{"id":"F2006B10164","name":"AD/GAF-N22/18 - Upper Engine Cowl Left Hand Stay - Removal","slug":"ad-gaf-n22-18-upper-engine-cowl-left-hand-stay-removal","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55791,"registerId":"commonwealth-F2006B10164-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GAF-N22/18 - Upper Engine Cowl Left Hand Stay - Removal","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)  GAF N22 and N24 Series Aeroplanes\n\n \n\nAD/GAF-N22/18 Upper Engine Cowl Left Hand Stay - Removal 6/78\n\nApplicability: All models N22, N22B and N24 referenced in SB No. N22.71.4. Document:  GAF SB No. N22.71.4.\n\nCompliance: Within 100 hours time in service after 30 June 1978.\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\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"This document prescribes removal of the left-hand upper engine cowl stay for the listed GAF N22/N24 models and sets a compliance window. The text contains no indication that the applicability or required action has been altered from the directive as issued here (Applicability: All models N22, N22B and N24 referenced in SB No. N22.71.4; Compliance: Within 100 hours time in service after 30 June 1978)."},"complexity_factors":["Narrow and specific technical scope (single component on specific aircraft models).","Clear compliance deadline tied to flight hours after a calendar date (adds scheduling constraint).","Dependency on an external document (GAF SB No. N22.71.4) for procedural and technical detail.","Absence of technical procedure, cost, enforcement, or follow-up detail in the AD text itself.","Historical nature of the directive (dates from 1978) may complicate locating supporting materials or records."],"plain_english_summary":"- What this instrument does: The Civil Aviation Safety Authority directive orders removal of the \"Upper Engine Cowl Left Hand Stay\" on the specified GAF aeroplane models. The directive refers operators to GAF Service Bulletin No. N22.71.4 for details on the work to be done (Document: GAF SB No. N22.71.4).\n\n- Who it affects: Owners/operators and maintenance organisations responsible for all GAF N22, N22B and N24 series aeroplanes referenced in the service bulletin (Applicability: All models N22, N22B and N24 referenced in SB No. N22.71.4).\n\n- How it works, mechanically: The directive requires removal of a specific component (the left hand stay for the upper engine cowl). The exact removal procedure and any associated instructions are contained in the referenced service bulletin (Document: GAF SB No. N22.71.4). The AD gives a compliance window: the removal must be completed within 100 hours time in service after 30 June 1978 (Compliance: Within 100 hours time in service after 30 June 1978).\n\n- Official rationale and limits of the text: This document supplies the mandatory action, the aircraft models covered, the service bulletin reference, and the compliance deadline. The directive text provided does not include an explicit safety justification, risk assessment or cost estimate. Any stated purpose in associated materials (for example, in the referenced service bulletin or in contemporaneous explanatory documents) is not reproduced here; operators must consult the service bulletin and any supporting material for the manufacturer’s or regulator’s explanation.\n\n- Who pays, who decides, and what changes in behaviour: The directive is issued by the Civil Aviation Safety Authority and binds the operators/owners of the listed aeroplanes to carry out the removal (issuer: Civil Aviation Safety Authority; Applicability as above). The text does not allocate costs or compensation; therefore removal-related labour, parts handling and any associated downtime are obligations that fall to the aircraft owner/operator or their appointed maintenance organisation. Behaviourally, affected operators must schedule and complete the component removal within the specified time window and record compliance in accordance with normal maintenance and airworthiness record practices (Compliance: Within 100 hours time in service after 30 June 1978; Document: GAF SB No. N22.71.4).\n\n- Implementation and compliance considerations (based on what the text shows):\n  - The AD’s technical detail is minimal in this text and relies on the referenced service bulletin for procedure, which means compliance requires obtaining and following that bulletin (Document: GAF SB No. N22.71.4).\n  - The directive sets a retrospective-style compliance deadline tied to a calendar date (30 June 1978) plus a flight-hours window, which may affect how operators schedule work (Compliance: Within 100 hours time in service after 30 June 1978).\n  - The document does not specify inspection, follow-up actions, defect-reporting, approval-for-return-to-service steps, or who approves any deviations; those matters must be checked in the service bulletin or other regulatory guidance.\n\n- Trade-offs and practical effects suggested by the text: The text creates a single mandatory maintenance action for a narrowly defined set of aircraft. The benefits, costs and any operational trade-offs (for example, increased maintenance downtime or changes to cowling attachment arrangements) are not quantified here and must be inferred from the service bulletin and operator maintenance planning.\n\n(References: Applicability: All models N22, N22B and N24 referenced in SB No. N22.71.4; Document: GAF SB No. N22.71.4; Compliance: Within 100 hours time in service after 30 June 1978.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive from 1978 addressing a specific mechanical issue on specific aircraft models. It has not expanded beyond its original narrow technical scope."},"complexity_factors":["Extremely short document (single page directive)","No defined terms section — uses standard aviation terminology only","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","Simple conditional structure: applicability → requirement → deadline","Single compliance action with clear deadline","No exceptions, exemptions, or nested conditions"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:**\nOrders owners and operators of specific GAF aircraft models (N22, N22B, and N24 series) to remove the left-hand stay (a support bracket) from the upper engine cowl (the cover over the engine).\n\n**Who it affects:**\nAnyone who owns or operates GAF N22, N22B, or N24 aeroplanes.\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. If you don't comply, your aircraft is not considered airworthy and cannot legally fly. This particular directive references a manufacturer's Service Bulletin (SB No. N22.71.4) which presumably identified a safety issue with this engine cowl stay — possibly risk of failure, interference, or structural fatigue.\n\n**Compliance deadline:**\nThe work must be done within 100 hours of flight time after 30 June 1978.\n\n**Key terms explained:**\n- **Airworthiness Directive (AD):** A mandatory regulatory notice requiring specific maintenance or modifications to ensure aircraft safety.\n- **Service Bulletin (SB):** A technical notice from the manufacturer recommending or requiring specific actions.\n- **Time in service:** Actual flight hours accumulated by the aircraft, not just calendar time."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gaf-n22-18-upper-engine-cowl-left-hand-stay-removal","history":"/api/acts/ad-gaf-n22-18-upper-engine-cowl-left-hand-stay-removal/history","analysis":"/api/acts/ad-gaf-n22-18-upper-engine-cowl-left-hand-stay-removal/analysis","conflicts":"/api/acts/ad-gaf-n22-18-upper-engine-cowl-left-hand-stay-removal/conflicts","importantCases":"/api/acts/ad-gaf-n22-18-upper-engine-cowl-left-hand-stay-removal/important-cases","documents":"/api/acts/ad-gaf-n22-18-upper-engine-cowl-left-hand-stay-removal/documents"}}