AD/PHZL/90 - Hub Mounting Bolt Holes

The instrument establishes a small set of core concepts and operational thresholds that determine who must act and when. First, applicability is model‑ and serial‑number based. The AD lists three Hartzell propeller model families: HC‑E5N‑3( ), HC‑E5N‑3( )(L), and HC‑E5B‑5( ). It then narrows applicability by serial number ceilings and a table of serial numbers expressly not affected, indicating that scope is not simply model‑based but serial‑number contingent. For HC‑E5N‑3( ) and HC‑E5N‑3( )(L), the AD notes installation on, but not limited to, Piaggio P‑180 Avanti aeroplanes and indicates serial numbers up to and including HF229 or KU92, with Table 1 listing many serial numbers that are not affected. For HC‑E5B‑5( ), the AD indicates installation on Grumman S‑2 Tracker aeroplanes with propeller SNs up to and including HN14.

Second, the AD differentiates populations by Time In Service. Two bands are highlighted in the background and used in the compliance timing: hubs with unknown hours, or between 1,800 and 4,500 hours TIS; and hubs with 1,800 hours or fewer, or 4,500 hours or more. Those bands produce different compliance windows and hour thresholds for when the single inspection must be performed. The AD therefore operationalises risk by age or usage metrics rather than by calendar date alone.

Third, the AD prescribes a single inspection method and a single corrective action. The inspection technique specified is eddy current inspection of the propeller mounting holes, to be conducted in accordance with Hartzell Service Bulletin HC‑SB‑61‑295, Revision 2, dated 1 August 2007 (this SB is the normative technical means by which the inspection is to be performed). The mandatory corrective action is replacement of the propeller hub if any crack is found, and that replacement is required "before further flight", which creates an immediate operational constraint if a crack is discovered.

Fourth, the AD gives operators alternative windows to comply. For the first population (TIS unknown or >1,800 and <4,500), the inspection must occur within 12 calendar months, within the next 150 hours TIS, or at the next scheduled airframe "A" check inspection. For the second population (TIS ≤1,800 or ≥4,500), the inspection must occur within 12 calendar months, within 600 hours TIS, or at the next scheduled airframe "B" check inspection, whichever is earlier. These alternatives allow operators to choose among time, flight hours, and existing maintenance checkpoints, but do not alter the substantive requirement that the eddy current inspection be carried out.

Fifth, there is an explicit cross‑reference to FAA AD 2007‑24‑14 Amdt 39‑15280 dated 21 November 2007. The AD does not incorporate that FAA AD by text, but it signals a connection to the FAA action as relevant background or parallel guidance.

Finally, the AD sets an effective date, 31 July 2008, and is signed by a CASA delegate. The AD is a one‑time inspection requirement rather than a recurring inspection schedule. The document therefore changes operational practice by imposing a one‑off mandated non‑destructive test for a defined sub‑population of propellers and creating an immediate removal‑from‑service rule if a crack is found.

The primary parties directly obliged by the AD are operators and owners of aircraft fitted with the specified Hartzell propeller models and serial number ranges, and maintenance organisations responsible for propeller inspections and repairs. The text identifies model numbers and installation contexts, for example HC‑E5N‑3( ) and HC‑E5N‑3( )(L) installed on Piaggio P‑180 Avanti aeroplanes and HC‑E5B‑5( ) installed on Grumman S‑2 Tracker aeroplanes, with serial number ceilings and a list of serials excluded by Table 1. Operators must therefore check their propeller model and serial number against the AD's applicability statement and Table 1 to determine whether the AD applies to a particular propeller.

Maintenance providers and engineers carrying out the mandated eddy current inspection are affected because the AD requires that the inspection be performed in accordance with Hartzell Service Bulletin HC‑SB‑61‑295, Revision 2, dated 1 August 2007. That SB will contain the technical procedure, tooling, and acceptance criteria that maintenance organisations must follow to comply with the AD. The AD thereby binds maintenance work to a specific manufacturer's SB.

Hartzell Propeller Inc. is implicated as the maker of the specified propeller models and the author of the referenced service bulletin, although the AD imposes duties on operators and maintenance organisations rather than the manufacturer. The FAA is referenced but not made an implementing authority by this AD; the AD simply notes FAA AD 2007‑24‑14 as related.

