AD/PHZL/81 - Propeller Attachment Bolts

The directive centres on several discrete technical and regulatory concepts that a legally literate audience must understand to assess its impact. The first is the airworthiness directive itself. An AD is a legally enforceable notice issued by CASA under Part 39 of the Civil Aviation Safety Regulations (CASR) 1998 (though the directive text does not cite the specific CASR provision). It mandates corrective action when an unsafe condition exists in a product type. Non-compliance renders the aircraft unairworthy and illegal to operate.

The second concept is the suspect component: propeller mounting bolts, P/N B-3339, from LFC Manufacturing Lot No. 12 or Lot No. 56. The background explains that bolts from Lot No. X (the directive does not name the lot number for the first issue, but it references “a certain manufacture lot” not properly absorbing installation torque, and “a different manufacture lot” with material surface pitting. The directive names only Lot Nos. 12 and 56 as suspect. Operators must identify whether their aircraft have these specific lots. The location of bolt identification marks is given in Figure 1 of the referenced ASB. This is a classic narrow scope: not all B-3339 bolts are suspect, only those from two identified manufacturing lots. Operators must verify the lot number on each bolt.

The third concept is incremental compliance requirements with varying intervals. The directive establishes three different inspection recurrence periods: for most aircraft, 120 hours TIS; for the Aerospatiale (Nord) 262(A) modified by STC SA2369SW, 100 hours TIS. The rationale for the difference is not stated in the directive. The initial inspection deadline is 50 hours TIS or 12 months, whichever first. This creates a complex schedule that maintenance planners must track. The “before further flight” condition for a failed torque check imposes immediate grounding risk. The terminating action of replacement within 12 months, regardless of inspection results, ensures permanent removal of suspect hardware.

The fourth concept is the relationship between the AD and the manufacturer’s service bulletin. The directive mandates that actions be performed “using paragraphs 3.A through 3.B.(5)” (for inspections) and “paragraph 3.C” (for replacement) of the ASB. The ASB is incorporated by reference. The operator must obtain the ASB to know the exact inspection procedures, torque values, and identification marks. The directive does not reproduce the ASB content. This is a common AD design that places reliance on proprietary manufacturer documents, which carry costs for operators who must purchase or access them.

The fifth concept is terminating action versus recurring checks. Many ADs allow indefinite recurring inspections as an alternative to replacement. Here, the directive imposes both: recurring checks until the terminating action is done, and then the terminating action must be completed within 12 months. This eliminates the option of indefinite inspection. The terminating action replaces suspect bolts with either non-suspect B-3339 bolts (from other lots) or approved equivalent part number bolts. “Approved equivalent” is not defined in the directive; presumably it requires CASA approval or data from the propeller manufacturer or STC holder. This introduces approval risk and potential delays if an equivalent part must be sourced and approved.

Finally, the directive notes the FAA counterpart. This suggests the US FAA determined an unsafe condition requiring AD action, and CASA adopted a substantially similar directive for Australian-registered aircraft. The directive does not discuss bilateral agreements or mutual recognition; it simply references the FAA AD. Operators with aircraft registered in multiple jurisdictions may need to track both versions. The directive is succinct, with no explanatory preamble beyond the background. It does not specify penalties for non-compliance, enforcement mechanisms, or appeal rights, but those are found in the general CASA enforcement framework.

The directive directly imposes legal duties on the registered operators of any Australian aircraft fitted with the listed Hartzell propeller models that have the suspect bolts installed. The propeller models specified are Hartzell HC-B3TN-2, HC-B3TN-3, HC-B3TN-5, HC-B3MN-3, HC-B4TN-3, HC-B4TN-5, HC-B4MN-5, HC-B4MP-3, HC-B4MP-5, and HC-B5MP-3. These are constant-speed, variable-pitch propellers typically found on turbine-powered general aviation and regional aircraft. The directive does not specify aircraft makes, models, or registrations; it applies by propeller and bolt configuration alone. This means any operator of an aircraft using one of those propellers must check whether P/N B-3339 bolts from Lots 12 or 56 are installed. The affected group is therefore narrower than all operators of those propellers , only those with the suspect bolts are subject to inspection and replacement duties. But because the source of the bolts may not be known without physical inspection, the directive effectively requires a preliminary investigation by all operators of those propeller models.

