{"id":"F2006B10764","name":"AD/HUSKY/1 - Seat Back","slug":"ad-husky-1-seat-back","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56213,"registerId":"commonwealth-F2006B10764-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HUSKY/1 - Seat Back","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)  Christen Industries A-1 (Husky) Series Aeroplanes\n\n \n\nAD/HUSKY/1 Seat Back 4/91\n\nApplicability: Model A-1 with serial numbers 1001 through 1125.\n\n \n\nRequirement: Action in accordance the technical requirements of FAA AD 90-20-05 Amdt 39-6741.\n\n \n\nNote: Christen SB 2 refers.\n\n \n\nCompliance: As specified in the Requirement Document with revised effective date of 18 April 1991; unless already accomplished.\n\n \n\nBackground:  A recent fatigue failure of the front seat resulted in the pilot falling backwards against the rear seat flight controls with subsequent loss of control of the aircraft. The actions in this AD will prevent failure of the front seat back assembly.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical failure mode in a specific aircraft model range. It has not expanded beyond its original purpose of preventing seat back fatigue failures."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 1 defined applicability criterion (serial number range)","Single requirement referencing external technical document rather than detailing steps internally","No nested conditional logic or exceptions","No cross-references to other Australian legislation or regulations beyond the enabling Civil Aviation Regulations 1998","Straightforward compliance date with single alternative (already accomplished)"],"plain_english_summary":"This is an **Airworthiness Directive** (AD) — essentially a mandatory safety fix ordered by Australia's aviation safety regulator for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain **Christen Industries A-1 (Husky) aeroplanes** (specifically serial numbers 1001 through 1125) to carry out a safety modification to the **front seat back assembly**.\n\n**Why it matters:**\nA pilot's seat back broke due to **metal fatigue** (wear and tear from repeated stress), causing the pilot to fall backward onto the rear seat controls. This led to **loss of control of the aircraft**. This directive prevents that dangerous failure from happening again.\n\n**What must be done:**\n- Follow the technical instructions in **FAA AD 90-20-05** (an American aviation safety order — Australia is adopting the same fix)\n- Reference **Christen Service Bulletin 2** for guidance\n- Complete the work by **18 April 1991** (unless already done)\n\n**Who it affects:**\nAnyone who owns, operates, or maintains the affected Husky aircraft models in Australia."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD’s operative scope is the set of Model A-1 (Husky) aeroplanes with serial numbers 1001–1125 and the mandated technical actions in the referenced FAA AD/Christen SB 2 (Applicability; Requirement; Note). The document notes a revised effective date (Compliance) but does not alter the set of aircraft or the technical scope; therefore the substantive scope has not been changed in this text."},"complexity_factors":["Narrow, specific applicability limited to Model A-1 serial numbers 1001–1125 (Applicability) — reduces scope complexity.","Technical requirements are not reproduced in the AD text but are fully delegated to an external FAA AD (Requirement) — adds a dependency on another document.","Reference to Christen Service Bulletin 2 for related instructions (Note) — requires cross-referencing multiple technical sources.","Compliance timing is governed by the referenced Requirement Document with a revised effective date (Compliance) — introduces a scheduling dependency.","Regulatory enforcement follows standard Airworthiness Directive practice under Civil Aviation Regulations (header), but this AD does not specify enforcement mechanics or penalties within its text."],"plain_english_summary":"What this rule does\n\n- This is an Airworthiness Directive (AD) for Christen Industries A-1 (Husky) aeroplanes. It applies only to Model A-1 aircraft with serial numbers 1001 through 1125 (Applicability).\n- It requires owners/operators to carry out the technical actions set out in FAA AD 90-20-05 Amdt 39-6741 (Requirement). The AD also refers to Christen Service Bulletin (SB) 2 for related work (Note).\n- The compliance timing is as specified in the Requirement Document and the AD’s revised effective date is 18 April 1991 (Compliance).\n\nWho is affected and who decides\n\n- Affected parties: owners and operators of Christen A-1 (Husky) aircraft with serial numbers 1001–1125 (Applicability).\n- Decision-maker and issuer: the Civil Aviation Safety Authority, under the Civil Aviation Regulations framework that publishes Airworthiness Directives (header and schedule).\n\nWhy it matters (stated purpose and mechanical effect)\n\n- The AD responds to a documented safety failure: a fatigue failure of a front seat that allowed a pilot to fall backwards into rear-seat flight controls, causing subsequent loss of control. The AD’s stated purpose is to prevent failure of the front seat back assembly (Background).\n- Mechanically, the AD compels operators to inspect, modify or repair the front seat back assembly in accordance with the referenced FAA AD and related service bulletin (Requirement; Note). Compliance means the aircraft must be brought into the condition specified by those technical documents (Compliance).\n\nWho pays, incentives and direct trade-offs\n\n- Costs and payment: the aircraft owners/operators must arrange and pay for the inspections/modifications/repairs required by the FAA AD and Christen SB 2 (Applicability; Requirement; Note). The text does not state cost amounts; it does make those actions mandatory for the affected serial-numbered aircraft (Requirement; Compliance).\n- Operational impact: affected aircraft will need to be taken out of service while the required work is performed, and operators face the opportunity cost of downtime and any parts/labour expenses (Requirement; Compliance). The AD does not set price controls or replacements; it specifies required technical action only.\n\nEffects on maintenance providers and private choice\n\n- Maintenance providers: independent repair stations and certificated mechanics can perform the work if they comply with the technical requirements in the FAA AD and service bulletin; this creates demand for their services among owners of the affected aircraft (Requirement; Note).\n- Choice and ownership: owners of the listed aircraft can choose how to comply (e.g., approved repair station, authorised service centre) but must complete the mandated actions by the dates in the Requirement Document (Requirement; Compliance).\n\nImplementation risk and enforcement\n\n- Implementation requires following an external technical document (FAA AD 90-20-05) and a service bulletin (Christen SB 2); operators must obtain and apply those instructions correctly to satisfy the AD (Requirement; Note). The AD text does not itself detail the technical steps, so compliance requires consulting the referenced documents (Requirement; Note).\n- Enforcement: as an Airworthiness Directive published under the Civil Aviation Regulations, compliance is mandatory for the listed aircraft; non-compliance risks regulatory action or grounding, although this AD text does not list specific penalties (header; Compliance).\n\nSummary statement\n\nThis AD mandates that owners/operators of Christen A-1 (Husky) aircraft serial numbers 1001–1125 implement the inspection/repair/modification measures set out in FAA AD 90-20-05 and Christen SB 2 to prevent fatigue failure of the front seat back assembly. The operator bears the cost and responsibility for arranging compliant maintenance and managing any aircraft downtime. (Applicability; Requirement; Note; Compliance; Background.)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-husky-1-seat-back","history":"/api/acts/ad-husky-1-seat-back/history","analysis":"/api/acts/ad-husky-1-seat-back/analysis","conflicts":"/api/acts/ad-husky-1-seat-back/conflicts","importantCases":"/api/acts/ad-husky-1-seat-back/important-cases","documents":"/api/acts/ad-husky-1-seat-back/documents"}}