AD/LJ45/8 - Engine Electrical Wire Bundles

The central concept is the airworthiness directive itself, a mandatory regulatory instrument issued under Part 39 of the Civil Aviation Safety Regulations. It imposes a legally enforceable requirement to correct a detected unsafe condition. The directive defines three key concepts: modification, inspection, and replacement. The modification is of the alternator wire bundle on the left‑hand engine only, reflecting the specific failure mode reported. The inspection is a “general visual inspection,” which the directive defines in Note 1 as: “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.” This definition is critical because it sets the scope of the inspection; it does not require specialised tools or disassembly beyond opening access panels, but it does contemplate that physical access may require stands or ladders. The replacement concept applies to fuses for hydraulic shutoff valves on certain aeroplanes, increasing their amperage rating to prevent a related failure. Another important concept is the Alternate Method of Compliance (AMOC). The directive states that later revisions of the listed service bulletins are acceptable for compliance if they have been approved by the FAA as an AMOC to FAA AD 2005‑24‑13. This acknowledges that CASA will accept FAA‑approved changes to the service documents without requiring a separate CASA AMOC approval, but only if the FAA has given its own AMOC clearance. The directive also references “Note 2” which explicitly cites FAA AD 2005‑24‑13 Amdt 39‑14393, making clear that the Australian directive is harmonised with the FAA’s parallel action. The concept of “time in service” triggers the compliance clock: 50 hours after the effective date. This is a calendar‑plus‑operational requirement, meaning an aircraft that flies more hours will need to comply sooner in absolute terms, but the clock does not start until 20 December 2005. The directive also implicitly relies on the concept of “approved data” - the service bulletins and their later revisions - as the only acceptable means of compliance unless an AMOC is sought from CASA itself (not just the FAA). Finally, the serial number ranges define the exact aircraft population affected, with different ranges for different requirements, reflecting production differences or service experience.

The primary duty‑holders are the owners and operators of Learjet Model 45 aeroplanes with serial numbers 45‑005 through 45‑273 inclusive and 45‑2001 through 45‑2029 inclusive. This is a relatively narrow fleet of approximately 274 aircraft (inferred from the inclusive ranges). Operators who fly these aeroplanes for private, business, charter, or air‑transport purposes must ensure compliance before further flight after the inspection, and within 50 hours for the initial modification and inspection. Maintenance organisations, whether approved Part 145 facilities or licensed aircraft maintenance engineers (LAMEs) working under an operator’s continuing airworthiness management system, are directly affected because they must perform the physical work and certify it. The directive imposes a specific timeline that may create scheduling pressures, particularly for operators with aircraft approaching the 50‑hour limit. The directive also affects suppliers of parts: the higher‑amperage fuses for the hydraulic shutoff valves must be sourced and fitted. The Bombardier service bulletins are the required data, so Bombardier and its authorised distributors are indirectly affected as sources of those documents and any associated modification kits. The FAA is referenced as the approving body for later revisions, so the FAA’s continued oversight of the service bulletins matters for Australian compliance. CASA itself is affected because the directive was issued by its delegate, and CASA’s enforcement and airworthiness surveillance staff will monitor compliance. The directive also affects aircraft insurers, who may require proof of compliance before covering these aircraft. Potential buyers of affected aircraft will also have an interest, because non‑compliance could ground the aircraft or reduce its value. Because the directive harmonises with an FAA AD, operators with aircraft operating under both Australian and US registrations must ensure compliance with both, though the Australian directive accepts FAA‑approved AMOCs for later revisions. The narrow serial number ranges mean that many Learjet 45 operators may be unaffected, but those within the ranges must act quickly. The compliance cost falls entirely on private parties; there is no government subsidy for the modification or inspection.

