{"id":"F2006B02310","name":"AD/ALF/14 Amdt 3 - Engine Oil System Health Monitoring","slug":"ad-alf-14-amdt-3-engine-oil-system-health-monitoring","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41540,"registerId":"commonwealth-F2006B02310-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/ALF/14 Amdt 3 - Engine Oil System Health Monitoring","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/ALF/14 Amdt 2 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)\n\nAlliedSignal (Lycoming) Turbine Engines \\- ALF502 and LF507 Series\n\nAD/ALF/14\n\nAmdt 3\n\n  \nEngine Oil System Health Monitoring 8/2001\n\nApplicability: AlliedSignal ALF 502L, ALF502R, and LF507 series engines installed in Canadair CL-600, BAe 146, and Avro RJ series aircraft.\n\nRequirement: 1. Carry out oil system health monitoring in accordance with AlliedSignal Service Bulletins (SB) LF 507-1H 79-5, LF507-1F 79-5, ALF502L 79-0171, and\n\nALF502R 79-9 for LF507-1H, -1F, ALF502L and ALF502R series engines as appropriate.\n\nWhere the service bulletins require:\n\n    (a) magnetic chip detector (MCD) debris be left to accumulate on the detector for assessment of a debris accumulation rating, it is permissible to remove the MCD debris for material analysis provided a record of debris accumulation is kept for subsequent assessment per the service bulletin requirements,\n\n    (b) a scavenge oil temperature check be carried out, it is permissible to use the procedures specified in the respective aircraft maintenance manuals in lieu of those specified in the service bulletins.\n\nIncorporation of an improved No.4 bearing configuration as per Honeywell (formerly AlliedSignal) SB ALF/LF 72-1030, Revision 3, dated 3 April 2001 or\n\nSB ALF/LF 72-1040, Revision 2, dated 3 April 2001 (as applicable) is a terminating action for Requirement 1 of this Directive (Refer AD/ALF/17). Upon incorporation of the improved bearing configuration, on-going oil system monitoring reverts to the respective aircraft manufacturer’s maintenance requirements.\n\n2. For ALF502R series engines equipped with oil filter by-pass valve, P/No 2-303- 432-01, replace or modify the oil filter by-pass valve in accordance with Avco Lycoming Textron Service Bulletin ALF502R-79-0162, Revision 2.\n\nNote 1: CAA (UK) AD 002-09-96 and FAA AD 2000-05-14 refer.\n\nNote 2: Incorporation of earlier versions of SB ALF/LF 72-1030 or SB ALF/LF 72- 1040 (as applicable) is also terminating action for Requirement 1 of this Directive.\n\nAlliedSignal (Lycoming) Turbine Engines \\- ALF502 and LF507 Series\n\nAD/ALF/14 Amdt 3 (Continued)\n\nCompliance: 1. Unless previously accomplished, initiate the oil health-monitoring program within 100 hours’ time in service from 26 March 1998.\n\n2. Unless previously accomplished, no later than 30 April 1998.\n\nThis Amendment becomes effective on 9 August 2001.\n\nBackground: A number of 4/5 bearing failures has resulted in separation of the LP turbine shaft.\n\nOne failure of the LPT shaft led to an overspeed condition that resulted in an uncontained engine failure and subsequent aircraft damage.\n\nThis amendment is issued to include the latest revisions of SBs ALF/LF 72-1030 and ALF/LF 72-1040, and reference the current FAA AD.\n\nAmendment 2 became effective on 7 September 2000 and included an additional SB reference to expand terminating action requirements.\n\nAmendment 1 became effective on 26 March 1998 and was issued to expand the applicability to include an additional engine model, to reference an FAA AD, to mandate the requirement to use oil filter by-pass valves previously mandated by AD/ALF/7, and to provide terminating action.\n\n![](image.002.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 29 June 2001\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 11 July 2001.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"This Amendment 3 does not materially expand the set of engines or aircraft affected or add new types of mandatory monitoring; it updates the AD to include the latest revisions of specific Honeywell service bulletins and to reference the current FAA AD (mechanical update). Earlier amendments did expand applicability and add requirements, but Amendment 3 is limited to revising SB references and clarifying terminating-action documents rather than widening the AD’s substantive scope."