{"id":"F2006B04588","name":"AD/BELL 212/56 - Tailboom Doubler","slug":"ad-bell-212-56-tailboom-doubler","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114326,"registerId":"commonwealth-F2006B04588-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 212/56 - Tailboom Doubler","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)  \nBell Helicopter Textron 212 Series Helicopters\n\nAD/BELL 212/56 Tailboom Doubler 6/95\n\nApplicability: Bell 212 helicopters S/N 30502, 30504 to 30999, 31101 to 31311, 32101 to 32142,\n\n35001 to 35056 and 35062.\n\nRequirement: 1. Conduct a detailed visual internal inspection for cracks in the tailboom skin and upper longerons under the P/N 212-030-099-089/-129 doubler from tailboom station (TS) 185 to TS 219. Inspect in accordance with Bell Alert Service Bulletin (ASB) 212-93-85, Revision A, Part I.\n\n2. Remove tailboom doubler P/N 212-030-099-089/-129 and reinstall in accordance with Bell ASB 212-93-85, Revision A, Part II.\n\nCompliance: 1. Inspect before 2500 hours time in service or before 25 hours time in service after 22 June 1995, whichever occurs later.\n\nRe-inspect at intervals not to exceed 100 hours time in service until modified in accordance with Requirement 2.\n\n2. Remove and reinstall doubler in accordance with Requirement 2 before 25 May 1996.\n\nBackground: Bell 212 operators have reported cracks in the upper longerons and skin around the longerons and under the doubler in the fin splice area. The problem was due to lack of adhesive, or the incorrect adhesive, in the doubler-skin bonded joint.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2222},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope addressing a specific structural adhesive defect in defined Bell 212 aircraft. No evidence of scope expansion beyond the original safety intent."},"complexity_factors":["References external technical document (Bell Alert Service Bulletin) for procedural details","Precise applicability limited to specific aircraft serial numbers requiring registry cross-checking","Technical aviation engineering terminology (tailboom, longerons, doubler, tailboom stations)","Conditional compliance deadline ('whichever occurs later')"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of specified Bell 212 helicopters to inspect and repair the tailboom where an improperly bonded reinforcement “doubler” has led to cracking of the skin and longerons. Inspections must be done before 2,500 flight hours or within 25 flight hours after 22 June 1995, repeated every 100 hours until permanent repair, and the doubler must be properly reinstalled per Bell’s service bulletin before 25 May 1996.\n\nIt prevents tailboom separation and possible catastrophic loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-212-56-tailboom-doubler","history":"/api/acts/ad-bell-212-56-tailboom-doubler/history","analysis":"/api/acts/ad-bell-212-56-tailboom-doubler/analysis","conflicts":"/api/acts/ad-bell-212-56-tailboom-doubler/conflicts","importantCases":"/api/acts/ad-bell-212-56-tailboom-doubler/important-cases","documents":"/api/acts/ad-bell-212-56-tailboom-doubler/documents"}}