{"id":"F2006B02179","name":"AD/AC-112/1 - Aileron Hinge Doublers - Inspection and Modification","slug":"ad-ac-112-1-aileron-hinge-doublers-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41409,"registerId":"commonwealth-F2006B02179-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC-112/1 - Aileron Hinge Doublers - Inspection and Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-description: CASA Airworthiness Directive\nmeta-generator: Aspose.Words for .NET 22.10.0\nmeta-keywords: Issue 11/1975,Aircraft below 5700 kg,Gulfstream (Rockwell) 112 Series Aeroplanes,Aileron Hinge Doublers - Inspection and Modification,1\ntitle: Airworthiness Directive - AD/AC-112/1 - Aileron Hinge Doublers - Inspection and Modification\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)  Gulfstream (Rockwell) 112 Series Aeroplanes\n\n \n\nAD/AC-112/1 Aileron Hinge Doublers - Inspection\n\nand Modification\n\nApplicability: All model 112 with S/Nos. 3 to 380. Document:  Rockwell International SB No. SB-112-35.\n\nCompliance: Within 100 hours time in service after 28 November 1975.\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\n11/75\n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive from 1975 addressing a specific technical defect in a specific aircraft model. It has not expanded beyond its original purpose of mandating inspection and modification of aileron hinge doublers."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 4 defined elements: applicability, reference document, compliance deadline, and technical subject","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","Single unconditional requirement with clear deadline","No exceptions, exemptions, or conditional logic","Technical content refers to external service bulletin rather than reproducing complex procedures"],"plain_english_summary":"This is an **Airworthiness Directive** (AD) issued by Australia's Civil Aviation Safety Authority (CASA). It is a mandatory safety order for owners and operators of specific Gulfstream (Rockwell) 112 series aeroplanes.\n\n**What it does:**\n- Requires inspection and modification of **aileron hinge doublers** (reinforcement plates where the aileron control surface attaches to the wing)\n- Applies to all Model 112 aircraft with serial numbers 3 through 380\n\n**Who must comply:**\n- Owners and operators of affected Gulfstream (Rockwell) 112 series aircraft\n- Must follow the technical instructions in Rockwell International Service Bulletin SB-112-35\n\n**When it must be done:**\n- Within 100 hours of flight time after 28 November 1975\n\n**Why it matters:**\nAirworthiness Directives are legally enforceable safety mandates. Non-compliance means the aircraft cannot legally fly in Australian airspace. This particular AD addresses potential structural issues with aileron hinge attachments that could affect flight safety if left unaddressed."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text of the directive does not indicate any change to scope from an earlier instrument; it applies to all model 112 aeroplanes with serial numbers 3 to 380 and mandates inspection and modification per Rockwell SB-112-35 within the stated 100-hour window (Applicability and Compliance sections). There is no entry in the provided text showing expansion or narrowing of that applicability."},"complexity_factors":["Narrow, specific applicability (model 112, S/N 3–380) which simplifies identification of affected aircraft.","Single mandated action type (inspect and modify aileron hinge doublers) rather than multiple, interlocking obligations.","Fixed, short compliance window (100 hours time in service after a specified date) that creates urgency but reduces long-term regulatory complexity.","Dependence on an external technical document (Rockwell SB-112-35) for procedural details, requiring access to and understanding of the Service Bulletin.","Potential operational complexity for operators: sourcing parts, qualified maintenance, and scheduling downtime even though the directive text itself is short."],"plain_english_summary":"What this directive does, mechanically\n\n- It requires operators of Gulfstream (Rockwell) model 112 aeroplanes, serial numbers 3 through 380, to inspect and modify the aileron hinge doublers in accordance with the manufacturer’s Service Bulletin Rockwell International SB-112-35. (Applicability: \"All model 112 with S/Nos. 3 to 380.\" Document: \"Rockwell International SB No. SB-112-35.\")\n\n- The inspection and any mandated modification must be completed within 100 hours time in service after 28 November 1975. (Compliance: \"Within 100 hours time in service after 28 November 1975.\")\n\nWho this affects and who pays\n\n- Aircraft operators and owners of the affected model 112 aeroplanes are required to arrange and pay for the inspection and any modification work called for by the Service Bulletin. The maintenance organisation or individual performing the work bears the labour and parts cost and must record completion.\n\nWho decides and how it is implemented\n\n- The Civil Aviation Safety Authority (CASA) has issued the directive, and the detailed technical steps are set out in the referenced Rockwell Service Bulletin SB-112-35. Operators must follow that bulletin’s procedures to satisfy the directive. (Document: \"Rockwell International SB No. SB-112-35.\")\n\nWhy the directive is issued (as stated or implied)\n\n- The directive requires inspection and modification of the aileron hinge doublers. The text of the directive itself does not set out the technical justification in detail; the associated Service Bulletin is the source of the recommended inspection/modification procedure. The directive’s observable aim is to make the inspection/modification mandatory for the listed serial-numbered aircraft within the stated compliance period. (See Applicability and Compliance sections.)\n\nPractical effects, costs, incentives and trade-offs\n\n- Direct cost: Operators must allocate maintenance labour time, pay for any replacement parts or repair materials, and accept aircraft downtime while work is done. (Compliance requirement and reference to SB-112-35.)\n\n- Incentives: Compliance avoids regulatory non‑conformity and any enforcement action; it also aligns the aircraft with the manufacturer’s recommended corrective action. Maintenance providers gain work from carrying out the inspections/modifications.\n\n- Trade-offs and opportunity cost: Time spent on the mandated inspection/modification is time the aircraft cannot be used for revenue or other operations until the work is completed.\n\n- Implementation risk and compliance burden: The directive depends on access to the referenced Service Bulletin for technical steps. If parts, tooling or suitably qualified maintenance personnel are scarce, operators may experience delays or higher costs. The directive itself prescribes the requirement and deadline; the Service Bulletin prescribes the technical method. (Document: SB-112-35; Compliance: \"Within 100 hours...\")\n\n- Bureaucratic discretion: The AD sets the applicability and the compliance timeframe; the detailed repair method is delegated to the manufacturer’s Service Bulletin. The AD does not, in its text, provide alternative compliance pathways, conditions for extension, or exemptions.\n\nNotes on concentration of effects\n\n- The obligation applies only to aircraft of a specific model and serial-number range (3–380). This makes the compliance costs concentrated on owners/operators of those specific airframes, while the administrative cost of issuing the directive is borne by the regulator.\n\nSource references\n\n- Applicability: \"All model 112 with S/Nos. 3 to 380.\" Document: \"Rockwell International SB No. SB-112-35.\"; Compliance: \"Within 100 hours time in service after 28 November 1975.\""}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-112-1-aileron-hinge-doublers-inspection-and-modification","history":"/api/acts/ad-ac-112-1-aileron-hinge-doublers-inspection-and-modification/history","analysis":"/api/acts/ad-ac-112-1-aileron-hinge-doublers-inspection-and-modification/analysis","conflicts":"/api/acts/ad-ac-112-1-aileron-hinge-doublers-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-ac-112-1-aileron-hinge-doublers-inspection-and-modification/important-cases","documents":"/api/acts/ad-ac-112-1-aileron-hinge-doublers-inspection-and-modification/documents"}}