},"complexity_factors":["Cross-reference to multiple manufacturer Service Bulletins (LF507-1H 79-5, LF507-1F 79-5, ALF502L 79-0171, ALF502R 79-9)","Conditional terminating action tied to specific SBs (ALF/LF 72-1030 Rev 3 or 72-1040 Rev 2) and earlier revisions","Two permissibility exceptions within Requirement 1 (MCD debris removal for analysis; use of aircraft maintenance manual procedures for scavenge oil temp checks)","Specific part-numbered mandatory action for a sub-group (oil filter by-pass valve P/No 2-303-432-01) with its own SB reference (ALF502R-79-0162 Rev 2)","Multiple compliance deadlines with retroactive start dates (100 hours from 26 March 1998; 30 April 1998) and an amendment effective date (9 August 2001)","References to other airworthiness directives (AD/ALF/17, CAA UK AD, FAA AD) creating external dependencies","Technical subject-matter (bearing configurations, MCD debris rating, scavenge oil temperature) requiring specialised maintenance procedures and record-keeping"],"plain_english_summary":"**What this instrument requires (mechanics)\n\n- Applies to AlliedSignal (Lycoming) ALF502L, ALF502R and LF507 series turbine engines when installed in Canadair CL-600, BAe 146 and Avro RJ aircraft. (Applicability)\n\n- Mandatory action: start and carry out an \"oil system health monitoring\" programme for the affected engines in accordance with the listed AlliedSignal (Honeywell) Service Bulletins (SBs) appropriate to each engine model. (Requirement 1)\n\n- Two specific permissibilities within that monitoring requirement: \n  - (a) Magnetic chip detector (MCD) debris may be removed for material analysis so long as a record of debris accumulation is kept for later rating assessment. (Requirement 1(a))\n  - (b) Scavenge oil temperature checks may be done using the aircraft maintenance manual procedures instead of those in the service bulletins. (Requirement 1(b))\n\n- Terminating action: fitting an improved No.4 bearing configuration per Honeywell SB ALF/LF 72-1030 Rev 3 or SB ALF/LF 72-1040 Rev 2 (as applicable) ends the AD monitoring requirement; after incorporation, ongoing oil monitoring follows the aircraft manufacturer’s normal maintenance schedule. Earlier revisions of those SBs also count as terminating action. (Requirement 1, cross-reference to AD/ALF/17)\n\n- Additional mandatory action for ALF502R engines fitted with a particular oil filter by-pass valve (P/No 2-303-432-01): replace or modify that valve per Avco Lycoming Textron SB ALF502R-79-0162 Rev 2. (Requirement 2)\n\n- Compliance timing: initiate the oil health-monitoring programme within 100 flight hours from 26 March 1998 unless already done; the valve replacement/modification must be done no later than 30 April 1998 if not previously done. The Amendment takes effect 9 August 2001. (Compliance)\n\n**Why it was issued (stated rationale)\n\n- The AD was issued because several No.4/No.5 bearing failures led to low-pressure turbine (LPT) shaft separations; one separation caused an LP turbine overspeed and an uncontained engine failure with aircraft damage. The AD’s stated purpose is to detect and address oil-system or bearing degradation before it progresses to catastrophic failure.\n\n**Practical effects and who pays / who decides\n\n- Who pays: aircraft owners/operators of the specified types bear the direct costs — labour, parts, downtime, debris analysis and record keeping, or the cost of incorporating the improved No.4 bearing or replacing/modifying the specified by‑pass valve.\n\n- Who decides: the Civil Aviation Safety Authority (via its delegate) mandates the AD; affected operators must follow the identified Service Bulletins and record compliance. Operators may choose the terminating modification (bearing upgrade) to stop the special monitoring requirement.\n\n- Behaviour changes required: operators must introduce a formal oil health-monitoring regime, perform specific inspections/tests or authorised equivalents, keep debris accumulation records, and carry out mandated part replacement/modification where applicable. Some operators will opt to install the improved bearing configuration to avoid ongoing monitoring.\n\n**Costs, incentives, trade-offs and implementation issues (testing the stated purpose)\n\n- Costs and compliance burden: the AD imposes recurring monitoring effort (inspections, MCD debris handling and records, temperature checks) and, for some, a one-off parts replacement or modification. There are labour, parts and aircraft-on-ground time costs, and administrative record-keeping obligations (Requirement 1 and Compliance).\n\n- Incentives: operators have a clear private incentive to accept the terminating action (bearing upgrade) where cost-effective, because it ends the special monitoring requirement and returns maintenance to standard schedules. That creates a substitution effect: pay once for parts/mods vs ongoing monitoring costs.