty limitations: AWAL Maintenance Direction No. 16-001 does not apply to any aircraft that has been flown off salt water (Compliance Note 3). Where that condition applies, the alternative pathway is not available.

Rights and delegated discretion

• Right to an alternative pathway: Operators of Limited Category aircraft administered by AWAL have a right to comply via AWAL Maintenance Direction No. 16-001, "as in force from time to time", providing a delegated, private-sector-administered compliance mechanism where the AWAL direction is accepted by CASA for that subset (Requirement 2). This creates an operational flexibility for those operators, subject to AWAL MD content and its applicability limitations.

• Right to rely on specified manual: The AD prescribes the Hamilton Standard Aluminium Blade Overhaul Manual No. 130B dated 1 March 1980 as the standard to follow for inspections, "as in force at the date of this AD" (Requirement 1). Operators are entitled to rely on that manual as the procedural source for the mandated inspection steps.

• Delegation to AWAL for maintenance direction content: By specifying compliance "as in force from time to time" for AWAL MD No. 16-001, the AD implicitly delegates to AWAL the procedural and interval details covered by that maintenance direction, subject to the AD’s overarching constraints (Requirement 2). AWAL thus exercises operational discretion to set and update the content of its maintenance direction for its administered aircraft.

Operational obligations implied by the AD

• Documentation and record-keeping: The calendar-time rule, the tie to reconditioning or inspection dates, and the alternative compliance pathway all impose a record-keeping obligation on operators to demonstrate when the clock began, that inspections occurred within the relevant calendar windows, and, where AWAL MD has been used, that AWAL MD requirements were complied with.

• Inspection scope specificity: The requirement emphasises inspection of corrosion under the Teflon friction strip and resin barrier. This narrows the technical duty; a superficial inspection that ignores these specified locations would not meet the AD text.

Limitations in the instrument

• The AD does not set out remedial actions to be taken if corrosion is found, beyond the inspection requirement and the cross-reference to the overhaul manual. The AD requires inspection per the manual, but the text does not list corrective steps or explicitly provide procedural detail for repair or blade removal beyond instructing compliance with the overhaul manual (Requirement 1). The absence of remedial direction means compliance practitioners must rely on the overhaul manual or other accepted maintenance practice to determine corrective actions.

• The AD does not contain penalty provisions in its text. It imposes duties but the mechanism for enforcement and penalties is not specified within the AD itself.

In sum, the AD creates three principal duties: perform blade removal inspections per the named manual; comply with the timing rules, including the six-year default and the AWAL alternative where applicable; and account for calendar time from first installation post-reconditioning. Rights consist of the permitted alternative compliance route for AWAL-administered Limited Category aircraft and the entitlement to use the specified overhaul manual as the procedural source.

The AD text itself does not specify criminal, civil, or administrative penalties, nor does it set out a formal enforcement procedure within the document. The instrument prescribes mandatory inspection requirements and commencement timing, but contains no express penalty provisions, sanctions, or enforcement mechanisms within the AD text provided (Requirement; Compliance; commencement). Therefore any enforcement or penalties must be derived from the broader regulatory framework under which CASA issues airworthiness directives, but such framework is not expressed in this AD document.

Practical enforcement implications evident from the AD

• Compliance obligation communicated: The AD identifies specific mandatory actions (blade removal and inspection per the named overhaul manual) and specific intervals (six years generally, AWAL route as an alternative with its own timing constraints). This creates an operational expectation of mandatory compliance that CASA has set out. The AD’s clarity on obligations facilitates inspection and audit of operator maintenance records by regulators or responsible authorities, even though the AD does not itself list enforcement instruments.

• Evidence and records central to any enforcement: The AD’s calendar-time rules and the requirement to observe periods "as in force" imply that documentary evidence will be necessary to demonstrate compliance. The commencement date and the rule that calendar periods commence from first post-reconditioning installation mean that maintenance logs, overhaul certificates, installation records and any AWAL maintenance direction compliance documentation will be the primary means by which an operator can show compliance.

• Delegated compliance pathway and third-party oversight: For AWAL-administered Limited Category aircraft that rely on AWAL Maintenance Direction No. 16-001 "as in force from time to time", enforcement of the AD’s obligations in practice may rest in part on oversight of AWAL’s maintenance direction and its application. The AD’s text does not detail CASA’s oversight or approval process for AWAL Maintenance Direction No. 16-001, but the existence of a delegated pathway creates an expectation that AWAL will maintain and apply the direction in a manner that ensures the AD’s safety purpose is met.

