{"id":"F2006L01697","name":"AD/LJ45/9 - Fuel System Contamination","slug":"ad-lj45-9-fuel-system-contamination","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":59458,"registerId":"commonwealth-F2006L01697-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Learjet 45 Series Aeroplanes","sectionType":"division","heading":"Learjet 45 Series Aeroplanes","content":"### Learjet 45 Series Aeroplanes\n\n| AD/LJ45/9 | Fuel System Contamination | 8/2006 TX |\n| --------- | ------------------------- | --------- |\n\n| Applicability: | Learjet Model 45 aeroplanes, serial numbers 45-005 through 45-295 inclusive, and 45-2001 through 45-2044 inclusive.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Review of Aeroplane Maintenance RecordsReview the aeroplane maintenance records to determine whether inspections identified by the inspection reference numbers (IRNs) in requirements 1(a) and 1(b) of this AD have been done.(a) IRN O2810001, Inspection/Service Requirement, “Wing Tanks” Perform Visual Inspection. Inspect for corrosion. (Refer to 5-10-00.), of Bombardier Learjet 45 M45 Maintenance Manual.(b) IRN O2820000, Inspection/Service Requirement, “Low Pressure Fuel Filter” Remove and inspect for contamination. Clean if necessary. (Refer to28-20-15.), of Bombardier Learjet 45 M45 Maintenance Manual.2. General Visual Inspections and Cleaning(a) During the records review required by requirement 1 of this AD, if it cannot be positively determined whether both IRNs have been done; Do the following:- Except as provided by requirement 2(b) of this AD, do the actions specified in requirements 2(a)(i) and 2(a)(ii) of this AD in accordance with Chapters 5-10-00 and 28-20-15, as applicable, of the Bombardier Learjet 45 M45 Maintenance Manual.(i) Do a general visual inspection of the inside of the wet wing fuel areas and the fuel pump screens for tape or adhesive tape residue.(ii) Clean the low pressure fuel filter, determining whether tape or adhesive tape residue is present, and do a general visual inspection of the filter for damage before installation. |\n\n|     | Note 1: For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”(b) If a crew alert system message of “L FUEL FILTER, R FUEL FILTER, LR FUEL FILTER, L FUEL PRESS LOW, R FUEL PRESS LOW, or LR FUEL PRESS LOW” occurs during flight or on the ground, do the actions required by requirements 2(a) of this AD.3. Corrective Actions(a) If any tape or adhesive tape residue is found during the general visual inspection required by requirement 1 or 2 of this AD, do the actions specified in paragraphs 3(a)(i) and 3(a)(ii) of this AD.(i) Clean the wing fuel tank in accordance with Chapter 20-71-00 of the Bombardier Learjet 45 M45 Maintenance Manual.(ii) Service the affected engine fuel filter and return any engine fuel control subjected to contaminated fuel for servicing to Honeywell Engines.(b) If any damage is found during the general visual inspection required by paragraph 2(a)(ii) of this AD do the applicable action specified in requirements 3(b)(i) or 3(b)(ii) of this AD in accordance with Chapter28-20-15 of the Bombardier Learjet 45 M45 Maintenance Manual.(i) For damage that is repairable: Repair damaged filter.(ii) For damage beyond repair: Replace the damaged filter with a new filter.4. Reporting RequirementSubmit a report of the applicable review and inspection results to CASA via the SDR system. The report must include the following, as applicable:(a) The aeroplane serial number;(b) The number of flight hours on the aeroplane; |\n| --- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n|             | (c) The applicable review and inspection results (both positive and negative findings), including a description, pictures, and pertinent information for any tape or adhesive tape residue found in the wing tank(s); and(d) Date of inspection of the wing tank(s);(e) The number of this AD.Note 2: FAA AD 2006-10-15 Amdt 39-14599 dated 9 May 2006 refers.                                                                                                                                                                                                                                         |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Compliance: | 1. Within 50 flight hours or 30 days after the effective date of this AD, whichever occurs first.2. (a) Within 50 flight hours or 30 days after the effective date of this AD, whichever occurs first2. (b) Before further flight, after the effective date of this AD unless the actions detailed in requirement 2(a) have already been done.3. Before further flight, after the effective date of this AD.4. Within 10 days after accomplishing the review required by requirement 1 of this AD or the general visual inspection required by requirement 2 of this AD if done.                       |\n|             | This Airworthiness Directive becomes effective on 5 June 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| Background: | This AD results from reports of tape found in the wing fuel tanks. The actions detailed in this AD are to prevent blocked fuel passages and fuel pump screens and the inability of the flight crew to transfer fuel from one wing tank to the other tank due to tape in the wing fuel tanks, which could result in a fuel imbalance and consequent failure of an engine; and to prevent contaminated fuel pump screens, engine fuel controls, and fuel nozzles due to tape adhesive dissolving in the fuel, which could result in potential erroneous readings of the fuel quantity indication system. