AD/LYC/112 - Lycoming Crankshaft Replacement

The AD rests on four interlocking operational concepts: applicability by engine model and date, identification by serial-number tables in an external service bulletin, mandatory replacement where a crankshaft is listed, and a temporal compliance window.

Applicability: The AD limits its reach to Lycoming engines in the AEIO-, IO-, O-, LIO-, LO- and TIO- prefixes within the 360 and 540 displacement series, rated at 300 HP or lower, and only where the engine was newly manufactured, rebuilt, overhauled after 01 March 1999, or where a crankshaft was installed after that date (Applicability). The criterion is objective (engine model and dates) but requires documentary proof of manufacture, overhaul, rebuild or crankshaft installation dates to determine capture.

Serial-number identification: The AD does not list serial numbers itself; it requires operators to consult Lycoming Mandatory Service Bulletin No. 566 dated 11 July 2005. That MSB contains Tables 1-4. Tables 1-3 map engine serial numbers to affected engines; Table 4 lists crankshaft serial numbers that trigger mandatory replacement or prohibition on installation. The AD repeatedly instructs use of those tables to determine whether a particular engine or crankshaft is affected (Requirement 1(a), 1(b), 2(a), 2(b), 3).

Replacement and prohibition mechanics: If an affected engine’s crankshaft serial number is listed in Table 4, the AD requires replacement with a crankshaft not listed in Table 4 (Requirement 1(b), 2(b)). The AD also forbids installation, after the effective date, of any crankshaft whose serial number appears in Table 4 into any engine (Requirement 3). The wording creates two different obligations: remedial replacement within a defined compliance window for engines already in service, and an ongoing prohibition on installing listed crankshafts into any engine after the AD takes effect.

Timing and scope of compliance: The AD sets explicit deadlines for accomplishing required replacements , within 50 hours time-in-service or six months after the effective date, whichever comes first (Compliance). The prohibition on installing listed crankshafts takes effect immediately after the AD’s effective date and is not limited by the 50-hour/6-month window (Requirement 3; Compliance).

Safety justification and linkage: The AD states the safety concern as a pattern of various crankshaft failures in Lycoming 360 and 540 series engines rated at 300 HP or lower, and links those failures to risks of total engine power loss, in-flight engine failure, and potential loss of the aeroplane (Background). The instrument also refers to the FAA Airworthiness Directive 2005-19-11 Amendment 39-14276 (Note), indicating international regulatory coordination on the identified hazard.

Document dependencies: The AD’s operative content depends on Lycoming MSB No. 566 (11 July 2005) and implicitly on the content of FAA AD 2005-19-11. The AD does not reproduce the serial-number tables in full; compliance requires access to MSB 566.

The AD directly compels actions by the registered owners and operators of aeroplanes fitted with the specified Lycoming engines, maintenance and overhaul organisations that install or supply crankshafts, and parts suppliers and distributors who sell Lycoming crankshafts. The text identifies affected parties by the equipment installed rather than by aircraft type or operator status (Applicability).

Owners and operators: Any owner/operator of an aircraft with one of the specified Lycoming 360 or 540 series engines that was manufactured new, rebuilt, overhauled after 01 March 1999, or that had a crankshaft installed after that date, must determine applicability by checking the relevant MSB tables and, where necessary, replace the crankshaft within the compliance window (Applicability; Requirement; Compliance). Owners and operators therefore bear the primary compliance obligation and the associated operational and economic consequences (replacement, removal, sourcing).

Maintenance organisations and mechanics: The AD requires replacement of crankshafts and verification of serial numbers. While the AD does not state who must carry out the physical work, the replacement is a maintenance action that will be performed by the organisation or individual responsible for engine maintenance; those entities must ensure the correct crankshaft SNs are fitted and that records properly reflect compliance. The AD’s requirement to verify engine SNs against MSB tables creates a documentation and parts-tracing task for maintenance providers.

