{"id":"F2006B11119","name":"AD/LEARJET 35/4 - Upper Wing Skin Fasteners - Inspection","slug":"ad-learjet-35-4-upper-wing-skin-fasteners-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56788,"registerId":"commonwealth-F2006B11119-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LEARJET 35/4 - Upper Wing Skin Fasteners - Inspection","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Gates Learjet 35 and 36 Series Aeroplanes\n\n \n\nAD/LEARJET 35/4 Upper Wing Skin Fasteners - Inspection 10/76\n\nApplicability: All model 35 with S/Nos. 35-001 to 35-054 and model 36 with S/Nos. 36-001 to 36-\n\n017.\n\n \n\nDocument: Gates Learjet SB 35/36-57-1A.\n\n \n\nCompliance: Within 150 hours time in service after 29 October 1976 unless modified in accordance with SB 35/36-57-1.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive applies to a narrowly defined set of serial-numbered Learjet 35/36 aeroplanes and requires inspection or modification within a stated service-time window. The text shows no alteration of that scope from an earlier or broader remit; it limits action to the listed aircraft and to compliance per the named service bulletin (Applicability; Document; Compliance)."},"complexity_factors":["Narrow and specific applicability by model and serial-number ranges (Applicability).","Single, short compliance requirement (150 hours after a fixed date) with a clear alternative (modify per SB) (Compliance).","Dependence on an external technical document (service bulletin) for the technical standard and modification method (Document).","Limited regulatory discretion or multiple compliance pathways in the text—no complex approval process described (Compliance; Document).","Temporal specificity tied to a historic date reduces ongoing administrative complexity but creates urgency for affected operators (Compliance)."],"plain_english_summary":"This AD requires owners/operators of specific Gates Learjet Model 35 (SN 35‑001–35‑054) and Model 36 (SN 36‑001–36‑017) to inspect upper wing skin fasteners or perform the Gates Learjet SB 35/36‑57‑1A modification that removes the inspection requirement. Actions must occur within 150 flight hours after 29 Oct 1976 unless already modified. It shifts inspection/modification costs, downtime and parts/labor responsibility to the operators while addressing an airworthiness safety concern."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on wing skin fastener inspections for early production Learjet 35/36 aircraft. It has not expanded beyond its original narrow safety purpose."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined applicability criteria (serial number ranges)","Single compliance requirement with one exception","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","No nested conditions or exceptions to exceptions","Straightforward temporal trigger (150 hours time in service after fixed date)"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:** It requires owners and operators of certain Gates Learjet 35 and 36 series aircraft to inspect the upper wing skin fasteners (the bolts/screws holding the top surface of the wing together). This inspection must happen within 150 hours of flying time after 29 October 1976.\n\n**Who it affects:** Only specific serial numbers:\n- **Learjet Model 35:** Serial numbers 35-001 through 35-054\n- **Learjet Model 36:** Serial numbers 36-001 through 36-017\n\n**The alternative:** If the aircraft has already been modified according to Service Bulletin SB 35/36-57-1, no inspection is needed.\n\n**Why it matters:** Wing skin fasteners are critical structural components. If they fail, the wing could lose integrity with catastrophic consequences. This AD ensures potential defects are caught before they cause accidents.\n\n**Key document reference:** Operators must follow Gates Learjet Service Bulletin 35/36-57-1A for the correct inspection procedure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-learjet-35-4-upper-wing-skin-fasteners-inspection","history":"/api/acts/ad-learjet-35-4-upper-wing-skin-fasteners-inspection/history","analysis":"/api/acts/ad-learjet-35-4-upper-wing-skin-fasteners-inspection/analysis","conflicts":"/api/acts/ad-learjet-35-4-upper-wing-skin-fasteners-inspection/conflicts","importantCases":"/api/acts/ad-learjet-35-4-upper-wing-skin-fasteners-inspection/important-cases","documents":"/api/acts/ad-learjet-35-4-upper-wing-skin-fasteners-inspection/documents"}}