Regulatory personnel within the Civil Aviation Safety Authority are implicated insofar as the AD is issued under CASA's powers; the instrument is signed by a CASA delegate. The AD does not, in the supplied text, list specific roles for CASA beyond issuance and the effective date.

Finally, there are indirect stakeholders. Owners and operators face operational planning implications because the inspection windows are tied to TIS bands and airframe scheduled "A" and "B" checks. If an inspection reveals a crack, the AD requires hub replacement "before further flight", which will have immediate logistics and cost consequences for the operator. These downstream consequences fall on the operator or owner in respect of arranging replacement hubs and maintenance downtime. The AD does not allocate or fund those costs in the text provided.

Duties imposed by the AD are concrete and limited in number. The primary duties are:

• Perform a one‑time eddy current inspection of the propeller mounting holes in accordance with Hartzell Service Bulletin HC‑SB‑61‑295, Revision 2, dated 1 August 2007 (Requirement 1). The AD prescribes the inspection method and the SB as the normative guidance.

• Replace the propeller hub if any crack is found (Requirement 2), and ensure replacement before further flight.

The compliance schedule for Requirement 1 is explicitly set out and differs by hub TIS band. For hubs with unknown TIS or with TIS greater than 1,800 hours but less than 4,500 hours, the mandatory inspection must be carried out within 12 calendar months, within the next 150 hours TIS, or at the next scheduled airframe "A" check inspection. For hubs with TIS of 1,800 hours or fewer, or 4,500 hours or more, the inspection must be carried out within 12 calendar months, within 600 hours TIS, or at the next scheduled airframe "B" check inspection, whichever occurs first. The AD therefore gives operators an option structure that ties the inspection to either a calendar deadline, an hours threshold, or an upcoming scheduled airframe maintenance event.

The AD provides an exclusion list in Table 1: specific serial numbers that are not affected. That list functions as a de facto right for the owners of those specific serials not to have to comply with the AD. Conversely, owners of propellers whose serial numbers are within the stated up‑to‑and‑including ceilings but not listed in Table 1 must comply.

Rights articulated in the AD are limited. The AD does not create affirmative entitlements such as compensation for downtime or replacement parts. It does, however, provide the operator with scheduling flexibilities; the operator can choose among the alternative compliance windows (calendar months, hours TIS, or next scheduled airframe check) to meet the inspection requirement. The AD also allows an operator to consult the referenced Hartzell SB, which defines the inspection procedure, meaning the operator has a named technical standard to follow.

The AD places an immediate operational restriction if a crack is found: the propeller hub must be replaced before further flight. This is a mandatory removal‑from‑service trigger rather than a discretionary corrective action. The AD does not in the supplied text provide any appeals, exemptions, or deferred compliance mechanisms. It also does not specify who bears replacement costs; the obligation to remove cracked hubs prior to flight implies the operator must carry out or arrange the replacement.

The AD references FAA AD 2007‑24‑14 but does not incorporate it as a parallel duty within the text here. The AD also cites the Hartzell SB as the technical standard; following that SB is part of the duty to comply.

The AD text provided does not set out explicit penalties, fines, or administrative sanctions within its own wording. The instrument records an effective date of 31 July 2008 and is issued under the authority of the Civil Aviation Safety Authority, signed by a delegate. It prescribes required actions and timing but does not, in the supplied excerpt, include a sanctions clause or enforcement procedure.

Because the instrument is an Airworthiness Directive, it operates as a mandatory regulatory requirement for those aircraft and propellers to which it applies. The AD itself instructs what must be done, when, and in what manner, for example mandating the eddy current inspection per Hartzell Service Bulletin HC‑SB‑61‑295, Revision 2, and mandating hub replacement before further flight if a crack is found. The AD therefore creates a legal obligation; failing to meet that obligation would mean non‑compliance with the AD. The AD text here, however, is silent on whether non‑compliance attracts a particular penalty or on the administrative enforcement steps CASA would take, and it does not describe procedural rights such as review, appeal, or application for relief.