• No remedial or corrective actions specified: The AD requires inspections per the overhaul manual but does not specify what corrective actions must follow a finding of corrosion. In enforcement terms, regulators seeking to determine whether an operator met the AD will need to review whether inspections were carried out according to the manual and whether subsequent repair or corrective processes were appropriate, as judged against the manual or other authoritative maintenance standards.

Limitations for compliance officers and auditors

• The absence of specified penalties in the AD text means that auditors and inspectors must refer to the wider CASA regulatory scheme to identify applicable sanctions or enforcement mechanisms for non-compliance. Those mechanisms are not contained in the AD itself.

• The AD does not state reporting obligations for inspection outcomes. If a regulator requires notification of defects or inspection results, that process is not specified here and would have to be drawn from other regulatory instruments or CASA guidance.

In summary, the AD imposes clear mandatory inspection duties and timing, but it does not itself articulate penalties or a detailed enforcement process. The AD’s practical enforceability therefore depends on regulators’ use of broader statutory powers and on the maintenance records and documentation that operators hold to demonstrate compliance with the inspection duties and calendar-time rules laid down in the AD.

Explicit cross-reference to Part 132 of CASR 1998. The AD refers to Limited Category aircraft "for which the Australian Warbirds Association Ltd (AWAL) is the administering authority under Part 132 of CASR 1998" and provides an alternative compliance pathway for those aircraft by referencing AWAL Maintenance Direction No. 16-001 (Requirement 2). The AD thereby establishes an intersection with the regulatory regime governing Limited Category aircraft administration, as embodied in Part 132 of CASR 1998. The AD does not reproduce Part 132; it uses Part 132 only to identify which Limited Category aircraft come within the AWAL-administered cohort.

Delegation of maintenance content to AWAL. By allowing compliance through AWAL Maintenance Direction No. 16-001 "as in force from time to time", the AD incorporates by reference a maintenance instrument that exists external to the AD and that AWAL may update. This creates a dynamic interaction with AWAL’s maintenance governance: the AD binds operators to an AWAL instrument whose content is not reproduced in the AD and which may change. The AD explicitly imposes a qualification that AWAL Maintenance Direction No. 16-001 does not apply to aircraft that have been flown off salt water (Compliance Note 3), thereby creating a boundary condition for the AWAL pathway.

Reference to Hamilton Standard overhaul manual. The AD requires inspections to be performed in accordance with Hamilton Standard Aluminium Blade Overhaul Manual No. 130B dated 1 March 1980, "as in force at the date of this AD" (Requirement 1). This ties the AD to a private-sector technical manual. The interaction is one where the AD imports technical procedures from an external source by reference, and freezes the imported manual to its content as at the AD date. The AD does not permit later revisions to the overhaul manual to be used for compliance unless the AD itself is amended.

Background reference to FAA AD. The Background section records that the FAA advised the risk and that FAA AD 81-13-06 R2 is relevant. The AD also notes that Amendment 1 in 1987 of "this Directive" extended inspection periods after initial inspection. While these references provide context, they do not create a legal cross-commitment to FAA ADs; rather they show that CASA considered FAA findings in formulating its AD. The AD itself is the operative regulatory instrument in Australia.

Interaction with maintenance and airworthiness record requirements. The AD’s calendar-time rule , that periods commence from the time the propeller is first installed following reconditioning or inspection in accordance with the AD and are uninterrupted, including storage , implies interaction with statutory or regulatory obligations on record keeping and maintenance log-keeping, as those records will be used to demonstrate compliance with the AD. The AD does not itself specify which record-keeping statute or regulation must be used, but the operational reality is that maintenance and installation records will be material to meeting the AD’s timing requirements.

No penalties or enforcement mechanism internal to the AD. The AD does not contain its own enforcement clauses or penalties. Any enforcement action or sanctions for non-compliance will therefore derive from the broader statutory regime under which CASA issues ADs, and possibly from regulation governing maintenance and airworthiness, none of which are reproduced in the AD text.

Limitations and delegation effects. The AD delegates the content and timing decisions for a subset of aircraft to AWAL by reference to AWAL Maintenance Direction No. 16-001 "as in force from time to time". This creates a flow of regulatory content from a private body into operator obligations under the AD. That delegation may interact with other legal obligations of AWAL as an administering authority under Part 132 of CASR 1998, although those interactions are not set out in the AD.