The directive also affects maintenance organisations that perform work on these propellers. They must be familiar with the ASB and have the capability to perform visual inspections and torque checks to the specified standards. The directive does not require CASA-approved maintenance organisations specifically; any person authorised under the regulations (e.g., LAME, approved maintenance organisations) can perform the tasks, provided they have access to the ASB. However, the torque check and replacement actions are likely to require specific skills and tooling. This imposes training and equipment costs on maintainers. The directive indirectly affects parts suppliers and distributors who handle P/N B-3339 bolts. They may need to segregate inventory from Lots 12 and 56 and ensure traceability. The terminating action creates a demand surge for replacement bolts not from suspect lots or for equivalent part numbers. This may lead to price increases or supply shortages if the non-suspect lots are also limited. The directive does not anticipate or mitigate such effects.

The Aerospatiale (Nord) 262(A) operators modified by STC SA2369SW face shorter inspection intervals (100 hours versus 120 hours). This imposes a disproportionate compliance burden on the small number of such aircraft likely in Australia. The rationale for the shorter interval is not given; it may be due to installation geometry, power settings, or operational history not disclosed in the directive. This disparate treatment may raise questions about regulatory consistency, but the directive does not offer justification. The directive also affects the civil liability landscape. If a propeller separates due to bolt failure and the operator had not complied, the operator faces not only regulatory penalties but also potential tort liability for any resulting harm. Conversely, an operator who complied may still face liability if the bolt failure is caused by a latent defect not covered by the directive, but the AD serves as a minimum standard.

The directive does not directly affect passengers, but their safety is the ultimate justification. From a free-market perspective, the directive substitutes a government-mandated compliance regime for the outcome of private contracting between operators, insurers, and manufacturers. Operators bear the cost; the manufacturer (Hartzell) may face reputational and warranty obligations but is not required by the directive to pay for replacement parts or labour. This is a classic case of regulatory cost externalisation onto downstream users. The directive does not include provisions for reimbursement, rebate, or compensation. Operators must absorb the cost of inspections and replacements. For fleets with many suspect bolts, this could be significant. The directive does not differentiate between commercial and private operators; the costs fall on both, but private operators may be less able to spread them over a large base.

The directive imposes specific duties on operators, some of which are absolute and others conditional. The primary duty under Requirement 1 is to perform an initial visual inspection and torque check of all eight mounting flange bolts when suspect bolts from the identified lots are present. This duty is triggered by the presence of the suspect bolts, not by default. If the operator confirms that no such bolts are installed, no further action under the directive is required (though other ADs may apply). The duty requires access to the ASB to locate identification marks and to follow the accomplishment instructions. The operator has a duty to keep records of the inspection, though the directive does not explicitly say so , but general CASR maintenance record-keeping obligations would apply. Under Compliance paragraph 1, this initial check must be done within 50 hours TIS or 12 months from the effective date, whichever comes first. An operator who delays beyond that violates the directive.

The second duty (Requirement 2 for most aircraft) is to perform repetitive torque checks at intervals of 120 hours TIS since last inspection. This is a recurring obligation that continues until either the terminating action is done or the operator removes the suspect bolts earlier. The interval runs from the last inspection, meaning each subsequent check restarts the clock. This is an open-ended duty with no upper limit unless the terminating action is completed. For the specific Aerospatiale 262(A) variant (Requirement 3), the interval is 100 hours TIS since last inspection. The operator must track which interval applies to their aircraft, based on whether it is modified by STC SA2369SW. If the modification status is unknown, the operator has a duty to ascertain it.

The most stringent duty is Requirement 4: if any bolt fails the torque check, the operator must replace all eight bolts before further flight. This imposes immediate grounding. There is no grace period, no ferry flight permission, and no deferral. The operator has no right to operate the aircraft even for maintenance positioning without compliance. The replacement must be with bolts not from the suspect lots or with approved equivalent part number bolts. The operator has a duty to source the correct replacement parts and ensure they are properly installed per ASB paragraph 3.B.(5) or 3.C as relevant. The operator has no right to use bolts from Lots 12 or 56, even if they pass a torque check at the moment; the terminating action requires their removal.