The key duty is compliance with the three requirements on the stated timelines. The operator or owner must ensure that, within 50 hours time in service after 20 December 2005, the left‑hand engine alternator wire bundle modification is completed and a general visual inspection of both engines is performed for clearance between wire harnesses and engine tubing. If any improper clearances are detected, they must be corrected before the aircraft is flown again. For aeroplanes in the narrower serial number ranges (45‑2001 through 45‑2015 and 45‑005 through 45‑254), the hydraulic shutoff valve fuses must be replaced with higher‑amperage fuses at the same time as or before the modification and inspection. The duty extends to ensuring that the work is carried out in accordance with the specific Bombardier service bulletins listed, or later revisions that have been approved by the FAA as an AMOC to FAA AD 2005‑24‑13. This means the operator must verify that the revision of the service bulletin used is either the original dated version or a later one with an FAA AMOC approval. The operator has a duty to keep records of compliance, including maintenance release endorsements, logbook entries, and copies of the service bulletins used. The right of the operator is to use an Alternative Method of Compliance if one is approved by CASA (not just the FAA for later revisions). The directive does not explicitly grant a right to petition CASA for an AMOC, but that right is inherent in Part 39 of CASR. The operator may also have a right to challenge the directive on procedural grounds, though the directive is issued under delegated authority and is legally binding. The directive also implicitly grants the right to operate the aircraft after compliance is achieved, and the right to use the later FAA‑approved revisions without seeking separate CASA approval. There is no right to extend the 50‑hour compliance period; any delay would require a specific exemption from CASA. The duty to maintain airworthiness continues after the directive is satisfied; the modifications and inspections do not immunise the aircraft from other airworthiness requirements. The operator also has a duty to ensure that any corrective actions for improper clearances are performed correctly and that no further unsafe condition arises from the work.

Non‑compliance with an airworthiness directive under the Civil Aviation Safety Regulations is a serious matter. The directive itself does not specify the penalty, but it is issued under Part 39 of CASR, which is supported by the Civil Aviation Act 1988. Contravention of a condition of an airworthiness certificate or of an airworthiness directive can attract civil penalty provisions. Under the Act, the maximum penalty for a strict liability offence by an individual can be up to 50 penalty units (currently $15,500) or more for a corporation, and imprisonment is possible for serious offences involving reckless endangerment. CASA also has the power to suspend or cancel the airworthiness certificate of an aircraft that is not compliant, effectively grounding it. The directive’s requirement to correct improper clearances before further flight makes immediate grounding the default consequence if an inspection reveals a clearance issue that is not corrected. An operator who flies an aircraft after discovering an improper clearance but before correction would breach that requirement. Similarly, failing to perform the initial modification and inspection within 50 hours is a breach that could lead to enforcement action. CASA may take administrative action, such as issuing a direction to ground the aircraft, imposing a fine, or initiating prosecution. The enforcement history for similar directives suggests that CASA often conducts surveillance and audits for compliance, and may impose enforceable undertakings. The directive does not create a private right of action, but non‑compliance could affect insurance coverage and civil liability if an accident occurs. The operator may also face reputational damage and increased scrutiny from CASA. The directive is legally binding; ignorance is not a defence. The penalty provisions apply to both the operator and any maintenance engineer who certifies the work if it is not done correctly. The directive also cross‑references the FAA AD, meaning that an aircraft that operates under both jurisdictions must comply with the Australian directive even if the FAA AD has been complied with in a different manner, unless the FAA AMOC applies to the exact revision used. This creates a risk of dual enforcement if there is a mismatch.

This directive is issued under the Civil Aviation Safety Regulations (CASR) 1998, specifically Part 39 which deals with airworthiness directives. It overrides any conflicting provisions in the aircraft’s type certificate or maintenance manual, because an AD is a mandatory requirement. The directive specifically references the FAA AD 2005‑24‑13 (Amdt 39‑14393) and accepts its AMOC process for later revisions of the service bulletins. This means that the Australian directive does not operate in isolation but is harmonised with the U.S. airworthiness system for these Learjet 45 aircraft. However, the Australian directive is a separate legal instrument; compliance with the FAA AD alone does not automatically satisfy AD/LJ45/8 unless the revisions used are FAA‑approved AMOCs. The directive also interacts with the Civil Aviation Regulations (CAR) 1988, particularly CAR 42ZE, which requires that maintenance be carried out in accordance with approved data. The service bulletins constitute approved data for the purposes of this directive. The directive also interacts with the continuing airworthiness management system required under CASR Part 42 (for large aeroplanes) or Part 91 (general operating and flight rules). Operators must record the directive in their airworthiness records, and the maintenance release must reflect compliance. The directive may also interact with other CASA airworthiness directives that apply to the Learjet 45; for example, AD/LJ45/1 through AD/LJ45/7 remain in force unless superseded. There is no indication of supersession here. The directive also interacts with the aircraft’s type certificate data sheet and any Supplemental Type Certificates (STCs). If the aircraft has been modified under an STC, the operator must ensure that the STC does not interfere with the required modifications or inspections. The directive’s acceptance of FAA‑approved AMOCs means that any operator who has obtained an FAA AMOC for a later revision need not seek a separate CASA AMOC, but the operator must ensure the FAA AMOC explicitly covers the Australian directive (the directive says “considered acceptable for compliance with the equivalent Requirements of this Directive”). The directive does not address what happens if the FAA AMOC was issued after the effective date of the Australian directive; presumably it still applies. The directive also does not mention any interaction with state or territory workplace health and safety laws, but maintenance activities would need to comply with those as well. Finally, the directive may interact with the aircraft’s lease or mortgage agreements, as compliance is likely a condition of airworthiness and thus of continued operation.

