AD/PHZL/79 Amdt 2 - Propeller Vibration Placard

The AD rests on a small set of interlocking operational and informational controls intended to limit engine/propeller operating regimes to reduce blade-vibration risk. The principal concepts in the text are:

• Applicability by hardware and engine condition: The AD applies to Hartzell propellers of a specified model series , denoted in the AD as Hartzell ( )HC-C2YK-( )( )( )/( )( )7666A-( ) , when installed on undampered, 200 horsepower Lycoming IO-360 engines. The AD therefore targets a particular propeller/engine combination rather than all Hartzell propellers or all IO-360 installations. Note 2 clarifies how to determine whether an IO-360 engine is “undampered”, by referring to the third section of the model designation and specifically the presence or absence of a numerical digit in its fourth position (example IO-360-A1B6), where a digit “6” in that fourth position indicates the incorporation of certain counterweights (6.3 order and 8th order counterweights) and thus crankshaft damping.

• Operational restriction communicated by placard and tachometer markings: The AD imposes engine speed bands to be avoided in continuous operation, and for aerobatic operations an additional caution above a specified rpm. Those limitations are not prohibitions on a single excursion; the text says “Avoid continuous operation Between 2000 and 2350 rpm” and “Above 2600 rpm in aerobatic flight” for aerobatic category aircraft. The mechanically mandated artefacts are (a) an in‑aircraft placard with exact wording and (b) tachometer face/bezel red arcs indicating the restricted ranges.

• Differentiation by aircraft category: The AD distinguishes between Normal Category aeroplanes, which are subject to the single restricted band (2000-2350 rpm), and Utility and Aerobatic Category aeroplanes, which are subject to the same band plus an aerobatic-specific restriction relating to speeds above 2600 rpm and a tachometer red arc between 2600 and 2700 rpm. That bifurcation changes the scope of required markings depending on the aircraft’s certification category.

• Documentation carriage requirement: The AD requires, “Include a copy of this AD with the aeroplane flight manual, if an aeroplane flight manual is carried.” This turns the AD into a document intended to be available to flight crews in conjunction with the AFM when one is present on the aeroplane.

• Inter-authority cross-reference: The AD explicitly references FAA AD 2007-26-09 (amendment 39-15311) in Note 3 and states that Amdt 2 “makes reference to the latest FAA AD which encompasses the equivalent requirement(s) of this AD.” It also records that compliance with earlier AD/PHZL/79 Amdt 1 satisfies the equivalent requirements of this AD.

Conceptually, the instrument uses physical,’in-cockpit’ controls (fixed placards and tachometer markings) to change pilot behaviour around specific rpm ranges identified as presenting a hazard for the applicable hardware/engine configuration.

The AD affects aeroplanes that meet the combined hardware and engine-condition description in the applicability paragraph. Concretely, affected aeroplanes are those that have installed Hartzell ( )HC-C2YK-( )( )( )/( )( )7666A-( ) variable-pitch propellers mounted on undampered 200 horsepower Lycoming IO-360 engines. The AD itself notes that these engines can be fitted to, but are not limited to, Mooney M20E and M20F, Piper PA-28R-200, and Pitts S-1T and S-2A aeroplanes. That list is explicitly presented as examples (Note 1), not an exhaustive catalogue.

The immediate operational actors who must ensure the AD is implemented are the persons or organisations responsible for the maintenance and continuing airworthiness of the affected aeroplanes. The AD’s requirement language , “Unless previously accomplished, remove any vibration placard that does not have the following statement and replace it...” and “re-mark the tachometer face or bezel” and “Include a copy of this AD with the aeroplane flight manual, if an aeroplane flight manual is carried” , imposes obligations on the operator/owner or the nominated maintenance provider who effects placard and instrument markings. The AD does not use statutory penalty language or list the enforcing official besides its signature by a CASA delegate (Mike Higgins), but the instrument is an aviation regulatory directive and therefore operates as a mandatory continuing airworthiness requirement from its effective date (8 June 2014) as stated in the Compliance paragraph.

