{"id":"F2006B11134","name":"AD/LEARJET/18 - Stall Warning System - Adjustment And Test","slug":"ad-learjet-18-stall-warning-system-adjustment-and-test","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56817,"registerId":"commonwealth-F2006B11134-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LEARJET/18 - Stall Warning System - Adjustment And Test","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 24 & 25 Series Aeroplanes\n\n \n\nAD/LEARJET/18 Stall Warning System - Adjustment And Test 7/79\n\nApplicability:  All models S/Nos. 24-329 to 24-357 and 25-206 to 25-278. When AAK 76-4 reduced approach speed system kit is installed, in models S/Nos. 24-100 to 24-328 and 25-003 to 25-201, 25-204 and 25-205.\n\n \n\nDocument: 1. Learjet SB No. 24/25-294; or\n\n \n\n2. FAA AD 79-12-05, Amendment 39-3614, para. B. Compliance: Within 300 hours time in service after 30 September 1979.\n\nBackground: Deleted S/Nos. 25-202 and 25-203 from the applicability in accordance with FAA AD 79-12-05 Amendment 39-3614.\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":3,"scope_assessment":{"changed":true,"description":"The AD narrows its applicability by explicitly deleting serial numbers 25-202 and 25-203 from the list of affected aircraft, as noted in the Background. This reduces the set of aircraft required to comply compared with the earlier FAA AD. (Background)"},"complexity_factors":["Technical subject-matter (aircraft stall warning system adjustment and test procedures). (Document)","Specific serial-number-based applicability, including conditional applicability when a particular kit (AAK 76-4) is installed. (Applicability)","Linkage to external technical documents (Learjet service bulletin or FAA AD) that specify the detailed procedures. (Document)","A fixed compliance window tied to aircraft time in service rather than calendar time. (Compliance)","A small change in scope recorded (deletion of serial numbers), requiring attention to updated applicability lists. (Background)"],"plain_english_summary":"This AD mandates a one‑time adjustment and test of the stall warning system on specified Gates Learjet 24 and 25 serial-number ranges, to be done per Learjet Service Bulletin No. 24/25‑294 or FAA AD 79‑12‑05 within 300 hours time‑in‑service after 30 September 1979. It affects the listed aircraft owners/operators, who must arrange qualified maintenance, bear the costs and schedule downtime to comply."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on stall warning system maintenance for a narrow range of aircraft. The 'Background' note indicates a minor technical correction (removing two serial numbers from applicability) consistent with the original safety purpose, not scope expansion."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability conditions (specific serial number ranges and conditional kit installation)","Single compliance action with alternative reference documents","No nested exceptions or conditional logic beyond basic 'and/or' applicability","No cross-references to other legislation beyond cited service bulletin and FAA AD","Straightforward deadline calculation (300 hours time in service from 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) that requires specific maintenance actions on certain aircraft.\n\n**What it does:** This directive orders owners and operators of specific **Gates Learjet 24 and 25 series aircraft** to adjust and test their **stall warning systems** — the equipment that alerts pilots when the plane is flying too slowly and at risk of stalling (losing lift).\n\n**Who it affects:**\n- **Specific aircraft serial numbers:** Learjet 24 models numbered 24-329 to 24-357, and Learjet 25 models numbered 25-206 to 25-278\n- **Plus older models** (serial numbers 24-100 to 24-328 and 25-003 to 25-205) **but only if** they have a specific modification kit installed (AAK 76-4 reduced approach speed system)\n\n**What must be done:** Operators must follow the procedures in either:\n- Learjet Service Bulletin No. 24/25-294, **or**\n- The equivalent US Federal Aviation Administration directive (FAA AD 79-12-05)\n\n**When:** Within 300 hours of flying time after 30 September 1979.\n\n**Why it matters:** Stall warning systems are critical safety equipment. This directive ensures these systems are properly calibrated to give pilots accurate warnings, preventing potential accidents during slow-speed flight phases like landing approaches."}},"importantCases":[],"_links":{"self":"/api/acts/ad-learjet-18-stall-warning-system-adjustment-and-test","history":"/api/acts/ad-learjet-18-stall-warning-system-adjustment-and-test/history","analysis":"/api/acts/ad-learjet-18-stall-warning-system-adjustment-and-test/analysis","conflicts":"/api/acts/ad-learjet-18-stall-warning-system-adjustment-and-test/conflicts","importantCases":"/api/acts/ad-learjet-18-stall-warning-system-adjustment-and-test/important-cases","documents":"/api/acts/ad-learjet-18-stall-warning-system-adjustment-and-test/documents"}}