The AD does refer to FAA AD 2007‑24‑14 as related material. That reference may be operationally useful for technical or compliance context but does not itself impose additional penalties under this AD. The AD does not state whether compliance records must be lodged with CASA or whether CASA will audit compliance. The supplied text does not describe an inspection verification process, service difficulty reporting obligations, or mandatory paperwork filings resulting from the inspection.

In practice, enforcement mechanisms for non‑compliance with airworthiness directives typically rest with the civil aviation regulator, but that practical enforcement regime and its sanctions are not articulated in this AD text. Therefore, within the four corners of the AD provided, readers should note that the AD prescribes mandatory actions and timing but does not itself state penalties or administrative enforcement processes.

The AD explicitly cross‑references a related FAA AD: FAA AD 2007‑24‑14 Amdt 39‑15280 dated 21 November 2007. The AD does not assert that it incorporates or displaces the FAA AD. Rather, it notes the FAA AD as a reference that presumably covers the same or a similar condition for the relevant Hartzell propellers. The inclusion of that FAA AD suggests coordination or parallel action between CASA and the FAA on this propeller safety issue, and it provides operators with an additional source of technical and regulatory context. The AD also prescribes that inspections be carried out in accordance with Hartzell Service Bulletin HC‑SB‑61‑295, Revision 2, dated 1 August 2007. That service bulletin is the technical standard referenced by the AD and will interact operationally with existing maintenance procedures and approvals; maintenance organisations will need to follow that SB to demonstrate compliance.

The AD does not reference or amend any other Australian legislative instrument within the supplied text. It does not include transitional provisions that would interact with other domestic regulatory requirements, nor does it expressly modify airworthiness approvals, aircraft certificates, or maintenance organisation approvals. The AD operates as a stand‑alone directive that imposes a specific inspection and corrective action requirement for a defined group of propellers.

Because the AD mandates work to be done per a manufacturer's service bulletin, it interacts with maintenance contracting and approved maintenance organisation procedures. Maintenance organisations must apply the SB's requirements where the AD applies. The AD also ties compliance timing to airframe scheduled "A" and "B" checks, which are part of existing maintenance scheduling regimes. Thus, the AD interacts operationally with aircraft maintenance schedules and existing airworthiness maintenance practices.

The supplied AD does not state how it interacts with warranties, insurance policies, or commercial contracts. It does not specify whether costs associated with compliance are recoverable from manufacturers or insurers. It also does not state whether compliance with the AD confers any immunity or defence against other legal claims. In the absence of such text, any legal interaction with warranties, insurance or contract law would need to be determined outside the AD on the facts and contractual terms.

Finally, by referencing the FAA AD and a Hartzell service bulletin, the AD situates itself within a multijurisdictional technical and regulatory ecosystem. Operators of internationally operated aircraft or those subject to FAA oversight may need to consider the overlapping technical directions, but this AD itself applies as an Australian regulatory instrument within the Australian civil aviation regime.

The supplied instrument does not include a sequence of amendments or revisions to the AD itself. It records an effective date and the date of issue but does not list prior versions of the same AD, nor does it mention any later amendments. The AD text contains the following temporal markers: it is dated 13 June 2008 in signature, and it states that the Airworthiness Directive becomes effective on 31 July 2008. The Hartzell Service Bulletin referenced is identified as Revision 2, dated 1 August 2007, which indicates that the SB was revised prior to the AD's issuance; however, the AD does not trace any earlier or later AD amendments.

The AD also references FAA AD 2007‑24‑14 Amendment 39‑15280 dated 21 November 2007. That reference indicates that related action occurred at the FAA in late 2007. The AD does not indicate whether it supersedes any prior CASA AD or whether it will be superseded in future. It also does not prescribe an expiration date or a revocation clause.

Because there is no amendment history provided in the supplied text, readers should treat the AD as a single‑issue instrument effective from 31 July 2008 and anchored to Hartzell SB HC‑SB‑61‑295 Revision 2, dated 1 August 2007. Any subsequent amendments, revocations or superseding ADs are not recorded here. Parties requiring knowledge of later changes to the regulatory obligation should consult CASA's official AD registry or follow‑up publications outside the four corners of the supplied AD.

