{"id":"F2006B11102","name":"AD/LEARJET 35/23 Amdt 2 - Flap System and Flap Sector Mounting Brackets","slug":"ad-learjet-35-23-amdt-2-flap-system-and-flap-sector-mounting-brackets","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56762,"registerId":"commonwealth-F2006B11102-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LEARJET 35/23 Amdt 2 - Flap System and Flap Sector Mounting Brackets","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nGates Learjet 35 and 36 Series Aeroplanes\n\nAD/LEARJET 35/23\n\nAmdt 2\n\n  \n\nFlap System and Flap Sector Mounting Brackets\n\n  \n1/87\n\nApplicability: All models Learjet with serial numbers listed in Requirement Document. Requirement: Modify in accordance with Gates Learjet SB AMK 86-4.\n\nCompliance: Unless already accomplished, within 100 hours time in service or at the next inspection for Maintenance Release issue after 31 January 1987 whichever is later.\n\nBackground: This Directive was initially issued due to cracking of the flap sector mounting brackets. A repetitive inspection was later included because of further cracking after inspection. This amendment now requires modification using steel sector mounting brackets and deletes the repetitive inspection.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment stays within the original scope of addressing flap sector mounting bracket failures. It simply updates the remedy from repetitive inspections to a permanent modification. The change is technical refinement, not scope expansion."},"complexity_factors":["Very short document (approximately 150 words)","Only 4 defined elements: Applicability, Requirement, Compliance, and Background","Single, clear mechanical modification with no conditional exceptions","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Straightforward timeline: fixed date (31 January 1987) with simple alternative (100 hours time in service)","No nested logic or exceptions to exceptions"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or modifications to aircraft.\n\n**What it does:**\nThis directive orders owners and operators of **Gates Learjet 35 and 36 series aircraft** to modify the flap system — specifically, the mounting brackets that hold the flap sector (a mechanical component that helps control the flaps, which are the hinged surfaces on the wings that help with takeoff and landing).\n\n**The problem:**\nThe original aluminium mounting brackets were cracking. This is dangerous because if these brackets fail, the flaps could malfunction, potentially causing loss of control during critical flight phases like landing.\n\n**The fix:**\nOwners must replace the aluminium brackets with stronger **steel brackets** following the manufacturer's Service Bulletin (SB AMK 86-4). This amendment removes the previous requirement for repetitive inspections because the steel modification permanently fixes the problem.\n\n**Who must comply:**\nAll Learjet 35 and 36 operators with serial numbers listed in the official requirement document, unless they've already made this modification.\n\n**When:**\nWithin 100 flight hours or by the next scheduled maintenance check after 31 January 1987, whichever comes later.\n\n**Why it matters:**\nThis prevents catastrophic structural failure. The amendment simplifies compliance by eliminating ongoing inspection requirements once the steel brackets are installed."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The AD's scope changed from requiring repetitive inspections of the flap sector mounting brackets to requiring a mandatory physical modification (replacement with steel sector mounting brackets). The amendment removes the earlier repetitive inspection requirement and replaces it with the modification mandated to be done per Gates Learjet SB AMK 86-4, with the same applicability to specified serial-numbered aircraft and the same compliance timing framework (Background; Requirement; Compliance)."},"complexity_factors":["Narrow applicability limited to serial numbers listed in an external Requirement Document (Applicability).","Technical implementation depends on a manufacturer service bulletin (Gates Learjet SB AMK 86-4) rather than being specified in full in the AD (Requirement).","Compliance timing uses an either/or rule (within 100 hours time in service or at next Maintenance Release inspection after a given date), which requires operators to check service history (Compliance).","Change in regulatory approach from repetitive inspections to mandatory modification requires coordination between operators and maintenance providers (Background).","Short document with limited procedural detail reduces regulatory complexity but increases dependence on external technical documents and maintenance competence."],"plain_english_summary":"This AD applies to certain Gates Learjet 35/36 aeroplanes (specified by serial number) and mandates a one-time modification: replace existing flap sector mounting brackets with steel brackets per Gates Learjet Service Bulletin AMK 86‑4, deleting the prior repetitive inspection requirement. Unless already done, the work must be completed within 100 hours TIS or at the next maintenance release after 31 Jan 1987. Affected owners/operators must fund and arrange the modification, trading recurring inspections for a single corrective upgrade to address bracket cracking."}},"importantCases":[],"_links":{"self":"/api/acts/ad-learjet-35-23-amdt-2-flap-system-and-flap-sector-mounting-brackets","history":"/api/acts/ad-learjet-35-23-amdt-2-flap-system-and-flap-sector-mounting-brackets/history","analysis":"/api/acts/ad-learjet-35-23-amdt-2-flap-system-and-flap-sector-mounting-brackets/analysis","conflicts":"/api/acts/ad-learjet-35-23-amdt-2-flap-system-and-flap-sector-mounting-brackets/conflicts","importantCases":"/api/acts/ad-learjet-35-23-amdt-2-flap-system-and-flap-sector-mounting-brackets/important-cases","documents":"/api/acts/ad-learjet-35-23-amdt-2-flap-system-and-flap-sector-mounting-brackets/documents"}}