Aircraft certificated as Normal Category are subject to a narrower set of marking actions than those certificated as Utility or Aerobatic Category. Utility/Aerobatic category aeroplanes face additional tachometer and placard requirements addressing aerobatic operation , namely the extra placard sentence “Above 2600 rpm in aerobatic flight” and the red arc between 2600 and 2700 rpm (red line). People who maintain flight manuals, and persons responsible for an aeroplane’s equipment and instrument markings, are also affected by the requirement to include a copy of the AD with the AFM, if carried.

Regulatory interaction affects affected parties insofar as the AD references an FAA AD and notes that compliance with the earlier Australian amendment Amdt 1 satisfies Amdt 2’s equivalent requirements; operators who have already complied with Amdt 1 therefore do not need to repeat the work to satisfy Amdt 2 (Note 4).

The AD imposes discrete duties, stated in the “Requirement” section. Those duties are procedural and physical:

Duties

• Placard replacement: For Normal Category aeroplanes the operator/maintainer must remove any existing vibration placard that does not bear the prescribed text and replace it with a placard reading exactly: “Avoid continuous operation Between 2000 and 2350 rpm”. For Utility and Aerobatic Category aeroplanes the replacement placard must read exactly: “Avoid continuous operation Between 2000 and 2350 rpm. Above 2600 rpm in aerobatic flight”. The duty is to remove non‑conforming placards and replace them with the specified wording, unless the task has already been accomplished.

• Tachometer re-marking: For Normal Category aeroplanes the duty is to re-mark the tachometer face or bezel with a red arc covering the restricted engine speed range between 2000 and 2350 rpm. For Utility and Aerobatic Categories the duty is to re-mark the tachometer face or bezel with a red arc between 2000 and 2350 rpm, and between 2600 and 2700 rpm (the AD labels the latter as the red line). The duty includes the physical act of re-marking unless previously done.

• Documentation carriage: The AD requires inclusion of a copy of the AD with the aeroplane flight manual, if an AFM is carried on the aeroplane. This duty is conditional on whether an AFM is carried.

• Timing: All required actions “must be taken from the effective date of this AD,” which is 8 June 2014, unless previously accomplished.

Rights and conditional relief

• Recognition of prior compliance: The AD expressly recognises that compliance with AD/PHZL/79 Amdt 1 constitutes compliance with the equivalent requirements of Amdt 2 (Note 4). That functions as a right to avoid duplication of work where Amdt 1 was already complied with.

• Applicability carve-out by engine configuration: The AD applies only to the specified Hartzell propeller models when installed on undampered 200 hp Lycoming IO-360 engines. Note 2 describes the method for identifying whether an IO-360 engine is undampered via its model designation. This creates an operational right to exclude certain installations where the engine does incorporate crankshaft dampers (for example, where the digit “6” in the fourth position of the third section of the model designation indicates counterweights/damping); such installations fall outside this AD’s stated applicability and therefore are not subject to its specific duties.

What the AD does not state (and therefore is not an express right or duty in the AD)

• The AD does not include an express statement of who must carry out the physical work (owner, operator, maintenance organisation). It states the actions that “must be taken” on affected aeroplanes but leaves the allocation of responsibility to normal continuing airworthiness practices. It also contains no penalty clauses in the text supplied.

• The AD does not define operational enforcement mechanisms or exemptions other than the note that earlier amendment compliance is sufficient. It does not excuse brief transits through a restricted rpm band, except by the textual phrase “Avoid continuous operation” which is the wording mandated for the placard; the AD does not further elaborate what constitutes “continuous” within its text.

All of the key duties are sourced verbatim from the Requirement, Compliance and Notes paragraphs of the AD as reproduced in the supplied text.

The AD text provided does not set out any express civil or criminal penalties, monetary fines, or enforcement procedures in statutory terms. The instrument is styled and issued as an Airworthiness Directive by the Civil Aviation Safety Authority (CASA), and its effective date is specified as 8 June 2014. The document is signed by the CASA delegate, Mike Higgins, which indicates the issuing authority within CASA for this directive.

