{"id":"F2006B10328","name":"AD/GULL/1 Amdt 1 - Wing Rib to Aileron Spar Joint - Inspection","slug":"ad-gull-1-amdt-1-wing-rib-to-aileron-spar-joint-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56084,"registerId":"commonwealth-F2006B10328-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GULL/1 Amdt 1 - Wing Rib to Aileron Spar Joint - Inspection","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)  Percival Vega Gull Series Aeroplanes\n\n \n\nAD/GULL/1\n\nAmdt 1\n\n\nWing Rib to Aileron Spar Joint - Inspection 11/67\n\n \n\nApplicability: All models not modified in accordance with Percival Mod. No. 130. Requirement:  1. Inspect the points of attachment of the outer wing ribs to the aileron false spar.\n\n2. If the area shows signs of faulty gluing or failure of joints, strengthen the rib to spar attachment in accordance with Percival Modification No. 130, or\n\n \n\n3. ANO 105.1.26.0.2.1.\n\n \n\nCompliance: At intervals not exceeding 12 months or 100 hours time in service whichever occurs first.\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":3,"scope_assessment":{"changed":true,"description":"The instrument is labelled as an amendment (\"Amdt 1\"), which indicates it modifies a prior AD. The supplied text does not include the original AD text or a change log, so the specific scope changes from the original instrument cannot be determined from this document alone."},"complexity_factors":["Limited applicability: only aircraft not already modified under Percival Mod. No.130 (Applicability).","Recurring compliance interval that uses a dual trigger (12 months or 100 hours TIS) (Compliance).","Corrective action requires following external technical documents (Percival Mod. No.130 or ANO 105.1.26.0.2.1), adding dependency on additional material (Requirement 2–3).","Directive states inspection and corrective outcome but does not include detailed inspection technique or acceptance criteria, requiring technical interpretation by maintenance providers (Requirement 1).","Binary corrective options create an operator choice that affects logistics and cost (Requirement 2–3)."],"plain_english_summary":"This AD requires owners/operators of Percival Vega Gull aeroplanes not modified by Percival Mod. No.130 to inspect the attachment points where outer wing ribs join the aileron false spar at intervals no greater than 12 months or 100 hours TIS.  \n\nIf faulty gluing or joint failure is found, the attachment must be strengthened by either Percival Mod. No.130 or the ANO 105.1.26.0.2.1 procedure; operators bear inspection and repair costs."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a narrow, targeted safety directive focused on a specific structural inspection for a single aircraft type (Percival Vega Gull). It has not expanded beyond its original purpose of ensuring airworthiness of this particular joint in these vintage aircraft."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 1 defined term implicitly referenced (Percival Modification No. 130)","Simple conditional structure: inspect → if problem found → repair","Single cross-reference to external document (ANO 105.1.26.0.2.1)","Clear, unambiguous compliance deadline (12 months/100 hours)","No nested exceptions or complex definitional sections"],"plain_english_summary":"This is an **Airworthiness Directive** (AD) — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nThis directive requires owners and operators of **Percival Vega Gull series aeroplanes** to regularly inspect a specific structural joint where the outer wing ribs connect to the aileron false spar (a structural component near the wing's control surfaces).\n\n**Who it affects:**\n- Owners and operators of all Percival Vega Gull aircraft that have **not** been modified according to \"Percival Modification No. 130\"\n- Maintenance engineers responsible for keeping these vintage aircraft airworthy\n\n**What must be done:**\n1. **Inspect** the wing rib to aileron spar attachment points\n2. **If problems found:** Either strengthen the joint using Percival Modification No. 130, or follow alternative instructions in Air Navigation Order 105.1.26.0.2.1 (an older aviation regulation reference)\n\n**How often:**\nEvery **12 months** or every **100 hours of flight time** — whichever comes first.\n\n**Why it matters:**\nThis addresses a known structural weakness that could lead to wing failure if left unchecked. The \"faulty gluing\" reference suggests these vintage wooden or fabric aircraft may suffer from adhesive degradation over time — a serious safety risk in flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gull-1-amdt-1-wing-rib-to-aileron-spar-joint-inspection","history":"/api/acts/ad-gull-1-amdt-1-wing-rib-to-aileron-spar-joint-inspection/history","analysis":"/api/acts/ad-gull-1-amdt-1-wing-rib-to-aileron-spar-joint-inspection/analysis","conflicts":"/api/acts/ad-gull-1-amdt-1-wing-rib-to-aileron-spar-joint-inspection/conflicts","importantCases":"/api/acts/ad-gull-1-amdt-1-wing-rib-to-aileron-spar-joint-inspection/important-cases","documents":"/api/acts/ad-gull-1-amdt-1-wing-rib-to-aileron-spar-joint-inspection/documents"}}