In summary, the AD interacts with other laws and instruments primarily by reference: it incorporates a specified overhaul manual "as in force at the date of this AD", it creates a compliance pathway tied to AWAL and to Part 132 of CASR 1998, and it acknowledges FAA findings and prior FAA ADs in its background. It does not itself reproduce broader statutory enforcement or record-keeping requirements.

The AD document records a small amendment history and references prior action primarily in the Background section.

• Original FAA identification and FAA AD reference: The Background notes that the FAA advised a risk of fatigue cracking leading to blade separation due to severe corrosion around the shank and blade fillet area, particularly under the Teflon friction strip, and cites FAA AD 81-13-06 R2 as relevant. That establishes the origin of concern and a prior FAA action addressing similar issues (Background).

• Amendment 1 (1987): The Background states that "Amendment 1 (1987) of this Directive was issued to extend the inspection period after initial inspection." That records a historic change in inspection interval policy for this directive. The AD does not reproduce the full text of Amendment 1 but documents that an extension of the inspection period took place in 1987 as Amendment 1 (Background).

• Amendment 2 (this AD, 2017): The current document is presented as Amendment 2 of AD/PHS/10. The Background states that Amendment 2 "allows for Limited Category aircraft administered by the Australian Warbird Association Ltd to have an extended inspection period by compliance with the requirements contained in AWAL Maintenance Direction 16-001." The instrument itself is labelled AD/PHS/10 Amdt 2 and dated 4/2017 in the table heading. This indicates that the current AD is a second amendment to an earlier Directive, with a new feature: an alternative compliance route for AWAL-administered Limited Category aircraft (Background; Requirement 2).

• Commencement and signature dates: The AD states that it "commences on 20 February 2017" and shows a delegate signature dated 15 February 2017 (commencement; signature). The tabular header also includes "4/2017" which corresponds to the AD versioning in 2017.

• AWAL submissions and rationale for Amendment 2: The Background records that AWAL requested that CASA review the AD and submitted maintenance reports and statements demonstrating that no significant corrosion had been found at previous propeller disassembly inspections at the six-year intervals. That material is recorded as informing CASA’s decision to permit an alternate compliance regime for AWAL-administered Limited Category aircraft (Background). The AD does not reproduce AWAL’s submissions but records that AWAL input was considered in the amendment.

No other amendments or subsequent revisions are referenced in the AD text. The instrument therefore presents a snapshot of the AD in its Amendment 2 form as of early 2017, incorporating the AWAL alternative compliance mechanism and reiterating earlier amendments such as the 1987 extension. The AD also freezes the procedural inspection requirement to a Hamilton Standard manual "as in force at the date of this AD", which limits any automatic carry-forward of subsequent revisions to that manual into AD compliance unless the AD itself is amended.

The AD text does not record or reference any litigation, court decisions, or judicial challenges in relation to AD/PHS/10 or its amendments. The Background section references FAA advisories and prior FAA ADs and notes AWAL submissions and maintenance reports, but there is no mention of legal proceedings or contested enforcement actions (Background).

Because the AD itself is an administrative directive issued by CASA and signed by a delegate, any litigation relating to the AD would be external to the document. The AD does not provide information about appeals, reviews, or disputes, nor does it cite any tribunal or court outcomes. The absence of litigation references in the AD should be taken as the instrument containing no recorded litigation history within its text.

Practitioners seeking litigation history must look beyond this document to judicial or administrative records, but such records are not included or summarised in the AD as provided. The AD contains only the technical and administrative content necessary to impose inspection requirements, and does not purport to provide a history of legal contestation.

The AD contains several operational and compliance "gotchas" that may be overlooked if read superficially.

1. Narrow applicability definition, with specific exclusions. The AD applies only to the listed Hamilton Standard Hydromatic propeller types with aluminium blades that use engine oil for pitch control. It explicitly does not apply to propellers with integral oil control or to propellers with steel blades (Applicability). Operators must verify both the propeller type number and the material and oil-control configuration. A propeller with a different oil control arrangement or blade material is outside the AD, even if otherwise similar.

2. Inspection procedure tied to a dated overhaul manual. The inspection must be done "in accordance with Hamilton Standard Aluminium Blade Overhaul Manual No. 130B dated 1 March 1980, as in force at the date of this AD" (Requirement 1). The AD locks the procedural standard to the manual as it existed at the AD date. Operators who attempt to use a later revision of the manual without confirmation that such use is acceptable under the AD will be out of step with the AD’s literal requirements.