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n30 May 2006","sortOrder":0},{"sectionNumber":"AD/LJ45/9","sectionType":"part","heading":"AD/LJ45/9","content":"## AD/LJ45/9","sortOrder":1},{"sectionNumber":"Fuel System Contamination","sectionType":"part","heading":"Fuel System Contamination","content":"## Fuel System Contamination","sortOrder":2},{"sectionNumber":"8/2006 TX","sectionType":"part","heading":"8/2006 TX","content":"## 8/2006 TX","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD stays within the original purpose set out in its background: to detect and remove tape/adhesive contamination in Learjet 45 wing fuel tanks and to address contaminated filters/engine fuel controls. It imposes inspections, cleaning/repair actions, and reporting consistent with that safety objective, without broadening to unrelated systems, aircraft types, or permanent operational constraints."},"complexity_factors":["Applicability limited to two contiguous serial-number ranges (narrow scope).","Cross-references to specific maintenance manual chapters (5-10-00, 28-20-15, 20-71-00) rather than reproducing procedures.","Two specific IRNs to check (O2810001 and O2820000) plus a defined term \"general visual inspection\" in Note 1.","Conditional logic: records review first; if inconclusive then inspections; immediate inspections triggered by listed crew-alert messages (Requirement 2(b)).","Several compliance timeframes: within 50 flight hours or 30 days, and actions required \"before further flight\" in some circumstances.","Corrective-action branching: different work depending on presence of residue versus filter damage, and repair-or-replace choice for damaged filters.","Reporting requirement with specific content and a 10-day deadline (adds administrative step)."],"plain_english_summary":"**What this instrument does (mechanically)\n\n- Applies to Bombardier Learjet Model 45 aeroplanes with serial numbers 45-005 through 45-295 and 45-2001 through 45-2044.  (See \"Applicability\".)\n\n- Requires operators to check the aeroplane maintenance records to confirm whether two specific inspections from the Learjet 45 maintenance manual were already done:\n  - IRN O2810001 — Wing Tanks: visual inspection for corrosion (Chapter 5-10-00), and\n  - IRN O2820000 — Low Pressure Fuel Filter: remove and inspect for contamination (Chapter 28-20-15).\n  (Requirement 1.)\n\n- If the records do not clearly show those inspections were done, the operator must perform them: a general visual inspection inside the wet wing fuel areas and fuel pump screens for tape or adhesive residue, and removal/cleaning/inspection of the low pressure fuel filter (Requirement 2(a)(i)–(ii)).  \"General visual inspection\" is defined in Note 1 (touching-distance visual check, may require access panels, mirror, normal lighting).\n\n- If certain crew-alert messages indicating fuel-filter or low fuel pressure occur in flight or on ground, the inspections in Requirement 2(a) must be done before further flight (Requirement 2(b)).\n\n- Corrective actions if tape/adhesive residue is found: clean the wing fuel tank per Chapter 20-71-00 of the maintenance manual; service the affected engine fuel filter; and return any engine fuel control exposed to contaminated fuel to Honeywell for servicing (Requirement 3(a)).\n\n- Corrective actions for damaged filters: repair if repairable or replace if beyond repair, per Chapter 28-20-15 (Requirement 3(b)).\n\n- Reporting: submit the review/inspection results to CASA via the Service Difficulty Reporting (SDR) system within 10 days of the inspection. Report must include aeroplane serial number, flight hours, inspection findings (positive and negative) with description and pictures where applicable, date of inspection, and AD number (Requirement 4).\n\n- Compliance timeframes: generally within 50 flight hours or 30 days after the AD’s effective date (whichever is first); some actions (e.g., after a crew-alert message) are required before further flight (\"Compliance\" section).\n\n\nWhy the rule exists (stated rationale and what it aims to prevent)\n\n- The AD follows reports that pieces of adhesive tape were found inside wing fuel tanks. The stated safety concerns are that tape or tape adhesive in fuel tanks can:\n  - block fuel passages or pump screens and prevent fuel transfer between tanks, causing fuel imbalance and possible engine failure, and\n  - contaminate fuel pump screens, engine fuel controls, and fuel nozzles if adhesive dissolves in fuel, and cause erroneous fuel quantity readings.\n\n\nWho this affects and who pays\n\n- Primary parties affected: aircraft operators/owners of the specified Learjet 45 serial-number range and their maintenance organisations (licensed engineers, MROs).\n- Who pays: the operator pays for record checks, inspections, cleaning, filter servicing/replacement, any engine fuel control servicing with Honeywell, the labour and aircraft downtime, and the administrative time to file the SDR report. CASA receives the reports and enforces compliance.