What the AD text does include about enforcement-related mechanics:

• Mandatory compliance timing: The Compliance paragraph states that “Unless previously accomplished, the required actions for Normal Category aeroplanes and Utility and Aerobatic Category aeroplanes must be taken from the effective date of this AD.” That phrasing establishes a hard start date for the obligations. Where an operator has already completed the actions required under AD/PHZL/79 Amdt 1, Note 4 states that such compliance constitutes compliance with the equivalent requirements of Amdt 2, which removes duplication for those operators.

• Delegated issuance: Signature by a CASA delegate (Mike Higgins) establishes that the directive is issued under CASA’s regulatory authority. The presence of the delegate’s signature is the administrative mechanism by which CASA promulgates and certifies the AD. The AD also references FAA AD 2007-26-09 in Note 3, indicating cross-referencing with foreign authority documents.

What is not stated in the supplied text and therefore not available as a source-grounded claim:

• The AD text supplied does not specify how CASA will verify compliance, whether through continuing airworthiness inspections, registration checks, ramp inspections, or during maintenance releases. It does not state whether non-compliance attracts specific fines, mandatory grounding, certificate action, or other statutory penalties within the AD itself. Those enforcement mechanisms, if they exist, are external to the text supplied and would ordinarily be provided by the governing aviation safety regulations and enforcement policies rather than the AD wording itself.

For practical purposes, the AD creates mandatory continuing airworthiness obligations with a stated effective date, and the issuing authority is CASA. The AD’s text recognises prior compliance with AD/PHZL/79 Amdt 1 as satisfying Amdt 2 requirements, thereby providing an administrative compliance pathway for affected parties who have already acted.

The AD explicitly records interactions with two categories of existing regulatory and operational instruments: prior Australian amendments (AD/PHZL/79 Amdt 1) and the equivalent FAA Airworthiness Directive.

• Link to AD/PHZL/79 Amdt 1: The Compliance section contains Note 4, which states that “Compliance with AD/PHZL/79 Amdt 1 constitutes compliance with the equivalent requirement(s) of this AD.” That is an express legal and administrative interaction. It prevents duplicative compliance work when the earlier Australian amendment has already been satisfied, and establishes Amdt 1 as an accepted means of achieving the required marking and placarding outcomes.

• Cross-reference to FAA AD: Note 3 refers to “FAA AD 2007-26-09 Amdt 39-15311, paragraph (k) refers.” The Background paragraph also states that Amdt 2 “makes reference to the latest FAA AD which encompasses the equivalent requirement(s) of this AD.” This establishes a cross-jurisdictional recognition and alignment: the CASA AD both recognises and references the FAA AD as covering equivalent matters. That creates a working interaction where compliance with the FAA AD (or compliance actions aligned with that FAA AD) will be understood to be relevant to meeting CASA’s requirements, to the extent stated.

• Interaction with flight manuals: The Background paragraph states that engine speed limitations were previously published in amendments to the Australian Civil MkI and MkII Flight Manuals. The Requirement then mandates inclusion of a copy of the AD with the aeroplane flight manual “if an aeroplane flight manual is carried.” This creates an operational interaction with the content and carriage of AFMs: the AD’s placard and tachometer marking requirements are intended to be reflected in operator-facing documentation (AFM amendments) and physically present on the aircraft. The AD therefore intersects with legal obligations around operating limitations and documentation carriage.

• Applicability vs engine configuration: Note 2 provides a specific method to determine whether an IO-360 engine is undampered, by inspecting the third section of the model designation and its fourth position digit. That is an interaction between the AD’s applicability provision and engine identification/serial designation practices embedded in type certificates and manufacturer model designations. Whether an engine is within the AD’s scope depends on that coding detail, which in turn interacts with maintenance records and logbooks where engine model designations are recorded.

What the AD text does not do

• The supplied text does not amend other statutory instruments, nor does it reproduce or amend the Civil Aviation Regulations or other Acts. It functions as an operational directive that links to existing documents (FAA AD and Flight Manuals) and to a prior Australian amendment. Any broader legal consequences (for example, how non-compliance might affect airworthiness certificates or continuing airworthiness responsibilities) are matters addressed by broader aviation regulation and enforcement practice, not restated within this AD text.

In short, the AD establishes an operational requirements layer that cross-references prior Australian ADs and FAA ADs, and that is intended to be reflected in AFMs where carried. Those links provide explicit pathways for satisfying the AD by prior compliance or by reference to internationally equivalent FAA requirements.