The supplied AD does not record any litigation history. There are no court cases, administrative appeals, or judicial reviews mentioned in the text. The instrument consists of the AD content, the technical requirements, applicability detail including Table 1 of serial numbers not affected, the compliance timing, the effective date, a link to a Hartzell service bulletin, and a reference to an FAA AD. It is signed by a CASA delegate and dated 13 June 2008. No litigation, challenges, or legal disputes are reported in the material provided.

Because the AD text itself contains no litigation history, researchers seeking litigation records would need to search external legal or administrative databases, regulatory decision records, or court archives. The absence of litigation references in the AD text does not imply that no disputes ever arose; it simply means this instrument does not include or summarise any such actions. Any post‑issuance contestation, enforcement action, or judicial treatment is not captured in the AD as supplied here.

There are several concrete drafting and operational details in the AD that can cause misinterpretation or non‑compliance if not read carefully.

• Serial number scope and exclusions. The AD sets model and serial number ceilings and then lists numerous serial numbers in Table 1 as "Not Affected". Operators must check both whether their propeller SN is at or below the stated ceilings (for example "up to and including HF229 or KU92" for certain models) and whether their specific SN appears in the Table 1 exclusion list. Failure to cross‑reference both rules could result in incorrectly assuming applicability. The Table 1 layout in the printed text is dense; careful transcription and verification against asset records is necessary.

• Parenthetical placeholders in model identifiers. The propeller model descriptions use parenthetical notation (for example HC‑E5N‑3( ), HC‑E5N‑3( )(L), HC‑E5B‑5( )). Users must ensure they correctly interpret these placeholders against their own propeller part and model descriptions in maintenance records. The AD text as supplied includes those placeholders and operators should match their equipment nomenclature precisely to ascertain applicability.

• Time In Service bands and "unknown" TIS. The AD distinguishes a population that includes "unknown" hours alongside a defined band (greater than 1,800 and less than 4,500). Operators whose propeller hub TIS records are incomplete or missing fall into that higher‑risk population and must follow the tighter inspection hour window (150 hours TIS or next A check). Understanding what constitutes hub TIS and ensuring accurate TIS records is therefore a compliance trigger. If TIS is genuinely unknown, the AD makes that a determinative factor for earlier inspection.

• Multiple compliance triggers. For each TIS band the AD offers three alternative compliance triggers: a calendar time limit (within 12 months), an hours limit (150 or 600 hours depending on band), or an upcoming airframe scheduled "A" or "B" check. Operators must apply whichever occurs first in the second band, and have choices in the first band structure. Misapplying the "whichever occurs first" rule where it is present could result in late inspection.

• Single inspection only. The AD is a one‑time eddy current inspection; it does not establish a recurring inspection interval. If hub cracking is a progressive issue, the one‑time nature could be misread as eliminating need for future inspections; the AD imposes only a single mandated inspection and a replacement requirement if cracking is found at that inspection.

• If a crack is found, ground effect. The AD requires that the hub be replaced "before further flight". That language leaves no flexibility and creates an immediate grounding obligation for that propeller until replacement is effected. Operators should plan for availability of replacement hubs and downtime.

• Reference to a specific SB revision. The inspection is to be performed in accordance with Hartzell Service Bulletin HC‑SB‑61‑295, Revision 2, dated 1 August 2007. Using an earlier or later revision without clear regulatory authorisation may be non‑compliant with the AD; operators should use the specified revision unless CASA issues a superseding AD or allows an alternative.

• Absence of stated penalties or enforcement procedure in the AD. The text does not set out enforcement steps or penalties. Operators should not interpret that silence as permission to disregard the AD; rather, they should seek clarity from CASA about enforcement expectations since the AD itself imposes binding operational requirements but does not detail enforcement procedures.

• Cross‑jurisdictional pilots. The AD references FAA AD 2007‑24‑14. Operators who operate internationally or who are subject to FAA oversight should reconcile the CASA AD and FAA AD to ensure consistent compliance across jurisdictions.

• Ambiguity in "installed on, but not limited to". The AD uses that phrase for HC‑E5N‑3( ) and HC‑E5N‑3( )(L) propellers installed on Piaggio P‑180 Avanti aeroplanes. This phrasing signals that the AD is not limited to Piaggio installations even if that installation is highlighted; operators of other aircraft types with the same propeller models and applicable serial numbers should treat the AD as potentially applicable.