Parts suppliers and distributors: The AD’s prohibition on installing crankshafts listed in Table 4 affects the supply chain. Suppliers must ensure they do not fit, sell, or supply crankshafts with serial numbers that appear in Table 4 for installation into any engine after the effective date (Requirement 3). This shifts the burden onto suppliers to check serial numbers when selling or supplying crankshafts intended for installation.

Regulators and delegated personnel: The AD is issued under the Civil Aviation Safety Authority delegate (signature block) and references the FAA AD (Note). Civil aviation regulators and their inspectors will be the enforcers; they must interpret compliance evidence such as maintenance records and parts serial numbers. The AD provides clear, table-based criteria for inspectors to check, but enforcement mechanisms and penalties are not set out in the AD text itself.

Other stakeholders: Aircraft purchasers, insurers, and financiers may be indirectly affected because the AD can influence aircraft availability and maintenance status. The AD’s requirement for replacement within 50 hours time-in-service or six months potentially triggers lead time and availability issues for spare crankshafts for affected owners and maintenance providers.

Uncertainty about scope for some operators: Determining whether an engine "had a crankshaft installed after 01 March 1999" requires access to maintenance history and parts records. The AD’s reliance on operator and maintenance documentation means parties without complete records may face uncertainty in applying the requirements.

Duties imposed by the AD are explicit and procedural. The AD’s text prescribes specific verification steps and replacement obligations, and sets enforceable time limits for remedial action.

Duty to determine applicability: Responsible persons must check whether their engine falls within the AD’s applicability criteria by reference to engine model, rating (300 HP or lower), and manufacture/overhaul/replacement dates (Applicability). That requires consulting maintenance records and the Lycoming MSB tables (Requirement 1(a), 2(a)).

Duty to consult MSB tables and verify serial numbers: The AD requires use of Lycoming MSB No. 566 Tables 1-4 to identify affected engine serial numbers and crankshaft serial numbers. For 540-series engines referenced in Tables 1 and 2, use Table 4 to verify crankshaft SNs; for 360-series engines referenced in Table 3, use Table 4 to verify crankshaft SNs (Requirement 1(a), 2(a)). The duty is procedural and hinges on accurate cross-referencing.

Duty to replace listed crankshafts: If the engine’s crankshaft serial number is listed in Table 4, the AD requires replacement with a crankshaft that is not listed in Table 4 (Requirement 1(b), 2(b)). This is a substantive equipment-change obligation, not just an inspection-only requirement.

Prohibition on installation of listed crankshafts: From the effective date, no crankshaft with a serial number listed in Table 4 may be installed into any engine (Requirement 3). That prohibition is prospective and applies regardless of engine model or manufacturing/overhaul history.

Timing duties: Replacements required under Requirements 1 and 2 must be completed within 50 hours time-in-service or six months after the AD’s effective date, whichever occurs first, unless already done (Compliance). The installation prohibition under Requirement 3 applies "after the effective date of this AD" and thus takes effect immediately on 28 October 2005 (Compliance; Requirement 3).

Record-keeping and proof of compliance: The AD does not specify record-keeping formalities, but compliance will be evidenced through maintenance records, parts documentation showing crankshaft serial numbers, and entries in aircraft logs. Therefore owners and maintenance providers have a de facto duty to retain and present those records for inspection.

Rights and constraints: The AD confers no express rights (such as an appeal mechanism or compensation right) in its text. The only textual "note" is a reference to FAA AD 2005-19-11, which is an informational linkage, not a grant of rights. The right to continue operating an aircraft with an affected crankshaft after the compliance deadline is removed by the mandatory replacement requirement. The AD does not provide alternatives or exemptions within its text; it mandates the specific remedy (replacement with crankshaft not in Table 4).

Operational discretion: The AD leaves limited discretion to operators about how to comply beyond the requirement that the replacement crankshaft not be listed in Table 4 and the timing limits. The AD does not prescribe a specific replacement crankshaft part number or service procedure; it prescribes an outcome (unlisted crankshaft) subject to verification via MSB tables.