The mandatory terminating action (Requirement 5) imposes a duty to replace all suspect bolts within 12 months of the effective date, regardless of whether they passed prior torque checks. This is a hard deadline. The operator has no right to extend the period by using recurring checks. The right under the directive is limited: the operator may choose either to use non-suspect P/N B-3339 bolts (from other lots) or approved equivalent part number bolts. The directive does not specify what constitutes an “approved equivalent” , it must be determined through the normal CASA approval process, such as via a PMA part or manufacturer part number substitution. The operator has the right to seek an alternative means of compliance (AMOC) from CASA, but the directive does not mention it; AMOC provisions exist generally under CASR Part 39. However, the directive does not indicate whether CASA will consider AMOC requests. The operator bears the cost of applying and the risk of refusal.

The directive does not grant any right to compensation from CASA, Hartzell, or the bolt manufacturer LFC Manufacturing for the costs of compliance. The operator must bear labour, parts, grounding, and administrative costs. The operator has a right to challenge the directive through judicial review, but the grounds would be narrow (procedural error, unreasonableness, etc.). The directive’s background acknowledges the discovery of defects, which likely satisfies the “unsafe condition” test. The operator has no right to defer compliance pending a challenge. The directive is enforceable immediately from the effective date.

The directive itself does not prescribe specific penalties. Instead, it relies on the civil and criminal penalty provisions of the Civil Aviation Act 1988 and the Civil Aviation Safety Regulations 1998. Operating an aircraft that does not comply with an applicable AD is a breach of CASR Part 39. Depending on the nature of the breach, penalties can include infringement notices (on-the-spot fines), civil penalties (up to thousands of dollars per contravention), and criminal penalties for deliberate or reckless violations. For corporations, penalties can be significantly higher. CASA also has the power to suspend or cancel the aircraft’s certificate of airworthiness, or issue a direction to ground the aircraft. The “before further flight” requirement in Requirement 4 means that any operator who flies after a failed torque check without replacing the bolts commits a serious offence.

Enforcement can be triggered by CASA inspectors during routine surveillance, audits of maintenance records, or as a result of an incident or accident investigation. The directive creates a clear, ascertainable standard: a logbook entry showing inspection and torque check within the required interval, and evidence of terminating action within 12 months. If records are absent or show non-compliance, CASA can take enforcement action regardless of whether the aircraft actually suffered any bolt failure. The directive does not provide any defence based on ignorance , the operator is presumed to know the AD applies. There is no de minimis exemption. Even a private owner flying a single experimental or amateur-built aircraft (though those are rare with these certified propellers) must comply if the propeller is within the applicability.

The reference to the FAA AD (2005-14-12) means that an aircraft operated in both US and Australian jurisdictions must comply with both. Non-compliance with the FAA AD could result in FAA enforcement action, including revocation of the aircraft’s US airworthiness certificate. CASA and the FAA have a bilateral agreement, but the enforcement mechanisms are separate. An operator found non-compliant in Australia might also face reporting to the FAA. The directive does not create a private right of action for third parties (e.g., passengers or insurers). However, non-compliance could be used as evidence of negligence in civil litigation if a bolt failure causes harm. Insurers may deny coverage for losses arising from non-compliance, as standard aviation insurance policies often exclude losses caused by non-compliance with mandatory maintenance or ADs.

The effective date of 29 September 2005 means that any failure to comply after that date is actionable. The directive does not have a sunset clause; it remains in force until superseded or withdrawn. If the terminating action concludes for a given aircraft, the directive no longer imposes ongoing duties for that aircraft, but the record of compliance must be kept. CASA can still audit past compliance. The directive does not specify maximum penalties, but typical CASA penalty ranges for non-compliance with an AD can be up to AUD 50,000 for individuals and AUD 250,000 for corporations, plus possible imprisonment for reckless endangerment under the Act. For operators of multiple aircraft, cumulative penalties can be enormous.

The directive sits within a broader regulatory framework of aviation safety legislation. It is issued under Part 39 of the CASR, which governs airworthiness directives. Other parts of CASR, such as Part 43 (maintenance), Part 91 (general operating and flight rules), and Part 42 (continuing airworthiness), interact with the directive. For example, CASR 42.65 requires operators to ensure that all ADs applicable to their aircraft are complied with. The directive’s inspection and torque check requirements are “maintenance” as defined in the regulations, and must be performed and certified accordingly. The engineer or organisation performing the work must record the action in the aircraft’s maintenance release or logbook, and sign it off under the relevant maintenance authorisation.