3. Calendar-time counting includes storage, is uninterrupted, and begins at a specific event. The AD defines calendar periods as commencing "from the time the propeller is first installed on an aircraft following reconditioning or inspection in accordance with the AD" and being "uninterrupted including all subsequent service and storage periods" (Compliance Note 2). Therefore the inspection interval clock starts at first installation post-reconditioning, not necessarily at overhaul completion, and storage periods are counted. If operators store a propeller for years, that period reduces the remaining interval before the next mandated blade removal inspection.

4. AWAL alternative has its own limits and exclusions. If an operator relies on AWAL Maintenance Direction No. 16-001 for a Limited Category aircraft administered by AWAL, note that the AWAL MD "expresses additional requirements at the Annual inspection of the propeller" and also that the blade removal inspection "must be completed at periods not exceeding 12 years calendar time in service" (Compliance Note 1). Also, AWAL MD "does not apply to any aircraft that has been flown off salt water" (Compliance Note 3). Operators of AWAL-administered aircraft that have ever flown off salt water cannot rely on the AWAL MD exemption and must follow the default AD requirements.

5. The AD prescribes inspection focus on areas that may be concealed. The AD requires inspection "particularly under the Teflon friction reduction strip and the resin corrosion barrier" (Requirement 1). Inspecting under these strips requires blade removal and possibly attention to hidden areas that might be missed during a superficial inspection. The AD’s text emphasises concealed-area corrosion as the initiating failure mode.

6. The AD does not specify corrective action steps. The instrument mandates inspection in accordance with the overhaul manual, but it does not itself set out remedial actions if corrosion is found. Practitioners must consult the specified overhaul manual for acceptable corrective steps and ensure that any repairs or replacements comply with relevant maintenance standards.

7. Dynamic content via "as in force from time to time". For AWAL-administered aircraft, compliance depends on AWAL Maintenance Direction No. 16-001 "as in force from time to time" (Requirement 2). This phrase allows AWAL to revise its maintenance direction without further amendment to the AD. Operators relying on AWAL MD must monitor AWAL MD updates and ensure current compliance, and AWAL must maintain appropriate governance. The phrase introduces a layer of external changeability into the AD compliance picture.

8. The AD does not state reporting obligations or enforcement steps. The AD contains no explicit reporting requirement for inspection findings, nor does it specify enforcement mechanisms or penalties. Operators should not infer the absence of enforcement; rather, they must recognise that enforcement, oversight and record-keeping expectations will be determined under broader regulatory frameworks not reproduced in the AD.

9. Two different calendar intervals exist depending on the pathway. The default blade removal inspection interval is six calendar years, but for AWAL-administered Limited Category aircraft, the blade removal inspection may be extended up to but not exceeding 12 years (Compliance; Note 1). Operators must ensure their fleet-specific classification and applicable pathway are correctly applied; mixing up the intervals could lead to non-compliance.

10. The AD is dated and binds to documents at a point in time. The requirement to use manuals "as in force at the date of this AD" means that later changes to the Hamilton Standard manual are not incorporated automatically. Similarly, the AD itself is dated and commenced on 20 February 2017. Practitioners should confirm whether there have been later ADs or amendments beyond AD/PHS/10 Amdt 2 before relying solely on this document.

These "gotchas" focus on precise applicability, the temporal and documentary anchors of the AD, and the practicalities of hidden-area inspection and record-keeping. Each is grounded in AD text and affects how an operator must organise maintenance, documentation, and reliance on delegated maintenance directions.

Compliance requires systematic verification of applicability, preparation of records, physical inspection per the named manual, and adherence to the calendar intervals and AWAL conditions set out in the AD. The AD’s express steps provide a compliance pathway; below are operationally actionable steps grounded in the AD text.

1. Confirm applicability

   • Identify the propeller type number installed on the aircraft and verify it is among the listed types: 22D30; 22D40; 23D40; 23E50; 23E60; 24D50; 24E60; 33D50; 33E60; 34D50; 34D51; 34E60; 43D50; 43D51; 43E60; 43H60 (Applicability).
   • Confirm the blade material is aluminium and that the propeller is non-counterweighted and uses engine oil for pitch control. If the propeller has integral oil control or steel blades, the AD does not apply (Applicability).