Interpreting ambiguous situations: The AD’s reliance on external tables and dates creates potential ambiguity in borderline cases (for example, incomplete records as to whether a crankshaft was installed after 01 March 1999). The AD itself does not set out dispute-resolution procedures or guidance on record insufficiency; such matters would be handled under broader regulatory enforcement processes beyond the AD text.

The AD text does not state penalties, fines, or the specific enforcement mechanisms to be used for non-compliance. It is an airworthiness directive issued by a delegate of the Civil Aviation Safety Authority (signature block), and it includes mandatory operative requirements and an effective date (5 October 2005 signature; effective 28 October 2005). Enforcement therefore rests on the regulator’s powers under aviation safety legislation and enforcement policy, but those statutory enforcement provisions are not reproduced or summarised in the AD itself.

Regulatory nature of the AD: In practice, an AD is a mandatory requirement aimed at maintaining an acceptable level of airworthiness. The AD’s operative text creates duties (replacement within 50 hours TIS or six months, and a ban on installing listed crankshafts) that are enforceable as requirements of the applicable civil aviation regulatory framework. The AD identifies the technical remedy and timing; questions about sanctions for non-compliance are addressed by the regulator under its enforcement powers, which are outside the four corners of this AD.

Evidence for enforcement: From the AD’s language, enforcement would proceed by verification of engine and crankshaft serial numbers against Lycoming MSB No. 566 Tables 1-4 and inspection of maintenance records to confirm the replacement work and timeliness (Requirement; Compliance). The AD supplies clear objective criteria for inspectors: engine model, dates, engine SNs in MSB tables, crankshaft SNs in Table 4, and elapsed time in service relative to the 50-hour/6-month deadline.

Remedial vs punitive action: The AD itself prescribes remedial action (replace listed crankshafts) rather than setting out penalties. Regulatory enforcement actions for non-compliance might include grounding, notices to comply, monetary penalties, or prosecution under the aviation safety statute , but such measures are not mentioned in the AD and therefore are not established by this source.

Interaction with continuing airworthiness obligations: The AD’s requirements sit within the broader regime of continuing airworthiness obligations. Operators are required to ensure their aircraft and engines are airworthy; compliance with applicable ADs is the normal method of discharging that obligation. Therefore failure to comply with this AD would be evidence that an operator has not met continuing airworthiness duties, which is the likely enforcement pathway even though the AD does not itself recite penalties.

International coordination noted: The AD includes a note referring to FAA AD 2005-19-11 Amendment 39-14276, indicating that other regulators have issued parallel measures; this supports cross-jurisdictional enforcement expectations for the same safety hazard. The AD does not, however, describe reciprocal enforcement arrangements.

The AD explicitly references an FAA Airworthiness Directive (FAA AD 2005-19-11 Amendment 39-14276) and requires use of Lycoming Mandatory Service Bulletin No. 566 dated 11 July 2005 (Note; Requirement). Beyond those references, the AD does not recite other legislative or regulatory provisions. Nevertheless, several interactions are implicit from the AD’s nature.

Dependence on manufacturer service material: Compliance with this AD depends on the content of Lycoming MSB No. 566; the AD instructs operators to use Tables 1-4 within that MSB to identify affected engines and crankshafts (Requirement). That makes the AD operationally interdependent with manufacturer service documentation. If MSB 566 were amended, superseded, or corrected, the practical effect on obligations would depend on subsequent regulatory guidance; this AD, as written, explicitly ties to MSB No. 566 as dated 11 July 2005.

Regulatory enforcement framework: While the AD does not cite the statutory provisions granting the Civil Aviation Safety Authority enforcement powers, the AD is issued by a CASA delegate and therefore is an instrument within the civil aviation regulatory system. Compliance obligations under ADs are routinely enforced under aviation legislation and regulations governing airworthiness and continued operation. The AD’s text does not specify those statutory provisions; operators must rely on the broader statutory and regulatory scheme for enforcement and potential sanctions.