To comply with the AD as written, follow these concrete steps derived from the instrument text.

1. Identify affected propellers. Check the aircraft's propeller records to determine whether the propeller is one of the Hartzell models specified: HC‑E5N‑3( ), HC‑E5N‑3( )(L), or HC‑E5B‑5( ). Confirm the propeller serial number and whether it falls within the serial number ceilings specified (for example up to and including HF229 or KU92 for certain models, up to and including HN14 for HC‑E5B‑5( )), and verify whether the specific serial number appears in Table 1 of serial numbers "Not Affected". If the propeller SN is listed in Table 1, the AD does not apply to that propeller per the AD text.

2. Determine TIS band. For propellers to which the AD applies, determine the hub Time In Service. If the TIS is unknown, treat the hub as part of the "unknown" population referenced in the AD. The AD distinguishes two populations: (a) TIS unknown, or between 1,800 and 4,500 hours; (b) TIS 1,800 hours or fewer, or 4,500 hours or more. The correct compliance window depends on this determination.

3. Schedule the one‑time inspection. For Requirement 1, schedule and perform a one‑time eddy current inspection of the propeller mounting holes in accordance with Hartzell Service Bulletin HC‑SB‑61‑295, Revision 2, dated 1 August 2007. Observe the following timing options as prescribed in the AD:

   • If TIS is unknown, or greater than 1,800 but fewer than 4,500 hours, perform the inspection within 12 calendar months, or within the next 150 hours TIS, or at the next scheduled airframe "A" check inspection, whichever of these the operator chooses under the AD structure.

   • If TIS is 1,800 hours or fewer, or 4,500 hours or more, perform the inspection within 12 calendar months, or within 600 hours TIS, or at the next scheduled airframe "B" check inspection, whichever occurs first.

   Ensure that whichever trigger applies is not missed by careful scheduling and record review. Use the specified Hartzell SB procedure and acceptance criteria. Confirm that the maintenance organisation performing the inspection follows the SB Revision 2 dated 1 August 2007.

4. Act on findings. If the eddy current inspection discovers any crack in the mounting holes or hub as identified in the SB and AD, the AD requires replacement of the propeller hub before further flight. Do not operate the aircraft with the cracked hub in service. Arrange hub replacement immediately and ensure subsequent maintenance conforms to any additional SB instructions or airworthiness requirements.

5. Recordkeeping. Although the AD supplied does not specify required paperwork, good practice is to record the inspection, findings, SB revision used, technicians and organisation performing the work, dates, and any corrective action including part numbers and serial numbers of replaced hubs. These records will demonstrate compliance with the AD if queried by regulators or during audits.

6. Use the referenced materials. Perform the inspection strictly in accordance with Hartzell Service Bulletin HC‑SB‑61‑295, Revision 2, dated 1 August 2007 as referenced by the AD. Consult FAA AD 2007‑24‑14 for additional technical context if relevant, but the Australian AD's mandatory method is the Hartzell SB identified.

7. Address logistics and downtime. If a crack is found, replacement is required before further flight. Operators should plan for potential aircraft downtime and procurement of a replacement hub. Note that the AD itself does not allocate funding for replacements, so operators should determine who bears costs under aircraft ownership, lease, warranty or insurance arrangements.

8. Note effective date and seek updates. The AD became effective on 31 July 2008 as stated in the document. Check with CASA for any subsequent ADs, amendments or additional guidance that might alter compliance obligations beyond the single inspection and replacement requirement contained here.

9. Consult CASA where uncertain. The AD does not specify enforcement mechanisms or avenues for relief or alternative compliance. If an operator believes an alternative methodology is necessary or wishes to seek an extension, they should consult CASA for formal authorisation or guidance rather than unilaterally deviating from the AD's requirements.

By following these steps , model and serial number confirmation, TIS determination, scheduling the mandated eddy current inspection per the specified SB within the prescribed window, immediate replacement if cracking is found, and careful recordkeeping , an operator will meet the obligations set out in the AD as supplied.