{"id":"F2006B10354","name":"AD/HILLER 12/27 Amdt 2 - Outer Gimbal Forward Attach Fitting - Inspection","slug":"ad-hiller-12-27-amdt-2-outer-gimbal-forward-attach-fitting-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115963,"registerId":"commonwealth-F2006B10354-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HILLER 12/27 Amdt 2 - Outer Gimbal Forward Attach Fitting - 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)  \nHiller UH-12 Series Helicopters\n\nAD/HILLER 12/27\n\nAmdt 2\n\n  \n\nOuter Gimbal Forward Attach Fitting \\- Inspection\n\n  \n12/84\n\nTX\n\nApplicability: All models UH-12D and UH-12E series which have been converted to turbine power by STC SH177WE or SH 178WE.\n\nRequirement: 1. Remove the paint from the outer gimbal forward attach fitting of the Hiller Engine Mount P/No. 63181-5.\n\n2. Using a dye penetrant or a magnetic particle inspection technique, inspect the gusset weld beads for cracks on both the front and rear sides of the gusset.\n\nNote: FAA AD B4-19-08 refers.\n\nCompliance: 1. Within 20 hours’ time in service after 06 November 1984 and thereafter at intervals not exceeding 600 hours’ time in service.\n\n2. Upon installation or reinstallation of engine mount assy P/N 63181-5.\n\nBackground: A recent overseas accident resulted from fatigue failure of the outer gimbal forward attach fitting. This directive has been amended to include repetitive inspections of the attach fitting.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amended to add repetitive inspections of the outer gimbal forward attach fitting. The directive applies specifically to UH-12D/E series with turbine conversion STCs SH177WE/SH178WE and sets an initial inspection deadline (within 20 hours after 6 Nov 1984), recurring 600‑hour intervals, and inspection upon installation/reinstallation of engine mount P/N 63181‑5."},"complexity_factors":["Narrow applicability: limited to UH-12D/E helicopters converted by STC SH177WE or SH178WE (clear but specific population).","Technical inspection methods required (dye‑penetrant or magnetic‑particle NDT).","Operational compliance timing: initial 20 hours after a fixed date, then recurring 600‑hour intervals (requires tracking/logging of hours).","Preparatory step: mandatory paint removal before inspection (adds labour/time).","Inspection required on installation/reinstallation of the engine mount assembly (adds event-driven compliance).","Potential follow-on work if cracks are found (repair cost and aircraft downtime).","Cross‑reference to FAA AD B4‑19‑08 (external regulatory linkage)."],"plain_english_summary":"Requires operators of *UH-12D* and *UH-12E* helicopters converted to turbine power under STCs SH177WE/SH178WE to remove paint and perform dye‑penetrant or magnetic‑particle inspection of the engine mount outer gimbal forward attach fitting (P/N 63181‑5), inspecting the gusset weld beads front and rear. \n\nCompliance: initial inspection within 20 hours’ time-in-service after 6 Nov 1984, then every 600 hours, and each time the mount is installed or reinstalled. The direct costs and operational burden fall on aircraft operators, who must arrange nondestructive testing and any resulting repairs."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 2 to an existing Airworthiness Directive. The amendment history note indicates it was expanded from a one-time inspection to include repetitive inspections, but this represents a refinement of the original safety purpose rather than scope creep. The directive remains tightly focused on the specific fatigue failure risk identified in the background."},"complexity_factors":["Single, specific technical requirement with clear procedural steps","Limited applicability (only two specific helicopter models with specific engine conversions)","Only 2 defined compliance triggers (time-in-service intervals and installation events)","No nested exceptions or conditional logic","Short document (approximately 200 words)","Single cross-reference to FAA AD B4-19-08 (informational only)","Straightforward temporal compliance structure (initial + recurring intervals)"],"plain_english_summary":"This CASA Airworthiness Directive mandates regular inspection of the outer gimbal forward attach fitting on Hiller UH‑12D/E helicopters that have been modified with the STC turbine conversions (SH177WE/SH178WE). Owners/operators must strip paint and inspect the weld beads using dye‑penetrant or magnetic‑particle methods. Initial inspection is required within 20 flight hours after 6 Nov 1984, then every 600 flight hours and whenever the engine‑mount assembly is (re)installed. Issued after a fatal fatigue failure to prevent catastrophic in‑flight engine‑mount separation."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hiller-12-27-amdt-2-outer-gimbal-forward-attach-fitting-inspection","history":"/api/acts/ad-hiller-12-27-amdt-2-outer-gimbal-forward-attach-fitting-inspection/history","analysis":"/api/acts/ad-hiller-12-27-amdt-2-outer-gimbal-forward-attach-fitting-inspection/analysis","conflicts":"/api/acts/ad-hiller-12-27-amdt-2-outer-gimbal-forward-attach-fitting-inspection/conflicts","importantCases":"/api/acts/ad-hiller-12-27-amdt-2-outer-gimbal-forward-attach-fitting-inspection/important-cases","documents":"/api/acts/ad-hiller-12-27-amdt-2-outer-gimbal-forward-attach-fitting-inspection/documents"}}