The directive incorporates by reference the Hartzell ASB No. HC-ASB-61-279, Revision 2. That ASB becomes mandatory requirement through the AD. The operator must have access to the ASB, and the ASB may itself reference other documents (e.g., propeller overhaul manuals, part catalogues). The directive does not specify whether a later revision of the ASB may be used; only Revision 2 is referenced. If Hartzell subsequently issues Revision 3, compliance with it might still satisfy the directive if it is equivalent or approved by CASA, but the operator cannot rely on that without formal AMOC. This creates a risk of obsolescence. The directive also references the FAA AD, which may include slightly different compliance times or definitions. For an aircraft holding both US and Australian certificates, the operator must comply with the more restrictive of the two. For Australian-only aircraft, the CASA directive controls, but the FAA AD’s technical content may be relevant for interpretation.

The directive does not interact with trade practices law directly, but the Australian Consumer Law (ACL) could apply if the bolts themselves were defective. The manufacturer (LFC Manufacturing, part of Hartzell?) may be liable for supplying defective goods, but the directive does not address that. The operator’s compliance costs could be recoverable from the manufacturer or supplier through warranty or tort claims, but the directive does not facilitate or require that. The directive overrides any private contractual arrangement that would permit use of the suspect bolts without inspection; no maintenance provider can agree to defer compliance. The directive also interacts with workers compensation and occupational health and safety laws in the context of mechanics performing inspections; the directive does not exempt them from workplace safety standards.

From an international law perspective, the directive implements obligations under the Chicago Convention via the Australian Air Navigation Act 1920. It also reflects CASA’s function to adopt foreign ADs when appropriate. No mutual recognition agreement with the FAA is invoked in the text. The directive might be affected by the Australia-US Bilateral Aviation Safety Agreement (BASA) and the Maintenance Annex Guidance (MAG), but the directive does not mention this. The practical effect for Australian operators using US-sourced parts is that they must comply with both ADs, which may be identical. The directive does not provide for alternative compliance if the operator has already complied with the FAA AD; in practice, CASA may accept FAA compliance as equivalent, but the directive does not state this. Operators should confirm with CASA.

The directive does not interact with state or territory laws, except possibly through general law of negligence. It also does not affect tax treatment: compliance costs are likely deductible business expenses for operators, but the directive does not address deductibility. For private recreational operators, the costs may not be deductible, increasing the burden.

The directive as presented is AD/PHZL/81, with a document date of 18 August 2005 and an effective date of 29 September 2005. The source text does not indicate any subsequent amendments, revisions, or cancellations. It is a single issuance. The user has provided the full text of the directive itself. There is no amendment history contained within the document because it is the original directive, not a consolidated version. However, the directive’s own number “10/2005” suggests it is the tenth AD issued in 2005 for that propeller family (PHZL prefix). The source does not provide any information about whether this directive supersedes an earlier AD or has been superseded by a later one. Given that it dates from 2005, it is likely that subsequent ADs have been issued for Hartzell propellers, but that is not in the source and cannot be asserted.

The directive refers to Hartzell ASB HC-ASB-61-279, Revision 2, dated 6 May 2005. That ASB may have itself been revised later, but the directive mandates that specific revision. If a later revision is more permissive or changes the identification marks, the operator cannot use it without an AMOC. The directive does not indicate whether it supersedes any earlier interim action, emergency AD, or proposal. Background suggests the directive resulted from discoveries during “routine propeller installation” and discovery of “material surface pitting” from another lot. This suggests a reactive AD, not a planned periodic update.

The signature is that of James Coyne as Delegate of CASA. The delegate’s authority comes from the Civil Aviation Act 1988, which allows delegation of powers to issue ADs. No amendment history implies no changes have been made to this AD since 2005. For a compliance professional, the practical challenge is verifying whether this AD is still current. The source text does not answer that. The deep dive must note that absence. The directive’s referencing of FAA AD 2005-14-12 means the FAA AD may have been superseded by later amendments; if FAA amended their AD, the CASA AD may still be in its original form, creating divergence. Operators should check the current CASA AD database for any later amendment or replacement.

The directive itself has no internal version number. The “AD/PHZL/81” is the unique identifier. There is no mention of whether it is part of a series; PHZL/81 may be the 81st AD for Hartzell propellers. The date 18 August 2005 is the signature date; the effective date is 29 September 2005, which is 42 days later, giving operators some lead time for the first compliance deadline (50 hours TIS or 12 months). This suggests a normal rulemaking process, not an emergency AD (which typically takes immediate effect). The directive does not include a summary of comments or cost-benefit analysis. For amendment history, the only factual statement from the source is that this directive was issued on that date and became effective on that date. No change history is provided.

