{"id":"F2006B11162","name":"AD/LJ45/1 Amdt 1 - Nose Wheel Squat Switch Assembly Lubrication","slug":"ad-lj45-1-amdt-1-nose-wheel-squat-switch-assembly-lubrication","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56858,"registerId":"commonwealth-F2006B11162-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LJ45/1 Amdt 1 - Nose Wheel Squat Switch Assembly Lubrication","content":"![](image.001.png)\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/LJ45/1 and issues the following AD under subregulation 39.1 (1) of CASR 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\nLearjet 45 Series Aeroplanes\n\nAD/LJ45/1\n\nAmdt 1\n\n  \n\nNose Wheel Squat Switch Assembly Lubrication\n\n  \n11/2003\n\nApplicability: Model 45 series aeroplanes, serial numbers (S/N) 45-005 through 45-071 inclusive modified per Bombardier Service Bulletin (SB) 45-32-3 and S/N 45-072 through 45- 114 inclusive.\n\nRequirement: 1. Apply grease to the rotating disk assembly of the squat switch mechanism of the nose wheel in accordance with Bombardier Aerospace Service Information Letter SIL 32-016 dated 30 March 2000.\n\n2. Replace the camrod of the nose wheel landing gear squat switch in accordance with Bombardier SB 45-32-8 Revision 2 dated 14 March 2001. Replacement of the camrod in accordance with either the original issue or Revision 1 of SB 45- 32-8 accomplished prior to the effective date of this Directive is considered acceptable as compliance with this Requirement.\n\nNote: FAA AD 2003-17-08 Amdt 39-13283 refers\n\nCompliance: For Requirement 1 \\-\n\nIf initially accomplished in accordance with the original issue of this Directive, repeat the lubrication at intervals not to exceed 30 days until Requirement 2 is accomplished.\n\nIf not accomplished in accordance with the original issue of this Directive, within 30 days from the effective date of this amendment and thereafter at intervals not to exceed 30 days until Requirement 2 is accomplished.\n\nFor Requirement 2 \\- Within 300 hours time in service or 12 months after the effective date of this Amendment, whichever occurs first.\n\nThis Amendment becomes effective on 30 October 2003.\n\nBackground: The original issue of this Directive required repetitive application of grease to the rotating disk assembly of the nose landing gear squat switch mechanism to prevent moisture contamination and subsequent formation of ice.\n\nLearjet 45 Series Aeroplanes\n\nAD/LJ45/1 Amdt 1 (continued)\n\nFormation of ice could result in bending or damaging of the nose landing gear squat switch assembly, which could drive the nose wheel to an uncommanded angle against the force of the steering system. This condition, if not corrected, could result in the aeroplane departing from the runway at high speeds during landing.\n\nThis Amendment introduces a terminating action for the Requirement 1 repetitive inspections.\n\nThe original issue of this Airworthiness Directive became effective on 1 November 2001.\n\n![Signature of Jim Coyne Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nJim Coyne\n\nDelegate of the Civil Aviation Safety Authority 18 September 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 8 October 2003.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Yes. The amendment replaces the original AD’s sole reliance on repetitive lubrication by introducing a terminating corrective action: replacement of the nose-wheel squat-switch camrod per Bombardier SB 45-32-8 (Requirement 2), which, once done, ends the 30-day lubrication cycle (Requirement 1). It also specifies compliance time limits (300 hours or 12 months) and accepts earlier SB revisions as compliant (see Requirements and Compliance sections)."},"complexity_factors":["Cross-references to multiple manufacturer documents (Bombardier SIL 32-016 and SB 45-32-8 Rev 2) and FAA AD (noted) increase procedural dependency","Applicability limited to specific serial-number ranges and a prior modification per SB 45-32-3 adds scope specificity","Two-step compliance structure: repetitive interim lubrication (Requirement 1) plus a terminating modification (Requirement 2)","Timing rules combine calendar and flight-hour limits (30-day lubrication interval; 300 hours or 12 months for replacement)","Acceptance of earlier SB revisions as compliant creates conditional compliance paths","Regulatory action revokes and reissues the original AD under CASR subregulation 39.1(1), which affects legal status and effective dates"],"plain_english_summary":"This Airworthiness Directive applies to specified Learjet 45 aeroplanes and requires temporary repetitive greasing of the nose-wheel squat-switch rotating disk to prevent moisture/ice contamination, then a terminating replacement of the squat-switch camrod per Bombardier service instructions. The greasing must be repeated at set intervals until the camrod is replaced; the camrod replacement must occur within 300 flight hours or 12 months. It matters because the measure addresses a failure mode that can drive the nose wheel to an uncommanded angle during landing."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose — addressing the nose wheel squat switch icing issue in Learjet 45 aircraft. The amendment introduces a terminating action (the camrod replacement) to end the repetitive lubrication requirement, but this is a natural evolution of the same safety issue rather than scope creep. The applicability, affected aircraft, and core safety objective remain unchanged from the original 2001 directive."},"complexity_factors":["Multiple conditional compliance paths based on whether prior maintenance was performed under the original directive","Nested timing requirements: 30-day intervals for temporary measure vs 300 hours/12 months for permanent fix","Cross-references to external technical documents (Bombardier Service Bulletin 45-32-8 Revision 2, Service Information Letter SIL 32-016, and FAA AD 2003-17-08)","Specific serial number ranges and modification status create applicability boundaries","Grandfathering clause allowing prior work under earlier revisions to count as compliance"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires operators of certain Learjet 45s (serials 45-005 through 45-114, including aircraft modified per SB 45‑32‑3 and all from 45‑072 on) to regularly grease the nose-wheel squat‑switch and to replace its camrod with an improved design within 300 flight hours or 12 months. It prevents ice buildup that can damage the switch and cause uncommanded nose-wheel steering and runway excursions."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-lj45-1-amdt-1-nose-wheel-squat-switch-assembly-lubrication","history":"/api/acts/ad-lj45-1-amdt-1-nose-wheel-squat-switch-assembly-lubrication/history","analysis":"/api/acts/ad-lj45-1-amdt-1-nose-wheel-squat-switch-assembly-lubrication/analysis","conflicts":"/api/acts/ad-lj45-1-amdt-1-nose-wheel-squat-switch-assembly-lubrication/conflicts","importantCases":"/api/acts/ad-lj45-1-amdt-1-nose-wheel-squat-switch-assembly-lubrication/important-cases","documents":"/api/acts/ad-lj45-1-amdt-1-nose-wheel-squat-switch-assembly-lubrication/documents"}}