The supplied text explicitly identifies this document as AD/PHZL/79 Amdt 2 and records an earlier amendment, AD/PHZL/79 Amdt 1. The effective date for AD/PHZL/79 Amdt 2 is stated as 8 June 2014. The Background paragraph describes the sequence of events leading to the current amendment:

• Original AD: The AD was originally issued to require placards to be fitted to limit operation of the propeller at certain engine speeds, to prevent failure of the propeller blade due to vibration. The Background links the original AD to engine speed limitations that were previously published in amendments to the Australian Civil MkI and MkII Flight Manuals.

• AD/PHZL/79 Amdt 1: AD/PHZL/79 Amdt 1 became effective on 7 August 2003. The Background states that Amdt 1 “corrected errors relating to the identification of undampered engines.” The Compliance section of Amdt 2 contains Note 4 which states that compliance with Amdt 1 constitutes compliance with the equivalent requirements of Amdt 2, confirming continuity between the two amendments and avoiding duplication for those who already acted under Amdt 1.

• AD/PHZL/79 Amdt 2: The current amendment, Amdt 2, is dated in the header as 12/2014 and signed 3 June 2014. Its effective date is 8 June 2014. The stated purpose of Amdt 2 in the Background is to update or reassert placarding and tachometer marking requirements and to make reference to the latest FAA AD which addresses equivalent requirements.

Specific dates mentioned in the supplied text:

• AD/PHZL/79 Amdt 1 effective date: 7 August 2003 (Background).
• AD/PHZL/79 Amdt 2 effective date: 8 June 2014 (Compliance).
• Amdt 2 signed by CASA delegate Mike Higgins on 3 June 2014 (signature date).

The AD also cites FAA AD 2007-26-09 Amdt 39-15311 (Note 3) as a cross-reference and states that paragraph (k) of that FAA AD refers. The Background indicates that engine speed limitations were already included in previous Civil Flight Manual amendments. The amendment history recorded in this text reflects a sequence of issuance, correction in Amdt 1 (identification of undampered engines), and later alignment with the FAA AD in Amdt 2.

No further amendment entries, versions, supersessions, or revocation statements appear in the supplied text beyond these references.

The supplied AD text does not reference any litigation, court proceedings, or case law. It contains no citations to judicial decisions, and it does not record any disputes, appeals or enforcement proceedings connected to AD/PHZL/79 or its amendments. The only authorities named in the document are the Civil Aviation Safety Authority (CASA), the delegate who signed the AD (Mike Higgins), and the FAA AD reference (FAA AD 2007-26-09 Amdt 39-15311).

Because the AD text supplied does not include litigation information, there are no source-grounded findings to report about legal challenges, judicial interpretation, or case law construing the AD’s requirements. Any commentary about litigation risk, historical disputes or judicial treatment of this AD would be outside the scope of the supplied text.

If a practitioner requires litigation history or cases that have interpreted or challenged AD/PHZL/79 or its amendments, those materials would need to be obtained from external legal or regulatory databases; they are not contained in the supplied instrument.

The AD contains several details that can lead to implementation errors if read or applied carelessly. Key pitfalls in the text that affect compliance and risk of misapplication include:

• Narrow applicability language: The propeller model notation in the applicability paragraph is presented as Hartzell ( )HC-C2YK-( )( )( )/( )( )7666A-( ). That bracketed and partially redacted form indicates a narrow set of model configurations. Implementers must take care to match the exact model series notation as presented; substituting a superficially similar Hartzell model may result in misapplication of the AD. The AD applies only when those specific propellers are installed on the stipulated 200 horsepower Lycoming IO-360 engines and when those engines are undampered (Applicability, Note 1 and Note 2).

• Determining “undampered” engines: Note 2 sets out an identification rule tied to the engine model designation: “Engine models of this series incorporate no crankshaft dampers unless the third section of the model designation exhibits a numerical digit in its fourth position, i.e. IO-360-A1B6. The digit '6' in the fourth position, indicates the incorporation of one 6.3 order and one 8th order counterweights.” Misreading or misrecording the engine model designation could lead to either unnecessary compliance work (on damped engines that are outside scope) or failure to act where required. Maintenance records and engine data plates must be consulted carefully.