\n- Who decides: CASA issues and enforces the AD; maintenance personnel follow the Bombardier Learjet 45 Maintenance Manual chapters cited in the AD; Honeywell is specified as the servicer for engine fuel controls contaminated by fuel (Requirement 3(a)(ii)).\n\n\nBehavioural and market effects, trade-offs, and implementation considerations\n\n- Behaviour changes required:\n  - Operators must check and, if necessary, perform specific inspections rather than rely on incomplete records (incentivises better record-keeping).\n  - Maintenance providers will perform cleaning/repairs and may route contaminated engine fuel controls to Honeywell.\n  - Operators may ground aircraft until required inspections or repairs are completed when crew-alert messages occur.\n\n- Costs and incentives:\n  - Immediate direct costs are inspection labour, possible filter replacements, wing-tank cleaning, and shipping/servicing costs for engine controls sent to Honeywell.\n  - Downtime (lost revenue) while inspections and remedial work are done is an operational cost to operators.\n  - Maintenance shops and Honeywell are likely to receive incremental business (concentrated benefit); costs are borne across many operators (diffuse cost).\n\n- Trade-offs and risks:\n  - Reliance on maintenance records can reduce unnecessary inspections if records are reliable, but inaccurate/incomplete records will trigger inspections and possible operational disruption.\n  - Specifying Honeywell for engine fuel-control servicing concentrates that work with one firm (explicit in Requirement 3(a)(ii)); that reduces operator choice over servicers for that component and may raise service or logistics costs.\n  - Possible supply or scheduling bottlenecks for replacement filters or Honeywell servicing could extend downtime.\n\n- Compliance and enforcement:\n  - Operators must file the SDR report within 10 days following the inspection. CASA will use those reports to monitor compliance and incidents.\n  - The AD cross-references several maintenance-manual chapters; compliance requires access to and adherence to those manufacturer procedures.\n\n\nImplementation risk and unintended consequences to watch for\n\n- If operators consistently interpret records as positive when they are not, contamination could be missed; conversely, overly cautious inspections create avoidable downtime and cost.\n- The instruction to return contaminated engine fuel controls to Honeywell centralises work and could create single-vendor dependence or delay. The text itself requires this (Requirement 3(a)(ii)).\n- Operators may choose replacement over repair when filter damage is found; that shifts cost from labour to parts and inventory demand.\n\n\nWhat to look for in practice (practical checklist)\n\n- Confirm applicability by serial number before taking action.\n- Review maintenance records specifically for IRN O2810001 and IRN O2820000.\n- If records are unclear or absent, schedule the visual inspection of wet wing areas and removal/inspection of the low pressure fuel filter within 50 flight hours or 30 days (or sooner if a relevant crew-alert message occurs).\n- If tape/adhesive residue or damage is found, follow Requirement 3: clean tanks, service filters, return affected engine fuel controls to Honeywell, repair or replace damaged filters per the manual, and submit SDR report to CASA within 10 days.\n\n(References: Requirement 1–4, Note 1, Compliance and Background sections of the AD.)"},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains focused scope on fuel system contamination in Learjet 45 aircraft. The requirements are tightly bounded to the specific safety issue (tape contamination) identified in the background, with no evidence of scope creep beyond the original safety purpose."},"complexity_factors":["Multiple nested conditional requirements (Requirements 1, 2(a), 2(b), 3(a), 3(b)) with cross-dependencies","Specific technical references to manufacturer manual chapters (5-10-00, 28-20-15, 20-71-00)","Defined term 'general visual inspection' with detailed technical definition spanning 4 sentences","Multiple compliance timeframes that vary by requirement and circumstance (50 flight hours/30 days, before further flight, 10 days after accomplishment)","Specific serial number ranges creating precise applicability boundaries","Six specific crew alert system messages triggering mandatory action","Cross-reference to FAA AD 2006-10-15 indicating harmonised international regulatory action"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires operators of certain Learjet 45 aircraft (specified serial ranges) to inspect wing fuel tanks and related components for adhesive tape or tape residue left from manufacturing/maintenance. \n\nTape residue can block fuel passages, contaminate pumps and gauges, and cause fuel imbalance or engine failure. Affected operators must inspect, clean or replace contaminated parts, and report findings to CASA within the prescribed timeframes."}},"importantCases":[],"_links":{"self":"/api/acts/ad-lj45-9-fuel-system-contamination","history":"/api/acts/ad-lj45-9-fuel-system-contamination/history","analysis":"/api/acts/ad-lj45-9-fuel-system-contamination/analysis","conflicts":"/api/acts/ad-lj45-9-fuel-system-contamination/conflicts","importantCases":"/api/acts/ad-lj45-9-fuel-system-contamination/important-cases","documents":"/api/acts/ad-lj45-9-fuel-system-contamination/documents"}}