2. Determine which compliance track applies

   • If the aircraft is a Limited Category aircraft administered by AWAL under Part 132 of CASR 1998, determine whether AWAL is the administering authority for that specific aircraft. If so, the operator may comply by following AWAL Maintenance Direction No. 16-001 "as in force from time to time" (Requirement 2).
   • If AWAL does not administer the aircraft, or if the aircraft has been flown off salt water (in which case AWAL MD does not apply), then the default six-year calendar interval applies (Compliance; Note 3).

3. Establish the calendar-time start date and tracking system

   • Determine the date the propeller was first installed on an aircraft following reconditioning or inspection in accordance with the AD. This date is the commencement of the calendar period for required inspections (Compliance Note 2).
   • Treat the interval as uninterrupted and inclusive of storage time. Record-keeping systems must therefore capture installation dates, reconditioning/inspection completion dates, storage periods, and any changes affecting installation status (Compliance Note 2).

4. Obtain and use the specified manual

   • Obtain Hamilton Standard Aluminium Blade Overhaul Manual No. 130B dated 1 March 1980, and ensure the inspection procedures are performed "in accordance" with that manual "as in force at the date of this AD" (Requirement 1). Use the manual’s processes for blade removal and the detailed visual inspection steps required.

5. Execute the inspection

   • Remove blades and conduct a visual inspection for evidence of corrosion in the blade fillet and shank area, with particular attention to the areas under the Teflon friction reduction strip and under the resin corrosion barrier, as specified in Requirement 1.
   • Ensure the maintenance personnel performing removals and inspections are qualified to work on propellers and familiar with the procedures in the specified overhaul manual.

6. Address findings in accordance with the overhaul manual

   • Should evidence of corrosion be found, follow the corrective and remedial procedures set out in Hamilton Standard Aluminium Blade Overhaul Manual No. 130B dated 1 March 1980. The AD itself does not list remedial steps, so compliance requires adherence to the overhaul manual and to any applicable maintenance or airworthiness standards used by the operator or maintenance organisation.

7. Schedule and observe inspection intervals

   • For most affected propellers, schedule blade removals and inspections at intervals not exceeding six calendar years in service (Compliance 1).
   • For AWAL-administered Limited Category aircraft complying with AWAL MD No. 16-001, ensure the blade removal inspection is completed at intervals not exceeding 12 years calendar time in service, and also comply with any additional AWAL MD annual inspection requirements cited by AWAL (Compliance Note 1; Requirement 2).

8. Document and retain inspection records

   • Record the date the blade removal inspection was performed, the person or organisation performing it, the manual used, the findings (including photographs of corrosion if present), and any corrective action taken. Maintain records sufficient to demonstrate compliance with the AD’s timing rules and the requirement that calendar periods are uninterrupted, including storage periods (Compliance Note 2).

9. For AWAL-administered aircraft, maintain AWAL compliance records

   • If relying on AWAL Maintenance Direction No. 16-001, retain a copy of the AWAL MD version "as in force" at the time of compliance, and records demonstrating the operator followed AWAL MD requirements, including any annual inspection items and the timing of the blade removal inspection (Requirement 2; Compliance Note 1).
   • Verify that the aircraft has not been flown off salt water; if it has, AWAL MD cannot be relied upon and the operator must revert to the default AD requirements (Compliance Note 3).

10. Monitor for changes and verify AD currency

• The AD was commended as commencing on 20 February 2017 and references documents "as in force at the date of this AD" or "as in force from time to time" (commencement; Requirement 1; Requirement 2). Operators should confirm whether any subsequent AD amendments or other CASA directives supersede or modify AD/PHS/10 Amdt 2. The AD itself does not incorporate later revisions of the Hamilton manual nor does it freeze AWAL MD beyond the "as in force" language for AWAL MD. Practically, operators should maintain a process to confirm whether later amendments exist.

Operational practice tips grounded in the AD

• Treat storage as active time for interval calculations. The AD makes storage part of the uninterrupted calendar period. Operators should plan inspections accordingly.

• Pay special attention to concealed areas. The AD’s emphasis on corrosion under the Teflon friction strip and resin barrier means that surface checks are insufficient. Inspections must access concealed surfaces per the overhaul manual.

• Retain the specific version of any AWAL maintenance direction used to claim compliance, since the AD allows AWAL MD "as in force from time to time" but evidence of compliance will require showing which AWAL MD version was followed and when.

• When in doubt about applicability or timing, rely on physical records: dates of reconditioning or inspection that trigger the calendar clock, installation dates after reconditioning, and any AWAL administration records.

By following these steps and documenting each action carefully, an operator will align maintenance practice with the AD’s requirements as stated in the instrument.