The source provides no indication of any amendments to AD/LJ45/8. It appears as a single, original issuance with an effective date of 20 December 2005. The document is a PDF image of the original CASA Airworthiness Directive form. There is no reference to a previous version, a superseded directive, or any amendment number. The AD number is AD/LJ45/8, which suggests it is the eighth directive issued for the Learjet 45 series. The background references FAA AD 2005‑24‑13, which is also a single version (Amdt 39‑14393). The service bulletins listed are dated 29 September 2005 and 22 April 2005. The directive itself is dated 15 December 2005 and signed by Charles Lenarcic as Delegate of CASA. The directive does not include any notation of revision, change, or correction. It is possible that later CASA actions have amended or revoked this directive, but the source does not contain that information. The compliance timeline is fixed: 50 hours time in service after the effective date. There is no provision for an alternative compliance time or extension. The directive also does not contain any sunset or termination clause; it remains in force until superseded or rescinded by CASA. Given that this is an older directive (2005), it is likely still current for the aircraft types within the serial number ranges, unless a later directive or a continued airworthiness notification has superseded it. The absence of amendment history in the source means that any subsequent changes would need to be researched separately. For the purposes of this deep dive, the directive stands as issued. The lack of amendment history also suggests that the directive was not controversial or subject to correction, unlike some ADs that require multiple revisions to clarify compliance.

The source does not mention any litigation related to AD/LJ45/8. There is no known reported case law involving this specific directive. This is not surprising given the narrow scope and the typical nature of airworthiness directives: they are administrative safety actions that operators generally comply with rather than litigate. However, the directive could have been the subject of litigation if an operator challenged the validity of the directive, the scope of application, or the method of compliance. There is also potential for litigation arising from an accident if the directive was not complied with and that non‑compliance contributed to injury or damage. The directive references a fire incident that triggered the FAA AD, and that incident may have led to civil litigation in the United States, but that is not part of this directive. In Australia, the Administrative Appeals Tribunal (AAT) or the Federal Court could hear a challenge to a CASA airworthiness decision, but no such challenge is recorded in the source. The directive also could have been involved in enforcement proceedings where a court or tribunal considered the penalty for non‑compliance. Again, no such proceedings are mentioned. The lack of litigation history may indicate that operators complied without dispute, or that the directive was straightforward. The source does not provide any case citations. Given that the directive harmonises with an FAA AD, litigation in the US could have influenced the Australian directive indirectly, but that is speculative. For the purposes of this deep dive, the litigation history is effectively nil based on the source. A legal researcher would need to search databases like AustLII, Westlaw, or CASA’s infringement and enforceable undertakings register to find any contested matters. The directive also could have been tested in a coronial inquest if a fire occurred on a non‑compliant aircraft, but again, no mention. The bottom line is that there is no litigation history reported in or implied by the source material.

