{"id":"F2006B02184","name":"AD/AC-112/14 Amdt 1 - Vertical Stabiliser Forward Spar Attachment Structure","slug":"ad-ac-112-14-amdt-1-vertical-stabiliser-forward-spar-attachment-structure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41414,"registerId":"commonwealth-F2006B02184-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC-112/14 Amdt 1 - Vertical Stabiliser Forward Spar Attachment Structure","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)  \nGulfstream (Rockwell) 112 Series Aeroplanes\n\nAD/AC-112/14\n\nAmdt 1\n\n  \n\nVertical Stabiliser Forward Spar Attachment Structure\n\n  \n3/88\n\nApplicability: Models 112 and 112B, serial numbers 3 to 544 and 13000. Models 112TC and 112TCA, serial numbers 13001 to 13309.\n\nRequirement: 1. Inspect for cracks in the fuselage frame and the vertical fin attachment fitting as shown in Part I of Gulfstream Aerospace SB 112-72A.\n\nNote: This inspection requirement is unchanged from the previous issue of this Directive.\n\n2. Modify the vertical fin attachment in accordance with Part II of Gulfstream Aerospace SB 112-72A.\n\nNote: Simple AC 43.13 type repairs are not equivalent.\n\nCompliance: For Requirement Para 1: Within 10 hours’ time in service after 7 May 1987.\n\nFor Requirement Para 2: Before further flight if cracks are found. Otherwise not later than 24 March 1989.\n\nBackground: Numerous reports have now been received of cracking in the vertical stabiliser forward spar attachment structure. The manufacturer has analysed the load paths through this critical area and determined that substantial reinforcement is required to prevent further cracking.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is an amendment (Amdt 1) to an existing Airworthiness Directive. The note explicitly states the inspection requirement is unchanged from the previous issue. The scope remains tightly focused on the specific structural defect in the specified aircraft models — exactly as originally intended for aviation safety directives."},"complexity_factors":["Very short document (under 300 words)","Only 2 substantive requirements with clear sequential logic","Minimal defined terms (only standard aviation references like 'time in service')","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","Simple conditional compliance structure (if cracks found → immediate action; else → deadline)","Single technical reference to manufacturer Service Bulletin 112-72A"],"plain_english_summary":"This CASA Airworthiness Directive orders owners/operators of specific Gulfstream (Rockwell) 112-series aeroplanes (serials 3–544, 13000–13309) to inspect and reinforce the vertical stabiliser forward spar attachment. Inspections must occur within 10 flight hours after 7 May 1987; if cracks are found, modification is required before further flight, otherwise by 24 March 1989. Only the manufacturer’s specified modification is acceptable. Failure risks loss of the vertical stabiliser and catastrophic control failure."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment retains the original inspection requirement (noted as unchanged) but imposes a mandatory modification of the vertical fin attachment per Gulfstream SB 112-72A (Requirement Para 2). It adds concrete compliance deadlines (10 hours TIS for inspection; before further flight if cracks found; otherwise by 24 March 1989) and restricts allowable repair methods (AC 43.13 repairs not equivalent)."},"complexity_factors":["Narrow applicability: specific models and serial number ranges (Applicability).","Two-step directive: mandatory immediate inspection (Requirement Para 1) and a follow-up modification (Requirement Para 2).","Short initial compliance window: inspection required within 10 hours’ time in service after 7 May 1987 (Compliance Para 1).","Differing modification timing: if cracks found, modify before further flight; if none, modify by 24 March 1989 (Compliance Para 2).","Method constraint: simple AC 43.13 type repairs explicitly not equivalent (Requirement Para 2 Note) — limits repair options and may raise parts/labor complexity.","Manufacturer-prescribed procedure: modification must follow Gulfstream Aerospace SB 112-72A (Requirement Para 2 and Part references).","Regulatory basis and enforcement under Part 39 / CASA airworthiness directive framework (header and schedule)."],"plain_english_summary":"Requires operators of specified Gulfstream (Rockwell) 112-series aeroplanes (listed serial numbers) to inspect the fuselage frame and vertical fin attachment for cracks and to modify the vertical fin attachment structure per Gulfstream SB 112-72A. Operators must inspect within 10 hours’ time in service after 7 May 1987; if cracks are found they must modify before further flight, otherwise by 24 March 1989. The Civil Aviation Safety Authority enforces compliance; aircraft owners/operators bear inspection, repair and downtime costs."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-112-14-amdt-1-vertical-stabiliser-forward-spar-attachment-structure","history":"/api/acts/ad-ac-112-14-amdt-1-vertical-stabiliser-forward-spar-attachment-structure/history","analysis":"/api/acts/ad-ac-112-14-amdt-1-vertical-stabiliser-forward-spar-attachment-structure/analysis","conflicts":"/api/acts/ad-ac-112-14-amdt-1-vertical-stabiliser-forward-spar-attachment-structure/conflicts","importantCases":"/api/acts/ad-ac-112-14-amdt-1-vertical-stabiliser-forward-spar-attachment-structure/important-cases","documents":"/api/acts/ad-ac-112-14-amdt-1-vertical-stabiliser-forward-spar-attachment-structure/documents"}}