• Exact placard wording required: The AD prescribes precise placard text. For Normal Category aircraft the required text is exactly “Avoid continuous operation Between 2000 and 2350 rpm”. For Utility and Aerobatic Category aeroplanes the required text adds “Above 2600 rpm in aerobatic flight”. Replacing an existing placard with paraphrased or shortened wording risks non-conformance with the AD’s explicit requirement. The AD says “remove any vibration placard that does not have the following statement and replace it with one that does,” which requires exactness.

• Tachometer marking specifics (ranges and arcs): The specified tachometer marking ranges are precise: between 2000 and 2350 rpm for both categories, and for Utility/Aerobatic an additional red arc between 2600 and 2700 rpm (the AD describes that latter as red line). Implementers should not assume alternative arc endpoints or that the AD permits different visual conventions; the AD requires re-marking the tachometer face or bezel with red arcs for the specified ranges.

• Conditional carriage requirement: The documentation requirement is conditional: “Include a copy of this AD with the aeroplane flight manual, if an aeroplane flight manual is carried.” Some operators might carry alternative documentation like an AFM supplement or POH (Pilot’s Operating Handbook) or rely on electronic copy; whether that fulfils the AD’s intent is a matter of administrative interpretation but the AD as written ties the obligation to carriage of an AFM. Operators must confirm whether their documentation practice satisfies the AD’s stated carriage requirement.

• Prior compliance recognition: Note 4 states that compliance with AD/PHZL/79 Amdt 1 constitutes compliance with equivalent requirements of this AD. Operators who have previously complied must ensure their prior work precisely matches Amdt 2’s requirements; sloppy assumptions that earlier compliance is sufficient without checking exact wording and tachometer ranges could result in non-conformity if the earlier action differed.

• Ambiguity in the word “continuous”: The placard wording mandated by the AD is “Avoid continuous operation Between 2000 and 2350 rpm.” The AD does not define “continuous operation” within its own text. That leaves room for interpretive uncertainty about permitted brief excursions through the band versus sustained operation therein. Operators and maintenance personnel should document the rationale for any operational interpretation and, where necessary, consult the AFM or manufacturer guidance. The AD text itself does not provide a definition.

• No enforcement detail in the AD: The AD does not set out consequences for non‑compliance in the supplied text. That does not mean non‑compliance is without effect in a regulatory sense; however, a gap exists between the AD’s requirements and explicit enforcement or penalty clauses in the document as supplied. Operators should not interpret the AD’s silence as permissive.

• Cross-reference to FAA AD paragraph (k): Note 3 points to FAA AD paragraph (k). Implementers copying FAA-mandated actions should check that paragraph (k) of the referenced FAA AD covers the same precise words and tachometer ranges required in this AD; reliance on the FAA AD as a substitute requires scrutiny to ensure textual equivalence.

Attention to these specific details will reduce the risk of inadvertent non-compliance due to misidentification of engines, incorrect placard wording, incorrect tachometer arc endpoints, or failure to verify the scope of prior compliance with Amdt 1.

The AD sets out a short, concrete compliance checklist. The following stepwise approach is grounded in the AD’s text and the associated Notes. Each step refers to the AD’s relevant provisions.

1. Confirm applicability (Applicability, Note 1 and Note 2)

   • Identify whether the aircraft has a Hartzell ( )HC-C2YK-( )( )( )/( )( )7666A-( ) variable-pitch propeller installed. Verify the exact model series designation against the notation in the AD.
   • Confirm the engine is a 200 horsepower Lycoming IO-360 model and determine whether it is “undampered” as defined in Note 2. Check the engine model designation (the third section’s fourth position digit). If the fourth position digit is “6” in the third section (e.g. IO-360-A1B6), the engine incorporates counterweights/damping and therefore is outside the AD’s stated applicability; if it is undampered per Note 2, the AD applies.

2. Check prior compliance (Compliance, Note 4)

   • Determine whether the aircraft already complied with AD/PHZL/79 Amdt 1 or this same AD earlier. If AD/PHZL/79 Amdt 1 compliance can be documented, Note 4 of the current AD states that such compliance constitutes compliance with the equivalent requirements of Amdt 2, and no further action is necessary for those equivalent items.