International regulatory harmonisation: The AD’s note referring to the FAA AD suggests coordinated regulatory responses to the same hazard. That linkage can create expectations on operators who move aircraft across jurisdictions or who rely on parts supplied internationally. However, the AD does not formalise mutual recognition or describe how foreign AD compliance satisfies domestic requirements; the linkage is informational.

Maintenance standards and approvals: Replacement of a crankshaft is a maintenance action normally performed consistent with approved maintenance practices and personnel authorisations. The AD does not lay down standards for who can perform the replacement or procedural steps; those matters are governed by other parts of the aviation regulatory framework and maintenance approval systems. The AD therefore interacts functionally with maintenance certification rules but does not restate them.

Supply chain and product liability: The AD’s installation prohibition (Requirement 3) has practical effects on supply: parts suppliers must ensure they do not supply prohibited crankshafts for installation. This creates an interface between the AD and commercial and contractual obligations in supply chains, but the AD itself does not address contractual or liability questions. Any contractual disputes, claims for cost recovery, or product liability issues resulting from compliance costs or parts defects would be governed by commercial law and tort law outside the AD text.

No express compensation or transitional relief: The AD imposes replacement duties and an installation ban without offering transitional exemptions, relief, or compensation mechanisms. Any relief, appeals, or special permissions would need to be sought through the regulator under its general processes rather than through the AD text.

The AD itself contains minimal amendment history in the supplied text. It records key dates and references but does not show any subsequent amendments or variations within the document.

Key dates in the instrument:

• Lycoming Mandatory Service Bulletin referenced: MSB No. 566 dated 11 July 2005 (Requirement; Note).
• Signature of the CASA delegate: 5 October 2005 (signature block).
• Stated effective date of the AD: 28 October 2005 (Compliance; effective date note).

The AD also includes a parenthetical note that FAA Airworthiness Directive 2005-19-11 Amendment 39-14276 is referred to (Note). The AD does not itself record any prior versions of the same AD, nor does it include textual amendments, corrections, or superseding notices in the supplied text.

No statutory amendment chronology is present. The AD does not indicate that it replaces or supersedes an earlier AD. If subsequent amendments were made to the AD after the effective date or if the MSB tables were updated, those changes are not part of this document as supplied. Compliance, as required by this instrument, depends on the MSB No. 566 dated 11 July 2005 and the AD effective date of 28 October 2005.

If a user needs to know whether there have been later amendments or superseding ADs, the supplied text does not provide that history. The AD’s reference to the FAA AD may be a pointer to parallel regulatory action, but the AD itself does not record an amendment trail beyond the dates and documents cited in the text.

The supplied AD contains no litigation history. There are no cases, appeals, or enforcement proceedings recited in the text, and no judicial determinations are mentioned. The document does not identify any disputes, nor does it record ministerial or delegated decisions that were subsequently challenged in court.

Potential areas that could give rise to litigation or disputes, based purely on the AD’s content and structure, include:

• Disputes about whether a particular engine falls within the AD’s applicability criteria, for example where records are incomplete as to whether the engine was rebuilt, overhauled, or received a crankshaft after 01 March 1999. The AD’s applicability is conditional on those dates and events (Applicability).
• Disputes about whether a specific crankshaft serial number is listed in Table 4 of Lycoming MSB No. 566, given that the AD does not reproduce the tables in the text; reliance on the manufacturer’s tables could generate disputes over accuracy or completeness (Requirement; MSB reference).
• Disputes over compliance timing, particularly the calculation of the 50 hours time-in-service or the six-month window where the AD imposes two alternative deadlines (Compliance). Disagreements could arise over logbook entries, hours accumulation, or whether replacement was done "unless accomplished earlier."
• Commercial disputes between owners and maintenance or overhaul shops concerning who bears the cost of replacement, especially where prior overhauls or parts installations post-01 March 1999 are relevant to capturing an engine under the AD. The AD does not address cost allocation, so contractual and commercial remedies would govern any dispute.