Several traps await an unwary operator. First, the serial number ranges for the three requirements are not identical. Requirement 1 applies to S/N 45‑005 through 45‑273 and 45‑2001 through 45‑2029. Requirement 3 (fuse replacement) applies to narrower ranges: 45‑2001 through 45‑2015 and 45‑005 through 45‑254. If an aeroplane falls in the overall range but outside the narrower fuse‑replacement ranges (e.g., S/N 45‑260), then only requirements 1 and 2 apply. An operator who assumes the same ranges for all requirements could waste time and money sourcing fuses not needed. Second, the compliance timing is not all at once. Requirement 1 must be done within 50 hours after 20 December 2005. Requirement 2 (corrective action) must be done before further flight after requirement 1 inspection; if the inspection reveals no clearance issues, no corrective action is needed. Requirement 3 must be concurrent with or prior to completing requirement 1. This means that for aeroplanes requiring fuse replacement, the operator cannot do the fuse replacement later; it must be done at the same time or before the modification and inspection. The word “concurrent” could cause confusion if the operator schedules the work in two phases. Third, the directive states that later revisions of the service bulletins are acceptable only if approved by the FAA as an AMOC to FAA AD 2005‑24‑13. This is a trap if Bombardier later issues revision B or C but the FAA has not specifically approved those revisions as an AMOC. An operator using an unapproved revision would be non‑compliant. The operator must check the FAA’s AMOC status for each revision. Fourth, the definition of “general visual inspection” is specific and may be narrower than what an operator expects. It does not require removal of components beyond access panels, but it does require stands or ladders if needed. An operator who tries to inspect from a distance or without proper access will not have performed the required inspection. Fifth, the directive does not provide an alternative compliance method for operators who prefer a different approach; they must either use the listed service bulletins (or FAA‑approved revisions) or apply to CASA for an AMOC. Relying solely on an FAA AMOC for a later revision is fine, but only if the FAA AMOC explicitly covers the revision. Sixth, the effective date is 20 December 2005, meaning the 50‑hour clock starts on that date. An aircraft that flew 40 hours between 20 December and 31 December must complete the work within 10 hours of the next flight. Operators with low‑utilisation aircraft could be caught if they do not track hours precisely. Seventh, the directive is signed by a CASA delegate; the signature block includes an image placeholder (likely a signature) that is not reproduced in the text, but the legal validity is clear. Eighth, the directive notes “2/2006 DM” on the header, which may be an administrative code but does not affect compliance. Finally, the directive does not address aircraft that are out of service for maintenance or storage. The 50‑hour clock still runs; if the aircraft is not flown, time in service does not increase, but the operator must still comply before further flight if the inspection/modification is not done. An aircraft that has zero hours time in service after the effective date still must comply before its next flight, but the 50‑hour limit would not apply until 50 hours are accumulated. The operator might think they have more time, but requirement 2 (corrective action before further flight) and the fuse requirement (concurrent with requirement 1) mean the aircraft cannot fly unmodified even if 50 hours have not elapsed.

Compliance requires a methodical, documented approach. The operator must first determine whether the aircraft’s serial number falls within the overall range (45‑005 to 45‑273 and 45‑2001 to 45‑2029). If not, the directive does not apply. If it does, the operator must obtain the applicable Bombardier Alert Service Bulletin for requirement 1: SB A40‑71‑01 for S/N 45‑2001 through 45‑2029, or SB A45‑71‑4 for S/N 45‑005 through 45‑273. These bulletins contain the “Accomplishment Instructions” that detail the modification of the electrical wire bundle for the alternator on the left‑hand engine. The operator should also obtain the latest revision of the bulletin and confirm with Bombardier or the FAA whether that revision has been approved as an AMOC to FAA AD 2005‑24‑13. Only if the FAA explicitly approves the revision as an AMOC can the later revision be used for compliance with the Australian directive. If in doubt, use the original dated versions (29 September 2005). Next, schedule the work within 50 hours time in service after 20 December 2005. The work must be performed by an appropriately authorised maintenance organisation or LAME. During the modification, the technician must also perform a general visual inspection of both left and right engines to verify that clearances between all wiring harnesses and engine tubing are proper, as defined by the service bulletin. The inspection must be documented. If any improper clearance is found, it must be corrected before further flight, using the same service bulletin’s instructions for corrective action. Corrective action may involve rerouting, adding clamps, or replacing components. For aeroplanes in the fuse‑replacement ranges (45‑2001 to 45‑2015 and 45‑005 to 45‑254), the operator must also replace the hydraulic shutoff valve fuses with higher‑amperage fuses per SB 40‑24‑01 or SB 45‑24‑6 (both dated 22 April 2005). Again, later revisions must be FAA‑approved AMOCs. This fuse replacement must be done concurrently with or prior to the requirement 1 modification and inspection. All work must be recorded in the aircraft’s maintenance records, including logbook entries referencing the airworthiness directive number, the service bulletins used and their revision status, the date of compliance, and total hours time in service at compliance. The maintenance release must be endorsed. The operator should retain copies of the service bulletins and the FAA AMOC approval if using later revisions. A final step is to verify that no other ADs or maintenance requirements conflict. The operator may choose to engage a CASA‑approved continuing airworthiness management organisation to oversee compliance. After compliance, the aircraft can continue to operate, but the operator must remain aware that the modifications may require periodic inspections or replacements as specified in the service bulletins (though not mentioned in the directive itself). Non‑compliance can be avoided by tracking hours and scheduling work promptly. If the operator finds it impossible to meet the 50‑hour deadline, they should apply to CASA for an extension or an AMOC before the deadline passes. Flying the aircraft after the deadline without compliance exposes the operator to enforcement action.