3. Placard replacement (Requirement)

   • If the aircraft is within scope and has not previously complied, remove any existing vibration placard that does not contain the exact prescribed text.

   • For Normal Category aeroplanes, install a placard with the exact wording:

     “Avoid continuous operation Between 2000 and 2350 rpm”

   • For Utility and Aerobatic Category aeroplanes, install a placard with the exact wording:

     “Avoid continuous operation Between 2000 and 2350 rpm. Above 2600 rpm in aerobatic flight”.

   • Ensure the placard is placed in the cockpit where vibration placards are typically displayed and where pilots will clearly see it during pre-flight and operation, consistent with human factors and flight crew documentation practices.

4. Tachometer re-marking (Requirement)

   • Re-mark the tachometer face or bezel with a red arc covering the restricted engine speed range between 2000 and 2350 rpm for both Normal and Utility/Aerobatic Categories.
   • For Utility and Aerobatic Category aeroplanes also re-mark the tachometer with a red arc between 2600 and 2700 rpm (the AD denotes this as the red line). Follow instrument marking standards and ensure that the re-marking is durable and clearly legible.
   • Document the tachometer re-marking in the aircraft maintenance records and, if applicable, in logbooks or maintenance releases.

5. Include a copy of the AD with the AFM (Requirement)

   • If an aeroplane flight manual is carried on the aircraft, include a copy of AD/PHZL/79 Amdt 2 with it. If an AFM is not carried, the AD does not require that a copy be carried elsewhere; follow local fleet or operator protocols for documentation.

6. Timing and record-keeping (Compliance)

   • Complete the placard replacement, tachometer re-marking, and AFM inclusion from the effective date, 8 June 2014, unless already completed. For audit and continuing airworthiness purposes, record the date and person/organisation who performed the work. Where maintenance release or logbook entries are used, record tasks appropriately.

7. Verify exactness and equivalence to earlier AD (Notes 3 and 4)

   • If relying on compliance with FAA AD 2007-26-09 (or previous AD/PHZL/79 Amdt 1) to satisfy CASA’s AD, confirm paragraph (k) of FAA AD 2007-26-09 and that the earlier Australian amendment’s actions are precisely equivalent in wording and tachometer arc specification. Maintain documentary evidence of equivalence.

8. Operational considerations

   • Revise any AFM limitations or supplements, if appropriate, to reflect the placard wording and tachometer markings, ensuring that crew briefings and operating procedures incorporate the engine speed avoidance ranges. The AD notes that engine speed limitations were previously published in amendments to the Australian Civil MkI and MkII Flight Manuals; ensure consistency between those publications and the current placard/tachometer markings where the AFM is used.

9. Maintenance and future changes

   • If a propeller or engine is changed such that the aircraft no longer meets the applicability (for example, the engine is replaced with one that incorporates crankshaft dampers), update records to reflect that the AD’s obligations no longer apply to that aircraft configuration. Conversely, if an affected propeller/engine combination is newly installed, ensure the AD requirements are implemented before returning the aircraft to operational use as required by continuing airworthiness practice.

10. Documentation for inspectors

• Keep clear records demonstrating compliance with the AD (placard installation, tachometer marking entries, AFM inclusion and dates). These records support continuing airworthiness inspections and any regulatory audits and confirm whether AD/PHZL/79 Amdt 1 was previously complied with.

Each of these steps is grounded in the AD language: the Applicability and Notes define scope; the Requirement sets out the placard text and tachometer arcs; the Compliance paragraph sets the effective date and the recognition of Amdt 1 compliance; Note 3 and Background provide pointers to FAA AD and prior flight manual amendments.

If there is any uncertainty about the exact interpretation , for example whether a non‑standard tachometer dial layout can comply with the marking requirement, how to treat electronic tachometers, or how to demonstrate non‑continuous operation in flight operations , operators should consult CASA or a nominated continuing airworthiness authority for administrative clarification, since the AD text does not define operational enforcement modalities or answer such instrument-specific questions.