{"id":"F2006B10034","name":"AD/G1159/31 Amdt 1 - Elevator Trim Tab Outboard Hinge Fittings - Inspection","slug":"ad-g1159-31-amdt-1-elevator-trim-tab-outboard-hinge-fittings-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55443,"registerId":"commonwealth-F2006B10034-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G1159/31 Amdt 1 - Elevator Trim Tab Outboard Hinge Fittings - Inspection","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)  \nGulfstream (Grumman) G1159 and G-IV Series Aeroplanes\n\nAD/G1159/31\n\nAmdt 1\n\n  \n\nElevator Trim Tab Outboard Hinge Fittings - Inspection\n\n  \n7/82\n\nApplicability: All model GII and GIIB aircraft.\n\nDocument: Grumman Customer Bulletin No. 325 Amendment 1. (FAA AD 82-11-02 Amdt. 39-\n\n4384 refers).\n\nCompliance: 1. Unless already accomplished, before further flight after 31 July 1982 \\- as detailed in the requirement document.\n\n2. Repeat inspection as detailed in the requirement document until repair or replacement as detailed in the Aircraft Service Change No. 315.\n\nBackground: Manufacturer reports trim tab hinge fitting cracks have occurred. Amendment 1 raised to cover increases in applicability and revisions to repeat inspection, repair or replacement requirements.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"The original directive (implied by 'Amendment 1') was narrower in scope. This amendment expanded applicability to cover more aircraft models and revised the ongoing inspection and repair requirements. However, the core purpose — inspecting hinge fittings for cracks — remained consistent. The expansion represents a typical safety evolution as more data became available about the defect."},"complexity_factors":["Very short document (under 200 words)","Only 4 defined elements: applicability, document reference, compliance deadline, and background","No nested conditional logic — simple 'unless already accomplished' exception","Single cross-reference to manufacturer bulletin and FAA AD","Clear, imperative language ('before further flight', 'repeat inspection')","No interpretive ambiguity — requirements are specific and actionable"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific Gulfstream business jets (GII and GIIB models) to inspect the **elevator trim tab outboard hinge fittings** — that's the hardware connecting small adjustable surfaces on the tail that help control the plane's pitch.\n\n**What it does:**\n- **Mandates inspection** of these hinge fittings for cracks\n- **Sets a deadline:** Must be done before flying after 31 July 1982\n- **Requires ongoing checks:** Repeat inspections until permanent repair or replacement is done\n\n**Who it affects:**\n- Owners and operators of Gulfstream GII and GIIB aircraft (these are older business jets, originally made by Grumman)\n- Maintenance organisations servicing these aircraft\n\n**Why it matters:**\nCracks in these hinge fittings could cause the trim tab to fail in flight. The trim tab helps pilots control the aircraft's nose position; if it fails, the plane becomes much harder to control. This directive was issued after the manufacturer reported actual cracks occurring in service — meaning this was a real safety risk, not theoretical.\n\nThis is **Amendment 1** — an updated version that expanded which aircraft are covered and changed the inspection/repair requirements based on new information."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The amendment expanded the set of affected aircraft (increased applicability) and revised the repeat inspection and repair/replacement requirements compared with the prior directive. This change is described in the Background and is implemented by the updated compliance instructions and references to Grumman Customer Bulletin No. 325 Amendment 1 and Aircraft Service Change No. 315 (Background; Document; Compliance 1–2)."},"complexity_factors":["Cross-reference to external technical documents (Grumman Customer Bulletin No. 325 Amendment 1 and Aircraft Service Change No. 315) required to know exact inspection and repair steps (Document).","Temporal compliance trigger (must be done before further flight after 31 July 1982) introduces operational scheduling constraints (Compliance 1).","Requirement for repeat inspections until repair/replacement creates ongoing compliance obligations and potential recurring costs (Compliance 2).","Technical nature of required work (inspection for cracks, repair or replacement of hinge fittings) requires specialist maintenance capability and parts (Background; Compliance 2).","Amendment broadens applicability and revises requirements relative to the prior directive, increasing the set of affected operators and procedural complexity (Background)."],"plain_english_summary":"This directive requires operators of Gulfstream (Grumman) GII and GIIB aircraft to inspect elevator trim tab outboard hinge fittings—initially before the next flight after 31 July 1982 if not already done—and to carry out repeat inspections until the fittings are repaired or replaced per the referenced service change, issued after reports of cracked fittings.\n\nOperators and maintenance providers bear inspection and repair costs and must obtain the manufacturer service documents to comply."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g1159-31-amdt-1-elevator-trim-tab-outboard-hinge-fittings-inspection","history":"/api/acts/ad-g1159-31-amdt-1-elevator-trim-tab-outboard-hinge-fittings-inspection/history","analysis":"/api/acts/ad-g1159-31-amdt-1-elevator-trim-tab-outboard-hinge-fittings-inspection/analysis","conflicts":"/api/acts/ad-g1159-31-amdt-1-elevator-trim-tab-outboard-hinge-fittings-inspection/conflicts","importantCases":"/api/acts/ad-g1159-31-amdt-1-elevator-trim-tab-outboard-hinge-fittings-inspection/important-cases","documents":"/api/acts/ad-g1159-31-amdt-1-elevator-trim-tab-outboard-hinge-fittings-inspection/documents"}}