None of these potential litigation themes are documented in the AD text itself. The document neither cites cases nor alleges that legal action has been taken in relation to this AD or the underlying crankshaft failures. The AD’s reference to the FAA AD suggests that similar regulatory action was taken elsewhere, but again no adjudicative outcomes are described.

This AD contains several technical and procedural particulars that can produce compliance traps if not precisely followed.

1. Applicability hinges on dates and past events: The AD applies only to engines "manufactured new, rebuilt, overhauled after 01 March 1999; OR that had a crankshaft installed after 01 March 1999" (Applicability). Determining whether a crankshaft was installed after that date may require inspecting past maintenance records. If records are incomplete, operators could inadvertently misclassify an engine as out of scope when it is in scope, or vice versa.

2. Reliance on external tables: The AD does not list serial numbers in its body; it mandates the use of Lycoming MSB No. 566 Tables 1-4 (Requirement). Access to and correct interpretation of those tables are essential. Errors in referencing the wrong table, or using an incorrect revision of the MSB, could lead to non-compliance.

3. Two-step verification for some engines: For 540-series engines the AD requires first checking Table 1 or Table 2 for engine SN, and then checking Table 4 for the crankshaft SN (Requirement 1(a)). For 360-series engines the operator must check Table 3 and then Table 4 (Requirement 2(a)). Misreading which tables apply to which engine series is a potential pitfall.

4. Immediate prohibition on installation: Requirement 3 prohibits installation of any crankshaft whose SN is listed in Table 4 "into any engine" after the effective date. This is a standing ban; unlike the replacement requirement with its 50-hour/6-month window, the installation ban is effective immediately after 28 October 2005 (Requirement 3; Compliance). Suppliers and maintenance organisations must ensure that they neither install nor supply those crankshafts for installation after that date.

5. Dual timelines for replacement actions: The AD sets two alternative compliance thresholds , 50 hours time-in-service or six months after the AD effective date, whichever occurs first (Compliance). Operators must calculate hours-in-service accurately; miscalculation could lead to non-compliance even where replacement was attempted within six months if more than 50 hours TIS elapsed first.

6. No detailed procedural guidance in the AD text: The AD prescribes outcomes (replacement with crankshaft not listed in Table 4) but does not set out the procedural steps, approved methods, or who may carry out the work (Requirement). Compliance therefore requires operators to rely on maintenance manuals, manufacturer instructions, or regulator guidance outside this document.

7. Documentation burden: Although the AD does not specify record-keeping, compliance will be proven through maintenance logs, parts serial-number records, and entries showing the time-in-service at the time of replacement. Inadequate records could make it difficult to demonstrate timely compliance.

8. Supply chain friction: Since the AD forbids installing listed crankshafts into any engine, suppliers selling used or refurbished crankshafts must be vigilant to avoid selling prohibited parts for installation. The AD does not provide a list in its text; suppliers must have access to MSB 566 Table 4 and check serial numbers before sale.

9. Interaction with FAA AD: The AD notes FAA AD 2005-19-11 but does not articulate whether compliance with that FAA AD satisfies the domestic AD, or whether procedural differences exist. Operators should not assume equivalence absent explicit regulator guidance.

10. No compensation or commercial relief in instrument: The AD imposes mandatory replacements and a ban on certain installations, but it offers no statement concerning cost recovery, who pays for replaced crankshafts, or transitional relief. Commercial arrangements must be resolved outside the AD’s text.

The AD sets a clear, table-driven compliance pathway. Below are concrete, source-grounded steps to achieve compliance based on the AD’s text (Requirement; Compliance; Applicability).