The source text contains absolutely no reference to any litigation, enforcement cases, appeals, or court decisions involving AD/PHZL/81. There is no mention of any challenge to its validity, no tribunal decisions, and no references to civil or criminal proceedings related to this directive. This is common for most airworthiness directives; they are typically not litigated directly. Challenges would be rare and would arise under administrative law, arguing that CASA exceeded its authority or that the directive is procedurally flawed. The directive’s background states it is based on discoveries of defects; that factual basis would be difficult to challenge. No case names, numbers, or outcomes are provided.

The directive does cite the FAA AD counterpart (2005-14-12). There may have been litigation in the US regarding that FAA AD, but the source does not mention any. Even if such litigation existed, it would not be binding in Australia. The directive’s simple and technical nature makes it unlikely that a court would overturn it absent clear error. The directive does not impose disproportionate penalties or require impossible actions; compliance times are reasonable (50 hours, 120 hours, 12 months). There is no indication of any litigation history in the source.

For a deep dive, this absence is itself notable. Operators should be aware that the directive has not been judicially tested, but that does not imply it is invalid. The lack of litigation may reflect that compliance costs were low enough to absorb, or that operators accepted the safety rationale. Alternatively, it could mean that any non-compliance went undetected. The directive’s age (2005) means any litigation would likely have concluded years ago. The absence of any reported case in Australia suggests that the directive did not generate controversy or hardship on a scale that warranted legal challenge. For the audience, this means the directive is a settled and stable regulatory requirement. No reliance can be placed on any court decision to modify compliance. The only way to change the directive is through CASA’s own review process.

Several aspects of the directive can trap unwary operators. The first is the distinction between the initial inspection deadline (50 hours TIS or 12 months, whichever first) and the repetitive check intervals (100 or 120 hours TIS since last inspection). An operator who completes the initial check at 50 hours then schedules the next check at 170 hours (50 + 120) might mistakenly think they can wait until 170 hours. But the repetitive interval is measured from the last inspection, so the second check is due at 50 + 120 = 170 hours TIS. However, if the initial check was done early, say at 20 hours TIS, then the next check would be due at 140 hours TIS. The operator must track the “since-last-inspection” interval precisely, not a calendar interval. This is easy to miscalculate, especially if multiple aircraft are managed.

The second gotcha is the difference in intervals for the Aerospatiale 262(A) modified by STC SA2369SW (100 hours versus 120 hours). An operator who owns both types must maintain separate tracking systems. The directive does not provide a definition of “modified by STC SA2369SW” , the operator must know whether their aircraft has that STC. If the aircraft was subsequently modified by another STC that supercedes SA2369SW, the operator may not know which interval applies. The wise operator would confirm the modification status and, if uncertain, assume the shorter interval.

The third gotcha is the “before further flight” requirement for a bolt failing the torque check. This is extremely strict: the aircraft cannot be flown even to a hangar or maintenance base. The operator must have replacement bolts on hand or accept grounding. The directive does not allow a ferry flight under a special flight permit if the purpose is to obtain replacement parts. The only options are to replace the bolts on-site or to be grounded. This imposes significant logistical and cost risks for operators at remote locations without immediate access to parts and mechanics.

The fourth gotcha is that the terminating action must be completed within 12 months, regardless of the recurring check results. An operator might think that if bolts repeatedly pass torque checks, they can defer replacement indefinitely. Not so. The 12-month deadline is absolute from the effective date. This creates a hard deadline that catches operators who were tracking only the recurring checks. The 12-month period runs from 29 September 2005, so terminating action must be completed by 29 September 2006. The operator who did not plan for that may find themselves scrambling.

The fifth gotcha is the definition of “approved equivalent part number bolts.” The directive does not specify what constitutes approved equivalence. It might require CASA approval, a Parts Manufacturer Approval (PMA) from the US FAA, or an equivalent from Hartzell. An operator using a bolt from a different manufacturer without confirming the approval status could still be non-compliant, even if the new bolt passes torque. The risk is that an approved equivalent might not exist, forcing the operator to use only non-suspect P/N B-3339 bolts, which could be scarce.

The sixth gotcha is that the directive requires replacement of all eight bolts, not just the failed one. A single bolt failure triggers a complete eight-bolt set replacement. The operator cannot replace only the failing bolt. This is a significant cost multiplier. The operator must also ensure that the replacement bolts are from non-suspect lots or are equivalent. There is no provision for using a mix; the entire set must meet the criteria.

