{"id":"F2006B10215","name":"AD/GAF-N22/66 Amdt 2 - Stub Fin Ribs","slug":"ad-gaf-n22-66-amdt-2-stub-fin-ribs","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55873,"registerId":"commonwealth-F2006B10215-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GAF-N22/66 Amdt 2 - Stub Fin Ribs","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)  \nGAF N22 and N24 Series Aeroplanes\n\nAD/GAF-N22/66\n\nAmdt 2\n\n  \nStub Fin Ribs 12/98\n\nApplicability: All Nomad N22 series and N24 series aircraft.\n\nRequirement: Action in accordance with ASTA Nomad Alert Service Bulletin ANMD-53-16 Revision 2.\n\nCompliance: Within 100 hours time in service after 5 November 1998 or before 10 February 1999, whichever occurs first; thereafter at intervals not to exceed 300 hours time in service or 12 calendar months, whichever occurs first.\n\nThis Amendment becomes effective on 5 November 1998.\n\nBackground: Cracks have been found in the stub fins of the Nomad tail section fatigue test article.\n\nFailure of the ribs would result in loss of structural stiffness in the stub fin, and possible loss of aircraft control. Amendment 1 increased the scope of the inspection to other areas of the stub fin structure.\n\nAmendment 2 is issued in response to revision 2 of the Requirement document which was prompted by a report from an operator of a crack at the forward end of the stub fin lower diaphragm. Tailplane resonance testing also indicated possible cracking of the stub fin front corner posts below the stub fin lower diaphragm.\n\nAmendment 1 of this Airworthiness Directive became effective on 14 September 1995.\n\nThe original issue of this Airworthiness Directive became effective on 16 September 1993.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"The original 1993 directive addressed cracks in stub fin ribs. Amendment 1 (1995) expanded inspections to 'other areas of the stub fin structure.' Amendment 2 (1998) further expanded the scope after new crack reports and testing revealed issues in the lower diaphragm and front corner posts — areas not originally covered. The directive has grown from a targeted rib inspection to a comprehensive stub fin structural integrity program."},"complexity_factors":["Single, specific technical requirement referencing an external manufacturer document (Service Bulletin ANMD-53-16 Rev 2)","Simple compliance timeline with clear 'whichever occurs first' logic (100 hours/3 months for initial; 300 hours/12 months for recurring)","No defined terms section — uses standard aviation terminology","No cross-references to other legislation or regulations beyond the enabling Civil Aviation Regulations 1998","Straightforward amendment history explaining evolution from 1993 original to 1998 Amendment 2","Narrow scope: applies only to two specific aircraft series (GAF N22 and N24)"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of GAF Nomad N22/N24 aircraft to inspect the tail \"stub fin\" for cracking and carry out remedial work per ASTA Nomad Alert Service Bulletin ANMD-53-16 Rev 2.  \n\nInspections must begin promptly and recur (short intervals), because fatigue cracks found in testing and service could cause stub-fin failure and loss of control—this AD tightens and expands earlier inspection requirements to prevent that hazard."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Scope has broadened from the original AD. The instrument's amendments expanded the inspection area beyond the initial stub fin ribs: Amendment 1 \"increased the scope of the inspection to other areas of the stub fin structure,\" and Amendment 2 followed Revision 2 of the requirement after an operator report of a crack at the forward end of the stub fin lower diaphragm and testing that indicated possible cracking of the stub fin front corner posts (text: \"Amendment 1 increased the scope...\"; \"Amendment 2... prompted by a report from an operator...\" and \"tailplane resonance testing also indicated possible cracking...\")."},"complexity_factors":["Relies on an external service document for technical steps (\"Requirement: Action in accordance with ASTA Nomad Alert Service Bulletin ANMD-53-16 Revision 2\").","Multiple compliance triggers and deadlines (initial within 100 hours TIS after 5 Nov 1998 or before 10 Feb 1999, then repeating every 300 hours TIS or 12 months) (\"Compliance: Within 100 hours...; thereafter at intervals not to exceed 300 hours... or 12 calendar months\").","Applies fleet‑wide to all Nomad N22 and N24 series aircraft (\"Applicability: All Nomad N22 series and N24 series aircraft\").","Safety‑critical consequences increase operational priority and enforcement risk (background: \"Cracks have been found... Failure of the ribs would result in loss of structural stiffness... and possible loss of aircraft control\").","Amendments expanded inspected areas, requiring operators to adjust inspection scope and possibly their maintenance procedures (\"Amendment 1 increased the scope... Amendment 2... prompted by a report... and tailplane resonance testing\")."],"plain_english_summary":"This Airworthiness Directive requires inspections of stub fin ribs on all GAF Nomad N22 and N24 aircraft, performed in accordance with ASTA Nomad Alert Service Bulletin ANMD-53-16 Revision 2. Initial inspection must occur within 100 hours time in service after 5 November 1998 or before 10 February 1999 (whichever is first); thereafter inspections recur every 300 hours TIS or 12 months. The measure responds to discovered cracks in the tail stub fin; rib failure would reduce fin stiffness and could risk loss of aircraft control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gaf-n22-66-amdt-2-stub-fin-ribs","history":"/api/acts/ad-gaf-n22-66-amdt-2-stub-fin-ribs/history","analysis":"/api/acts/ad-gaf-n22-66-amdt-2-stub-fin-ribs/analysis","conflicts":"/api/acts/ad-gaf-n22-66-amdt-2-stub-fin-ribs/conflicts","importantCases":"/api/acts/ad-gaf-n22-66-amdt-2-stub-fin-ribs/important-cases","documents":"/api/acts/ad-gaf-n22-66-amdt-2-stub-fin-ribs/documents"}}