1. Identify engines in the fleet that match the model and rating criteria: List all installed Lycoming engines in the AEIO-, IO-, O-, LIO-, LO- and TIO- prefixes for the 360 and 540 series rated at 300 HP or lower. For each engine, establish whether it was manufactured new, rebuilt, or overhauled after 01 March 1999, or whether a crankshaft was installed after 01 March 1999 (Applicability).

2. Obtain Lycoming Mandatory Service Bulletin No. 566 dated 11 July 2005: The AD requires using that MSB and its Tables 1-4 to determine whether an engine or crankshaft is affected (Requirement; MSB reference). Ensure you have the MSB in the edition dated 11 July 2005 as cited.

3. Cross-check engine serial numbers against Tables 1-3 as applicable:

   • For AEIO-540, IO-540, O-540, and TIO-540 series engines, check Tables 1 and 2 for the engine serial number (Requirement 1(a)).
   • For AEIO-360, IO-360, O-360, LIO-360, and LO-360 series engines, check Table 3 for the engine serial number (Requirement 2(a)).

4. For engines identified in Tables 1-3, verify crankshaft serial number(s) against Table 4: If the engine SN appears in the appropriate table, use Table 4 to locate the crankshaft serial number for that engine and determine whether that crankshaft SN is listed in Table 4 (Requirement 1(a), 2(a)).

5. If the crankshaft SN is listed in Table 4, replace it: The AD requires that crankshafts with SNs listed in Table 4 be removed and replaced with crankshafts that are not listed in Table 4 (Requirement 1(b), 2(b)). The AD does not prescribe a specific replacement part number; the only stated constraint is that the replacement crankshaft must not have a SN listed in Table 4.

6. Observe the compliance timeline for required replacements: Unless accomplished earlier, replacements required under Requirements 1 and 2 must be completed within 50 hours time-in-service or six months after the AD’s effective date (28 October 2005), whichever occurs first (Compliance). Calculate total time-in-service accurately against aircraft logs to determine the relevant deadline.

7. Do not install any crankshaft whose SN is listed in Table 4 into any engine after the effective date: Requirement 3 is a standing prohibition that applies “after the effective date of this AD.” Ensure purchasing, inventory, and maintenance procedures prevent such installations.

8. Document the work and preserve records: Although the AD does not specify detailed record-keeping requirements, proof of compliance will depend on engine and crankshaft serial-number records and logbook entries showing the date/hours at which crankshaft replacement occurred. Maintain records linking the engine SN, removed crankshaft SN, replacement crankshaft SN, dates, and time-in-service at replacement.

9. Coordinate with suppliers and maintenance providers: Ensure spare parts suppliers, overhaul shops, and maintenance organisations are aware of the prohibition on installing Table 4 crankshafts and will only supply crankshafts not listed in Table 4. Verify and record serial numbers on any supplied crankshaft.

10. If records are incomplete, take a conservative approach: Where historical records are insufficient to determine whether an engine or crankshaft meets the AD’s applicability criteria, the AD’s safety rationale and mandatory replacement requirement suggest that operators should obtain definitive evidence (for example, contact Lycoming or the maintenance organisation that undertook the overhaul) and, if doubt remains, follow the AD’s procedures to confirm or rectify the situation.

11. Reference FAA AD as relevant: The AD notes FAA AD 2005-19-11 Amendment 39-14276 (Note). That FAA AD may contain parallel requirements or additional guidance; consult both documents where cross-jurisdictional operations or imported parts are involved.

12. Seek regulator guidance for edge cases: The AD contains no procedural exemptions, alternative methods of compliance, or appeal mechanics. For special relief or interpretation questions (for example, disputed serial-number listings, ambiguous record evidence, or supply constraints), contact the regulator or delegate as appropriate to obtain formal guidance beyond the AD text.

Following these steps aligns actions with the explicit prescriptions of the AD: verify applicability using MSB 566 tables, replace listed crankshafts with unlisted ones within the prescribed timeline, and do not install crankshafts with serial numbers in Table 4 after the AD’s effective date.