The seventh gotcha is the potential interaction with other ADs. The directive specifically addresses propeller mounting bolts. There may be separate ADs for the propeller hub, blade, or other components that also require recurring inspections or replacements. The operator must ensure that compliance with AD/PHZL/81 does not inadvertently conflict with other requirements. The directive does not provide a cross-reference list.

Compliance with AD/PHZL/81 requires a systematic approach integrating documentation, physical inspection, record-keeping, and parts management. The first step is to identify whether the subject aircraft has any of the Hartzell propeller models listed in the applicability. If not, the directive does not apply and no further action is needed. If the aircraft does have one of those models, the next step is to determine whether P/N B-3339 mounting bolts from LFC Manufacturing Lots 12 or 56 are installed. This requires consulting maintenance records, parts tags, and physically inspecting the bolts for identification marks as described in Figure 1 of the Hartzell ASB HC-ASB-61-279, Revision 2. If no such bolts are found, the operator should document that fact and keep the record for audit purposes. No further action under the directive is required, but the record is prudent.

If suspect bolts are present, the operator must obtain a copy of the referenced ASB. The directive requires that all actions be performed in accordance with paragraphs 3.A through 3.C of that ASB. The operator cannot perform the torque check or replacement using only common sense; the specific torque values and inspection criteria in the ASB must be followed. The initial visual inspection and torque check must be scheduled within 50 hours TIS after the effective date of 29 September 2005 or within 12 months (i.e., by 29 September 2006), whichever occurs first. Because the effective date is before publication of this deep dive, operators reading this now must check if they are already late. For most readers, the compliance deadline has long passed; but the analytical steps remain valid for understanding the structure.

For all aircraft except the Aerospatiale 262(A) with STC SA2369SW, after the initial check, repetitive torque checks must be performed every 120 hours TIS since the last inspection. For the Aerospatiale variant, the interval is 100 hours TIS since last inspection. The operator must schedule these checks on a continuous basis until the terminating action is completed. Each check requires torque verifying all eight bolts using the ASB procedure. The operator must track the hours flown since the last check and ensure the next check occurs before the limit is reached.

If any bolt fails the torque check (i.e., it does not achieve the specified torque or is below minimum), the aircraft must not be flown again until all eight bolts are replaced with approved parts. Replacement must be done per ASB paragraph 3.C for terminating action or possibly 3.B.(5) for immediate replacement. The operator should have replacement parts available before starting the torque check to avoid prolonged grounding. The replacement bolts must be from non-suspect lots (i.e., not LFC Lots 12 or 56) or must be approved equivalent part number bolts. The operator should confirm the approval status with the supplier or CASA.

The mandatory terminating action requires that within 12 months of the effective date (by 29 September 2006), all suspect bolts must be replaced regardless of prior torque check results. This is a one-time action. Once completed, no further recurring checks under this directive are needed. The operator must ensure the replacement is documented in the aircraft maintenance records, including the part numbers, lot numbers (if applicable), the ASB reference, and the date. The maintenance release should be endorsed by an authorised person (e.g., LAME or approved maintenance organisation).

After final replacement, the operator should keep a copy of the directive and the ASB along with the maintenance records for the life of the aircraft. Future owners or operators will need to confirm that the terminating action was done. The directive does not specify record retention periods, but general CASR maintenance record-keeping rules require retention for at least the life of the component. For a propeller mounting bolt, that means permanently.

To avoid non-compliance, the operator should also check whether the FAA AD counterpart has been superseded, and whether CASA has issued any amendment to AD/PHZL/81. Even though the directive appears in its original form, CASA may have later issued an amendment or an alternative means of compliance bulletin. Regular checks of the CASA AD register are advisable. The operator should also verify that the Hartzell ASB used is still current; using a later revision may be acceptable if equivalent, but the safest approach is to use Revision 2 as referenced, unless an AMOC is obtained.

Costs of compliance include labour for inspections and torque checks (approximately 1-2 hours per check), potential grounding costs if bolts fail, cost of the ASB (if not already held), shipping costs for replacement parts, and the parts themselves. The operator should budget for these. Because the directive does not offer compensation, the operator must decide whether to absorb the cost or seek recovery from the propeller manufacturer or bolt supplier under warranty or product liability.