\n\n- Trade-offs and opportunity costs: the operator must trade immediate upgrade cost and downtime against continued monitoring costs and the (probabilistic) risk of bearing failure. The AD does not set economic thresholds; it leaves the operator to choose whether to take terminating action.\n\n- Implementation risk and bureaucratic discretion: the AD relies on compliance with manufacturer SBs and on records kept by operators. Effective risk mitigation therefore depends on proper execution of SB procedures and accurate debris-rating assessments. The delegate prescribes the remedy but delegates the technical details to SBs and maintenance manuals, so consistent interpretation and execution by maintenance organisations is material to outcomes.\n\n- Effects on private enterprise and competition: maintenance organisations and parts suppliers incur additional work and revenue from inspections, analysis and modifications. Aircraft operators pay those costs. The AD does not change aircraft ownership rules or market entry; it imposes a technical maintenance obligation on a defined subset of engine/airframe combinations.\n\n**Concentrated benefits / diffuse costs and other distributional points\n\n- Benefits (reduced risk of uncontained failure) are concentrated on operators and passengers of the affected aircraft and on insurers; costs are concentrated on those same operators (they bear direct compliance costs). There is no authorisation of subsidised costs or indemnities in the AD text.\n\n**Reference points in the AD text\n\n- Requirement 1 and its sub-clauses (monitoring, MCD debris permissibility, scavenge oil temperature check permissibility);\n- Terminating action references SB ALF/LF 72-1030 Rev 3 and SB ALF/LF 72-1040 Rev 2 (and earlier revisions);\n- Requirement 2 (ALF502R by-pass valve replacement/modification);\n- Compliance timing (initiate within 100 hours from 26 March 1998; other deadline 30 April 1998).\n\nOverall: the AD mandates oil-system monitoring and targeted modifications to reduce the risk of bearing failures and consequent catastrophic engine events. It prescribes monitoring methods, allows limited procedural alternatives, and provides a clear terminating modification path that transfers costs from ongoing monitoring to a one‑off parts/modification expense.**"},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"The legislation maintains its original scope — addressing oil system health monitoring for specific AlliedSignal/Honeywell engines. While Amendment 3 updates referenced service bulletins to their latest revisions and adds current FAA AD references, this represents normal iterative safety regulation rather than scope creep. The core purpose (preventing bearing failures through oil system monitoring) remains unchanged from the original 1998 directive."},"complexity_factors":["Multiple cross-references to external service bulletins (4 different SBs referenced, with specific revision dates)","Conditional logic: different requirements apply to different engine sub-models (LF507-1H, -1F, ALF502L, ALF502R)","Nested exceptions and terminating actions: Requirement 1 has two explicit exceptions (items a and b), plus a terminating action that references another AD (AD/ALF/17)","Historical layering: references to previous amendments (1 and 2) and their effective dates, plus two foreign regulatory references (UK CAA and FAA ADs)","Specific part numbers and document revision dates that must be tracked precisely (e.g., 'P/No 2-303-432-01', 'Revision 3, dated 3 April 2001')"],"plain_english_summary":"This AD replaces an earlier order and requires ongoing oil-system health monitoring and, for some engines, a hardware modification to prevent bearing failures in AlliedSignal/Honeywell ALF502/LF507 turbofan engines used on Canadair CL‑600, BAe 146 and Avro RJ aircraft. It mandates debris and oil‑temperature checks to detect early bearing damage, allows analysis/alternate procedures with records, and lets operators stop special monitoring if an improved No.4 bearing configuration is installed. It addresses past uncontained failures and aims to prevent catastrophic engine breakup."}},"importantCases":[],"_links":{"self":"/api/acts/ad-alf-14-amdt-3-engine-oil-system-health-monitoring","history":"/api/acts/ad-alf-14-amdt-3-engine-oil-system-health-monitoring/history","analysis":"/api/acts/ad-alf-14-amdt-3-engine-oil-system-health-monitoring/analysis","conflicts":"/api/acts/ad-alf-14-amdt-3-engine-oil-system-health-monitoring/conflicts","importantCases":"/api/acts/ad-alf-14-amdt-3-engine-oil-system-health-monitoring/important-cases","documents":"/api/acts/ad-alf-14-amdt-3-engine-oil-system-health-monitoring/documents"}}